[Petrous plasmacytoma revealed by a painful peripheral facial palsy].

PubMed

Lagarde, J; Cret, C; Karlin, L; Ameri, A

2011-01-01

The classical hypothesis of Bell's palsy, tempting in cases of peripheral facial palsy of rapid onset, must nevertheless be evoked with caution particularly if an intense pain is present, which should lead to search for a tumor of the skull base, especially the petrous bone. A 43-year-old man presented a peripheral facial palsy of rapidly progressive onset. A petrous bone tumor was diagnosed on the CT scan, which revealed an aspect of a glomic tumor or a metastatic lesion. The final histological diagnosis was plasmacytoma. This type of tumor has been rarely reported in this location. The radiological features are not specific at all, underlying the importance of searching for some associated signs such as a monoclonal protein and performing a histological examination when the firm diagnosis of a systemic disease like multiple myeloma has not been possible. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Endoscopic Infracochlear Approach for Drainage of Petrous Apex Cholesterol Granulomas: A Case Series.

PubMed

Wick, Cameron C; Hansen, Alexander R; Kutz, Joe Walter; Isaacson, Brandon

2017-07-01

To describe the feasibility and technical nuances of a transcanal endoscopic infracochlear approach for drainage of petrous apex cholesterol granulomas. Retrospective case review. Tertiary care university hospital. A 32-year-old man with bilateral petrous apex cholesterol granulomas and a 54-year-old man with a left-sided petrous apex granuloma each with symptoms necessitating surgical intervention. Transcanal endoscopic infracochlear approach for drainage of the cholesterol granulomas. Operation efficacy, corridor size, and perioperative morbidity. All three cholesterol granulomas were successful drained without violating the cochlea, jugular bulb, or carotid artery. The dimensions of the infracochlear surgical corridor measured 5 mm × 6 mm, 3.5 mm × 3.5 mm, and 6 mm × 4 mm, respectively. All corridors facilitated visualization within the cyst and allowed lyses of adhesions for additional cyst content eradication. All patients had resolution of their acute symptoms. Two of the three subjects had serviceable hearing before and after their procedures. One patient required revision surgery 2-months after their initial procedure secondary to recurrent symptoms from acute hemorrhage within the cyst cavity. The infracochlear tract in this patient was noted to be patent. A transcanal endoscopic infracochlear approach is feasible for the management of cholesterol granuloma. The surgical access was wide enough to introduce the endoscope into the petrous apex cavity in each case. Further studies are needed to compare the efficacy and perioperative morbidity versus the traditional postauricular transtemporal approaches.

Gradenigo's Syndrome in a Patient with Chronic Suppurative Otitis Media, Petrous Apicitis, and Meningitis.

PubMed

Taklalsingh, Nicholas; Falcone, Franco; Velayudhan, Vinodkumar

2017-09-28

BACKGROUND Gradenigo's syndrome includes the triad of suppurative otitis media, ipsilateral sixth (abducens) cranial nerve palsy and facial pain in the distribution of the fifth (trigeminal) cranial nerve. Gradenigo's syndrome is rare, and the diagnosis is easily overlooked. This case is the first to report Gradenigo's syndrome presenting with meningitis on a background of chronic suppurative otitis media (CSOM) and petrous apicitis (apical petrositis). CASE REPORT A 58-year-old male African American presented with headaches and confusion. Magnetic resonance imaging (MRI) of the head showed petrous apicitis with mastoiditis and abscess formation in the cerebellomedullary cistern (cisterna magna). The case was complicated by the development of palsy of the fourth (trochlear) cranial nerve, fifth (trigeminal) cranial nerve, and sixth (abducens) cranial nerve, with radiological changes indicating infection involving the seventh (facial) cranial nerve, and eighth (vestibulocochlear) cranial nerve. Cerebrospinal fluid (CSF) culture results were positive for Klebsiella pneumoniae, sensitive to ceftriaxone. The patient improved with surgery that included a left mastoidectomy and debridement of the petrous apex, followed by a ten-week course of antibiotics. Follow-up MRI showed resolution of the infection. CONCLUSIONS This report is of an atypical case of Gradenigo's syndrome. It is important to recognize that the classical triad of Gradenigo's syndrome, suppurative otitis media, ipsilateral sixth (abducens) cranial nerve palsy and facial pain in the distribution of the fifth (trigeminal) cranial nerve, may also involve chronic suppurative otitis media (CSOM), which may lead to involvement of other cranial nerves, petrous apicitis (apical petrositis), and bacterial meningitis.

[A case of petrous ridge meningioma manifested as pneumocephalus followed by Eustachian tube insufflation].

PubMed

Yamaguchi, Shinya; Gi, Hidefuku; Uno, Jyunji; Ikai, Yoshiaki; Inoha, Satoshi; Nagaoka, Shintarou; Nishio, Shunji

2009-05-01

A 50-year-old female, who had a headache after Eustachian tube insufflation for her ear congestion, came to our hospital. CT and MRI revealed pneumocephalus and petrous ridge meningioma which destroyed petrous bone and air cells. Eustachian tube insufflation was considered to make the air coming into the middle ear, mastoid air cell and then into the intracranial space destroying the tumor. At surgery, there was subdural hematoma around the tumor. Total removal of the tumor and the hematoma membrane was performed. Histologically, the tumor was transitional meningioma and the cluster of meningioma cells were noted in the subdural hematoma membrane.

Modification of tenascin-R expression following unilateral labyrinthectomy in rats indicates its possible role in neural plasticity of the vestibular neural circuit.

PubMed

Gaal, Botond; Jóhannesson, Einar Örn; Dattani, Amit; Magyar, Agnes; Wéber, Ildikó; Matesz, Clara

2015-09-01

We have previously found that unilateral labyrinthectomy is accompanied by modification of hyaluronan and chondroitin sulfate proteoglycan staining in the lateral vestibular nucleus of rats and the time course of subsequent reorganization of extracellular matrix assembly correlates to the restoration of impaired vestibular function. The tenascin-R has repelling effect on pathfinding during axonal growth/regrowth, and thus inhibits neural circuit repair. By using immunohistochemical method, we studied the modification of tenascin-R expression in the superior, medial, lateral, and descending vestibular nuclei of the rat following unilateral labyrinthectomy. On postoperative day 1, tenascin-R reaction in the perineuronal nets disappeared on the side of labyrinthectomy in the superior, lateral, medial, and rostral part of the descending vestibular nuclei. On survival day 3, the staining intensity of tenascin-R reaction in perineuronal nets recovered on the operated side of the medial vestibular nucleus, whereas it was restored by the time of postoperative day 7 in the superior, lateral and rostral part of the descending vestibular nuclei. The staining intensity of tenascin-R reaction remained unchanged in the caudal part of the descending vestibular nucleus bilaterally. Regional differences in the modification of tenascin-R expression presented here may be associated with different roles of individual vestibular nuclei in the compensatory processes. The decreased expression of the tenascin-R may suggest the extracellular facilitation of plastic modifications in the vestibular neural circuit after lesion of the labyrinthine receptors.

Ruptured petrous carotid pseudoaneurysm due to tuberculous otitis: endovascular treatment.

PubMed

Yagci, A B; Ardiç, F N; Oran, I; Bir, F; Karabulut, N

2006-03-15

We report the imaging findings and endovascular treatment in an unusual case of petrous internal carotid artery pseudoaneurysm due to primary tuberculous otitis. The aneurysm was recognized and ruptured during a surgical intervention for otitis. Successful endovascular treatment of the aneurysm was performed by occlusion of the parent vessel using detachable balloon and coils.

Ruptured Petrous Carotid Pseudoaneurysm Due to Tuberculous Otitis: Endovascular Treatment

PubMed Central

Yagci, A.B.; Ardiç, F.N.; Oran, I.; Bir, F.; Karabulut, N.

2006-01-01

Summary We report the imaging findings and endovascular treatment in an unusual case of petrous internal carotid artery pseudoaneurysm due to primary tuberculous otitis. The aneurysm was recognized and ruptured during a surgical intervention for otitis. Successful endovascular treatment of the aneurysm was performed by occlusion of the parent vessel using detachable balloon and coils. PMID:20569552

Immunohistochemical profile of various neurotransmitters, neurotrophins and MIB-1 in cholesteatomas of the petrous bone.

PubMed

Artico, Marco; Bronzetti, Elena; Lo Vasco, Vincenza Rita; Ionta, Brunella; Alicino, Valentina; D'Ambrosio, Anna; Magliulo, Giuseppe

2008-01-01

Compared to the normal epidermal epithelium, cholesteatomas have altered growth properties characterized by the excessive growth of keratinocytes leading to mucosal destruction. Either congenital or acquired, these lesions, which grow in the middle ear space, the petrous apex or the mastoid of temporal bones, are mostly considered benign skin tumoral lesions. However, many questions remain concerning their pathophysiology. Numerous studies have been proposed to identify those cholesteatoma lesions at risk of recurrence, a possible event that may cause hearing loss. We examined patients with petrous apex or mastoid cholesteatoma in order to analyze the expression of various neurotransmitters, neurotrophins and their receptors and the Ki-67 antigen for identification of a possible relationship between clinical outcome and histopathological behaviour in terms of the proliferative activity of cholesteatomas. Expression of the analyzed molecules was studied using immunohistochemical methods in seven adult patients with petrous apex cholesteatoma who underwent surgical removal of the lesion. Our results, in accordance with published data, confirm that Molecular Immunology Borstel-1 (MIB-1) and certain neurotransmitters could be useful in the prognostic evaluation of the risk of recurrence of aggressive forms of cholesteatoma.

Gradenigo’s Syndrome in a Patient with Chronic Suppurative Otitis Media, Petrous Apicitis, and Meningitis

PubMed Central

Taklalsingh, Nicholas; Falcone, Franco; Velayudhan, Vinodkumar

2017-01-01

Patient: Male, 58 Final Diagnosis: Bacterial meningitis Symptoms: Altered mental status • headache • neck stiffness • vomiting Medication: — Clinical Procedure: — Specialty: Infectious Diseases Objective: Rare disease Background: Gradenigo’s syndrome includes the triad of suppurative otitis media, ipsilateral sixth (abducens) cranial nerve palsy and facial pain in the distribution of the fifth (trigeminal) cranial nerve. Gradenigo’s syndrome is rare, and the diagnosis is easily overlooked. This case is the first to report Gradenigo’s syndrome presenting with meningitis on a background of chronic suppurative otitis media (CSOM) and petrous apicitis (apical petrositis). Case Report: A 58-year-old male African American presented with headaches and confusion. Magnetic resonance imaging (MRI) of the head showed petrous apicitis with mastoiditis and abscess formation in the cerebellomedullary cistern (cisterna magna). The case was complicated by the development of palsy of the fourth (trochlear) cranial nerve, fifth (trigeminal) cranial nerve, and sixth (abducens) cranial nerve, with radiological changes indicating infection involving the seventh (facial) cranial nerve, and eighth (vestibulocochlear) cranial nerve. Cerebrospinal fluid (CSF) culture results were positive for Klebsiella pneumoniae, sensitive to ceftriaxone. The patient improved with surgery that included a left mastoidectomy and debridement of the petrous apex, followed by a ten-week course of antibiotics. Follow-up MRI showed resolution of the infection. Conclusions: This report is of an atypical case of Gradenigo’s syndrome. It is important to recognize that the classical triad of Gradenigo’s syndrome, suppurative otitis media, ipsilateral sixth (abducens) cranial nerve palsy and facial pain in the distribution of the fifth (trigeminal) cranial nerve, may also involve chronic suppurative otitis media (CSOM), which may lead to involvement of other cranial nerves, petrous apicitis

[Preliminary experience on endoscopic endonasal management of petrous apex cholesterol granuloma].

PubMed

Wang, Jin; Chen, Lei; Yang, Jing

2015-05-01

To explore the feasibility and related aspects on endoscopic endonasal management of petrous apex cholesterol granuloma. Retrospective data analysis was performed on 3 cases in which the endoscopic endonasal approach was used to manage this lesion between 2011 and 2014. Case information including radiological data, surgical technique, symptoms, and complications was reviewed. The main clinical manifestations in these 3 patients were tinnitus, hearing loss at the hearing threshold of 40-50 dBHL. After operation, all 3 patients showed disappearance of their tinnitus and improvement of the hearing threshold of 10-30 dBHL (follow-up 6-45 months). Permanent drainage route was performed in 1 case which communicated with sphenoid sinus. While the other 2 cases which drained to pharyngeal recess resulted in drainage route blocking within the 3-6 months after surgery, but without obvious symptoms. This procedure for the drainage of petrous apex cholesterol granuloma showed to be effective, safe and minimally invasive. Although there is no recurrence in short-term, however, long-term surveillance and large case series are necessary, especially to the maitainence of permanent drainage.

CT venography: use in selecting a surgical approach for the treatment of petrous apex cholesterol granulomas.

PubMed

Isaacson, Brandon; Kutz, Joe Walter; Mendelsohn, Dianne; Roland, Peter S

2009-04-01

To demonstrate the use of computed tomographic (CT) venography in selecting a surgical approach for cholesterol granulomas. Retrospective case review. Tertiary referral center. Three patients presented with symptomatic petrous apex cholesterol granulomas with extensive bone erosion involving the jugular fossa. Computed tomographic venography was performed on each patient before selecting a surgical approach for drainage. Localization of the jugular bulb in relation to the petrous carotid artery and basal turn of the cochlea was ascertained in each subject. Three patients with large symptomatic cholesterol granulomas were identified. Conventional CT demonstrated extensive bone erosion involving the jugular fossa in each patient. The location of the jugular bulb and its proximity to the petrous carotid artery and basal turn of the cochlea could not be determined with conventional temporal bone CT and magnetic resonance imaging. Computed tomographic venography provided the exact location of the jugular bulb in all 3 patients. The favorable position of the jugular bulb in all 3 cases permitted drainage of these lesions using an infracochlear approach. Computed tomographic venography provided invaluable information in 3 patients with large symptomatic cholesterol granulomas. All 3 patients were previously thought to be unsuitable candidates for an infracochlear or infralabyrinthine approach because of the unknown location of the jugular bulb.

Posterior fossa meningiomas: surgical experience in 161 cases.

PubMed

Roberti, F; Sekhar, L N; Kalavakonda, C; Wright, D C

2001-07-01

We report the clinical, radiological, and surgical findings of patients with posterior fossa meningiomas surgically treated at our institution over the last 6 years. We reviewed 161 consecutive cases of posterior fossa meningiomas operated on between April 1993 and April 1999 at The George Washington University Medical Center. There were 128 female and 33 male patients (mean age 47 years, range of 10-81 years). Meningiomas were classified as petroclival (110 cases), foramen magnum (21 cases), cerebellar hemispheric, lateral tentorial (14 cases), cerebellopontine angle (9 cases), and jugular foramen (7 cases). Mean tumor equivalent diameter (TED) = (D1xD2xDE)(1/3) was 3.1 cm (range of 0.53-8.95). Head pain (50% of cases) and disturbance of gait (44%) were the most common presenting symptoms, and cranial neuropathies the most common neurological signs on admission. Mean preoperative performance status (Karnofsky scale) was 80.2 (range 40-100). Surgical approaches to these tumors included partial labyrinthectomy petrous apicectomy, fronto-temporal/fronto-temporal orbitozygomatic osteotomy, retrosigmoidal, extreme lateral, transpetrosal, and combined. In 38 cases a staged procedure was performed. Gross-total resection was achieved in 57% of patients, and subtotal/partial in 43%. Surgical mortality was 2.5% and complications were encountered in 41% of patients. Postoperative CSF leak occurred in 22 cases (13.6%). The mean follow-up was 19 months, ranging from 0.2 to 63.6, and the mean performance status of patients with a follow-up of at least 12 months was 77 (range of 40-100). Recurrence or progression of disease was found in 13.7% of cases (follow-up 2 years or more). Our experience suggests that although posterior fossa meningiomas represent a continuing challenge for contemporary neurosurgeons, such tumors may be completely or subtotally removed with low rate of mortality and acceptable morbidity, allowing most of these patients to achieve a good outcome in a long

Cholesterol granuloma of the petrous apex: establishment of a drainage route into the superior tympanic cavity--technical note.

PubMed

Kamiguchi, H; Kawase, T; Toya, S; Inoue, Y

1996-09-01

A 40-year-old male presented with a cholesterol granuloma of the petrous apex manifesting as progressive hearing loss and tinnitus. The lesion was treated via an extradural middle cranial fossa approach employing a new procedure to establish a drainage pathway into the superior tympanic cavity which preserved his hearing. The pathway was formed by a groove 5 mm wide and deep in the anterolateral aspect of the petrous bone, crossing the major petrosal nerve and carotid artery, running around the cochlea, crossing the tensor tympanic muscle, and entering the superior tympanic cavity above the orifice of the eustachian tube. This procedure is easy to perform without special techniques.

Long-term potentiation and depression after unilateral labyrinthectomy in the medial vestibular nucleus of rats.

PubMed

Pettorossi, Vito Enrico; Dutia, Mayank; Frondaroli, Adele; Dieni, Cristina; Grassi, Silvarosa

2003-01-01

We previously demonstrated in rat brainstem slices that high-frequency stimulation (HFS) of the vestibular afferents induces long-term potentiation (LTP) in the ventral part (Vp) of the medial vestibular nucleus (MVN) and long-term depression (LTD) in the dorsal part (Dp). Both LTP and LTD depend on N-methyl-D-aspartate receptor activation, which increases synaptic efficacy; however, in the Dp, LTP reverses to LTD because of the activation of gamma-aminobutyric acid-ergic neurons. Here we show that the probability of inducing long-term effects in the MVN of rat brainstem slices is altered after unilateral labyrinthectomy (UL). In fact, LTP occurs less frequently in the ventral contra-lesional side compared with sham-operated rats. In the dorsal ipsi-lesional side, LTD is reduced and LTP enhanced, while the opposite occurs in the dorsal contra-lesional side. These changes in synaptic plasticity may be useful for re-balancing the tonic discharge of the MVN of the two sides during vestibular compensation, and for enhancing the dynamic responses of the deafferented MVN neurons in the long term.

Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. III. Responses after labyrinthectomy

NASA Technical Reports Server (NTRS)

Lasker, D. M.; Hullar, T. E.; Minor, L. B.; Shelhamer, M. J. (Principal Investigator)

2000-01-01

The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in four squirrel monkeys after unilateral labyrinthectomy. Spontaneous nystagmus was measured at the beginning and end of each testing session. During the period that animals were kept in darkness (4 days), the nystagmus at each of these times measured approximately 20 degrees /s. Within 18-24 h after return to the light, the nystagmus (measured in darkness) decreased to 2.8 +/- 1.5 degrees /s (mean +/- SD) when recorded at the beginning but was 20.3 +/- 3.9 degrees /s at the end of the testing session. The latency of the VOR measured from responses to steps of acceleration (3,000 degrees /s(2) reaching a velocity of 150 degrees /s) was 8.4 +/- 0.3 ms for responses to ipsilesional rotations and 7.7 +/- 0.4 ms for contralesional rotations. During the period that animals were kept in darkness after the labyrinthectomy, the gain of the VOR measured during the steps of acceleration was 0.67 +/- 0.12 for contralesional rotations and 0.39 +/- 0.04 for ipsilesional rotations. Within 18-24 h after return to light, the VOR gain for contralesional rotations increased to 0.87 +/- 0.08, whereas there was only a slight increase for ipsilesional rotations to 0.41 +/- 0. 06. A symmetrical increase in the gain measured at the plateau of head velocity was noted after the animals were returned to light. The VOR evoked by sinusoidal rotations of 2-15 Hz, +/-20 degrees /s, showed a better recovery of gain at lower (2-4 Hz) than at higher (6-15 Hz) frequencies. At 0.5 Hz, gain decreased symmetrically when the peak amplitude was increased from 20 to 100 degrees /s. At 10 Hz, gain was decreased for ipsilesional half-cycles and increased for contralesional half-cycles when velocity was raised from 20 to 50 degrees /s. A model incorporating linear and nonlinear pathways was used to simulate the data. Selective increases in the gain for the linear pathway accounted for the

Rapid compensatory changes in GABA receptor efficacy in rat vestibular neurones after unilateral labyrinthectomy

PubMed Central

Yamanaka, Toshiaki; Him, Aydin; Cameron, Susan A; Dutia, Mayank B

2000-01-01

The inhibitory effects of the GABAA agonist muscimol and the GABAB agonist baclofen on tonically active medial vestibular nucleus (MVN) neurones were recorded in slices of the rat dorsal brainstem in vitro, to determine whether any changes occurred in the functional efficacy of GABAergic inhibition in these cells during the initial rapid stage of ‘vestibular compensation’, the behavioural recovery that takes place after unilateral labyrinthectomy (UL). These experiments were carried out in preparations where the midline was cut, severing all commissural connections between the two vestibular nuclei. Slices of the MVN were prepared from normal animals and animals that had been unilaterally labyrinthectomised 4 h earlier. The mean in vitro discharge rate of MVN neurones in the rostral region of the ipsi-lesional nucleus after UL was significantly higher than that in control slices, confirming our earlier reports of an increase in intrinsic excitability of these cells in the early stage of vestibular compensation. The in vitro discharge rates of caudal ipsi-lesional MVN cells, and rostral and caudal contra-lesional MVN cells, were not different from controls. Muscimol and baclofen caused reversible, dose-related inhibition of the tonic discharge rate of MVN cells in control slices. In slices prepared from UL animals, MVN cells in the rostral region of the ipsi-lesional nucleus showed a marked downregulation of their response to both muscimol and baclofen, seen as a rightward shift and a decrease in slope of the dose-response relationships for the two agonists. In the contra-lesional nucleus, there was a small but significant upregulation of the responsiveness of both rostral and caudal MVN cells to baclofen, and a marked upregulation of the responsiveness of caudal MVN cells to muscimol. In slices from animals that had undergone bilateral labyrinthectomy 4 h earlier, the downregulation of the functional efficacy of GABA receptors in the rostral MVN cells did not

In Vivo Imaging of Glial Activation after Unilateral Labyrinthectomy in the Rat: A [18F]GE180-PET Study.

PubMed

Zwergal, Andreas; Günther, Lisa; Brendel, Matthias; Beck, Roswitha; Lindner, Simon; Xiong, Guoming; Eilles, Eva; Unterrainer, Marcus; Albert, Nathalie Lisa; Becker-Bense, Sandra; Brandt, Thomas; Ziegler, Sibylle; la Fougère, Christian; Dieterich, Marianne; Bartenstein, Peter

2017-01-01

The functional relevance of reactive gliosis for recovery from acute unilateral vestibulopathy is unknown. In the present study, glial activation was visualized in vivo by [ 18 F]GE180-PET in a rat model of unilateral labyrinthectomy (UL) and compared to behavioral vestibular compensation (VC) overtime. 14 Sprague-Dawley rats underwent a UL by transtympanic injection of bupivacaine/arsenilate, 14 rats a SHAM UL (injection of normal saline). Glial activation was depicted with [ 18 F]GE180-PET and ex vivo autoradiography at baseline and 7, 15, 30 days after UL/SHAM UL. Postural asymmetry and nystagmus were registered at 1, 2, 3, 7, 15, 30 days after UL/SHAM UL. Signs of vestibular imbalance were found only after UL, which significantly decreased until days 15 and 30. In parallel, [ 18 F]GE180-PET and ex vivo autoradiography depicted glial activation in the ipsilesional vestibular nerve and nucleus on days 7 and 15 after UL. Correlation analysis revealed a strong negative association of [ 18 F]GE180 uptake in the ipsilesional vestibular nucleus on day 7 with the rate of postural recovery ( R  = -0.90, p  < 0.001), suggesting that glial activation accelerates VC. In conclusion, glial activation takes place in the ipsilesional vestibular nerve and nucleus within the first 30 days after UL in the rat and can be visualized in vivo by [ 18 F]GE180-PET.

In Vivo Imaging of Glial Activation after Unilateral Labyrinthectomy in the Rat: A [18F]GE180-PET Study

PubMed Central

Zwergal, Andreas; Günther, Lisa; Brendel, Matthias; Beck, Roswitha; Lindner, Simon; Xiong, Guoming; Eilles, Eva; Unterrainer, Marcus; Albert, Nathalie Lisa; Becker-Bense, Sandra; Brandt, Thomas; Ziegler, Sibylle; la Fougère, Christian; Dieterich, Marianne; Bartenstein, Peter

2017-01-01

The functional relevance of reactive gliosis for recovery from acute unilateral vestibulopathy is unknown. In the present study, glial activation was visualized in vivo by [18F]GE180-PET in a rat model of unilateral labyrinthectomy (UL) and compared to behavioral vestibular compensation (VC) overtime. 14 Sprague-Dawley rats underwent a UL by transtympanic injection of bupivacaine/arsenilate, 14 rats a SHAM UL (injection of normal saline). Glial activation was depicted with [18F]GE180-PET and ex vivo autoradiography at baseline and 7, 15, 30 days after UL/SHAM UL. Postural asymmetry and nystagmus were registered at 1, 2, 3, 7, 15, 30 days after UL/SHAM UL. Signs of vestibular imbalance were found only after UL, which significantly decreased until days 15 and 30. In parallel, [18F]GE180-PET and ex vivo autoradiography depicted glial activation in the ipsilesional vestibular nerve and nucleus on days 7 and 15 after UL. Correlation analysis revealed a strong negative association of [18F]GE180 uptake in the ipsilesional vestibular nucleus on day 7 with the rate of postural recovery (R = −0.90, p < 0.001), suggesting that glial activation accelerates VC. In conclusion, glial activation takes place in the ipsilesional vestibular nerve and nucleus within the first 30 days after UL in the rat and can be visualized in vivo by [18F]GE180-PET. PMID:29312111

Responses of non-eye movement central vestibular neurons to sinusoidal horizontal translation in compensated macaques after unilateral labyrinthectomy

PubMed Central

Lin, Nan; Wei, Min

2014-01-01

After vestibular labyrinth injury, behavioral deficits partially recover through the process of vestibular compensation. The present study was performed to improve our understanding of the physiology of the macaque vestibular system in the compensated state (>7 wk) after unilateral labyrinthectomy (UL). Three groups of vestibular nucleus neurons were included: pre-UL control neurons, neurons ipsilateral to the lesion, and neurons contralateral to the lesion. The firing responses of neurons sensitive to linear acceleration in the horizontal plane were recorded during sinusoidal horizontal translation directed along six different orientations (30° apart) at 0.5 Hz and 0.2 g peak acceleration (196 cm/s2). This data defined the vector of best response for each neuron in the horizontal plane, along which sensitivity, symmetry, detection threshold, and variability of firing were determined. Additionally, the responses of the same cells to translation over a series of frequencies (0.25–5.0 Hz) either in the interaural or naso-occipital orientation were obtained to define the frequency response characteristics in each group. We found a decrease in sensitivity, increase in threshold, and alteration in orientation of best responses in the vestibular nuclei after UL. Additionally, the phase relationship of the best neural response to translational stimulation changed with UL. The symmetry of individual neuron responses in the excitatory and inhibitory directions was unchanged by UL. Bilateral central utricular neurons still demonstrated two-dimension tuning after UL, consistent with spatio-temporal convergence from a single vestibular end-organ. These neuronal data correlate with known behavioral deficits after unilateral vestibular compromise. PMID:24717349

N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

PubMed Central

Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

N-acetyl-L-leucine accelerates vestibular compensation after unilateral labyrinthectomy by action in the cerebellum and thalamus.

PubMed

Günther, Lisa; Beck, Roswitha; Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p < 0.03) and the N-acetyl-L-leucine groups (p < 0.01), compared to the sham treatment group, but not in the N-acetyl-D-leucine group (comparison for applied dose of 24 mg i.v. per rat, equivalent to 60 mg/kg body weight, in each group). The course of postural compensation in the DL- and L-group was accelerated by about 6 days relative to controls. The effect of N-acetyl-L-leucine on postural compensation depended on the dose: in contrast to 60 mg/kg, doses of 15 mg/kg and 3.75 mg/kg had no significant effect. N-acetyl-L-leucine did not change the compensation of nystagmus or head roll tilt at any dose. Measurements of the regional cerebral glucose metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by

Long-term Symptom-specific Outcomes for Patients With Petrous Apex Cholesterol Granulomas: Surgery Versus Observation.

PubMed

Stevens, Shawn M; Manning, Amy; Pensak, Myles L; Samy, Ravi N

2017-02-01

Review long-term symptom-specific outcomes for petrous apex cholesterol granulomas (PACG). Retrospective review. Tertiary center. Adults with PACG were assessed from 1998 to 2015. Symptomatic patients were stratified into surgical and observation subgroups. Resolution rates of individual symptoms and chief complaints were assessed as was the impact of surgical approach and stent usage on symptom-specific outcomes. Symptom recurrence rates were tabulated. Twenty-seven patients were included whose mean age was 44.8 ± 3.3 years. Fourteen and 13 patients stratified into the surgical and observation subgroups respectively. The surgical subgroup trended toward a longer follow-up period (mean 68.5 vs. 33.8 mo; p = 0.06). Overall, the most frequent symptoms encountered were headache (52%), aural fullness, tinnitus, and vestibular complaints (41% each). Visual complaints, retro-orbital pain, and cranial neuropathies were less common (18%, 15%, 11%). The overall symptom resolution rate was significantly higher in the surgical subgroup (48% vs. 26%, p = 0.03). In both subgroups, headache, retro-orbital pain, and visual complaints had the highest resolution rates. Vestibular complaints and tinnitus were very unlikely to resolve. Significantly more patients in the surgical group resolved their chief complaints (70% vs. 25%, p = 0.02). While approach type and stent usage did not significantly influence symptom outcomes, all patients with symptom recurrence (11%) were initially managed without stents. Symptom-specific outcomes were better in patients managed surgically for PACG. Individual symptom resolution rates were highly variable. Some symptoms were refractory regardless of management strategy. Surgical approach and stent usage did not significantly influence symptom outcomes.

Detailed anatomy knowledge: first step to approach petroclival meningiomas through the petrous apex. Anatomy lab experience and surgical series.

PubMed

Altieri, Roberto; Sameshima, Tetsuro; Pacca, Paolo; Crobeddu, Emanuela; Garbossa, Diego; Ducati, Alessandro; Zenga, Francesco

2017-04-01

Petroclival meningiomas are a challenge for neurosurgeons due to the complex anatomy of the region that is rich of vessels and nerves. A perfect and detailed knowledge of the anatomy is very demanding in neurosurgery, especially in skull base surgery. The authors describe the microsurgical anatomy to perform an anterior petrosectomy based on their anatomical and surgical experience and perform a literature review. The temporal bone is the most complex and fascinating bone of skull base. The apex is located in the angle between the greater wing of the sphenoid and the occipital bone. Removing the petrous apex exposes the clivus. The approach directed through the temporal bone in this anatomical area is referred to as an anterior petrosectomy. The area that must be drilled is the rhomboid fossa that is defined by the Kawase, premeatal, and postmeatal triangles. In Division of Neurosurgery - University of Turin, 130 patients, from August 2013 to September 2015, underwent surgical resection of intracranial meningiomas. In this group, we have operated 7 PCMs and 5 of these were approached performing an anterior petrosectomy with good results. In our conclusions, we feel that this surgery require an advanced knowledge of human anatomy and a specialized training in interpretation of radiological and microsurgical anatomy both in the dissection lab and in the operating room.

Petrous Apex Cholesterol Granulomas: Outcomes, Complications, and Hearing Results From Surgical and Wait-and-Scan Management.

PubMed

Grinblat, Golda; Vashishth, Ashish; Galetti, Francesco; Caruso, Antonio; Sanna, Mario

2017-12-01

1. To analyze the surgical outcomes in the management of petrous apex cholesterol granulomas (PACG) with a brief literature review.2. To evaluate the importance of wait-and-scan management option. Retrospective review. Quaternary referral center for otology and skull base surgery. Charts of 55 patients with at least 12 months of follow-up were analyzed for demographic, clinical, audiometric, and radiological features. Patients were divided into surgical group (SG) (n = 31) and wait-and-scan (n = 24) (WS) group. Surgical approach was chosen as per hearing status and PACG extension and relation to nearby neurovascular structures and included either drainage by transmastoid-infralabyrinthine approach (TM-IL)/transcanal-infracochlear approach (TC-IC) or resection by infratemporal fossa type B approach (ITF-B). The combination of ITF-B with trans-otic (TO) approach or TO approach solely was used in unserviceable hearing cases. Postoperative outcomes and complications were evaluated in SG. Postoperative symptom relief was observed in 24 patients (77.4%). Diplopia and paresthesia recovered in each case and improvement in headache, dizziness, tinnitus, and hearing loss was observed in 87.1% cases. Serviceable hearing was preserved in 24 of 26 cases. Postoperative complication rate was 32.2% including incidences of profound hearing loss, facial nerve paresis, carotid artery injury and intraoperative CSF leaks. Revision surgery was required in 3 (9.6%) cases, after TM-IL approach. Surgical drainage is preferable to more aggressive resection procedures, with the latter reserved for recurrent lesions or lesions with severe hearing loss/involvement of critical neurovascular structures. ITF-B approach provides adequate cyst and neurovascular control for resection, while avoiding brain retraction. An initial wait-and-scan approach can be used in most patients where symptoms and imaging justify so.

The Effect of Resection Angle on Stress Distribution after Root-End Surgery.

PubMed

Monteiro, Jaiane Bandoli; Dal Piva, Amanda Maria de Oliveira; Tribst, João Paulo Mendes; Borges, Alexandre Luiz Souto; Tango, Rubens Nisie

2018-01-01

This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application. A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45 º occlusal load of 200 N/cm 2 on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS). MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group. Apicectomy at 90 º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45 ° could be a good choice for clinicians.

The Effect of Resection Angle on Stress Distribution after Root-End Surgery

PubMed Central

Monteiro, Jaiane Bandoli; Dal Piva, Amanda Maria de Oliveira; Tribst, João Paulo Mendes; Borges, Alexandre Luiz Souto; Tango, Rubens Nisie

2018-01-01

Introduction: This study aimed to investigate the influence of the resection angle on the stress distribution of retrograde endodontic treated maxillary incisors under oblique-load application. Methods and Materials: A maxillary central incisor which was endodontically treated and restored with a fiber glass post was obtained in a 3-dimensional numerical model and distributed into three groups according to type of resection: control; restored with fiber post without retrograde obturation, R45 and R90 with 45º and 90º resection from tooth axial axis, respectively and restored with Fuji II LC (GC America). The numerical models received a 45º occlusal load of 200 N/cm2 on the middle of lingual surface. All materials and structures were considered linear elastic, homogeneous and isotropic. Numerical models were plotted and meshed with isoparametric elements, and the results were analyzed using maximum principal stress (MPS). Results: MPS showed greater stress values in the bone tissue for control group than the other groups. Groups with apicectomy showed acceptable stress distribution on the fiber post, cement layer and root dentin, presenting more improved values than control group. Conclusion: Apicectomy at 90º promotes more homogeneity on stress distribution on the fiber post, cement layer and root dentin, which suggests less probability of failure. However, due to its facility and stress distribution also being better than control group, apicectomy at 45° could be a good choice for clinicians. PMID:29707013

Petrous apex cholesterol granuloma: importance of pedicled nasoseptal flap in addition to silicone T-tube for prevention of occlusion of drainage route in transsphenoidal approach--a technical note.

PubMed

Shibao, Shunsuke; Toda, Masahiro; Tomita, Toshiki; Saito, Katsuya; Ogawa, Kaoru; Kawase, Takeshi; Yoshida, Kazunari

2015-01-01

Recently, petrous apex cholesterol granulomas (CGs) have been treated via the endoscopic endonasal transsphenoidal approach (EEA) using a silicone tube, to prevent drainage route occlusion. Occlusion of the drainage route has led to problems with recurrence. The aim of this report is to describe the use of a surgical technique to prevent drainage route occlusion. In surgical technique, the posterolateral wall of the sphenoid sinus was opened by EEA. After cyst debridement, a vascularized nasoseptal flap with a width of approximately 4 cm was inserted into the lumen with a silicone T-tube with a diameter of 7 mm. This technique was used in two patients: the first patient during the second operation after recurrence following occlusion of the drainage route, and the second patient during the first operation. Opening of the cyst wall was confirmed endoscopically in both patients 12-24 months after surgery, even after removal of the T-tube. In conclusion, the use of a pedicled nasoseptal flap with a silicone tube is useful to prevent CG recurrence, by paranasal cavitization of the cystic cavity.

Refractory Positional Vertigo With Apogeotropic Horizontal Nystagmus After Labyrinthitis: Surgical Treatment and Identification of Dysmorphic Ampullae.

PubMed

Ahmed, Sameer; Heidenreich, Katherine D; McHugh, Jonathan B; Altschuler, Richard A; Carender, Wendy J; Telian, Steven A

2015-09-01

To describe the rationale, intraoperative details, and histopathologic findings discovered when treating an unusual case of apogeotropic horizontal canal positional vertigo with a transmastoid labyrinthectomy. A single case report. Therapeutic. Resolution of apogeotropic nystagmus and improvement of positional vertigo. The apogeotropic variant of horizontal canal positional vertigo can be a difficult entity to treat. This report describes a patient who developed profound sensorineural hearing loss and vertigo after an acute left labyrinthitis. Ten months later, she developed vertigo with apogeotropic positional nystagmus involving the left horizontal semicircular canal. Particle repositioning maneuvers and vestibular physical therapy were unsuccessful. In addition, she developed intermittent positional vertigo affecting the ipsilateral vertical semicircular canals. Given the persistence of her vertigo, multiple canal involvement, and patient preference for definitive treatment, a transmastoid labyrinthectomy was performed. Intraoperatively, the ampulla of the horizontal canal as well as that of the other canals was grossly abnormal as later confirmed on histology. After surgery, her apogeotropic nystagmus and vertigo resolved, and her balance ability gradually improved to a highly functional level. This case illustrates a unique form of positional vertigo that developed and persisted after acute labyrinthitis. Conservative measures were unsuccessful and a transmastoid labyrinthectomy documented dense inflammatory tissue involving all three ampullae. We postulate that the post-labyrinthitic inflammatory changes resulted in mass loading of the membranous ampullae, causing abnormal nystagmus patterns and positional vertigo, which resolved after the labyrinthectomy.

Petrous apex cholesterol granuloma: maintenance of drainage pathway, the histopathology of surgical management and histopathologic evidence for the exposed marrow theory.

PubMed

Hoa, Michael; House, John W; Linthicum, Fred H

2012-08-01

(1) To assess the maintenance of drainage pathway patency in patients who undergo surgical management of cholesterol granulomas, (2) to review the histopathologic and radiologic changes associated with surgical drainage of petrous apex (PA) cholesterol granulomas, and (3) to provide histopathologic evidence regarding the exposed marrow theory of PA cholesterol granulomas. Retrospective case review and histopathologic analysis. Tertiary referral center. Records of 17 patients with surgically managed PA cholesterol granulomas were reviewed. Histopathologic analysis was performed on temporal bones of 11 patients with PA cholesterol granulomas from the Temporal Bone repository at the House Research Institute. Surgical drainage of PA cholesterol granulomas; follow-up radiologic imaging (computed tomography or magnetic resonance imaging), when available. Primary outcome is demonstrated maintenance of a PA outflow drainage pathway after the surgical drainage procedure as assessed by radiologic imaging, available histopathology, and/or recurrence of symptoms indicating failure of maintenance. Other measures include need for revision surgery and histopathology findings. A majority (65%) of patients exhibited maintenance of their PA drainage pathway. Histopathologic evidence suggests that the PA drainage pathway can be maintained for many years after surgical drainage. Recurrence of symptoms was related to obstruction of the drainage pathway by fibrous tissue and/or granulomatous tissue. Placement of a stent improved the patient's chance of remaining symptom-free, with recurrence of symptoms and revision surgery required in only 2 stent cases (18%) as compared with 83% of those with no stent (p ≤ 0.035). Histopathologic evidence for the exposed marrow theory of PA cholesterol granulomas was found. The majority of patients who undergo surgical drainage of PA cholesterol granulomas remain symptom-free after surgical drainage. Histopathologic analysis of temporal bone

An Ambulatory Surgery Service Feasibility Study at Madigan Army Medical Center, Tacoma, Washington

DTIC Science & Technology

1978-08-01

sturmdorf) Benign Intraoral lesions Cervical cone Branchial arch appendages, Colpotomy, diagnostic excision Cryotherapy (alone)" Basla cell CA...petrous pyramid, atti- ceantrotomy, closure of fistula, exteneeration of air cells of petrous pyramid, mastoid antrotomy, removal of outer attic wall...here admission forms will be filled out. Patients will then take those forms to the Admissions Office and return to that clinic for stamin up of 1

[Integration of the functional signal of intraoperative EMG of the facial nerve in to navigation model for surgery of the petrous bone].

PubMed

Strauss, G; Strauss, M; Lüders, C; Stopp, S; Shi, J; Dietz, A; Lüth, T

2008-10-01

PROBLEM DEFINITION: The goal of this work is the integration of the information of the intraoperative EMG monitoring of the facial nerve into the radiological data of the petrous bone. The following hypotheses are to be examined: (I) the N. VII can be determined intraoperatively with a high reliability by the stimulation-probe. A computer program is able to discriminate true-positive EMG signals from false-positive artifacts. (II) The course of the facial nerve can be registered in a three-dimensional area by EMG signals at a nerve model in the lab test. The individual items of the nerve can be combined into a route model. The route model can be integrated into the data of digital volume tomography (DVT). (I) Intraoperative EMG signals of the facial nerve were classified at 128 measurements by an automatic software. The results were correlated with the actual intraoperative situation. (II) The nerve phantom was designed and a DVT data set was provided. Phantom was registered with a navigation system (Karl Storz NPU, Tuttlingen, Germany). The stimulation probe of the EMG-system was tracked by the navigation system. The navigation system was extended by a processing unit (MiMed, Technische Universität München, Germany). Thus the classified EMG parameters of the facial route can be received, processed and be generated to a model of the facial nerve route. The operability was examined at 120 (10 x 12) measuring points. The evaluation of the examined algorithm for classification EMG-signals of the facial nerve resulted as correct in all measuring events. In all 10 attempts it succeeded to visualize the nerve route as three-dimensional model. The different sizes of the individual measuring points reflect the appropriate values of Istim and UEMG correctly. This work proves the feasibility of an automatic classification of an intraoperative EMG signal of the facial nerve by a processing unit. Furthermore the work shows the feasibility of tracking of the position of the

Chronic periapical periodontitis containing mature human hair shaft: a case report.

PubMed

Sharif, Mohammad Owaise; Yar, Riaz; Oliver, Richard

2011-04-01

A case is reported of a 44-year-old male who was referred with persistent pus discharge associated with his UL2 which had been root treated on two occasions. Radiographic examination revealed a radiolucency of approximately 8 mm diameter. An apicectomy was performed and histopathological examination revealed the presence of mature birefringent hair-shaft structures within a chronic periapical periodontitis. This article presents a rare occurrence, the presence of human hair in the periapical tissues.

Expanding the endoscopic transpterygoid corridor to the petroclival region: anatomical study and volumetric comparative analysis.

PubMed

Freeman, Jacob L; Sampath, Raghuram; Quattlebaum, Steven Craig; Casey, Michael A; Folzenlogen, Zach A; Ramakrishnan, Vijay R; Youssef, A Samy

2017-07-21

OBJECTIVE The endoscopic endonasal transmaxillary transpterygoid (TMTP) approach has been the gateway for lateral skull base exposure. Removal of the cartilaginous eustachian tube (ET) and lateral mobilization of the internal carotid artery (ICA) are technically demanding adjunctive steps that are used to access the petroclival region. The gained expansion of the deep working corridor provided by these maneuvers has yet to be quantified. METHODS The TMTP approach with cartilaginous ET removal and ICA mobilization was performed in 5 adult cadaveric heads (10 sides). Accessible portions of the petrous apex were drilled during the following 3 stages: 1) before ET removal, 2) after ET removal but before ICA mobilization, and 3) after ET removal and ICA repositioning. Resection volumes were calculated using 3D reconstructions generated from thin-slice CT scans obtained before and after each step of the dissection. RESULTS The average petrous temporal bone resection volumes at each stage were 0.21 cm 3 , 0.71 cm 3 , and 1.32 cm 3 (p < 0.05, paired t-test). Without ET removal, inferior and superior access to the petrous apex was limited. Furthermore, without ICA mobilization, drilling was confined to the inferior two-thirds of the petrous apex. After mobilization, the resection was extended superiorly through the upper extent of the petrous apex. CONCLUSIONS The transpterygoid corridor to the petroclival region is maximally expanded by the resection of the cartilaginous ET and mobilization of the paraclival ICA. These added maneuvers expanded the deep window almost 6 times and provided more lateral access to the petroclival region with a maximum volume of 1.5 cm 3 . This may result in the ability to resect small-to-moderate sized intradural petroclival lesions up to that volume. Larger lesions may better be approached through an open transcranial approach.

Surgery for vertigo: 10-year audit from a contemporary vertigo clinic.

PubMed

Patnaik, U; Srivastava, A; Sikka, K; Thakar, A

2015-12-01

To present the profile of patients undergoing surgical treatment for vertigo at a contemporary institutional vertigo clinic. A retrospective analysis of clinical charts. The charts of 1060 patients, referred to an institutional vertigo clinic from January 2003 to December 2012, were studied. The clinical profile and long-term outcomes of patients who underwent surgery were analysed. Of 1060 patients, 12 (1.13 per cent) were managed surgically. Of these, disease-modifying surgical procedures included perilymphatic fistula repair (n = 7) and microvascular decompression of the vestibular nerve (n = 1). Labyrinth destructive procedures included transmastoid labyrinthectomy (n = 2) and labyrinthectomy with vestibular nerve section (n = 1). One patient with vestibular schwannoma underwent both a disease-modifying and destructive procedure (translabyrinthine excision). All patients achieved excellent vertigo control, classified as per the American Academy of Otolaryngology - Head and Neck Surgery 1995 criteria. With the advent of intratympanic treatments, surgical treatments for vertigo have become further limited. However, surgery with directed intent, in select patients, can give excellent results.

Sequential [(18)F]FDG µPET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity.

PubMed

Zwergal, Andreas; Schlichtiger, Julia; Xiong, Guoming; Beck, Roswitha; Günther, Lisa; Schniepp, Roman; Schöberl, Florian; Jahn, Klaus; Brandt, Thomas; Strupp, Michael; Bartenstein, Peter; Dieterich, Marianne; Dutia, Mayank B; la Fougère, Christian

2016-01-01

Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [(18)F]Fluoro-deoxyglucose ([(18)F]FDG)-µPET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4 h). This was followed by early vestibular compensation over 1-2 days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7 days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9 days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [(18)F]FDG-µPET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery.

Anatomic variation of the abducens nerve in a single cadaver dissection: the "petrobasilar canal".

PubMed

Pizzolorusso, Felice; Cirotti, Andrea; Pizzolorusso, Gianfranco

2017-04-01

Anatomic variations of the petrosphenoid ligament, Dorello's canal and the course of the abducens nerve have been extensively described over the past years. In the present report of a single cadaver dissection, we describe an unusual course of the abducens nerve at the level of the petrous bone. The right abducens nerve did not enter Dorello's canal, but ran below the petrous bone through a narrow canal in the petrobasilar suture, which we called the "petrobasilar canal". No anatomic variations of the left abducens nerve were noted.

Subtemporal-anterior transtentoral approach to middle cranial fossa microsurgical anatomy.

PubMed

Xu, Zhiming; Wang, Weimin; Zhang, Jingjing; Liu, Wei; Feng, Yugong; Li, Gang

2014-11-01

This study aimed to describe the topography of inferior and external dura mater of the middle cranial fossa through subtemporal-anterior transpetrosal approach and discuss the feasibility of improving the approach. Eight formalin-fixed adult cadaveric heads were studied, with the bones milled away in the lateral triangle region of the petrous bone, Kawase rhombus region, and inner triangle region of the petrous apex. The distances between the targets in these regions, as well as the angles after the dissection of zygomatic arch, were measured, and then the exposed petroclival and retrochiasmatic areas were observed under the microscope. There were significant variations in the distances between targets in the 3 milled regions among the specimens. After the dissection of zygomatic arch, the surgical view got an average increase of 12 degrees. The subtemporal anterior transpetrosal approach, as an improved subtemporal approach, can expose the lesions optimally, causing no injury to the hearing and reducing injuries to temporal lobe. On the other hand, the lateral bone of the petrous parts of the temporal bone is removed so as to improve the view to the retrochiasmatic area and expand the operative field.

Do Parameters Of Irradiation Influences The Apical Sealing Of Er:YAG Laser Apicetomies?

NASA Astrophysics Data System (ADS)

Marques, Aparecida Maria Cordeiro; dos Santos, Jean Nunes; Pinheiro, Antonio Luiz Barbosa

2011-08-01

Failures on the sealing of the tooth apex are responsible for many failures of apical surgeries. The Er:YAG laser has been proposed as an alternative for the use of rotator instruments on surgical endodontics. 12 human extracted canines had root endodontic treatment being the apical limit was set at 1mm before the apical foramen and were distributed into 2 groups. On group I, apicectomy was performed with the Er:YAG laser (250 mJ/15 Hz). Apical cut was performed of perpendicular mode with 3mm from the apical foramen. On Group II, the same procedures and the same sequence as above was used, varying only the parameters of the Er:YAG laser (400 mJ/6 Hz). The specimens were divided into groups and fixed, by the cervical third, on wax. Impermeabilization of the residual root apical third was performed following the same procedures used in the cervical third but the residual apex was left free from the impermeabilization. After that, the roots were immersed in a 2% methylene blue solution and placed in a bacteriological oven for 48 h. The segments were visually observed and the one showing greatest level of dye leakage was selected and kept in individual container and coded accordingly. Apical staining was measured using a stereoscopic magnifying glass; a compass; and caliper. The results showed that Group I showed significantly different higher mean level of dye leakage (5.67±4.9, p<0.05). There was a significantly difference between the groups. It is concluded that the apicectomies carried out with 400 mJ/6 Hz showed the smallest infiltration value.

Temporal bone radiography using the orthopantomograph

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatezawa, T.

1981-09-01

Temporal bone radiographs obtained with an Orthopantomograph were compared with conventional radiographs. In acoustic neurinoma, cholesteatoma, otitis media, and middle fossa tumors, both methods demonstrated the abnormalities well. In two cases with lesions extending beyond the range of conventional projections, the broad orthopantomographic coverage was very valuable. Mastoid air cells, the mastoid process, petrous ridge, and internal auditory meatus were well demonstrated by both techniques. Orthopantomography was found to be superior in the demonstration of the petrous apex, while the superior semicircular canal was better demonstrated on the conventional views. Bilateral symmetry was particularly good and because of fewer films,more » radiation exposure was considerably less with orthopantomography. For many applications, orthopantomography is an adequate convenient substitute for conventional methods of examining the temporal bones.« less

Inner ear dysplasia is common in children with Down syndrome (trisomy 21).

PubMed

Blaser, Susan; Propst, Evan J; Martin, Daniel; Feigenbaum, Annette; James, Adrian L; Shannon, Patrick; Papsin, Blake C

2006-12-01

Middle and external ear anomalies are well recognized in Down syndrome (DS, trisomy 21). Inner ear anomalies are much less frequently described. This study reviews inner ear morphology on imaging to determine the prevalence of cochlear and vestibular anomalies in children with DS. The authors conducted a retrospective review of imaging features of (DS) inner ear structures. Fifty-nine sequential patients with DS with imaging of the inner ear were identified by a radiology report text search program. Quantitative biometric assessment of the inner ear was performed on patients with high-resolution computed tomography or magnetic resonance images of the petrous bone. Petrous imaging was performed for evaluation of inflammatory disease or hearing loss. Spinal imaging, which included petrous views, was performed in most cases to exclude C1 to 2 dislocation, a potential complication of DS. Measurements were compared with normative data. Inner ear dysplasia is much more common in DS than previously reported. Inner ear structures are universally hypoplastic. Vestibular malformations are particularly common and a small bony island of the lateral semicircular canal (<3 mm in diameter) appears highly typical. Additional findings in some patients were persistent lateral semicircular anlage with fusion of the lateral semicircular canal and vestibule into a single cavity, vestibular aqueduct and endolymphatic sac fossa enlargement, cochlear nerve canal hypoplasia, and stenosis or duplication of the internal auditory canal. Stenosis of the external meatus, poor mastoid pneumatization, middle ear and mastoid opacification, and cholesteatoma were common, as expected.

Analysis of various tracts of mastoid air cells related to CSF leak after the anterior transpetrosal approach.

PubMed

Tamura, Ryota; Tomio, Ryosuke; Mohammad, Farrag; Toda, Masahiro; Yoshida, Kazunari

2018-03-16

OBJECTIVE The anterior transpetrosal approach (ATPA) was established in 1984 and has been particularly effective for petroclival tumors. Although some complications associated with this approach, such as venous hemorrhage in the temporal lobe and nervous disturbances, have been resolved over the years, the incidence rate of CSF leaks has not greatly improved. In this study, some varieties of air cell tracts that are strongly related to CSF leaks are demonstrated. In addition, other pre- and postoperative risk factors for CSF leakage after ATPA are discussed. METHODS Preoperative and postoperative target imaging of the temporal bone was performed in a total of 117 patients who underwent ATPA, and various surgery-related parameters were analyzed. RESULTS The existence of air cells at the petrous apex, as well as fluid collection in the mastoid antrum detected by a postoperative CT scan, were possible risk factors for CSF leakage. Tracts that directly connected to the antrum from the squamous part of the temporal bone and petrous apex, rather than through numerous air cells, were significantly related to CSF leak and were defined as "direct tract." All patients with a refractory CSF leak possessed "unusual tracts" that connected to the attic, tympanic cavity, or eustachian tube, rather than through the mastoid antrum. CONCLUSIONS Preoperative assessment of petrous pneumatization types is necessary to prevent CSF leaks. Direct and unusual tracts are particularly strong risk factors for CSF leaks.

Traumatic aneurysms of the internal carotid artery at the base of the skull. Two cases treated surgically.

PubMed

Magnan, P E; Branchereau, A; Cannoni, M

1992-01-01

Internal carotid aneurysms at the base of the skull after blunt trauma are infrequent but their management is difficult, leading many surgeons to only attempt ligation. We report 2 cases presenting with high traumatic aneurysms, following motorcycle accidents. The 2 aneurysms underwent repair by a venous graft. The petrous portion of the carotid artery was approached and controlled by an ENT surgeon. This "infratemporal" approach was used exposing the facial nerve, combined with temporary anterior sub-luxation of the temporomaxillary joint to expose the lower part of the carotid canal which was opened up with a drill in order to control the carotid artery in the petrous canal. Both patients developed facial nerve palsies which improved within 3 months. Postoperative angiography showed patent vein grafts and the patients were doing well, without any symptoms 18 and 24 months later.

Vestibular-related neuroscience and manned space flight

NASA Technical Reports Server (NTRS)

Igarashi, Makoto

1988-01-01

The effects of weightlessness on the human vestibular system are examined, reviewing the results of recent investigations. The functional, neurophysiological, and neurochemical changes which occur during adaptation to weightlessness are discussed; theoretical models proposed to explain the underlying mechanism are outlined; and particular attention is given to the author's experiments on squirrel monkeys. There, good correlations were found between (1) the recovery of locomotor balance function in the acute compensation phase after unilateral labyrinthectomy and (2) the bilateral imbalance in the optical density of GABA-like immunoreactivity.

The treatment of pseudoaneurysms with flow diverters after malignant otitis externa.

PubMed

Németh, Tamás; Szakács, László; Bella, Zsolt; Majoros, Valéria; Barzó, Pál; Vörös, Erika

2017-12-01

Background We report a case of bilateral malignant otitis externa complicated with bilateral petrous internal carotid artery pseudoaneurysms and their successful treatment with a flow diverter. Case report A 68-year-old woman with serious complications of type II diabetes mellitus had malignant otitis externa on the right side. She was treated with combined antibiotic therapy and underwent mastoidectomy for mastoiditis. She presented at our hospital with acute hemorrhage from the right external auditory canal. The emergency computed tomography (CT) angiography revealed a multiobulated pseudoaneurysm at the petrous segment of the right internal carotid artery. The pseudoaneurysm was treated with a 5 × 40-mm Surpass flow diverter. Three months later, she developed a malignant external otitis on the left side. As the infection progressed, a left-sided mastoiditis, a brain abscess, and a pseudoaneurysm at the petrous segment of the left internal carotid artery developed. The pseudoaneurysm caused bleeding from the left ear, and was treated with a 5 × 50-mm Surpass flow diverter. No recurrent bleeding was observed. Four months later, a follow-up angiography showed complete occlusion of the pseudoaneurysm on the left side, but a residual aneurysm could be detected on the right side. One year after the first intervention, the follow-up CT and magnetic resonance angiography revealed the complete occlusion of the aneurysms bilaterally. Conclusion The use of a flow diverter appears to be an efficient and safe method to occlude carotid pseudoaneurysms even in an inflammatory milieu.

Artifacts produced during electrical stimulation of the vestibular nerve in cats. [autonomic nervous system components of motion sickness

NASA Technical Reports Server (NTRS)

Tang, P. C.

1973-01-01

Evidence is presented to indicate that evoked potentials in the recurrent laryngeal, the cervical sympathetic, and the phrenic nerve, commonly reported as being elicited by vestibular nerve stimulation, may be due to stimulation of structures other than the vestibular nerve. Experiments carried out in decerebrated cats indicated that stimulation of the petrous bone and not that of the vestibular nerve is responsible for the genesis of evoked potentials in the recurrent laryngeal and the cervical sympathetic nerves. The phrenic response to electrical stimulation applied through bipolar straight electrodes appears to be the result of stimulation of the facial nerve in the facial canal by current spread along the petrous bone, since stimulation of the suspended facial nerve evoked potentials only in the phrenic nerve and not in the recurrent laryngeal nerve. These findings indicate that autonomic components of motion sickness represent the secondary reactions and not the primary responses to vestibular stimulation.

Comparison of autopsy findings and injury severity scores in deaths due to traumatic asphyxia (perthes syndrome).

PubMed

Arslan, M N; Kertmen, Ç; Esen Melez, I; Melez, D O

2018-05-01

Traumatic asphyxia is a rare clinical syndrome usually caused by sudden and severe thoracic and/or thoracoabdominal compression. It presents with craniofacial cyanosis, petechiae, and subconjunctival haemorrhages. The present study employed a postmortem retrospective methodology to analyse autopsy findings and accompanying injuries in cases of death due to traumatic asphyxia. Four years of case files from a morgue department at a forensic medicine institute were searched and 53 cases of lethal traumatic asphyxia were found. These cases were then classified into groups and compared using the Injury Severity Score (ISS) and New Injury Severity Score (NISS) indices to measure trauma. The individuals had died due to occupational (n = 28; 52.8%), farm (n = 10; 18.9%), traffic (n = 9; 17.0%) or household (n = 6; 11.3%) accidents. At the external examination, conjunctival petechiae (60.4%) and petechiae on the face/neck (52.8%); at the autopsy, subpleural petechiae (58.5%) and petrous ridge hemorrgahe (without skull base fracture) (56.6%) were the most common findings. A finding of petrous ridge hemorrgahe was very common in the cases without any accompanying injuries (Group A in which mean Injury Severity Score was 0.83 ± 0.98). Traumatic asphyxia is usually suspected from the given circumstances before an autosopy is performed. In cases without hospitalisation, any of the following signs may lead the physician to diagnose traumatic asphyxia as the cause of death: petechiae on the upper parts of the body and conjunctiva, petechiae on serous membranes (including subpleural regions), signs of petrous ridge haemorrhage without skull base fracture. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Various origins of the duplicated middle cerebral artery.

PubMed

Tutar, Nihal Uslu; Töre, Hüseyin Gürkan; Kirbaş, Ismail; Tarhan, Nefise Cağla; Coşkun, Mehmet

2008-10-01

We describe the features of a duplicated middle cerebral artery identified by computed tomographic angiography that originates from a previously undefined origin, ie, from the petrous portion of the internal carotid artery. Recognition of this anomaly is important in patients with a possible aneurysm, which was not present in our patient.

Nicergoline facilitates vestibular compensation in aged male rats with unilateral labyrinthectomy.

PubMed

Rampello, L; Drago, F

1999-05-28

The ergoline derivatives, nicergoline (NIC) or dihydroergocristine (DHE) were administered at various doses (0.1, 0.5 and 1 mg/kg) to aged male rats subjected to labyrinth unilateral lesion (LBX). The nystagmus rate appeared to be lower in animals treated with DHE or NIC 1mg/kg than in saline-injected rats, when observed on day 1 and 2 after operation. The number of falls in the rotorod test of LBX animals was decreased by NIC 0.5 or 1 mg/kg at all observation times. This parameter was affected by DHE only at the higher dose. These results suggest that NIC facilitates vestibular compensation of LBX rats. DHE appeared to be less potent in this respect. Since both drugs act on central dopaminergic neurotransmission, it is possible that this neurotransmission may be involved in their mechanism of action.

Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey

NASA Technical Reports Server (NTRS)

Igarashi, M.; Ohashi, K.; Yoshihara, T.; MacDonald, S.

1989-01-01

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.

The History and Evolution of Surgery on the Vestibular Labyrinth.

PubMed

Naples, James G; Eisen, Marc D

2016-11-01

The history of surgery on the vestibular labyrinth is rich but sparsely documented in the literature. The story begins over a century ago with the labyrinthectomy in an era that consisted exclusively of ablative surgery for infection or vertigo. Improved understanding of vestibular physiology and pathology produced an era of selective ablation and hearing preservation that includes semicircular canal occlusion for benign paroxysmal positional vertigo. An era of restoration began with a discovery of superior semicircular canal dehiscence and its repair. The final era of vestibular replacement is upon us as the possibility of successful prosthetic vestibular implantation becomes reality. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

Carcinoma of the middle ear and external auditory canal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahn, S.S.; Kim, J.A.; Goodchild, N.

1983-07-01

Thirty-one patients with malignant tumors of the middle ear and external auditory canal (EAC) were observed at the University of Virginia Hospital from 1956 through 1980. Of 27 patients with carcinoma, 21 had squamous cell carcinoma, 4 had basal cell carcinoma and 2 had adenoid cystic carcinoma. The 27 patients with carcinoma are reviewed with regard to clinical presentation, treatment modality, results and complications. The majority (67%) of patients had a history of chronic ear drainage, 22% had a previous mastoidectomy or polypectomy and 7% had an associated cholesteatoma. Eighty percent of patients with carcinoma limited to EAC were alivemore » and well at 5 years, compared to 43% of patients with involvement of the middle ear. Fifty-six percent of patients without invasion of the petrous bone were alive at 5 years compared to only 20% of patients with petrous bone involvement. The data strongly suggest that survival depends on the extent of disease. The corrected disease free 5 year survival rates were 14% for patients who had surgery alone and 50% for those who had surgery and radiotherapy. Of the three patients with advanced disease who received radiotherapy alone, none survived five years.« less

Upper Nasopharyngeal Corridor for Transnasal Endoscopic Drainage of Petroclival Cholesterol Granulomas: Alternative Access in Conchal Sphenoid Patients.

PubMed

Turan, Nefize; Baum, Griffin R; Holland, Christopher M; Ahmad, Faiz U; Henriquez, Oswaldo A; Pradilla, Gustavo

2016-03-01

Background Cholesterol granulomas arising at the petrous apex can be treated via traditional open surgical, endoscopic, and endoscopic-assisted approaches. Endoscopic approaches require access to the sphenoid sinus, which is technically challenging in patients with conchal sphenoidal anatomy. Clinical Presentation A 55-year-old woman presented with intermittent headaches and tinnitus. Formal audiometry demonstrated moderately severe bilateral hearing loss. CT of the temporal bones and sella revealed a well-demarcated expansile lytic mass. MRI of the face, orbit, and neck showed a right petrous apex mass measuring 22 × 18 × 19 mm that was hyperintense on T1- and T2-weighted images without enhancement, consistent with a cholesterol granuloma. The patient had a conchal sphenoidal anatomy. Operative Technique Herein, we present an illustrative case of a low-lying petroclival cholesterol granuloma in a patient with conchal sphenoidal anatomy to describe an alternative high nasopharyngeal corridor for endoscopic transnasal transclival access. Postoperative Course Postoperatively, the patient's symptoms recovered and no complications occurred. Follow-up imaging demonstrated a patent drainage tract without evidence of recurrence. Conclusion In patients with a conchal sphenoid sinus, endoscopic transnasal transclival access can be gained using a high nasopharyngeal approach. This corridor facilitates safe access to these lesions and others in this location.

PubMed Central

Zanoletti, E.; Borsetto, D.; Opocher, G.; Mazzoni, A.; Martini, A.

2017-01-01

SUMMARY Endolymphatic sac tumour (ELST) is infrequent, as emerges from small series reported in the literature. It is a slow-growing malignancy with local aggressiveness and a low risk of distant metastases. It is often misdiagnosed because of the late onset of symptoms and difficulty in obtaining a biopsy. Its frequency is higher in von Hippel-Lindau (VHL) disease (a genetic systemic syndrome involving multiple tumours), with a prevalence of around 25%. The diagnosis is based on radiology, with specific patterns on contrast-enhanced MRI and typical petrous bone erosion on bone CT scan. Our experience of ELST in the years between 2012-2015 concerns 7 cases, one of which was bilateral, in patients with VHL disease. Four of the 7 patients underwent 5 surgical procedures at our institution. Each case is described in detail, including clinical symptoms, and the intervals between symptom onset, diagnosis and therapy. Postoperative morbidity was low after early surgery on small tumours, whereas extensive surgery for large tumours was associated with loss of cranial nerve function (especially VII, IX, X). The critical sites coinciding with loss of neurological function were the fallopian canal, jugular foramen, petrous apex and intradural extension into the posterior cranial fossa. Early surgery on small ELST is advocated for patients with VHL disease, in whom screening enables a prompt diagnosis and consequently good prognosis. PMID:29165437

Microsurgical anatomy of the abducens nerve.

PubMed

Joo, Wonil; Yoshioka, Fumitaka; Funaki, Takeshi; Rhoton, Albert L

2012-11-01

The aim of this study is to demonstrate and review the detailed microsurgical anatomy of the abducens nerve and surrounding structures along its entire course and to provide its topographic measurements. Ten cadaveric heads were examined using ×3 to ×40 magnification after the arteries and veins were injected with colored silicone. Both sides of each cadaveric head were dissected using different skull base approaches to demonstrate the entire course of the abducens nerve from the pontomedullary sulcus to the lateral rectus muscle. The anatomy of the petroclival area and the cavernous sinus through which the abducens nerve passes are complex due to the high density of critically important neural and vascular structures. The abducens nerve has angulations and fixation points along its course that put the nerve at risk in many clinical situations. From a surgical viewpoint, the petrous tubercle of the petrous apex is an intraoperative landmark to avoid damage to the abducens nerve. The abducens nerve is quite different from the other nerves. No other cranial nerve has a long intradural path with angulations and fixations such as the abducens nerve in petroclival venous confluence. A precise knowledge of the relationship between the abducens nerve and surrounding structures has allowed neurosurgeon to approach the clivus, petroclival area, cavernous sinus, and superior orbital fissure without surgical complications. Copyright © 2012 Wiley Periodicals, Inc.

Fatal carotid dissection after blunt head trauma.

PubMed

Tartara, F; Regolo, P; Servadei, F; Versari, P P; Giovanelli, M

2000-06-01

Occurrence of internal carotid artery injuries associated with skull base fracture has been reported. A. report a case of fatal intracranial carotid dissection related to petrous fracture involving the carotid canal. Identification of carotid lesions may be difficult and generally related to appearance of unexpected neurological deficit. Skull base fractures may be considered an indirect sign for detection of vascular injury. Patterns of the fracture are of paramount importance; routine CT scan may fail to detect basilar fractures and high definition fine-cut CT scan should be executed to carefully identify and evaluate fractures. Temporal and sphenoid bone fractures are common in head trauma and involvement of the course of the carotid artery is frequent. The involvement of the intracranial carotid artery course represents a direct risk factor for lesions of the petrous, lacerum and cavernous segments of the carotid artery. Early diagnosis of post-traumatic vascular injury may lead to prognosis improvement because of effectiveness of heparin anticoagulant therapy. Then vascular screening is recommendable in cases with complex fractures of the skull base and particularly fracturing along the course of the carotid artery. Magnetic resonance angiography may be considered the first line diagnostic tools for vascular screening. Angiography may be reserved for patients with a proven lesion or rapid neurological deterioration taking into account the possibility of interventional treatment.

Round window chamber and fustis: endoscopic anatomy and surgical implications.

PubMed

Marchioni, Daniele; Soloperto, Davide; Colleselli, Elena; Tatti, Maria Fatima; Patel, Nirmal; Jufas, Nicholas

2016-11-01

The round window region is of critical importance in the anatomy of the middle ear. The aim of this paper is to describe its anatomy from an endoscopic point of view, emphasizing structures that have important surgical implications, in particular the fustis and the subcochlear canaliculus. The fustis, a smooth bony structure that forms the floor of the round window region, is a constant and important structure. It seems to indicate the round window membrane and the correct position of scala tympani. A structure connecting the round window region to the petrous apex, named the subcochlear canaliculus, is also described. A retrospective review of video recordings of endoscopic dissection and surgical procedures, carried out between June 2014 and February 2015, was conducted across two Tertiary university referral centers. A total of 42 dissections were analyzed in the study. We observed the fustis in all the cases and we identify two different anatomical conformations. The subcochlear canaliculus was found in 81.0 %, with a pneumatization direct to the petrous apex in 47.7 %. Conformation and limits of the round window niche may influence the surgical view of the round window membrane. Endoscopic approaches allow a very detailed view, which enables a comprehensive exploration of the round window region. Accurate knowledge of the anatomical relationships of this region has important advantages during middle ear surgery.

Mastoidectomy simulation with combined visual and haptic feedback.

PubMed

Agus, Marco; Giachetti, Andrea; Gobbetti, Enrico; Zanetti, Gianluigi; Zorcolo, Antonio; John, Nigel W; Stone, Robert J

2002-01-01

Mastoidectomy is one of the most common surgical procedures relating to the petrous bone. In this paper we describe our preliminary results in the realization of a virtual reality mastoidectomy simulator. Our system is designed to work on patient-specific volumetric object models directly derived from 3D CT and MRI images. The paper summarizes the detailed task analysis performed in order to define the system requirements, introduces the architecture of the prototype simulator, and discusses the initial feedback received from selected end users.

Gradenigo's syndrome--surgical management in a child.

PubMed

Humayun, Hassan Nabeel; Akhtar, Shabbir; Ahmed, Shakeel

2011-04-01

Otits media is a common problem. Some of its complications that were seen frequently in the preantibiotic era are rare today. We report a case of an 8 year boy who presented with earache, retro-orbital pain and diplopia secondary to a sixth nerve palsy--Gradenigo's syndrome. In this syndrome infection from the middle ear spreads medially to the petrous apex of the temporal bone. Work-up includes CT scan of the temporal bones. Timely management with intravenous antibiotics (+ surgery) is needed to prevent intra-cranial complications.

As solid as a rock-comparison of CE- and MPS-based analyses of the petrosal bone as a source of DNA for forensic identification of challenging cranial bones.

PubMed

Kulstein, Galina; Hadrys, Thorsten; Wiegand, Peter

2018-01-01

Short tandem repeat (STR) typing from skeletal remains can be a difficult task. Dependent on the environmental conditions of the provenance of the bones, DNA can be degraded and STR typing inhibited. Generally, dense and compact bones are known to preserve DNA better. Several studies already proved that femora and teeth have high DNA typing success rates. Unfortunately, these elements are not present in all cases involving skeletal remains. Processing partial or singular skeletal elements, it is favorable to select bone areas where DNA preservation is comparably higher. Especially, cranial bones are often accidentally discovered during criminal investigations. The cranial bone is composed of multiple parts. In this examination, we evaluated the potential of the petrous bone for human identification of skeletal remains in forensic case work. Material from different sections of eight unknown cranial bones and-where available-additionally other skeletal elements, collected at the DNA department of the Institute of Legal Medicine in Ulm, Germany, from 2010 to 2017, were processed with an optimized DNA extraction and STR typing strategy. The results highlight that STR typing from the petrous bones leads to reportable profiles in all individuals, even in cases where the analysis of the parietal bone failed. Moreover, the comparison of capillary electrophorese (CE) typing to massively parallel sequencing (MPS) analysis shows that MPS has the potential to analyze degraded human remains and is even capable to provide additional information about phenotype and ancestry of unknown individuals.

Endolymphatic sac tumour in von Hippel-Lindau disease: management strategies.

PubMed

Zanoletti, E; Girasoli, L; Borsetto, D; Opocher, G; Mazzoni, A; Martini, A

2017-10-01

Endolymphatic sac tumour (ELST) is infrequent, as emerges from small series reported in the literature. It is a slow-growing malignancy with local aggressiveness and a low risk of distant metastases. It is often misdiagnosed because of the late onset of symptoms and difficulty in obtaining a biopsy. Its frequency is higher in von Hippel-Lindau (VHL) disease (a genetic systemic syndrome involving multiple tumours), with a prevalence of around 25%. The diagnosis is based on radiology, with specific patterns on contrast-enhanced MRI and typical petrous bone erosion on bone CT scan. Our experience of ELST in the years between 2012-2015 concerns 7 cases, one of which was bilateral, in patients with VHL disease. Four of the 7 patients underwent 5 surgical procedures at our institution. Each case is described in detail, including clinical symptoms, and the intervals between symptom onset, diagnosis and therapy. Postoperative morbidity was low after early surgery on small tumours, whereas extensive surgery for large tumours was associated with loss of cranial nerve function (especially VII, IX, X). The critical sites coinciding with loss of neurological function were the fallopian canal, jugular foramen, petrous apex and intradural extension into the posterior cranial fossa. Early surgery on small ELST is advocated for patients with VHL disease, in whom screening enables a prompt diagnosis and consequently good prognosis. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Influence of the parameters of the Er:YAG laser on the apical sealing of apicectomized teeth.

PubMed

Marques, Aparecida Maria Cordeiro; Gerbi, Marleny Elizabeth M M; dos Santos, Jean Nunes; Noia, Manuela Pimentel; Oliveira, Priscila Chagas; Brugnera Junior, Aldo; Zanin, Fátima Antonia Aparecida; Pinheiro, Antonio Luiz Barbosa

2011-07-01

Failures in the sealing of the tooth apex have been considered to be responsible for most of the failures of apical surgeries. The Er:YAG laser has been proposed as an alternative for the use of rotator instruments in surgical endodontics due to its precision, lack of vibration, less post-operative discomfort, bacterial reduction, and less stress for patients and professionals. Following approval by the ethics committee, 12 extracted human canines without previous endodontic treatment with anatomically normal roots and free from apical lesions were washed in running tap water and disinfected. The teeth were sectioned axially at the crown-root junction and submitted to routine endodontic treatment. The apical limit was set at 1 mm before the apical foramen. The root canals were routinely filled with Gutta-Percha points and Sealer 26 and were randomly distributed into two groups (n = 6). In group I, apicectomy was performed with the Er:YAG laser (KAVO KEY Laser II®, Germany, λ = 2.940 nm, pulsed mode, 2051 tip, with air spray cooling, 250 mJ/15 Hz). Apical cut was performed of perpendicular mode 3 mm from the apical foramen. In group II, the same procedures and the same sequence as above was used, varying only the parameters of the Er:YAG laser (400 mJ/6 Hz). Sealing of the cervical end the apex was carried out with acrylic resin; the roots were covered by a layer of epoxy glue and two layers of nail polish. The specimens were divided into groups and fixed, by the cervical third, on wax. Impermeabilization of the residual root apical third was performed following the same procedures used in the cervical third but the residual apex was left free from the impermeabilization. After that, the roots were immersed in a 2% methylene blue solution and placed in a bacteriological oven for 48 h and then washed in running tap water for 2 h. The samples were sagittally split into two parts. The segments were visually observed and the one showing the greatest

Primary tuberculous petrositis.

PubMed

Sethi, Ashwani; Sabherwal, Anup; Gulati, Achal; Sareen, Deepika

2005-11-01

Tuberculous osteomyelitis of the temporal bone is a rare and dangerous entity that should be included in the differential diagnosis of infectious processes of the base of the skull. We present the case of an 11-year-old child who presented with diplopia, ear discharge and hearing loss. The radiological and histopathological findings revealed tuberculous otitis with osteomyelitis and an abscess in the petrous apex. The child responded to anti-tuberculous chemotherapy. The diagnosis and management of tuberculous osteomyelitis are discussed and a brief review of the literature is presented.

Skull base trauma: diagnosis and management.

PubMed

Samii, Madjid; Tatagiba, Marcos

2002-03-01

The singular anatomical relationship of the base of the skull is responsible for the particular problems that may arise after injury. Extensive dural laceration and severe neurovascular damage may accompany skull base injuries. Trauma to the anterior skull base is frequently related to the paranasal sinuses, and trauma to the middle and the posterior skull base usually affects the petrous bone. Injury to the anterior fossa including the paranasal sinuses may produce CSF leakage, damage the olfactory nerves, optic nerves, and orbita contents. Fractures may affect the carotid canal, injure the internal carotid artery and result in carotid-cavernous fistula. Trauma to the petrous bone may cause facial palsy and deafness, and CSF leakage with otorrhoea or paradoxal rhinoliquorrhoea. Trauma to the posterior fossa may lacerate the major venous sinuses, and affect the cranio-cervical stability. Each one of these injuries will need a particular strategy. Decision making for management as a whole must consider all aspects, including the fact that these injuries frequently involve polytraumatized patients. Decisions regarding the timing of surgery and the sequence of the surgical procedures must be made with great care. Modern surgical techniques and recent technologies including functional preservation of the olfactory nerves in frontobasal trauma, visual evoked potentials, assisted optic nerve decompression, facial nerve reconstruction, interventional technique for intravascular repair of vascular injuries, and recent developments in cochlea implants and brain stem implants, all contributed significantly to improve outcome and enhance the quality of life of patients. This article reviews basic principles of management of skull base trauma stressing the role of these advanced techniques.

Searching for the mother missed since the Second World War.

PubMed

Zupanič Pajnič, Irena; Petaros, Anja; Balažic, Jože; Geršak, Ksenija

2016-11-01

The aim of the study was to perform the genetic identification of a human cranium from a Second World War gravesite in Slovenia and find out if it belonged to the mother of a woman used as a family reference. Both genetic and anthropological examinations were carried out. The genetic examination was performed on 2 molars and petrous bone. Prior to DNA isolation 0.5 g of tooth and bone powder was decalcified. The DNA was purified in a Biorobot EZ1 (Qiagen) device. The nuclear DNA of the samples was quantified and short tandem repeat (STR) typing performed using two different autosomal and Y-STR kits. Up to 22.4 ng DNA/g of powder was obtained from samples analyzed. We managed to obtain nuclear DNA for successful STR typing from the left second molar and from the petrous bone. Full autosomal genetic profile including amelogenin locus revealed the male origin of the cranium that was further confirmed by the analyses of Y-STRs. The same conclusions were adopted after the anthropological analysis which identified the cranium as that of a very young Caucasoid male. The male origin of the cranium rejected the possibility of motherhood for the compared daughter. For traceability in the event of contamination, we created an elimination database including genetic profiles of the nuclear and Y-STRs of all persons that had been in contact with the analyzed cranium and no match was found. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Surgical resection of skull-base chordomas: experience in case selection for surgical approach according to anatomical compartments and review of the literature.

PubMed

Shimony, Nir; Gonen, Lior; Shofty, Ben; Abergel, Avraham; Fliss, Dan M; Margalit, Nevo

2017-10-01

Chordoma is a rare bony malignancy known to have a high rate of local recurrence after surgery. The best treatment paradigm is still being evaluated. We report our experience and review the literature. We emphasize on the difference between endoscopic and open craniotomy in regard to the anatomical compartment harboring the tumor, the limitations of the approaches and the rate of surgical resection. We retrospectively collected all patients with skull-base chordomas operated on between 2004 and 2014. Detailed radiological description of the compartments being occupied by the tumor and the degree of surgical resection is discussed. Eighteen patients were operated on in our facility for skull-base chordoma. Seventeen endoscopic surgeries were done in 15 patients, and 7 craniotomies were done in 5 patients. The mean age was 48.9 years (±19.8 years). When reviewing the anatomical compartments, we found that the most common were the upper clivus (95.6%) and lower clivus (58.3%), left cavernous sinus (66.7%) and petrous apex (∼60%). Most of the patients had intradural tumor involvement (70.8%). In all craniotomy cases, there was residual tumor in multiple compartments. In the endoscopic cases, the most difficult compartments for total resection were the lower clivus, and lateral extensions to the petrous apex or cavernous sinus. Our experience shows that the endoscopic approach is a good option for midline tumors without significant lateral extension. In cases with very lateral or lower extensions, additional approaches should be added trying to achieve complete resection.

Expanded Endoscopic Endonasal Approaches to Skull Base Meningiomas

PubMed Central

Prosser, J. Drew; Vender, John R.; Alleyne, Cargill H.; Solares, C. Arturo

2012-01-01

Anterior cranial base meningiomas have traditionally been addressed via frontal or frontolateral approaches. However, with the advances in endoscopic endonasal treatment of pituitary lesions, the transphenoidal approach is being expanded to address lesions of the petrous ridge, anterior clinoid, clivus, sella, parasellar region, tuberculum, planum, olfactory groove, and crista galli regions. The expanded endoscopic endonasal approach (EEEA) has the advantage of limiting brain retraction and resultant brain edema, as well as minimizing manipulation of neural structures. Herein, we describe the techniques of transclival, transphenoidal, transplanum, and transcribiform resections of anterior skull base meningiomas. Selected cases are presented. PMID:23730542

The effects of area postrema lesions and selective vagotomy on motion-induced conditioned taste aversion

NASA Technical Reports Server (NTRS)

Fox, Robert A.; Sutton, R. L.; Mckenna, Susan

1991-01-01

Conditioned taste aversion (CTA) is one of several behaviors which was suggested as a putative measure of motion sickness in rats. A review is made of studies which used surgical disruption of area postrema or the vagus nerve to investigate whether CTA and vomiting induced by motion may depend on common neural pathways or structures. When the chemoreceptive function of the area postrema (AP) is destroyed by complete ablation, rats develop CTA and cats and monkeys develop CTA and vomit. Thus the AP is not crucially involved in either CTA or vomiting induced by motion. However, after complete denervation of the stomach or after labyrinthectomy rats do not develop CTA when motion is used as the unconditioned stimulus. Studies of brainstem projections of the vagus nerve, the area postrema, the periaqueductal grey, and the vestibular system are used as the basis for speculation about regions which could mediate both motion-induced vomiting and behavioral food aversion.

Composition and distribution of elements and ultrastructural topography of a human cardiac calculus.

PubMed

Cheng, Ching-Li; Chang, Hsiao-Huang; Huang, Pei-Jung; Chu, Yu-Ting; Lin, Shan-Yang

2013-04-01

Trace elements (TEs) may contribute to the formation of calculi or stones or be involved in the aetiopathogenesis of stone diseases. The compositions and spatial distribution of elements from the inner nucleus to outer crust of the cardiac calculus were investigated by energy-dispersive X-ray fluorescence (EDXRF) spectrometer. The surface topograph, distribution map of elements, elemental and chemical compositions were also determined by environmental scanning electron microscope (ESEM)-energy-dispersive X-ray (EDX) analysis. Twenty-five elements were identifiable from 18 positions on the cardiac calculus by EDXRF spectrometer, in which the highest concentrations of toxic TEs (Ni, Pt, Hg, Sn, Pb, W, Au, Al, Si) and higher levels of essential TEs (Ca, Sr, Cr, P) were detected. A moderate positive Pearson's correlation between TEs concentrations of Mg, Ca or P and location differences from centre to periphery in the cardiac calculus was observed. A positive correlation was also found for Ca/Zn and Ca/Cu, indicating the gradual increase of calcium concentration from inner nucleus to outer crust of cardiac calculus. The drop-like nodules/crystals on the surface of petrous part of cardiac calculus were observed from ESEM analysis. ESEM-EDX analysis determined the calculus to be predominantly composed of calcium hydroxyapatite and cholesterol, as indicated by the petrous surface and drop-like nodules/crystals, respectively. This composition was confirmed using a portable Raman analyser. The spatial distribution analysis indicated a gradual increase in Mg, P and Ca concentrations from the inner nucleus to the outer crust of the cardiac calculus. The major chemical compositions of calcium hydroxyapatite and cholesterol were detected on this cardiac calculus.

Clival giant cell tumor - A rare case report and review of literature with respect to current line of management

PubMed Central

Patibandla, Mohana Rao; Thotakura, Amit Kumar; Rao, Marabathina Nageswara; Addagada, Gokul Chowdary; Nukavarapu, Manisha Chowdary; Panigrahi, Manas Kumar; Uppin, Shantiveer; Challa, Sundaram; Dandamudi, Srinivas

2017-01-01

Giant-cell tumor (GCT) involving the skull base is rare. Sphenoid bone is the most commonly involved bone followed by petrous temporal bone. Histopathology and radiological features of these lesions are similar to GCT involving bone elsewhere. Unlike other sites, skull base is not an ideal site for the radical surgery. Hence adjuvant treatment has pivotal role. Radiation therapy with intensity-modulated radiation therapy, stereotactic radiosurgery or chemotherapy with adriamycin are promising as described in some case reports. Bisphosphonates showed good control in local recurrence. In vitro studies with Zolendronate loaded bone cement and phase 2 trials of Denosumab showed hopeful results, may be useful in future. PMID:28413541

[Neurosurgery in a patient on dual antiplatelet therapy. Case report and the review of the literature].

PubMed

Lubnin, A Yu; Karnaukhov, V V; Moshkin, A V; Rylova, A V; Shimansky, V N

A neurosurgical intervention in a patient on dual antiplatelet therapy is a serious challenge for both the neurosurgeon and anesthesiologist.. The article describes a clinical case of a successful urgent neurosurgical intervention (ventriculoperitoneostomy for obstructive hydrocephalus caused by a large meningioma of the posterior surface of the petrous pyramid) in a patient on dual antiplatelet therapy (DAT) due to a recently placed coronary stent.. Given a high risk of coronary stent thrombosis, the surgery was performed in the presence of ongoing DAT. There were no intracranial hemorrhagic complications, but subcutaneous hemorrhagic complications developed. The article discusses the features of managing similar patients whose number is growing.

Role of different sensory inputs for maintenance of body posture in sitting rat and rabbit.

PubMed

Deliagina, T; Beloozerova, I N; Popova, L B; Sirota, M G; Swadlow, H A; Grant, G; Orlovsky, G N

2000-10-01

In this paper, we describe the postural activity in sitting rats and rabbits. An animal was positioned on the platform that could be tilted in the frontal plane for up to +/-20-30 degrees, and postural corrections were video recorded. We found that in both rat and rabbit, the postural reactions led to stabilization of the dorsal-side-up trunk orientation. The result of this was that the trunk tilt constituted only approximately 50% (rat) and 25% (rabbit) of the platform tilt. In addition, in the rabbit the head orientation was also stabilized. Trunk stabilization persisted in the animals subjected to the bilateral labyrinthectomy and blindfolding, suggesting that the somatosensory input is primarily responsible for trunk stabilization. Trunk stabilization was due to extension of the limbs on the side moving down, and flexion of the opposite limbs. EMG recordings showed that the limb extension was caused by the active contraction of extensor muscles. We argue that signals from the Golgi tendon organs of the extensor muscles may considerably contribute to elicitation of postural corrective responses to the lateral tilt.

Endoscopic Skull Base Surgery

PubMed Central

Senior, Brent A

2008-01-01

Endoscopic skull base surgery has undergone rapid advancement in the past decade moving from pituitary surgery to suprasellar lesions and now to a myriad of lesions extending from the cribriform plate to C2 and laterally out to the infratemporal fossa and petrous apex. Evolution of several technological advances as well as advances in understanding of endoscopic anatomy and the development of surgical techniques both in resection and reconstruction have fostered this capability. Management of benign disease via endoscopic methods is largely accepted now but more data is needed before the controversy on the role of endoscopic management of malignant disease is decided. Continued advances in surgical technique, navigation systems, endoscopic imaging technology, and robotics assure continued brisk evolution in this expanding field. PMID:19434274

[Apical petrositis, osteomyelitis of the base of the skull bones and of the first cervical vertebra in a 5 year-old children following chicken pox].

PubMed

Bogomil'sky, M R; Polunin, M M; Zelikovich, E I; Soldatsky, Yu L; Burova, O V

2016-01-01

This publication was designed to describe a rare case of development of apicalpetrositis in a child presenting with acute otitis mediafollowing chicken pox experienced in the preceding period. We carried out the study with the use of computed tomography (CT) that demonstrated destruction of the temporal bone, bones of the base of the skull and of the first cervical vertebra. The treatment strategy chosen for the management of this condition that included antibiotic therapy and expectant observation proved justified and can be recommended as an algorithm of choice taking into consideration the difficulty of surgical approach to the apex of the petrous pyramid. However, this approach is associated with the high risk of disability arising from the potential injury to the craniocerebral nerves.

Differential diagnoses of cerebral hemiatrophy in childhood: a review of literature with illustrative report of two cases.

PubMed

Uduma, Felix Uduma; Emejulu, Jude-Kennedy C; Motah, Mathieu; Okere, Philip C N; Ongolo, Pierre C; Muna, W

2013-03-20

Childhood cerebral hemiatrophy is an uncommon clinical entity. Its aetiologies are diverse but can generally be grouped into congenital and acquired. The congenital type is intrauterine in origin while the acquired type occurs early in life, usually before two year of life. When childhood cerebral hemiatrophy occurs, it evokes a spectrum of compensatory calvarial sequlae. These include ipsilateral calvarial thickening, diploe widening, hyper-pneumatization of paranasal sinues/ mastoids, elevation of petrous bone and small middle cranial fossa. MRI is very effective in high lightening brain atrophy, associated parenchymal changes and even the above enumerated skull changes. Our two case reports of left hemi-cerebral atrophy in male Cameroonian children seen in our MRI practice aptly demonstrated some of the aforementioned radiological features of childhood cerebral hemiatrophy noted in literature review.

Diagnostic and therapeutic strategy in Menière's disease. Guidelines of the French Otorhinolaryngology-Head and Neck Surgery Society (SFORL).

PubMed

Nevoux, J; Franco-Vidal, V; Bouccara, D; Parietti-Winkler, C; Uziel, A; Chays, A; Dubernard, X; Couloigner, V; Darrouzet, V; Mom, T

2017-12-01

The authors present the guidelines of the French Otorhinolaryngology-Head and Neck Surgery Society (Société française d'oto-rhino-laryngologie et de chirurgie de la face et du cou: SFORL) for diagnostic and therapeutic strategy in Menière's disease. A work group was entrusted with a review of the scientific literature on the above topic. Guidelines were drawn up, then read over by an editorial group independent of the work group. The guidelines were graded according to the literature analysis and recommendations grading guide published by the French National Agency for Accreditation and Evaluation in Health (January 2000). Menière's disease is diagnosed in the presence of the association of four classical clinical items and after eliminating differential diagnoses on MRI. In case of partial presentation, objective audiovestibular tests are recommended. Therapy comprises medical treatment and surgery, either conservative or sacrificing vestibular function. Medical treatment is based on lifestyle improvement, betahistine, diuretics or transtympanic injection of corticosteroids or gentamicin. The main surgical treatments, in order of increasing aggressiveness, are endolymphatic sac surgery, vestibular neurotomy and labyrinthectomy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Non-Pharmacological Countermeasure to Decrease Landing Sickness and Improve Functional Performance

NASA Technical Reports Server (NTRS)

Rosenberg, M. J. F.; Kreutzberg, G. A.; Galvan-Garza, R. C.; Mulavara, A. P.; Reschke, M. F.

2017-01-01

Upon return from long-duration spaceflight, 100% of crewmembers experience motion sickness (MS) symptoms. The interactions between crewmembers' adaptation to a gravitational transition, the performance decrements resulting from MS and/or use of promethazine (PMZ), and the constraints imposed by mission task demands could significantly challenge and limit an astronaut's ability to perform functional tasks during gravitational transitions. Stochastic resonance (SR) is "noise benefit": adding noise to a system might increase the information (examples to the left and above). Stochastic vestibular stimulation (SVS), or low levels of noise applied to the vestibular system, improves balance and locomotor performance (Goel et al. 2015, Mulavara et al. 2011, 2015). In hemi-lesioned rat models, Samoudi et al. 2012 found that SVS increased GABA release on the lesioned, but not the intact side. Activation of the GABA pathway is important in modulating MS and promoting adaptability (Cohen 2008) and was seen to reverse MS symptoms in rats after unilateral labyrinthectomy (Magnusson et al. 2000). Thus, SVS could be used to promote GABA pathways to reduce MS and promote adaptability, eliminate the need for PMZ or other performance-inhibiting drugs.

Adaptive Changes in Sensorimotor Coordination and Motion Sickness Following Repeated Exposures to Virtual Environments

NASA Technical Reports Server (NTRS)

Harm, D. L.; Taylor, L. C.; Bloomberg, J. J.

2007-01-01

Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. The purpose of this research was to compare disturbances in sensorimotor coordination produced by dome and head-mounted virtual environment displays and to examine the effects of exposure duration, and repeated exposures to VR systems. The first study examined disturbances in balance control, and the second study examined disturbances in eye-head-hand (EHH) and eye-head coordination.

Primary Ewing's Sarcoma of the Temporal Bone: A Rare Case Report and Literature Review.

PubMed

Gupta, Divya; Gulati, Achal; Purnima

2017-09-01

Ewing's sarcoma is a malignant, round cell tumor arising from the bones and primarily affecting children and adolescent, accounting for 3 % of all childhood malignancies. Although the long bones and the trunk are typically affected, rare cases of it involving isolated bones throughout the body have been reported. Involvement of the skull bones is rare, constituting 1-6 % of the total Ewing's sarcoma cases but those affecting the cranial bones are rarer still, constituting only 1 %. We describe an 8 months old infant having Ewing sarcoma, of the petrous and mastoid parts of temporal bone along with the occipital bone, whose clinical presentation mimicked mastoiditis with facial nerve palsy. We discuss the clinical and therapeutic course of an extensive primary Ewing sarcoma of the temporal bone, which was treated without performing surgery and review this entity's literature in detail.

Malignant external otitis: CT evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtin, H.D.; Wolfe, P.; May, M.

1982-11-01

Malignant external otitis is an aggressive infection caused by Pseudomonas aeruginosa that most often occurs in elderly diabetics. Malignant external otitis often spreads inferiorly from the external canal to involve the subtemporal area and progresses medially towards the petrous apex leading to multiple cranial nerve palsies. The computed tomographic (CT) findings in malignant external otitis include obliteration of the normal fat planes in the subtemporal area as well as patchy destruction of the bony cortex of the mastoid. The point of exit of the various cranial nerves can be identified on CT scans, and the extent of the inflammatory massmore » correlates well with the clinical findings. Four cases of malignant external otitis are presented. In each case CT provided a good demonstration of involvement of the soft tissues at the base of the skull.« less

Recurrence of a nasopharyngeal carcinoma manifesting as a cerebellopontine angle mass.

PubMed

Kong, Min Han; Jeevanan, Jahendran; Jegan, Thanabalan

2013-12-01

As many as 31% of patients with nasopharyngeal carcinoma present with intracranial extension. Despite this high percentage, extension to the cerebellopontine angle is rare. The mechanism of tumor spread to the cerebellopontine angle is not completely understood. The most likely mechanism is direct extension to the skull base with involvement of the petrous apex and further extension posteriorly via the medial tentorial edge. We report the case of a 46-year-old woman with nasopharyngeal carcinoma who had been treated initially with chemoradiation and subsequently with stereotactic radiosurgery for residual tumor. One year later, she presented with an intracranial recurrence of the nasopharyngeal carcinoma in the cerebellopontine angle; the recurrence mimicked a benign tumor on magnetic resonance imaging. The tumor was ultimately diagnosed as an undifferentiated carcinoma of nasopharyngeal origin. She was treated with palliative chemotherapy.

Light up the "no-man's land" on the brain stem.

PubMed

Kawase, T

1995-12-01

The ventral surface of the brain stem is anatomically surrounded by the clivus anteriorly, brain stem posteriorly and by the petrous pyramid and cranial nerves from IIIrd to XIIth laterally in the deep posterior cranial fossa. Neurosurgical extra-axial pathologies arising from the area are aneurysms on the vertebro-basilar artery, benign tumors such as clival meningiomas, chordomas, chondromas, trigeminal neurinomas and prepontine epidermoid tumors. Surgical access to the area had been difficult for long years since the neurosurgery was established, because located deeply in such a surgical blindness, so-called "no-man's land". However, recent technical development of "skull base surgery" is opening new doors to light up the surgical darkness of the "no-man's land". This paper reviews the history, development, technique and future prospect of the skull base surgery to open the "no-man's land".

P14.05 How far can they grow... - Two clinical examples

PubMed Central

Espírito Santo, V.; Mendes, M.; Almendra, R.; Veiga, A.; Velon, A.; Guimarães, P.

2017-01-01

Abstract Introduction: Cerebral metastases are the most common form of central nervous system (CNS) tumours in adults. However, malignant neoplasm may also involve structures external to the brain, such as tissue surrounding the base of the skull, and then metastasize to the brain either by direct invasion or by spreading by the cranial nerves. CASE1: A 74 year-old man, with a past history of chronic kidney disease due to renal artery thrombosis and hypertension, was admitted in the emergency room (ER) complaining of persisting pain in the superior half of the right hemiface and frontal region, refractory to analgesia, with 2 months of evolution. He also referred diplopia in the right eye, homolateral hearing loss and asthenia. Neurological examination revealed psychomotor retardation, right VI cranial nerve paralysis, right sensorineural hypoacusis and dysphagia. Brain and neck MRI showed a lesion in right nasopharynx that invaded the bony structures of the base of the skull, in particular the petrous apex, clivus and great sphenoid wing. It also had an endocranial soft tissue component that occupied the cistern of Gasser’s ganglion. He was diagnosed with a nasopharynx malignant neoplasm. His clinical status deteriorated rapidly and he died 1 month later. CASE2: A 68 year-old woman, with a past history of left great sphenoid wing meningioma that was removed 2 years ago, was admitted in the ER complaining of tinnitus and hearing loss in the left ear and dizziness. Neurological examination revealed peripheral left facial paralysis, which the patient claims to have arisen shortly after the previous surgery and left conductive hypoacusis. Brain MRI showed a lesion in the left parotid gland that invaded the petrous bone, infiltrating the jugular foramen and carotid canal, causing deformation of these vascular structures. She was diagnosed with a parotid gland malignant neoplasm that slowly grow in the last 2 years. By this moment, she is still waiting for a

Hepatocellular carcinoma metastasizing to the skull base involving multiple cranial nerves.

PubMed

Kim, Soo Ryang; Kanda, Fumio; Kobessho, Hiroshi; Sugimoto, Koji; Matsuoka, Toshiyuki; Kudo, Masatoshi; Hayashi, Yoshitake

2006-11-07

We describe a rare case of HCV-related recurrent multiple hepatocellular carcinoma (HCC) metastasizing to the skull base involving multiple cranial nerves in a 50-year-old woman. The patient presented with symptoms of ptosis, fixation of the right eyeball, and left abducens palsy, indicating disturbances of the right oculomotor and trochlear nerves and bilateral abducens nerves. Brain contrast-enhanced computed tomography (CT) revealed an ill-defined mass with abnormal enhancement around the sella turcica. Brain magnetic resonance imaging (MRI) disclosed that the mass involved the clivus, cavernous sinus, and petrous apex. On contrast-enhanced MRI with gadolinium-chelated contrast medium, the mass showed inhomogeneous intermediate enhancement. The diagnosis of metastatic HCC to the skull base was made on the basis of neurological findings and imaging studies including CT and MRI, without histological examinations. Further studies may provide insights into various methods for diagnosing HCC metastasizing to the craniospinal area.

Comparison of temporal bone fractures in children and adults.

PubMed

Kang, Ho Min; Kim, Myung Gu; Hong, Seok Min; Lee, Ho Yun; Kim, Tae Hyun; Yeo, Seung Geun

2013-05-01

Contrary to our expectation, that the clinical characteristics of temporal bone fracture would differ in children and adults, we found that the two groups were similar. Most studies of temporal bone fractures have been performed in adults. To our knowledge, no study has investigated differences in temporal bone fractures in children and adults. We therefore investigated differences in temporal bone fractures in adults and children by examining the manifestations and clinical symptoms of temporal bone fractures in pediatric patients. The demographic and clinical characteristics were assessed in 32 children and 186 adults with temporal bone fractures. All patients underwent computed tomography of the temporal bone. Causes of fracture, gender distribution, manifestations of temporal bone fracture, and clinical symptoms were similar in adults and children (p > 0.05 each). Petrous fracture, ear fullness, dizziness, and tinnitus were significantly more frequent in adults than in children (p < 0.05 each).

Genome flux and stasis in a five millennium transect of European prehistory.

PubMed

Gamba, Cristina; Jones, Eppie R; Teasdale, Matthew D; McLaughlin, Russell L; Gonzalez-Fortes, Gloria; Mattiangeli, Valeria; Domboróczki, László; Kővári, Ivett; Pap, Ildikó; Anders, Alexandra; Whittle, Alasdair; Dani, János; Raczky, Pál; Higham, Thomas F G; Hofreiter, Michael; Bradley, Daniel G; Pinhasi, Ron

2014-10-21

The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (~22 × ) and seven to ~1 × coverage, to investigate the impact of these on Europe's genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence.

Detection of human cytomegalovirus and Epstein-Barr Virus in symptomatic and asymptomatic apical periodontitis lesions by real-time PCR.

PubMed

Ozbek, Selcuk-M; Ozbek, Ahmet; Yavuz, Muhammed-Selim

2013-09-01

Recent studies have investigated the occurrence of human cytomegalovirus and Epstein-Barr Virus in samples from apical periodontitis lesions and a role in the pathogenesis of this disease has been suggested. Because genotype distribution and seroprevalence of EBV and HCMV differ among populations, it is important to determine the presence of these viruses in endodontic periapical lesions of different populations. The aims of this study were to determine the presence of HCMV and EBV DNAs in samples from Turkish patients with symptomatic and asymptomatic apical periodontitis lesions using real-time polymerase chain reaction method and to evaluate their presence in both symptomatic and asymptomatic apical periodontitis lesions. Periapical samples were collected from 12 asymptomatic and 16 symptomatic periapical lesions in conjunction with apicectomy. HCMV and EBV DNAs were identified in the samples by real-time PCR. The chi-squared test with Yates's correction or the Fisher's exact test was used to analyse the significance of differences. HCMV DNA was detected in 10 of the 16 (62.5%) symptomatic and in five of the 12 (41.7 %) asymptomatic periapical study lesions. The EBV DNA was identified in seven of the 16 (43.7 %) symptomatic and three of the 12 (25 %) asymptomatic periapical lesions. The difference in occurrence of HCMV and EBV DNA between symptomatic and asymptomatic periapical lesions was not statistically significant. (All comparisons have p > 0.05). Our findings suggest that HCMV and EBV is a frequent inhabitant of both symptomatic and asymptomatic apical periodontitis lesions of endodontic origin in Turkish population.

Microbial community in persistent apical periodontitis: a 16S rRNA gene clone library analysis.

PubMed

Zakaria, M N; Takeshita, T; Shibata, Y; Maeda, H; Wada, N; Akamine, A; Yamashita, Y

2015-08-01

To characterize the microbial composition of persistent periapical lesions of root filled teeth using a molecular genetics approach. Apical lesion samples were collected from 12 patients (23-80 years old) who visited the Kyushu University Hospital for apicectomy with persistent periapical lesions associated with root filled teeth. DNA was directly extracted from each sample and the microbial composition was comprehensively analysed using clone library analysis of the 16S rRNA gene. Enterococcus faecalis, Candida albicans and specific fimA genotypes of Porphyromonas gingivalis were confirmed using polymerase chain reaction (PCR) analysis with specific primers. Bacteria were detected in all samples, and the dominant findings were P. gingivalis (19.9%), Fusobacterium nucleatum (11.2%) and Propionibacterium acnes (9%). Bacterial diversity was greater in symptomatic lesions than in asymptomatic ones. In addition, the following bacteria or bacterial combinations were characteristic to symptomatic lesions: Prevotella spp., Treponema spp., Peptostreptococcaceae sp. HOT-113, Olsenella uli, Slackia exigua, Selemonas infelix, P. gingivalis with type IV fimA, and a combination of P. gingivalis, F. nucleatum, and Peptostreptococcaceae sp. HOT-113 and predominance of Streptococcus spp. On the other hand, neither Enterococcus faecalis nor C. albicans were detected in any of the samples. Whilst a diverse bacterial species were observed in the persistent apical lesions, some characteristic patterns of bacterial community were found in the symptomatic lesions. The diverse variation of community indicates that bacterial combinations as a community may cause persistent inflammation in periapical tissues rather than specific bacterial species. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Clinical Significance of an Unusual Variation

PubMed Central

Murugan, M. Senthil; Sudha, R.; Bhargavan, Rajesh

2016-01-01

The infrahyoid muscles are involved in vocalisation and swallowing; among these, the sternothyroid muscle is derived from the common primitive sheet. The improper differentiation of this muscle may therefore result in morphological variations. We report an unusual variation found during the dissection of a 65-year-old male cadaver at the Sri Manakula Vinayagar Medical College, Madagadipet, Pondicherry, India, in 2015. An anomalous belly of the right sternothyroid muscle was observed between the internal jugular (IJ) vein and the internal carotid artery with an additional insertion into the tympanic plate and petrous part of the temporal bone and the presence of a levator glandulae thyroideae muscle. The anomalous muscle may compress the IJ vein if it is related to the neurovascular structures of neck; hence, knowledge of variations of the infrahyoid muscles can aid in the evaluation of IJ vein compression among patients with idiopathic symptoms resulting from venous congestion. PMID:28003898

Two Immigrants with Tuberculosis of the Ear, Nose, and Throat Region with Skull Base and Cranial Nerve Involvement

PubMed Central

Richardus, Renate A.; Jansen, Jeroen C.; Steens, Stefan C. A.; Arend, Sandra M.

2011-01-01

We report two immigrants with tuberculosis of the skull base and a review of the literature. A Somalian man presented with bilateral otitis media, hearing loss, and facial and abducens palsy. Imaging showed involvement of both mastoid and petrous bones, extending via the skull base to the nasopharynx, suggesting tuberculosis which was confirmed by characteristic histology and positive auramine staining, while Ziehl-Neelsen staining and PCR were negative. A Sudanese man presented with torticollis and deviation of the uvula due to paresis of N. IX and XI. Imaging showed a retropharyngeal abscess and lysis of the clivus. Histology, acid-fast staining, and PCR were negative. Both patients had a positive Quantiferon TB Gold in-tube result and improved rapidly after empiric treatment for tuberculosis. Cultures eventually yielded M. tuberculosis. These unusual cases exemplify the many faces of tuberculosis and the importance to include tuberculosis in the differential diagnosis of unexplained problems. PMID:21541186

Genome-wide patterns of selection in 230 ancient Eurasians

PubMed Central

Mathieson, Iain; Lazaridis, Iosif; Rohland, Nadin; Mallick, Swapan; Patterson, Nick; Roodenberg, Songül Alpaslan; Harney, Eadaoin; Stewardson, Kristin; Fernandes, Daniel; Novak, Mario; Sirak, Kendra; Gamba, Cristina; Jones, Eppie R.; Llamas, Bastien; Dryomov, Stanislav; Pickrel, Joseph; Arsuaga, Juan Luís; de Castro, José María Bermúdez; Carbonell, Eudald; Gerritsen, Fokke; Khokhlov, Aleksandr; Kuznetsov, Pavel; Lozano, Marina; Meller, Harald; Mochalov, Oleg; Moiseyev, Vayacheslav; Rojo Guerra, Manuel A.; Roodenberg, Jacob; Vergès, Josep Maria; Krause, Johannes; Cooper, Alan; Alt, Kurt W.; Brown, Dorcas; Anthony, David; Lalueza-Fox, Carles; Haak, Wolfgang; Pinhasi, Ron; Reich, David

2016-01-01

Ancient DNA makes it possible to directly witness natural selection by analyzing samples from populations before, during and after adaptation events. Here we report the first scan for selection using ancient DNA, capitalizing on the largest genome-wide dataset yet assembled: 230 West Eurasians dating to between 6500 and 1000 BCE, including 163 with newly reported data. The new samples include the first genome-wide data from the Anatolian Neolithic culture whose genetic material we extracted from the DNA-rich petrous bone and who we show were members of the population that was the source of Europe’s first farmers. We also report a complete transect of the steppe region in Samara between 5500 and 1200 BCE that allows us to recognize admixture from at least two external sources into steppe populations during this period. We detect selection at loci associated with diet, pigmentation and immunity, and two independent episodes of selection on height. PMID:26595274

Genome flux and stasis in a five millennium transect of European prehistory

PubMed Central

Gamba, Cristina; Jones, Eppie R.; Teasdale, Matthew D.; McLaughlin, Russell L.; Gonzalez-Fortes, Gloria; Mattiangeli, Valeria; Domboróczki, László; Kővári, Ivett; Pap, Ildikó; Anders, Alexandra; Whittle, Alasdair; Dani, János; Raczky, Pál; Higham, Thomas F. G.; Hofreiter, Michael; Bradley, Daniel G; Pinhasi, Ron

2014-01-01

The Great Hungarian Plain was a crossroads of cultural transformations that have shaped European prehistory. Here we analyse a 5,000-year transect of human genomes, sampled from petrous bones giving consistently excellent endogenous DNA yields, from 13 Hungarian Neolithic, Copper, Bronze and Iron Age burials including two to high (~22 × ) and seven to ~1 × coverage, to investigate the impact of these on Europe’s genetic landscape. These data suggest genomic shifts with the advent of the Neolithic, Bronze and Iron Ages, with interleaved periods of genome stability. The earliest Neolithic context genome shows a European hunter-gatherer genetic signature and a restricted ancestral population size, suggesting direct contact between cultures after the arrival of the first farmers into Europe. The latest, Iron Age, sample reveals an eastern genomic influence concordant with introduced Steppe burial rites. We observe transition towards lighter pigmentation and surprisingly, no Neolithic presence of lactase persistence. PMID:25334030

Penetrating brain injury caused by nail guns: two case reports and a review of the literature.

PubMed

Luo, Wei; Liu, Hai; Hao, Shuyu; Zhang, Ying; Li, Jingsheng; Liu, Baiyun

2012-01-01

To the best of the authors' knowledge, there are few case reports of penetrating brain injuries (PBI) caused by nail guns and these have usually involved incomplete penetration of the skull. Complete penetration of a nail into the intracranial cavity is extremely rare. Here, two such cases are presented. In the first, the nail entered through the right temporal bone, lodged in the right temporal lobe and was removed via craniotomy with intra-operative ultrasound guidance. In the second, the nail destroyed the left parietal bone, damaged the left internal capsule and lodged in the left temporal lobe near the left petrous apex and the brain stem. According to the latest literature retrieval, this is the first reported case of nail-gun injury to the internal capsule. The position of the nail precluded removal without further neurologic damage. Treatment strategies designed to optimize outcome, with or without surgery, and possible complications are discussed in this report.

Spiral Form of the Human Cochlea Results from Spatial Constraints.

PubMed

Pietsch, M; Aguirre Dávila, L; Erfurt, P; Avci, E; Lenarz, T; Kral, A

2017-08-08

The human inner ear has an intricate spiral shape often compared to shells of mollusks, particularly to the nautilus shell. It has inspired many functional hearing theories. The reasons for this complex geometry remain unresolved. We digitized 138 human cochleae at microscopic resolution and observed an astonishing interindividual variability in the shape. A 3D analytical cochlear model was developed that fits the analyzed data with high precision. The cochlear geometry neither matched a proposed function, namely sound focusing similar to a whispering gallery, nor did it have the form of a nautilus. Instead, the innate cochlear blueprint and its actual ontogenetic variants were determined by spatial constraints and resulted from an efficient packing of the cochlear duct within the petrous bone. The analytical model predicts well the individual 3D cochlear geometry from few clinical measures and represents a clinical tool for an individualized approach to neurosensory restoration with cochlear implants.

Effects of lesions of the caudal cerebellar vermis on cardiovascular regulation in awake cats

NASA Technical Reports Server (NTRS)

Holmes, M. J.; Cotter, L. A.; Arendt, H. E.; Cass, S. P.; Yates, B. J.

2002-01-01

The vestibular system is known to participate in cardiovascular regulation during movement and postural alterations. The present study considered whether lesions of two regions of the posterior cerebellar vermis (the nodulus and uvula) that provide inputs to vestibular nucleus regions that affect control of blood pressure would alter cardiovascular responses during changes in posture. Blood pressure and heart rate were monitored in awake cats during nose-up tilts up to 60 degrees in amplitude before and following aspiration lesions of the nodulus or uvula; in most animals, cardiovascular responses were also recorded following the subsequent removal of vestibular inputs. Lesions of the nodulus or uvula did not affect baseline blood pressure or heart rate, although cardiovascular responses during nose-up tilts were altered. Increases in heart rate that typically occurred during 60 degrees nose-up tilt were attenuated in all three animals with lesions affecting both dorsal and ventral portions of the uvula; in contrast, the heart rate responses were augmented in the two animals with lesions mainly confined to the nodulus. Furthermore, following subsequent removal of vestibular inputs, uvulectomized animals, but not those with nodulus lesions, experienced more severe orthostatic hypotension than has previously been reported in cerebellum-intact animals with bilateral labyrinthectomies. These data suggest that the cerebellar nodulus and uvula modulate vestibulo-cardiovascular responses, although the two regions play different roles in cardiovascular regulation.

Diagnostic validity of periapical radiography and CBCT for assessing periapical lesions that persist after endodontic surgery.

PubMed

Kruse, Casper; Spin-Neto, Rubens; Reibel, Jesper; Wenzel, Ann; Kirkevang, Lise-Lotte

2017-10-01

Traditionally, healing after surgical endodontic retreatment (SER); i.e. apicectomy with or without a retrograde filling, is assessed in periapical radiographs (PR). Recently, the use of cone beam CT (CBCT) has increased within endodontics. Generally, CBCT detects more periapical lesions than PR, but basic research on the true nature of these lesions is missing. The objective was to assess the diagnostic validity of PR and CBCT for determining inflammation in SER cases that were re-operated (SER-R) due to unsuccessful healing, using histology of the periapical lesion as reference for inflammation. Records from 149 patients, receiving SER 2004-10, were screened. In total 108 patients (119 teeth) were recalled for clinical follow-up examination, PR and CBCT, of which 74 patients (83 teeth) participated. Three observers assessed PR and CBCT as "successful healing" or "unsuccessful healing" using Rud and Molven's criteria. SER-R was offered to all non-healed teeth with expected favourable prognosis for subsequent functional retention. During SER-R, biopsy was performed and histopathology verified whether or not inflammation was present. All re-operated cases were assessed non-healed in CBCT while 11 of these were assessed successfully healed in PR. Nineteen biopsies were examined. Histopathologic diagnosis revealed 42% (teeth = 8) without periapical inflammation, 16% (teeth = 3) with mild inflammation and 42% (teeth = 8) with moderate to intense inflammation. A correct diagnosis was obtained in 58% with CBCT (true positives) and 63% with PR (true positives+true negatives). Of the re-operated teeth, 42% had no periapical inflammatory lesion, and hence no benefit from SER-R. Not all lesions observed in CBCT represented periapical inflammatory lesions.

Detection of human cytomegalovirus and Epstein-Barr Virus in symptomatic and asymptomatic apical periodontitis lesions by real-time PCR

PubMed Central

Ozbek, Selcuk M.; Yavuz, Muhammed S.

2013-01-01

Objectives: Recent studies have investigated the occurrence of human cytomegalovirus and Epstein-Barr Virus in samples from apical periodontitis lesions and a role in the pathogenesis of this disease has been suggested. Because genotype distribution and seroprevalence of EBV and HCMV differ among populations, it is important to determine the presence of these viruses in endodontic periapical lesions of different populations. The aims of this study were to determine the presence of HCMV and EBV DNAs in samples from Turkish patients with symptomatic and asymptomatic apical periodontitis lesions using real-time polymerase chain reaction method and to evaluate their presence in both symptomatic and asymptomatic apical periodontitis lesions. Study Design: Periapical samples were collected from 12 asymptomatic and 16 symptomatic periapical lesions in conjunction with apicectomy. HCMV and EBV DNAs were identified in the samples by real-time PCR. The chi-squared test with Yates’s correction or the Fisher’s exact test was used to analyse the significance of differences. Results: HCMV DNA was detected in 10 of the 16 (62.5%) symptomatic and in five of the 12 (41.7 %) asymptomatic periapical study lesions. The EBV DNA was identified in seven of the 16 (43.7 %) symptomatic and three of the 12 (25 %) asymptomatic periapical lesions. The difference in occurrence of HCMV and EBV DNA between symptomatic and asymptomatic periapical lesions was not statistically significant. (All comparisons have p > 0.05). Conclusions: Our findings suggest that HCMV and EBV is a frequent inhabitant of both symptomatic and asymptomatic apical periodontitis lesions of endodontic origin in Turkish population. Key words:Human cytomegalovirus, Epstein-Barr Virus, apical periodontitis, Polymerase chain reaction method. PMID:23722135

The use of mineral trioxide aggregate in endodontics.

PubMed

Casella, G; Ferlito, S

2006-03-01

Mineral trioxide aggregate (MTA), composed mainly of tricalcic silicate, tricalcic alluminate, bismuth oxide, is a particular endodontic cement. It is made of hydrophilic fine particles that harden in the presence of dampness or blood. It is biocompatible, radiopaque and it is harder to infiltrate, compared to classic materials for root filling such as amalgam, cements, Super-EBA, and IRM. and SEM studies of sections and copies in resin of root neoapices filled with amalgam, IRM, Super-EBA and MTA, as well as tests of microinfiltration have shown that MTA has excellent sealing capacities. It requires a working time of about 5 min and a hardening time that varies from 2 h and 45 min to 4 h according to the density of the air entrapped during mixing and the dampness of the receiving site. The long hardening time reduces internal tensions and the incidence of marginal infiltration, but it forces to definitively fill the tooth in the following sitting, with an interval of at least 3 days from the MTA application. Clinical experience shows how MTA is a material of choice in cases not only of endodontic surgery, apicectomy and retrograde filling but also in the sealing filling of perforations of the pulp chamber and of the root, stripping, internal reabsorptions, readaptations, lacerations, and apical transports. It has been used with success also in direct cappings and in apexifications instead of calcium hydroxide, leading to quicker therapies and more predictable The authors outline the operative phases of the different treatments proposed, make a survey of the most important studies published so far and hope that a new sealing cement with more reduced hardening times will soon be available.

Vertebral artery pexy for microvascular decompression of the facial nerve in the treatment of hemifacial spasm.

PubMed

Ferreira, Manuel; Walcott, Brian P; Nahed, Brian V; Sekhar, Laligam N

2011-06-01

Hemifacial spasm (HFS) is caused by arterial or venous compression of cranial nerve VII at its root exit zone. Traditionally, microvascular decompression of the facial nerve has been an effective treatment for posterior inferior and anterior inferior cerebellar artery as well as venous compression. The traditional technique involves Teflon felt or another construct to cushion the offending vessel from the facial nerve, or cautery and division of the offending vein. However, using this technique for severe vertebral artery (VA) compression can be ineffective and fraught with complications. The authors report the use of a new technique of VA pexy to the petrous or clival dura mater in patients with HFS attributed to a severely ectatic and tortuous VA, and detail the results in a series of patients. Six patients with HFS due to VA compression underwent a retrosigmoid craniotomy, combined with a far-lateral approach in some patients. On identification of the site of VA compression, the vessel was mobilized adequately for the decompression. Great care was taken to avoid kinking the perforating vessels arising from the VA. Two 8-0 nylon sutures were passed through to the wall of the VA and then through the clival or petrous dura, and then tied to alleviate compression on cranial nerve VII. Patients were followed for at least 1 year postoperatively (mean 2.7 years, range 1-4 years). All 6 patients had complete resolution of their HFS. Facial function was tested postoperatively, and was stable when compared with the preoperative baseline. Two of the 3 patients with preoperative tinnitus had resolution of this symptom after the procedure. Postoperative imaging demonstrated VA decompression of the facial nerve and no evidence of stroke in all patients. One patient suffered from hearing loss, another developed a postoperative transient unilateral vocal cord paralysis, and a third patient developed a pseudomeningocele that resolved with the placement of a lumbar drain

Calcified Suprasellar Xanthogranuloma Presenting with Primary Amenorrhea in a 17-Year-Old Girl: Case Report and Literature Review.

PubMed

Ben Nsir, Atef; Thai, Quoc-Anh; Chaieb, Larbi; Jemel, Hafedh

2015-09-01

Xanthogranuloma, also known as cholesterol granuloma, is an extremely rare intracranial neoplasm most commonly located in the middle ear, petrous apex, or choroid plexus. Exclusively suprasellar xanthogranulomas are exceptional and this report presents a very rare case in the pediatric population, particularly unique due to the presence of calcification. A 17-year-old girl presented with primary amenorrhea with computed tomography and magnetic resonance imaging showing a large calcified enhancing suprasellar mass, which was presumptively diagnosed as a craniopharyngioma on the basis of its clinical and radiologic appearance. Gross total resection of a well-encapsulated, exclusively suprasellar tumor was achieved, without postoperative neurologic deficits. Histologic examination found fibrous tissue with abundant cholesterol clefts, multinucleated giant cells, and hemosiderin deposits but no epithelial cells. The final histologic diagnosis was a xanthogranuloma. Xanthogranuloma, although extremely rare in the pediatric population, may present as a calcified suprasellar mass and manifest with primary amenorrhea. The prognosis after gross total resection is likely favorable; however, long-term follow-up is indicated for these rare neoplasms. Copyright © 2015 Elsevier Inc. All rights reserved.

Successful Treatment of Symptomatic Intracranial Carotid Artery Stenosis Using a 24-mm Long Bare Metal Coronary Stent.

PubMed

Rehman, Azeem A; Turner, Ryan C; Lucke-Wold, Brandon P; Boo, SoHyun

2017-06-01

Intracranial arterial atherosclerosis represents a common cause of stroke. Despite aggressive and optimal medical management, many patients will unfortunately suffer additional cerebrovascular events. The role of endovascular intervention for intracranial atherosclerotic disease continues to be uncertain, particularly in regard to extensive, symptomatic stenosis. We present a case of a 42-year-old man with a complex medical history who presented with recurrent ischemic stroke in the ipsilateral hemisphere despite optimal medical management. Given the length of stenosis and the luminal size of the intracranial cavernous and petrous segments of the internal carotid artery, we used a bare metal coronary stent (4.0 mm × 24 mm). This represents one of the longest stents deployed for intracranial disease reported in the literature. This case illustrates that a long coronary stent might be successfully used to manage extensive intracranial lesions. We also review the efficacy of using 1 very long stent versus multiple overlapping stents, with reference to the coronary angiography literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Toward an endovascular internal carotid artery classification system.

PubMed

Shapiro, M; Becske, T; Riina, H A; Raz, E; Zumofen, D; Jafar, J J; Huang, P P; Nelson, P K

2014-02-01

Does the world need another ICA classification scheme? We believe so. The purpose of proposed angiography-driven classification is to optimize description of the carotid artery from the endovascular perspective. A review of existing, predominantly surgically-driven classifications is performed, and a new scheme, based on the study of NYU aneurysm angiographic and cross-sectional databases is proposed. Seven segments - cervical, petrous, cavernous, paraophthlamic, posterior communicating, choroidal, and terminus - are named. This nomenclature recognizes intrinsic uncertainty in precise angiographic and cross-sectional localization of aneurysms adjacent to the dural rings, regarding all lesions distal to the cavernous segment as potentially intradural. Rather than subdividing various transitional, ophthalmic, and hypophyseal aneurysm subtypes, as necessitated by their varied surgical approaches and risks, the proposed classification emphasizes their common endovascular treatment features, while recognizing that many complex, trans-segmental, and fusiform aneurysms not readily classifiable into presently available, saccular aneurysm-driven schemes, are being increasingly addressed by endovascular means. We believe this classification may find utility in standardizing nomenclature for outcome tracking, treatment trials and physician communication.

Transposition of the paraclival carotid artery: a novel concept of self-retaining vascular retraction during endoscopic endonasal skull base surgery technical report.

PubMed

Freeman, Jacob L; Sampath, Raghuram; Casey, Michael A; Quattlebaum, Steven Craig; Ramakrishnan, Vijay R; Youssef, A Samy

2016-08-01

Fixed retraction of the internal carotid artery (ICA) has previously been described for use during transcranial microscopic surgery. We report the novel use of a self-retaining microvascular retractor for static repositioning and protection of the ICA during expanded endonasal endoscopic approaches to the paramedian skull base. The transmaxillary, transpterygoid approach was performed in five cadaver heads (ten sides). The self-retaining microvascular retractor was used to laterally reposition the pterygopalatine fossa contents during exposure of the pterygoid base/plates and the paraclival ICA to expose the petrous apex. Maximum ICA retraction distance was measured in the x-axis for all ten sides. The average horizontal distance of ICA retraction measured at the mid-paraclival segment for all ten sides was 4.75 mm. In all cases, the carotid artery was repositioned without injury to the vessel or disruption of the surrounding neurovascular structures. Static repositioning of the ICA and other delicate neurovascular structures was effectively performed during endonasal, endoscopic cadaveric surgery of the skull base and has potential merits in live patients.

Pneumatic processes in the temporal bone of chimpanzee (Pan troglodytes) and gorilla (Gorilla gorilla).

PubMed

Sherwood, R J

1999-08-01

The ontogeny of human temporal bone pneumatization has been well studied from both comparative and clinical perspectives. While a difference in the extent of air cell distribution has been noted in our closest living relatives, chimpanzees and gorillas, the processes responsible have been relatively unexplored. To examine these processes, a large, age-graded series of hominoid skulls was radiographed and the progress of pneumatization recorded. Additionally, a subsample of 30 chimpanzees and 12 gorillas was subjected to high-resolution CT scanning. Neonatal specimens show a well-developed mastoid antrum, as well as a capacious hypotympanum extending into the petrous apex. In African apes, as in humans, the mastoid antrum serves as the focus for air cell expansion into the mastoid and immediately adjacent areas. In chimpanzees and gorillas, however, a pronounced lateral structure, described as the squamous antrum, serves as the focus of pneumatization for anterior structures such as the squamous and zygomatic. The diminution of this structure in Homo sapiens explains the difference in air cell distribution in these regions. Copyright 1999 Wiley-Liss, Inc.

Persistent extraradicular infection in root-filled asymptomatic human tooth: scanning electron microscopic analysis and microbial investigation after apical microsurgery.

PubMed

Signoretti, Fernanda G C; Endo, Marcos S; Gomes, Brenda P F A; Montagner, Francisco; Tosello, Fernanda B; Jacinto, Rogério C

2011-12-01

Procedural accidents have a negative effect on healing and might contribute to the persistence of infections in inaccessible apical areas, requiring surgical intervention. This report describes a case of persistent apical periodontitis of a lower left first molar associated with the sinus tract and a periapical lesion that required nonsurgical endodontic retreatment and apical surgery for resolution. The tooth had received endodontic treatment 3 years ago and had to be retreated using the crown-down technique with chemical auxiliary substance (2% chlorhexidine gel), foramen patency, and enlargement and was filled in a single appointment. The occlusal access cavity was immediately restored with composite resin. After 1 month, it could be observed that the sinus tract persisted and, radiographically, the lesion remained unaltered. Therefore, endodontic microsurgery was indicated. Apical microsurgery was performed under magnification with the use of a dental operating microscope including apicectomy, root end with ultrasound, and sealing with mineral trioxide aggregate. A microbiological sample was collected from the apical lesion. The resected distal root apex was observed by scanning electron microscopy. The following species were detected: Actinomyces naeslundii and Actinomyces meyeri, Propionibacterium propionicum, Clostridium botullinum, Parvimonas micra, and Bacteroides ureolyticus; scanning electron microscopic analysis revealed bacterial biofilm surrounding the apical foramen and external radicular surface. Gutta-percha overfilling at the apex because of a zip caused during initial endodontic treatment could be observed. A 6-month follow-up showed apparent radiographic periapical healing, which progressed after 24 months. Gram-positive anaerobic bacteria and extraradicular biofilm seem to participate in the maintenance of persistent periapical pathology, and endodontic retreatment followed by periapical microsurgery proved to be a successful alternative in the

Transzygomatic approach with intraoperative neuromonitoring for resection of middle cranial fossa tumors.

PubMed

Son, Byung Chul; Lee, Sang Won; Kim, Sup; Hong, Jae Taek; Sung, Jae Hoon; Yang, Seung-Ho

2012-02-01

The authors reviewed the surgical experience and operative technique in a series of 11 patients with middle fossa tumors who underwent surgery using the transzygomatic approach and intraoperative neuromonitoring (IOM) at a single institution. This approach was applied to trigeminal schwannomas (n = 3), cavernous angiomas (n = 3), sphenoid wing meningiomas (n = 3), a petroclival meningioma (n = 1), and a hemangiopericytoma (n = 1). An osteotomy of the zygoma, a low-positioned frontotemporal craniotomy, removal of the remaining squamous temporal bone, and extradural drilling of the sphenoid wing made a flat trajectory to the skull base. Total resection was achieved in 9 of 11 patients. Significant motor pathway damage can be avoided using a change in motor-evoked potentials as an early warning sign. Four patients experienced cranial nerve palsies postoperatively, even though free-running electromyography of cranial nerves showed normal responses during the surgical procedure. A simple transzygomatic approach provides a wide surgical corridor for accessing the cavernous sinus, petrous apex, and subtemporal regions. Knowledge of the middle fossa structures is essential for anatomic orientation and avoiding injuries to neurovascular structures, although a neuronavigation system and IOM helps orient neurosurgeons.

Epidermoid cyst in Meckel's cave with unusual computed tomography and magnetic resonance imaging findings. Case report.

PubMed

Arai, Atsushi; Sasayama, Takashi; Koyama, Junji; Fujita, Atsushi; Hosoda, Kohkichi; Kohmura, Eiji

2010-01-01

A 27-year-old woman presented with headache and occasional numbness over her right face. Computed tomography revealed a hypodense mass in the middle cranial fossa and another adjacent hyperdense mass in the posterior fossa with erosion of the right petrous apex. Magnetic resonance imaging revealed the lesion in the middle cranial fossa as iso- to hypointense on T(1)-weighted and hyperintense on T(2)-weighted imaging, with peripheral enhancement after gadolinium administration, and the adjacent lesion in the posterior fossa as hyperintense on T(1)-weighted and hypointense on T(2)-weighted imaging. During surgery, these lesions mimicking two adjacent distinct tumors were revealed to connect through Meckel's cave. The hypodense lesion in the middle cranial fossa consisted of pearly-like solid contents, and the hyperdense lesion in the posterior cranial fossa consisted of viscid dark-green materials. The tumors were gross totally resected with endoscopic assistance. Histological examination confirmed that the tumor was an epidermoid cyst. The present case cyst indicates that although the diffusion-weighted imaging sequence is useful for detection of intracranial epidermoid cysts, epidermoid cysts including viscous materials with unusual radiological findings could complicate the preoperative diagnosis.

Dangerous extracranial-intracranial anastomoses and supply to the cranial nerves: vessels the neurointerventionalist needs to know.

PubMed

Geibprasert, S; Pongpech, S; Armstrong, D; Krings, T

2009-09-01

Transarterial embolization in the external carotid artery (ECA) territory has a major role in the endovascular management of epistaxis, skull base tumors, and dural arteriovenous fistulas. Knowledge of the potential anastomotic routes, identification of the cranial nerve supply from the ECA, and the proper choice of embolic material are crucial to help the interventionalist avoid neurologic complications during the procedure. Three regions along the skull base constitute potential anastomotic routes between the extracranial and intracranial arteries: the orbital, the petrocavernous, and the upper cervical regions. Branches of the internal maxillary artery have anastomoses with the ophthalmic artery and petrocavernous internal carotid artery (ICA), whereas the branches of the ascending pharyngeal artery are connected to the petrocavernous ICA. Branches of both the ascending pharyngeal artery and the occipital artery have anastomoses with the vertebral artery. To avoid cranial nerve palsy, one must have knowledge of the supply to the lower cranial nerves: The petrous branch of the middle meningeal artery and the stylomastoid branch of the posterior auricular artery form the facial arcade as the major supply to the facial nerve, and the neuromeningeal trunk of the ascending pharyngeal artery supplies the lower cranial nerves (CN IX-XII).

Use of the Ascent balloon for a 2-in-1 remodeling technique: feasibility and initial experience: case report.

PubMed

Clarençon, Frédéric; Pérot, Guillaume; Biondi, Alessandra; Di Maria, Federico; Szatmary, Zoltan; Chiras, Jacques; Sourour, Nader

2012-03-01

To present the feasibility of using the Ascent balloon, a new double-lumen remodeling balloon, for a new 2-in-1 technique allowing coiling through the lumen of the balloon without the use of an additional coiling microcatheter. Remodeling technique had enlarged the indications for endovascular treatment of intracranial aneurysm. Nevertheless, one of the limitations of this technique is that it requires using 2 devices in the same parent artery. A 55-year-old woman presented with a 7.7 × 4.5-mm incidental anterior communicating artery aneurysm. Only 1 A1 segment (left side) was patent on the cerebral angiogram. A 6F Fargo Max guiding catheter was positioned in the left petrous internal carotid artery. The Ascent balloon was placed in front of the neck of the aneurysm after navigation on a Traxcess 0.014-in guidewire. Coiling of the aneurysm sac was performed via 1 lumen of the device under iterative inflations of the balloon through the second lumen. This new 2-in-1 technique using a sole remodeling balloon without an additional coiling microcatheter is very promising, especially in cases of a small-caliber parent artery.

Localization of congenital tegmen tympani defects.

PubMed

Tóth, Miklós; Helling, Kai; Baksa, Gábor; Mann, Wolf

2007-12-01

This study sets out to demonstrate the normal developmental steps of the tegmen tympani and thus explains the typical localization of congenital tegmental defects. For this study, 79 macerated and formalin-fixed human temporal bones from 14th fetal week to adults were observed and prepared. Macroscopic and microscopic examination of the prenatal and postnatal changes of the tegmen tympani during its development. Temporal bones from 14th fetal week to adults underwent descriptive anatomic studies to understand the normal development of the tegmen tympani and to find a possible cause of its congenital defects. The medial part of the tegmen tympani develops from the otic capsule during chondral ossification, thus forming the tegmental process of the petrous part. The lateral part shows membranous ossification. The tegmental process cases a temporary bony dehiscence lateral to the geniculate ganglion between the 23rd and 25th fetal week. Congenital defects develop near the geniculate ganglion and seem to be due to an incomplete development of tegmental process of otic capsule. Because of that, congenital lesion of the tegmen tympani can be defined as an inner ear defect.

Effect of Intracranial Stenosis Revascularization on Dynamic and Static Cerebral Autoregulation.

PubMed

Ortega-Gutierrez, Santiago; Samaniego, Edgar A; Huang, Amy; Masurkar, Arjun; Zheng-Lin, Binbin; Derdeyn, Colin P; Hasan, David; Marshall, Randolph; Petersen, Nils

2018-06-01

Severe intracranial stenosis might lead to acute cerebral ischemia. It is imperative to better assess patients who may benefit from immediate reperfusion and blood pressure management to prevent injury to peri-infarct tissue. We assessed cerebral autoregulation using static and dynamic methods in an 81-year-old woman suffering acute cerebral ischemia from severe intracranial stenosis in the petrous segment of the left internal carotid artery (LICA). Static cerebral autoregulation, which is evaluated by magnetic resonance imaging and magnetic resonance perfusion studies showed a progression of infarcts and a large perfusion-diffusion mismatch in the entire LICA territory between the second and third days after onset despite maximized medical therapy. Dynamic methods, including transfer function analysis and mean velocity index, demonstrated an increasingly impaired dynamic cerebral autoregulation (DCA) on the affected side between these days. Revascularization through acute intracranial stenting resulted in improved perfusion in the LICA territory and normalization of both dynamic and static cerebral autoregulation. Thus, DCA, a noninvasive bedside method, may be useful in helping to identify and select patients with large-vessel flow-failure syndromes that would benefit from immediate revascularization of intracranial atherosclerotic disease.

Modulated discharge of Purkinje and stellate cells persists after unilateral loss of vestibular primary afferent mossy fibers in mice

PubMed Central

Yakhnitsa, V.

2013-01-01

Cerebellar Purkinje cells are excited by two afferent pathways: climbing and mossy fibers. Climbing fibers evoke large “complex spikes” (CSs) that discharge at low frequencies. Mossy fibers synapse on granule cells whose parallel fibers excite Purkinje cells and may contribute to the genesis of “simple spikes” (SSs). Both afferent systems convey vestibular information to folia 9c–10. After making a unilateral labyrinthectomy (UL) in mice, we tested how the discharge of CSs and SSs was changed by the loss of primary vestibular afferent mossy fibers during sinusoidal roll tilt. We recorded from cells identified by juxtacellular neurobiotin labeling. The UL preferentially reduced vestibular modulation of CSs and SSs in folia 8–10 contralateral to the UL. The effects of a UL on Purkinje cell discharge were similar in folia 9c–10, to which vestibular primary afferents project, and in folia 8–9a, to which they do not project, suggesting that vestibular primary afferent mossy fibers were not responsible for the UL-induced alteration of SS discharge. UL also induced reduced vestibular modulation of stellate cell discharge contralateral to the UL. We attribute the decreased modulation to reduced vestibular modulation of climbing fibers. In summary, climbing fibers modulate CSs directly and SSs indirectly through activation of stellate cells. Whereas vestibular primary afferent mossy fibers cannot account for the modulated discharge of SSs or stellate cells, the nonspecific excitation of Purkinje cells by parallel fibers may set an operating point about which the discharges of SSs are sculpted by climbing fibers. PMID:23966673

Vestibular short latency responses to pulsed linear acceleration in unanesthetized animals

NASA Technical Reports Server (NTRS)

Jones, T. A.

1992-01-01

Linear acceleration transients were used to elicit vestibular compound action potentials in non-invasively prepared, unanesthetized animals for the first time (chicks, Gallus domesticus, n = 33). Responses were composed of a series of up to 8 dominant peaks occurring within 8 msec of the stimulus. Response amplitudes for 1.0 g stimulus ranged from 1 to 10 microV. A late, slow, triphasic, anesthesia-labile component was identified as a dominant response feature in unanesthetized animals. Amplitudes increased and latencies decreased as stimulus intensity was increased (MANOVA P less than 0.05). Linear regression slope ranges were: amplitudes = 1.0-5.0 microV/g; latencies = -300 to -1100 microseconds/g. Thresholds for single polarity stimuli (0.035 +/- 0.022 g, n = 11) were significantly lower than those of alternating polarity (0.074 +/- 0.028 g, n = 18, P less than 0.001). Bilateral labyrinthectomy eliminated responses whereas bilateral extirpation of cochleae did not significantly change response thresholds. Intense acoustic masking (100/104 dB SL) produced no effect in 2 animals, but did produce small to moderate effects on response amplitudes in 7 others. Changes were attributed to effects on vestibular end organs. Results of unilateral labyrinth blockade (tetrodotoxin) suggest that P1 and N1 preferentially reflect ipsilateral eighth nerve compound action potentials whereas components beyond approximately 2 msec reflect activity from vestibular neurons that depend on both labyrinths. The results demonstrate that short latency vestibular compound action potentials can be measured in unanesthetized, non-invasively prepared animals.

Short latency vestibular evoked potentials in the chicken embryo

NASA Technical Reports Server (NTRS)

Jones, S. M.; Jones, T. A.

1996-01-01

Electrophysiological responses to pulsed linear acceleration stimuli were recorded in chicken embryos incubated for 19 or 20 days (E19/E20). Responses occurred within the first 16 ms following the stimulus onset. The evoked potentials disappeared following bilateral labyrinthectomy, but persisted following cochlear destruction alone, thus demonstrating that the responses were vestibular. Approximately 8 to 10 response peaks could be identified. The first 4 positive and corresponding negative components (early peaks with latencies < 6.0 ms) were scored and latencies and amplitudes quantified. Vestibular response latencies were significantly longer (P < 0.01) and amplitudes significantly smaller (P < 0.001) than those observed in 2-week-old birds. Mean response threshold for anesthetized embryos was -15.9dBre 1.0 g/ms, which was significantly higher (P < 0.03) than those observed in 2-week-old birds (-23.0dBre 1.0 g/ms). Latency/intensity functions (that is, slopes) were not significantly different between embryos and 2-week-old animals, but amplitude/intensity functions for embryos were significantly shallower than those for 2-week-old birds (P < 0.001). We presume that these differences reflect the refinement of sensory function that occurs following 19 to 20 days of incubation. The recording of vestibular evoked potentials provides an objective, direct and noninvasive measure of peripheral vestibular function in the embryo and, as such, the method shows promise as an investigative tool. The results of the present study form the definitive basis for using vestibular evoked potentials in the detailed study of avian vestibular ontogeny and factors that may influence it.

Efferent-Mediated Responses in Vestibular Nerve Afferents of the Alert Macaque

PubMed Central

Sadeghi, Soroush G.; Goldberg, Jay M.; Minor, Lloyd B.; Cullen, Kathleen E.

2009-01-01

The peripheral vestibular organs have long been known to receive a bilateral efferent innervation from the brain stem. However, the functional role of the efferent vestibular system has remained elusive. In this study, we investigated efferent-mediated responses in vestibular afferents of alert behaving primates (macaque monkey). We found that efferent-mediated rotational responses could be obtained from vestibular nerve fibers innervating the semicircular canals after conventional afferent responses were nulled by placing the corresponding canal plane orthogonal to the plane of motion. Responses were type III, i.e., excitatory for rotational velocity trapezoids (peak velocity, 320°/s) in both directions of rotation, consistent with those previously reported in the decerebrate chinchilla. Responses consisted of both fast and slow components and were larger in irregular (∼10 spikes/s) than in regular afferents (∼2 spikes/s). Following unilateral labyrinthectomy (UL) on the side opposite the recording site, similar responses were obtained. To confirm the vestibular source of the efferent-mediated responses, the ipsilateral horizontal and posterior canals were plugged following the UL. Responses to high-velocity rotations were drastically reduced when the superior canal (SC), the only intact canal, was in its null position, compared with when the SC was pitched 50° upward from the null position. Our findings show that vestibular afferents in alert primates show efferent-mediated responses that are related to the discharge regularity of the afferent, are of vestibular origin, and can be the result of both afferent excitation and inhibition. PMID:19091917

Efferent-mediated responses in vestibular nerve afferents of the alert macaque.

PubMed

Sadeghi, Soroush G; Goldberg, Jay M; Minor, Lloyd B; Cullen, Kathleen E

2009-02-01

The peripheral vestibular organs have long been known to receive a bilateral efferent innervation from the brain stem. However, the functional role of the efferent vestibular system has remained elusive. In this study, we investigated efferent-mediated responses in vestibular afferents of alert behaving primates (macaque monkey). We found that efferent-mediated rotational responses could be obtained from vestibular nerve fibers innervating the semicircular canals after conventional afferent responses were nulled by placing the corresponding canal plane orthogonal to the plane of motion. Responses were type III, i.e., excitatory for rotational velocity trapezoids (peak velocity, 320 degrees/s) in both directions of rotation, consistent with those previously reported in the decerebrate chinchilla. Responses consisted of both fast and slow components and were larger in irregular (approximately 10 spikes/s) than in regular afferents (approximately 2 spikes/s). Following unilateral labyrinthectomy (UL) on the side opposite the recording site, similar responses were obtained. To confirm the vestibular source of the efferent-mediated responses, the ipsilateral horizontal and posterior canals were plugged following the UL. Responses to high-velocity rotations were drastically reduced when the superior canal (SC), the only intact canal, was in its null position, compared with when the SC was pitched 50 degrees upward from the null position. Our findings show that vestibular afferents in alert primates show efferent-mediated responses that are related to the discharge regularity of the afferent, are of vestibular origin, and can be the result of both afferent excitation and inhibition.

Cochlear Implantation After Partial or Subtotal Cochleoectomy for Intracochlear Schwannoma Removal-A Technical Report.

PubMed

Plontke, Stefan K; Kösling, Sabrina; Rahne, Torsten

2018-03-01

To describe the technique for surgical tumor removal, cochlear implant (CI) electrode placement and reconstruction of the surgical defect in patients with intracochlear schwannomas. Retrospective case review. Tertiary referral center. Ten patients (five men, five women, mean age 48 ± 12 yr) with profound or severe to profound hearing loss due to intralabyrinthine schwannomas with intracochlear location. Surgical tumor removal through extended round window approach, partial or subtotal cochleoectomy with or without labyrinthectomy and reconstruction of the surgical defect with cartilage, perichondrium or temporal muscle fascia, and bone pâté. Eight patients received a cochlear implant in the same procedure. Retrospective evaluation of clinical outcome including safety aspects (adverse events) and audiological performance at early follow up in cases of cochlear implantation. The tumor was successfully removed in all cases without macroscopic (operation microscope and endoscope) tumor remnants in the bony labyrinth apart from one case with initial transmodiolar growth. One patient needed revision surgery for labyrinthine fistula. At short-term follow up (3-month post-surgery), good hearing results with the cochlear implant were obtained in all but one patient with a word recognition score of 100% for numbers, and 64 ± 14% for monosyllables (at 65 dB SPL in quiet). Surgical tumor removal and cochlear implantation is a promising treatment strategy in the management of intralabyrinthine schwannoma with intracochlear location, further extending the indication range for cochlear implantation. It is, however, of importance to observe the long-term outcome in these patients and to address challenges like follow up with magnetic resonance imaging.

Foramen ovale puncture, lesioning accuracy, and avoiding complications: microsurgical anatomy study with clinical implications.

PubMed

Peris-Celda, Maria; Graziano, Francesca; Russo, Vittorio; Mericle, Robert A; Ulm, Arthur J

2013-11-01

Foramen ovale (FO) puncture allows for trigeminal neuralgia treatment, FO electrode placement, and selected biopsy studies. The goals of this study were to demonstrate the anatomical basis of complications related to FO puncture, and provide anatomical landmarks for improvement of safety, selective lesioning of the trigeminal nerve (TN), and optimal placement of electrodes. Both sides of 50 dry skulls were studied to obtain the distances from the FO to relevant cranial base references. A total of 36 sides from 18 formalin-fixed specimens were dissected for Meckel cave and TN measurements. The best radiographic projection for FO visualization was assessed in 40 skulls, and the optimal trajectory angles, insertion depths, and topographies of the lesions were evaluated in 17 specimens. In addition, the differences in postoperative pain relief after the radiofrequency procedure among different branches of the TN were statistically assessed in 49 patients to determine if there was any TN branch less efficiently targeted. Most severe complications during FO puncture are related to incorrect needle placement intracranially or extracranially. The needle should be inserted 25 mm lateral to the oral commissure, forming an approximately 45° angle with the hard palate in the lateral radiographic view, directed 20° medially in the anteroposterior view. Once the needle reaches the FO, it can be advanced by 20 mm, on average, up to the petrous ridge. If the needle/radiofrequency electrode tip remains more than 18 mm away from the midline, injury to the cavernous carotid artery is minimized. Anatomically there is less potential for complications when the needle/radiofrequency electrode is advanced no more than 2 mm away from the clival line in the lateral view, when the needle pierces the medial part of the FO toward the medial part of the trigeminal impression in the petrous ridge, and no more than 4 mm in the lateral part. The 40°/45° inferior transfacial-20° oblique

Implant placement after marsupialization of a dentigerous cyst.

PubMed

Karamanis, S; Kitharas, T; Tsoukalas, D; Parissis, N

2006-01-01

This paper presents a case of a dentigerous cyst accompanied by a history of inflammation, resorption of the roots of the first molar and the lingual aspect of the distal root of the second molar, and devitalization of the 2 premolars. The treatment option chosen was marsupialization of the cyst, extraction of the involved teeth, endodontic treatment of both premolars, and implant insertion in the area of the first mandibular molar at a later stage. Twelve months postsurgery the area of interest was almost flattened and the radiographic examination revealed total disappearance of the radiolucency. An implant of 15 x 4 mm was inserted in the area of the first mandibular molar. Despite the excellent implant stability achieved, a thin central zone of the defect remained void of bone. After complete excision of soft tissue the defect was filled with an alloplastic bone substitute. Eight months later (20 months postsurgery), the implant was uncovered and the restorative procedure completed. The implant and the crown have been functioning sign and symptom free for 48 months. Marsupialization was preferred instead of enucleation due to (1) proximity of the cyst to the mandibular canal; (2) need for apicectomy of both premolars to gain good access for enucleation; (3) refusal of the patient to undergo a second surgery for bone harvesting; (4) lower probability for postoperative contamination; (5) need of small quantity of bone substitute; (6) easier extraction of the impacted second molar due to its coronal movement. The disadvantages of the treatment were the long healing period and the discomfort of the patient at the early stages of marsupialization. It was judged that the advantages outweighed the disadvantages in this case. We discuss the findings of other authors who support the conservative approach to jaw cysts in a young population, and the concerns that exist in the literature about the ability of osseoconductive graft materials to generate vital bone and achieve

The Magnus-Rademaker Scientific Film Collection: Ethical Issues on Animal Experimentation (1908-1940).

PubMed

Koehler, Peter J; Lameris, Bregt

2016-01-01

The Magnus-Rademaker scientific film collection (1908-1940) deals with the physiology of body posture by the equilibrium of reflex musculature contractions for which experimental studies were carried out with animals (e.g., labyrinthectomies, cerebellectomies, and brain stem sections) as well as observations done on patients. The films were made for demonstrations at congresses as well as educational objectives and film stills were published in their books. The purpose of the present study is to position these films and their makers within the contemporary discourse on ethical issues and animal rights in the Netherlands and the earlier international debates. Following an introduction on animal rights and antivivisection movements, we describe what Magnus and Rademaker thought about these issues. Their publications did not provide much information in this respect, probably reflecting their adherence to implicit ethical codes that did not need explicit mentioning in publications. Newspaper articles, however, revealed interesting information. Unnecessary suffering of an animal never found mercy in Magnus' opinion. The use of cinematography was expanded to the reduction of animal experimentation in student education, at least in the case of Rademaker, who in the 1930s was involved in a governmental committee for the regulation of vivisection and cooperated with the antivivisection movement. This resulted not only in a propaganda film for the movement but also in films that demonstrate physiological experiments for students with the purpose to avert repetition and to improve the teaching of experiments. We were able to identify the pertinent films in the Magnus-Rademaker film collection. The production of vivisection films with this purpose appears to have been common, as is shown in news messages in European medical journals of the period.

Chronic exposure to hypergravity affects thyrotropin-releasing hormone levels in rat brainstem and cerebellum

NASA Technical Reports Server (NTRS)

Daunton, N. G.; Tang, F.; Corcoran, M. L.; Fox, R. A.; Man, S. Y.

1998-01-01

In studies to determine the neurochemical mechanisms underlying adaptation to altered gravity we have investigated changes in neuropeptide levels in brainstem, cerebellum, hypothalamus, striatum, hippocampus, and cerebral cortex by radioimmunoassay. Fourteen days of hypergravity (hyperG) exposure resulted in significant increases in thyrotropin-releasing hormone (TRH) content of brainstem and cerebellum, but no changes in levels of other neuropeptides (beta-endorphin, cholecystokinin, met-enkephalin, somatostatin, and substance P) examined in these areas were found, nor were TRH levels significantly changed in any other brain regions investigated. The increase in TRH in brainstem and cerebellum was not seen in animals exposed only to the rotational component of centrifugation, suggesting that this increase was elicited by the alteration in the gravitational environment. The only other neuropeptide affected by chronic hyperG exposure was met-enkephalin, which was significantly decreased in the cerebral cortex. However, this alteration in met-enkephalin was found in both hyperG and rotation control animals and thus may be due to the rotational rather than the hyperG component of centrifugation. Thus it does not appear as if there is a generalized neuropeptide response to chronic hyperG following 2 weeks of exposure. Rather, there is an increase only of TRH and that occurs only in areas of the brain known to be heavily involved with vestibular inputs and motor control (both voluntary and autonomic). These results suggest that TRH may play a role in adaptation to altered gravity as it does in adaptation to altered vestibular input following labyrinthectomy, and in cerebellar and vestibular control of locomotion, as seen in studies of ataxia.

Evaluation of the chemical model of vestibular lesions induced by arsanilate in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vignaux, G.; Univ Caen, Caen, F-14000; Chabbert, C.

Several animal models of vestibular deficits that mimic the human pathology phenotype have previously been developed to correlate the degree of vestibular injury to cognate vestibular deficits in a time-dependent manner. Sodium arsanilate is one of the most commonly used substances for chemical vestibular lesioning, but it is not well described in the literature. In the present study, we used histological and functional approaches to conduct a detailed exploration of the model of vestibular lesions induced by transtympanic injection of sodium arsanilate in rats. The arsanilate-induced damage was restricted to the vestibular sensory organs without affecting the external ear, themore » oropharynx, or Scarpa's ganglion. This finding strongly supports the absence of diffusion of arsanilate into the external ear or Eustachian tubes, or through the eighth cranial nerve sheath leading to the brainstem. One of the striking observations of the present study is the complete restructuring of the sensory epithelia into a non sensory epithelial monolayer observed at 3 months after arsanilate application. This atrophy resembles the monolayer epithelia observed postmortem in the vestibular epithelia of patients with a history of lesioned vestibular deficits such as labyrinthectomy, antibiotic treatment, vestibular neuritis, or Ménière's disease. In cases of Ménière's disease, aminoglycosides, and platinum-based chemotherapy, vestibular hair cells are destroyed, regardless of the physiopathological process, as reproduced with the arsanilate model of vestibular lesion. These observations, together with those presented in this study of arsanilate vestibular toxicity, suggest that this atrophy process relies on a common mechanism of degeneration of the sensory epithelia.« less

Vestibular lesion-induced developmental plasticity in spinal locomotor networks during Xenopus laevis metamorphosis.

PubMed

Beyeler, Anna; Rao, Guillaume; Ladepeche, Laurent; Jacques, André; Simmers, John; Le Ray, Didier

2013-01-01

During frog metamorphosis, the vestibular sensory system remains unchanged, while spinal motor networks undergo a massive restructuring associated with the transition from the larval to adult biomechanical system. We investigated in Xenopus laevis the impact of a pre- (tadpole stage) or post-metamorphosis (juvenile stage) unilateral labyrinthectomy (UL) on young adult swimming performance and underlying spinal locomotor circuitry. The acute disruptive effects on locomotion were similar in both tadpoles and juvenile frogs. However, animals that had metamorphosed with a preceding UL expressed restored swimming behavior at the juvenile stage, whereas animals lesioned after metamorphosis never recovered. Whilst kinematic and electrophysiological analyses of the propulsive system showed no significant differences in either juvenile group, a 3D biomechanical simulation suggested that an asymmetry in the dynamic control of posture during swimming could account for the behavioral restoration observed in animals that had been labyrinthectomized before metamorphosis. This hypothesis was subsequently supported by in vivo electromyography during free swimming and in vitro recordings from isolated brainstem/spinal cord preparations. Specifically, animals lesioned prior to metamorphosis at the larval stage exhibited an asymmetrical propulsion/posture coupling as a post-metamorphic young adult. This developmental alteration was accompanied by an ipsilesional decrease in propriospinal coordination that is normally established in strict left-right symmetry during metamorphosis in order to synchronize dorsal trunk muscle contractions with bilateral hindlimb extensions in the swimming adult. Our data thus suggest that a disequilibrium in descending vestibulospinal information during Xenopus metamorphosis leads to an altered assembly of adult spinal locomotor circuitry. This in turn enables an adaptive compensation for the dynamic postural asymmetry induced by the vestibular imbalance

Neurocinematography in Pre-World War II Netherlands: The Magnus-Rademaker Collection.

PubMed

Koehler, Peter J; Lameris, Bregt; Hielscher, Eva

2016-01-01

Historical films made by neuroscientists have shown up in several countries during past years. Although originally supposed to have been lost, we recently found a collection of films produced between 1909 and 1940 by Rudolf Magnus (1873-1927), professor of pharmacology (Utrecht) and his student Gysbertus Rademaker (1887-1957), professor of physiology (1928, succeeding Willem Einthoven) and neurology (1945, both in Leiden). Both collections deal with the physiology of body posture by the equilibrium of reflex musculature contractions for which experimental studies were done with animals (labyrinthectomies, cerebellectomies, and brainstem sections) and observations on patients. The films demonstrate the results of these studies. Moreover, there are films with babies showing tonic neck reflexes and moving images capturing adults with cerebellar symptoms following cerebellectomies for tumors and several other conditions. Magnus' studies resulted in his well-known Körperstellung (1924, "Body Posture") and Rademaker's research in his Das Stehen (1931, "Standing"). The films probably had an educative and scientific purpose. Magnus demonstrated his films at congresses, including the Eighth International Congress of Physiologists (Vienna, 1910) and Rademaker screened his moving images at meetings of the Amsterdam Neurologists Society (at several occasions as reflected in the Winkler-Monakow correspondence and the Nederlands Tijdschrift voor Geneeskunde). Next to these purposes, the films were used to analyze movement and a series of images from the films were published in articles and books. The films are important historical sources that provide a portrait of the pre-World War II era in neuroscience, partly answering questions on how physicians dealt with patients and researchers with their laboratory animals. Moreover, the films confirm that cinematography was an important scientific tool in neuroscience research.

7-T magnetic resonance imaging of the inner ear's anatomy by using dual four-element radiofrequency coil arrays and the VIBE sequence

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Nam; Heo, Phil; Kim, Young-Bo; Han, Gyu-Cheol

2015-02-01

An ultra-high-field magnetic resonance (MR) scanner and a specially-optimized radiofrequency (RF) coil and sequence protocol are required to obtain high-resolution images of the inner ear that can noninvasively confirm pathologic diagnoses. In phantom studies, the MR signal distribution of the gradient echo MR images generated by using a customized RF coil was compared with that of a commercial volume coil. The MR signal intensity of the customized RF coil decreases rapidly from near the RF coil plane toward the exterior of the phantom. However, the signal sensitivity of this coil is superior on both sides of the phantom, corresponding to the petrous pyramid. In in-vivo 7-T MR imaging, a customized RF coil and a volumetric-interpolated breath-hold examination imaging sequence are employed for visualization of the inner ear's structure. The entire membranous portion of the cochlear and the three semicircular canals, including the ductus reunions, oval window, and round window with associated nervous tissue, were clearly depicted with sufficient spatial coverage for adequate inspection of the surrounding anatomy. Developments from a new perspective to inner ear imaging using the 7-T modality could lead to further improved image sensitivity and, thus, enable ultra-structural MR imaging.

Secretory meningioma: clinicopathologic features of eight cases.

PubMed

Nishio, S; Morioka, T; Suzuki, S; Hirano, K; Fukui, M

2001-07-01

The clinical and morphological features of eight patients with meningothelial meningiomas with numerous pseudopsammoma bodies (secretory meningiomas) are presented. The six female and two male patients ranged in age from 43 to 68 years. Tumours were located at the petroclival region in two, the lateral parasellar region in two, the petrous apex in one and the sphenoid ridge in three patients. On magnetic resonance imaging, they were iso or hypointense on T1-weighted images, and hyper or isointense on T 2-weighted images. Peritumoral brain edema was absent in five cases, and was mild to moderate in three cases. Serum carcinoembryonic antigen (CEA) levels were measured preoperatively in three patients, with one having an elevated serum CEA level which re turned to normal following tumour resection. Immunohistochemical analysis on the resected tumour tissues, pseudopsammoma bodies and surrounding tumour cells were shown to be CEA-positive. Ultrastructurally, pseudopsammoma bodies were composed of granular and filamentous materials located predominantly in the intracellular lumina, which were lined by microvilli. While these morphological features of focal epithelial and secretory differentiation of tumour cells call attention to the broad spectrum of differentiation properties of meningiomas, the biological behavior of the eight tumours reported herein corresponded to those of meningiomas in general. Copyright 2001 Harcourt Publishers Ltd.

Internal Carotid Artery Sacrifice for Radical Resection of Skull Base Tumors

PubMed Central

Lawton, Michael T.; Spetzler, Robert F.

1996-01-01

When dealing with skull base tumors that encase the internal carotid artery (ICA), the surgeon must decide between ICA preservation and incomplete tumor resection, or radical resection with ICA sacrifice. In our experience with more than 300 anterior skull base tumors, the ICA was sacrificed in only 10 patients. These tumors were malignant, except for one meningioma that occluded the ICA and produced translent ischemic symptoms. All patients had the ICA resected with the tumor, and all patients underwent revascularization (cervical ICA-MCA saphenous bypass, n = 4; cervical-to-supraclinoid bypass, n = 1; petrous-to-supraclinoid bypass, n = 3; bonnet bypass, n = 2). This small patient series reflects our practice of preserving the ICA whenever possible. We recommend preserving the ICA with benign tumors because they do not invade the artery, or do so only to a limited extent. In addition, similar rates of tumor recurrence are seen after aggressive resection with or without ICA sacrifice. In contrast, we recommend radical tumor resection and sacrifice of the ICA with malignant tumors because they directly threaten the integrity of the ICA and the patient's survival. The ICA should not be considered a limitation to radical tumor resection because the ICA can be reconstructed safely with an appropriate bypass procedure. PMID:17170986

Beethoven's autopsy revisited: A pathologist sounds a final note.

PubMed

Oiseth, Stanley J

2017-08-01

This review of the original autopsy report of Beethoven's remains indicates Paget's disease within the skull, which was dense and twice normal thickness, with dilated vessels at the petrous bone. The facial nerves were enlarged and the eighth nerves atrophied despite their sharing a common meatus at the internal auditory canal. Nephrolithiasis and pyelonephritis with cortical and perinephric abscesses were also reported. The hypercalcaemia was probably caused by hyperparathyroidism, which may be associated with Paget's disease, and both may have played a role in his psychiatric symptoms as well as in his abdominal pain and gastrointestinal complaints. Since Paget's disease may also be associated with gout, some of the joint pains could be attributable to this as well. Hypovitaminosis A from chronic pancreatitis is suggested as a cause of painful eyes and either quinine abuse or severe hypercalcaemia as a cause of arrhythmias. Beethoven died of terminal cirrhosis with chronic pancreatitis, most likely related to chronic excessive intake of alcohol. Thus, Paget's disease, complicated by hyperparathyroidism, gout, and attempts to find relief of symptoms through the use of alcohol, quinine, and possibly salicylates can explain virtually all of Beethoven's medical problems, some of which appear to have influenced his musical compositions.

Combined use of covered stent and flow diversion to seal iatrogenic carotid injury with vessel preservation during transsphenoidal endoscopic resection of clival tumor.

PubMed

Shakir, Hakeem J; Garson, Alex D; Sorkin, Grant C; Mokin, Maxim; Eller, Jorge L; Dumont, Travis M; Popat, Saurin R; Leonardo, Jody; Siddiqui, Adnan H

2014-01-01

Transsphenoidal tumor resection can lead to internal carotid artery (ICA) injury. Vascular disruption is often treated with emergent vessel deconstruction, incurring complications in a subset of patients with poor collateral circulation and resulting in minor and major ischemic strokes. We attempted a novel approach combining a covered stent graft (Jostent) and two flow diverter stents [Pipeline embolization devices (PEDs)] to treat active extravasation from a disrupted right ICA that was the result of a transsphenoidal surgery complication. This disruption occurred during clival tumor surgery and required immediate sphenoidal sinus packing. Emergent angiography revealed continued petrous carotid artery extravasation, warranting emergent vessel repair or deconstruction for treatment. To preserve the vessel, we utilized a covered Jostent. Due to tortuosity and lack of optimal wall apposition, there was reduced, yet persistent extravasation from an endoleak after Jostent deployment that failed to resolve despite multiple angioplasties. Therefore, we used PEDs to divert the flow. Flow diversion relieved the extravasation. The patient remained neurologically intact post-procedure. This case demonstrates successful combined use of a covered stent and flow diverters to treat acute vascular injury resulting from transsphenoidal surgery. However, concerns remain, including the requirement of dual antiplatelet agents increasing postoperative bleeding risks, stent-related thromboembolic events, and delayed in-stent restenosis rates.

Cerebrospinal fluid leakage and Chiari I malformation with Gorham's disease of the skull base: A case report.

PubMed

Nagashima, Hiroaki; Mizukawa, Katsu; Taniguchi, Masaaki; Yamamoto, Yusuke; Kohmura, Eiji

Gorham's syndrome is a rare bone disorder characterized by massive osteolysis of unknown etiology. There are no reports of comorbidity involving cerebrospinal fluid (CSF) leakage and Chiari I malformation with Gorham's syndrome. Here, we report an unusual case of an acute presyrinx state complicated by bacterial meningitis due to CSF leakage and Chiari I malformation associated with Gorham's disease of the skull base. A 25-year-old woman with Chiari I malformation associated with Gorham's syndrome presented with aggressive paresthesia following bacterial meningitis. Axial magnetic resonance imaging (MRI) and computed tomography (CT) cisternography revealed CSF leakage in the right petrous apex. A presyrinx state was diagnosed based on the clinical symptoms and MRI findings. With resolution of the bacterial meningitis, the spinal edema and tonsillar ectopia also improved. Surgical repair of the CSF leakage was performed by an endoscopic endonasal transsphenoidal approach to prevent recurrence of meningitis. The postoperative course was uneventful. Skull base osteolysis in Gorham's syndrome may induce Chiari I malformation and CSF leakage. We should pay attention to acute progression of clinical symptoms because Gorham's syndrome may predispose to development of Chiari I malformation and may be complicated by CSF leakage. Copyright © 2017 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

Correlation of Fos expression and circling asymmetry during gerbil vestibular compensation

NASA Technical Reports Server (NTRS)

Kaufman, G. D.; Shinder, M. E.; Perachio, A. A.

1999-01-01

Vestibular compensation is a central nervous system process resulting in recovery of functional movement and control following a unilateral vestibular lesion. Small pressure injections of phosphorothioate 20mer oligonucleotides were used to probe the role of the Fos transcription protein during vestibular compensation in the gerbil brainstem. During isoflurane gas anesthesia, antisense probes against the c-fos mRNA sequence were injected into the medial vestibular and prepositus nuclei unilaterally prior to a unilateral surgical labyrinthectomy. Anionic dyes, which did not interact with the oligonucleotides, were used to mark the injection site and help determine the extent of diffusion. The antiFos oligonucleotide injections reduced Fos expression at the injection site in neurons which normally express Fos after the lesion, and also affected circling behavior induced by hemilabyrinthectomy. With both ipsilateral and contralateral medial vestibular and prepositus nuclei injections, less ipsilateral and more contralateral circling was noted in animals injected with antiFos injections as compared to non-injected controls. The degree of change in these behaviors was dependent upon the side of the injection. Histologically, antiFos injections reduced the number of Fos immunolabeled neurons around the injection site, and increased Fos expression contralaterally. The correlation of the number of neurons with Fos expression to turning behavior was stronger for contralateral versus ipsilateral turns, and for neurons in the caudal and ipsilateral sub-regions of the medial vestibular and prepositus nuclei. The results are discussed in terms of neuronal firing activity versus translational activity based on the asymmetrical expression of the Fos inducible transcription factor in the medial vestibular and prepositus nuclei. Although ubiquitous in the brain, transcription factors like Fos can serve localized and specific roles in sensory-specific adaptive stimuli. Antisense

The Frog Vestibular System as a Model for Lesion-Induced Plasticity: Basic Neural Principles and Implications for Posture Control

PubMed Central

Lambert, François M.; Straka, Hans

2011-01-01

Studies of behavioral consequences after unilateral labyrinthectomy have a long tradition in the quest of determining rules and limitations of the central nervous system (CNS) to exert plastic changes that assist the recuperation from the loss of sensory inputs. Frogs were among the first animal models to illustrate general principles of regenerative capacity and reorganizational neural flexibility after a vestibular lesion. The continuous successful use of the latter animals is in part based on the easy access and identifiability of nerve branches to inner ear organs for surgical intervention, the possibility to employ whole brain preparations for in vitro studies and the limited degree of freedom of postural reflexes for quantification of behavioral impairments and subsequent improvements. Major discoveries that increased the knowledge of post-lesional reactive mechanisms in the CNS include alterations in vestibular commissural signal processing and activation of cooperative changes in excitatory and inhibitory inputs to disfacilitated neurons. Moreover, the observed increase of synaptic efficacy in propriospinal circuits illustrates the importance of limb proprioceptive inputs for postural recovery. Accumulated evidence suggests that the lesion-induced neural plasticity is not a goal-directed process that aims toward a meaningful restoration of vestibular reflexes but rather attempts a survival of those neurons that have lost their excitatory inputs. Accordingly, the reaction mechanism causes an improvement of some components but also a deterioration of other aspects as seen by spatio-temporally inappropriate vestibulo-motor responses, similar to the consequences of plasticity processes in various sensory systems and species. The generality of the findings indicate that frogs continue to form a highly amenable vertebrate model system for exploring molecular and physiological events during cellular and network reorganization after a loss of vestibular function

Neuronal detection thresholds during vestibular compensation: contributions of response variability and sensory substitution.

PubMed

Jamali, Mohsen; Mitchell, Diana E; Dale, Alexis; Carriot, Jerome; Sadeghi, Soroush G; Cullen, Kathleen E

2014-04-01

The vestibular system is responsible for processing self-motion, allowing normal subjects to discriminate the direction of rotational movements as slow as 1-2 deg s(-1). After unilateral vestibular injury patients' direction-discrimination thresholds worsen to ∼20 deg s(-1), and despite some improvement thresholds remain substantially elevated following compensation. To date, however, the underlying neural mechanisms of this recovery have not been addressed. Here, we recorded from first-order central neurons in the macaque monkey that provide vestibular information to higher brain areas for self-motion perception. Immediately following unilateral labyrinthectomy, neuronal detection thresholds increased by more than two-fold (from 14 to 30 deg s(-1)). While thresholds showed slight improvement by week 3 (25 deg s(-1)), they never recovered to control values - a trend mirroring the time course of perceptual thresholds in patients. We further discovered that changes in neuronal response variability paralleled changes in sensitivity for vestibular stimulation during compensation, thereby causing detection thresholds to remain elevated over time. However, we found that in a subset of neurons, the emergence of neck proprioceptive responses combined with residual vestibular modulation during head-on-body motion led to better neuronal detection thresholds. Taken together, our results emphasize that increases in response variability to vestibular inputs ultimately constrain neural thresholds and provide evidence that sensory substitution with extravestibular (i.e. proprioceptive) inputs at the first central stage of vestibular processing is a neural substrate for improvements in self-motion perception following vestibular loss. Thus, our results provide a neural correlate for the patient benefits provided by rehabilitative strategies that take advantage of the convergence of these multisensory cues.

Neuronal detection thresholds during vestibular compensation: contributions of response variability and sensory substitution

PubMed Central

Jamali, Mohsen; Mitchell, Diana E; Dale, Alexis; Carriot, Jerome; Sadeghi, Soroush G; Cullen, Kathleen E

2014-01-01

The vestibular system is responsible for processing self-motion, allowing normal subjects to discriminate the direction of rotational movements as slow as 1–2 deg s−1. After unilateral vestibular injury patients’ direction–discrimination thresholds worsen to ∼20 deg s−1, and despite some improvement thresholds remain substantially elevated following compensation. To date, however, the underlying neural mechanisms of this recovery have not been addressed. Here, we recorded from first-order central neurons in the macaque monkey that provide vestibular information to higher brain areas for self-motion perception. Immediately following unilateral labyrinthectomy, neuronal detection thresholds increased by more than two-fold (from 14 to 30 deg s−1). While thresholds showed slight improvement by week 3 (25 deg s−1), they never recovered to control values – a trend mirroring the time course of perceptual thresholds in patients. We further discovered that changes in neuronal response variability paralleled changes in sensitivity for vestibular stimulation during compensation, thereby causing detection thresholds to remain elevated over time. However, we found that in a subset of neurons, the emergence of neck proprioceptive responses combined with residual vestibular modulation during head-on-body motion led to better neuronal detection thresholds. Taken together, our results emphasize that increases in response variability to vestibular inputs ultimately constrain neural thresholds and provide evidence that sensory substitution with extravestibular (i.e. proprioceptive) inputs at the first central stage of vestibular processing is a neural substrate for improvements in self-motion perception following vestibular loss. Thus, our results provide a neural correlate for the patient benefits provided by rehabilitative strategies that take advantage of the convergence of these multisensory cues. PMID:24366259

Short latency compound action potentials from mammalian gravity receptor organs

NASA Technical Reports Server (NTRS)

Jones, T. A.; Jones, S. M.

1999-01-01

Gravity receptor function was characterized in four mammalian species using far-field vestibular evoked potentials (VsEPs). VsEPs are compound action potentials of the vestibular nerve and central relays that are elicited by linear acceleration ramps applied to the cranium. Rats, mice, guinea pigs, and gerbils were studied. In all species, response onset occurred within 1.5 ms of the stimulus onset. Responses persisted during intense (116 dBSPL) wide-band (50 to 50 inverted question mark omitted inverted question mark000 Hz) forward masking, whereas auditory responses to intense clicks (112 dBpeSPL) were eliminated under the same conditions. VsEPs remained after cochlear extirpation but were eliminated following bilateral labyrinthectomy. Responses included a series of positive and negative peaks that occurred within 8 ms of stimulus onset (range of means at +6 dBre: 1.0 g/ms: P1=908 to 1062 micros, N1=1342 to 1475 micros, P2=1632 to 1952 micros, N2=2038 to 2387 micros). Mean response amplitudes at +6 dBre: 1.0 g/ms ranged from 0.14 to 0.99 microV. VsEP input/output functions revealed latency slopes that varied across peaks and species ranging from -19 to -51 micros/dB. Amplitude-intensity slopes also varied ranging from 0.04 to 0.08 microV/dB for rats and mice. Latency values were comparable to those of birds although amplitudes were substantially smaller in mammals. VsEP threshold values were considerably higher in mammals compared to birds and ranged from -8.1 to -10.5 dBre 1.0 g/ms across species. These results support the hypothesis that mammalian gravity receptors are less sensitive to dynamic stimuli than are those of birds.

Morphologically mixed chemical-electrical synapses formed by primary afferents in rodent vestibular nuclei as revealed by immunofluorescence detection of connexin36 and vesicular glutamate transporter-1

PubMed Central

Nagy, James I.; Bautista, Wendy; Blakley, Brian; Rash, John E.

2013-01-01

Axon terminals forming mixed chemical/electrical synapses in the lateral vestibular nucleus of rat were described over forty years ago. Because gap junctions formed by connexins are the morphological correlate of electrical synapses, and with demonstrations of widespread expression of the gap junction protein connexin36 (Cx36) in neurons, we investigated the distribution and cellular localization of electrical synapses in the adult and developing rodent vestibular nuclear complex, using immunofluorescence detection of Cx36 as a marker for these synapses. In addition, we examined Cx36 localization in relation to that of the nerve terminal marker vesicular glutamate transporter-1 (vglut-1). An abundance of immunolabelling for Cx36 in the form of Cx36-puncta was found in each of the four major vestibular nuclei of adult rat and mouse. Immunolabelling was associated with somata and initial dendrites of medium and large neurons, and was absent in vestibular nuclei of Cx36 knockout mice. Cx36-puncta were seen either dispersed or aggregated into clusters on the surface of neurons, and were never found to occur intracellularly. Nearly all Cx36-puncta were localized to large nerve terminals immunolabelled for vglut-1. These terminals and their associated Cx36-puncta were substantially depleted after labyrinthectomy. Developmentally, labelling for Cx36 was already present in the vestibular nuclei at postnatal day 5, where it was only partially co-localized with vglut-1, and did not become fully associated with vglut-1-positive terminals until postnatal day 20 to 25. The results show that vglut-1-positive primary afferent nerve terminals form mixed synapses throughout the vestibular nuclear complex, that the gap junction component of these synapses contain Cx36, that multiple Cx36-containing gap junctions are associated with individual vglut-1 terminals and that the development of these mixed synapses is protracted over several postnatal weeks. PMID:23912039

A rodent model for artificial gravity: VOR adaptation and Fos expression.

PubMed

Kaufman, Galen; Weng, Tianxiang; Ruttley, Tara

2005-01-01

Vestibulo-ocular reflex (VOR) adaptation and brainstem Fos expression as a result of short radius cross-coupling stimuli were investigated to find neural correlates of the inherent Coriolis force asymmetry from an artificial gravity (AG) environment. Head-fixed gerbils (Meriones unguiculatus, N=79) were exposed, in the dark, to 60--90 minutes of cross-coupled rotations, combinations of pitch (or roll) and yaw rotation, while binocular horizontal, vertical, and torsional eye position were determined using infrared video-oculography. Centripetal acceleration in combination with angular cross-coupling was also studied. Simultaneous sinusoidal rotations in two planes (yaw with roll or pitch) provided a net symmetrical stimulus for the right and left labyrinths. In contrast, a constant velocity yaw rotation during sinusoidal roll or pitch provided the asymmetric stimulus model for AG. We found orthogonally oriented half-cycle VOR gain changes. The results depended on the direction of horizontal rotation during asymmetrical cross-coupling, and other aspects of the stimulus, including the phase relationship between the two rotational inputs, the symmetry of the stimulus, and training. Fos expression also revealed laterality differences in the prepositus and inferior olivary C subnucleus. In contrast the inferior olivary beta and ventrolateral outgrowth were labeled bilaterally. Additional cross-coupling dependent labeling was found in the flocculus, hippocampus, and several cortical regions, including the perirhinal and temporal association cortices. Analyses showed significant differences across the brain regions for several factors (symmetry, rotation velocity and direction, the presence of centripetal acceleration or a visual surround, and training). Finally, animals compensating from a unilateral surgical labyrinthectomy who received multiple cross-coupling training sessions had improved half-cycle VOR gain in the ipsilateral eye with head rotation toward the intact

The mixed blessing of treating symptoms in acute vestibular failure--evidence from a 4-aminopyridine experiment.

PubMed

Beck, Roswitha; Günther, Lisa; Xiong, Guoming; Potschka, Heidrun; Böning, Guido; Bartenstein, Peter; Brandt, Thomas; Jahn, Klaus; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2014-11-01

Early symptomatic treatment of acute unilateral vestibulopathy is thought to impede the course of ensuing central vestibular compensation (VC). Despite the great clinical importance of this hypothesis there is no experimental evidence of its validity. The present study addressed this question by investigating the direct effect of 4-aminopyridine (4-AP) on ocular motor and postural symptoms in acute unilateral vestibulopathy as well as its long-term consequences for VC in a rat model of chemical unilateral labyrinthectomy (UL). After UL, one group of Sprague-Dawley rats was treated with 4-AP p.o. (1mg/kg/day), another with 0.9% NaCl solution p.o. for 3days. Behavioural testing for symptoms of vestibular tone imbalance was done 1day before and 1, 2, 3, 5, 7, 9, 15, 21, and 30days after UL. In addition, sequential whole-brain [(18)F]-FDG-μPET was performed before and 1, 3, 7, 15, and 30days after UL to examine and visualize 4-AP-induced modulation of VC. Administration of 4-AP on days 1-3 significantly improved postural imbalance 2h after administration compared to that in controls. This effect was only transient. Remarkably, the 4-AP group had a prolonged and impaired course of postural compensation compared to that of controls. The μPET revealed a significant increase of regional cerebral glucose metabolism (rCGM) in the vestibulocerebellum 2h after administration of 4-AP. However, the 4-AP group exhibited a persistent asymmetry of rCGM after day 3 in the vestibular nuclei and posterolateral thalami. In conclusion, this study confirms the hypothesis that early pharmacological abatement of vestibular symptoms impedes VC. Copyright © 2014 Elsevier Inc. All rights reserved.

Solitary lung metastasis from intracranial hemangiopericytoma 18 years after initial resection.

PubMed

Doxtader, Erika E; Mukhopadhyay, Sanjay; Prayson, Richard A

2015-07-01

We report a 29-year-old woman who presented with severe headache, nausea and vomiting. A lesion was found in the left petrous ridge and near-total resection was performed. Pathologic examination showed anaplastic hemangiopericytoma (World Health Organization Grade III). Hemangiopericytoma is an uncommon mesenchymal tumor that rarely occurs in an intracranial location. Prior studies have reported a surprisingly high rate of late recurrence and extracranial metastases from intracranial hemangiopericytomas, including metastases to the lungs. Resection was followed by external beam radiation. The tumor recurred intracranially 6 and 13 years later and was treated with gamma knife stereotactic radiosurgery. At year 14, she noticed a lump in her neck and underwent parotidectomy for a mucoepidermoid carcinoma. This new diagnosis prompted a staging chest CT scan which showed a 4mm right upper lobe lung nodule along with additional < 5 mm indeterminate nodules. Over the next 3 years, the nodule increased to 8mm. Wedge biopsy of the lung nodule showed metastatic hemangiopericytoma, histologically similar to the intracranial hemangiopericytoma. Both the primary and the lung metastasis were positive for CD34 and STAT-6. To the best of our knowledge, this is the longest reported interval between a resected intracranial hemangiopericytoma and a histologically confirmed solitary metastasis to the lung. Copyright © 2015 Elsevier Ltd. All rights reserved.

Java brucea and Chinese herbal medicine for the treatment of cholesterol granuloma in the suprasellar and sellar regions: A case report and literature review.

PubMed

Sun, Zhe; Cao, Yang; Zhai, Lin-Zhu

2017-02-01

A cholesterol granuloma (CG) is usually found in the middle ear, papilla, orbits, petrous apex, and choroid plexus, but is highly uncommon in the skull. In spite of benign clinicopathological lesions, bone erosion can be seen occasionally in the patient with CG. The optimal treatment strategy is radical surgery, but complete excision is usually impossible due to anatomical restrictions and a risk of injury to the key structures located nearby. Here, we report a patient with CGs in the suprasellar and sellar regions who was successfully treated with Java brucea and Chinese herbal medicine. A 31-year-old man presenting with progressive decreased vision in both eyes was analyzed. A skull magnetic resonance imaging (MRI) scan showed a low-density tumor in the uprasellar and sellar regions and histopathological examination revealed a CG. The patient was referred the surgery and radiotherapy. In the meantime, brucea soft capsules and herbal medicine combined were administered to him. The related clinical symptoms and signs resolved significantly after several months, as his therapy progressed. The patient showed no sign of recurrence during the treatment period. Furthermore, he was still alive and disease-free at 37 months of follow-up visit. Overall, brucea soft capsules and a Chinese herbal formula treatment combined could be beneficial in improving the patient's quality of life with CG in the skull.

Direct radiocarbon dating and DNA analysis of the Darra-i-Kur (Afghanistan) human temporal bone.

PubMed

Douka, Katerina; Slon, Viviane; Stringer, Chris; Potts, Richard; Hübner, Alexander; Meyer, Matthias; Spoor, Fred; Pääbo, Svante; Higham, Tom

2017-06-01

The temporal bone discovered in the 1960s from the Darra-i-Kur cave in Afghanistan is often cited as one of the very few Pleistocene human fossils from Central Asia. Here we report the first direct radiocarbon date for the specimen and the genetic analyses of DNA extracted and sequenced from two areas of the bone. The new radiocarbon determination places the find to ∼4500 cal BP (∼2500 BCE) contradicting an assumed Palaeolithic age of ∼30,000 years, as originally suggested. The DNA retrieved from the specimen originates from a male individual who carried mitochondrial DNA of the modern human type. The petrous part yielded more endogenous ancient DNA molecules than the squamous part of the same bone. Molecular dating of the Darra-i-Kur mitochondrial DNA sequence corroborates the radiocarbon date and suggests that the specimen is younger than previously thought. Taken together, the results consolidate the fact that the human bone is not associated with the Pleistocene-age deposits of Darra-i-Kur; instead it is intrusive, possibly re-deposited from upper levels dating to much later periods (Neolithic). Despite its Holocene age, the Darra-i-Kur specimen is, so far, the first and only ancient human from Afghanistan whose DNA has been sequenced. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anatomy of Meckel's cave and the trigeminal ganglion: anatomical landmarks for a safer approach to them.

PubMed

Arslan, Mehmet; Deda, Haluk; Avci, Emel; Elhan, Alaittin; Tekdemir, Ibrahim; Tubbs, R Shane; Silav, Gokalp; Yilmaz, Erdal; Baskaya, Mustafa Kemal

2012-01-01

Surgical approaches to Meckel's cave (MC) are often technically difficult and sometimes associated with postoperative morbidity. The relationship of surgical landmarks to relevant anatomy is important. Therefore, we attempted to delineate quantitatively their anatomy and the relationships between MC and surrounding structures. With the aid of a surgical microscope, MC and its contents were studied in 15 formalin-fixed cadaver head specimens. Measurements were made and their relationships were observed. The distance from the zygomatic arch and the lateral end of the petrous ridge to MC was 26.5 and 34.4 mm, respectively. The distance from the arcuate eminence, the facial nerve hiatus, and the foramen spinosum to MC was 16.6, 12.8 and 7.46 mm respectively. The TG lay 5.81 mm posterior to the foramen ovale. The distance from the abducens, trochlear and oculomotor nerves to the trigeminal ganglion was 1.87, 5.53 and 6.57 mm respectively. The distance from the posterior and the anterior walls of the sigmoid sinus to the trigeminal porus was 43.6 and 33.1 mm respectively. The trigeminal porus was on average 7.19 mm from the anterior wall of the internal acoustic meatus. The anatomical landmarks as presented herein regarding MC may be used for a safer skull base approach to the region.

Dorello's Canal for Laymen: A Lego-Like Presentation.

PubMed

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-06-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students.

Dorello's Canal for Laymen: A Lego-Like Presentation

PubMed Central

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-01-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students. PMID:23730547

Time-saving and fail-safe dissection method for vestibulocochlear organs in gross anatomy classes.

PubMed

Suzuki, Ryoji; Konno, Naoaki; Ishizawa, Akimitsu; Kanatsu, Yoshinori; Funakoshi, Kodai; Akashi, Hideo; Zhou, Ming; Abe, Hiroshi

2017-09-01

Because the vestibulocochlear organs are tiny and complex, and are covered by the petrous part of the temporal bone, they are very difficult for medical students to dissect and visualize during gross anatomy classes. Here, we report a time-saving and fail-safe procedure we have devised, using a hand-held hobby router. Nine en bloc temporal bone samples from donated human cadavers were used as trial materials for devising an appropriate procedure for dissecting the vestibulocochlear organs. A hand-held hobby router was used to cut through the temporal bone. After trials, the most time-saving and fail-safe method was selected. The performance of the selected method was assessed by a survey of 242 sides of 121 cadavers during gross anatomy classes for vestibulocochlear dissection. The assessment was based on the observation ratio. The best procedure appeared to be removal of the external acoustic meatus roof and tympanic cavity roof together with removal of the internal acoustic meatus roof. The whole procedure was completed within two dissection classes, each lasting 4.5 hr. The ratio of surveillance for the chorda tympani and three semicircular canals by students was significantly improved during 2013 through 2016. In our dissection class, "removal of the external acoustic meatus roof and tympanic cavity roof together with removal of the internal acoustic meatus roof" was the best procedure for students in the limited time available. Clin. Anat. 30:703-710, 2017. © 2017Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.

PubMed

Kockro, Ralf A; Hwang, Peter Y K

2009-05-01

We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. The virtual model was based on the tomographic data of the Visible Human Project. The male Visible Human's computed tomographic data were volumetrically reconstructed as virtual bone tissue, and the individual photographic slices provided the basis for segmentation of the middle and inner ear structures, cranial nerves, vessels, and brainstem. These structures were created by using outlining and tube editing tools, allowing structural modeling either directly on the basis of the photographic data or according to information from textbooks and cadaver dissections. For training and teaching, the virtual model was accessed in the previously described 3-dimensional workspaces of the Dextroscope or Dextrobeam (Volume Interactions Pte, Ltd., Singapore), whose interfaces enable volumetric exploration from any perspective and provide virtual tools for drilling and measuring. We have simulated several cranial base procedures including approaches via the floor of the middle fossa and the lateral petrous bone. The virtual model suitably illustrated the core facts of anatomic spatial relationships while simulating different stages of bone drilling along a variety of surgical corridors. The system was used for teaching during training courses to plan and discuss operative anatomy and strategies. The Virtual Temporal Bone and its surrounding 3-dimensional workspace provide an effective way to study the essential surgical anatomy of this complex region and to teach and train operative strategies, especially when used as an adjunct to cadaver dissections.

Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics.

PubMed

Lockwood, Charles A; Lynch, John M; Kimbel, William H

2002-12-01

The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade.

Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

PubMed Central

Lockwood, Charles A; Lynch, John M; Kimbel, William H

2002-01-01

The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. PMID:12489757

The cochlea in skull base surgery: an anatomy study.

PubMed

Wang, Jian; Yoshioka, Fumitaka; Joo, Wonil; Komune, Noritaka; Quilis-Quesada, Vicent; Rhoton, Albert L

2016-11-01

OBJECTIVE The object of this study was to examine the relationships of the cochlea as a guide for avoiding both cochlear damage with loss of hearing in middle fossa approaches and injury to adjacent structures in approaches directed through the cochlea. METHODS Twenty adult cadaveric middle fossae were examined using magnifications of ×3 to ×40. RESULTS The cochlea sits below the floor of the middle fossa in the area between and below the labyrinthine segment of the facial nerve and greater petrosal nerve (GPN) and adjacent to the lateral genu of the petrous carotid. Approximately one-third of the cochlea extends below the medial edge of the labyrinthine segment of the facial nerve, geniculate ganglion, and proximal part of the GPN. The medial part of the basal and middle turns are the parts at greatest risk in drilling the floor of the middle fossa to expose the nerves in middle fossa approaches to the internal acoustic meatus and in anterior petrosectomy approaches. Resection of the cochlea is used selectively in extending approaches through the mastoid toward the lateral edge of the clivus and front of the brainstem. CONCLUSIONS An understanding of the location and relationships of the cochlea will reduce the likelihood of cochlear damage with hearing loss in approaches directed through the middle fossa and reduce the incidence of injury to adjacent structures in approaches directed through the cochlea.

Transparent model of temporal bone and vestibulocochlear organ made by 3D printing.

PubMed

Suzuki, Ryoji; Taniguchi, Naoto; Uchida, Fujio; Ishizawa, Akimitsu; Kanatsu, Yoshinori; Zhou, Ming; Funakoshi, Kodai; Akashi, Hideo; Abe, Hiroshi

2018-01-01

The vestibulocochlear organ is composed of tiny complex structures embedded in the petrous part of the temporal bone. Landmarks on the temporal bone surface provide the only orientation guide for dissection, but these need to be removed during the course of dissection, making it difficult to grasp the underlying three-dimensional structures, especially for beginners during gross anatomy classes. We report herein an attempt to produce a transparent three-dimensional-printed model of the human ear. En bloc samples of the temporal bone from donated cadavers were subjected to computed tomography (CT) scanning, and on the basis of the data, the surface temporal bone was reconstructed with transparent resin and the vestibulocochlear organ with white resin to create a 1:1.5 scale model. The carotid canal was stuffed with red cotton, and the sigmoid sinus and internal jugular vein were filled with blue clay. In the inner ear, the internal acoustic meatus, cochlea, and semicircular canals were well reconstructed in detail with white resin. The three-dimensional relationships of the semicircular canals, spiral turns of the cochlea, and internal acoustic meatus were well recognizable from every direction through the transparent surface resin. The anterior semicircular canal was obvious immediately beneath the arcuate eminence, and the topographical relationships of the vestibulocochlear organ and adjacent great vessels were easily discernible. We consider that this transparent temporal bone model will be a very useful aid for better understanding of the gross anatomy of the vestibulocochlear organ.

Schwannoma originating from lower cranial nerves: report of 4 cases.

PubMed

Oyama, Hirofumi; Kito, Akira; Maki, Hideki; Hattori, Kenichi; Noda, Tomoyuki; Wada, Kentaro

2012-02-01

Four cases of schwannoma originating from the lower cranial nerves are presented. Case 1 is a schwannoma of the vagus nerve in the parapharyngeal space. The operation was performed by the transcervical approach. Although the tumor capsule was not dissected from the vagus nerve, hoarseness and dysphagia happened transiently after the operation. Case 2 is a schwannoma in the jugular foramen. The operation was performed by the infralabyrinthine approach. Although only the intracapsular tumor was enucleated, facial palsy, hoarseness, dysphagia and paresis of the deltoid muscle occurred transiently after the operation. The patient's hearing had also slightly deteriorated. Case 3 is a dumbbell-typed schwannoma originating from the hypoglossal nerve. The hypoglossal canal was markedly enlarged by the tumor. As the hypoglossal nerves were embedded in the tumor, the tumor around the hypoglossal nerves was not resected. The tumor was significantly enlarged for a while after stereotactic irradiation. Case 4 is an intracranial cystic schwannoma originating from the IXth or Xth cranial nerves. The tumor was resected through the cerebello-medullary fissure. The tumor capsule attached to the brain stem was not removed. Hoarseness and dysphagia happened transiently after the operation. Cranial nerve palsy readily occurs after the removal of the schwannoma originating from the lower cranial nerves. Mechanical injury caused by retraction, extension and compression of the nerve and heat injury during the drilling of the petrous bone should be cautiously avoided.

Limitations of titanium dioxide and aluminum oxide as ossicular replacement materials: an evaluation of the effects of porosity on ceramic prostheses.

PubMed

Trabandt, Nicolaus; Brandes, Gudrun; Wintermantel, Erich; Lenarz, Thomas; Stieve, Martin

2004-09-01

Because the performance of titanium dioxide (TiO2) has not yet been assessed in the unique environment of the middle ear, its role as an ossicular replacement prototype in the form of a total ossicular replacement prosthesis (TORP) was tested and compared with aluminum oxide (Al2O3), once considered to be a suitable implant material. Ossiculoplasty was performed by implanting TORPs into the tympanic cavities of rabbits. After an implantation period of 28, 84, or 300 days, the petrous bones were extracted, whereby the biocompatibility of the prostheses was examined using light microscopy and scanning electron microscopy to determine morphologic changes in situ. Proper implant placement and functionality was tested via manual manipulation. Mucosa was seen covering most of the implants by day 84. Inflammatory cells were not observed in any of the specimens examined. The macroporous TiO2 TORPs were subjected to osseous infiltration, material dissolution, and fragmentation, whereas the microporous TiO2 implants were subjected to an increasing frequency of fissure formations. The Al2O3 prostheses demonstrated signs of material dissolution by producing encapsulated aggregates during the experimental trial period. Neither the macroporous nor microporous oxide ceramics were able to withstand the oscillatory stress to which they were continually subjected. Although porosity allows for the rapid integration of an implant material into a biological environment, its properties are not suited to fulfill the requirements of strength and long-term stability, which are demanded of middle ear prostheses.

From labyrinthine aplasia to otocyst deformity.

PubMed

Giesemann, Anja Maria; Goetz, Friedrich; Neuburger, Jürgen; Lenarz, Thomas; Lanfermann, Heinrich

2010-02-01

Inner ear malformations (IEMs) are rare and it is unusual to encounter the rarest of them, namely labyrinthine aplasia (LA) and otocyst deformity. They do, however, provide useful pointers as to the early embryonic development of the ear. LA is characterised as a complete absence of inner ear structures. While some common findings do emerge, a clear definition of the otocyst deformity does not exist. It is often confused with the common cavity first described by Edward Cock. Our purpose was to radiologically characterise LA and otocyst deformity. Retrospective analysis of CT and MRI data from four patients with LA or otocyst deformity. Middle and inner ear findings were categorised by two neuroradiologists. The bony carotid canal was found to be absent in all patients. Posterior located cystic structures were found in association with LA and otocyst deformity. In the most severe cases, only soft tissue was present at the medial border of the middle ear cavity. The individuals with otocyst deformity also had hypoplasia of the petrous apex bone. These cases demonstrate gradual changes in the two most severe IEMs. Clarification of terms was necessary and, based on these findings, we propose defining otocyst deformity as a cystic structure in place of the inner ear, with the cochlea, IAC and carotid canal absent. This condition needs to be differentiated from the common cavity described by Edward Cook. A clear definition of inner ear malformations is essential if outcomes following cochlear implantation are to be compared.

Severity and presence of atherosclerosis signs within the segments of internal carotid artery: CBCT's contribution.

PubMed

Damaskos, Spyros; da Silveira, Heraldo L D; Berkhout, Erwin W R

2016-07-01

This study aims to assess with cone-beam computed tomography the distribution and interrelation of the presence of calcifications along the course of the internal carotid artery and to associate their severity with their allocation within the segments of internal carotid artery, gender, and age. Using a documented visual scale, 161 cone-beam computed tomography scans were evaluated on the allocation and severity of intracranial calcifications within the segments of the internal carotid artery. Calcifications were detected along the petrous (C2: 11.8%), lacerum (C3: 23.6%), cavernous (C4: 92.5%), and ophthalmic-clinoid (C5/C6: 65.8%) segments. The Friedman test showed significant differences in severity distribution among these segments; the highest degree was found in the C4 segment (P < .05). The Wilcoxon signed-rank test showed no significant differences between calcifications on the right or left side or between severities within the C1 (extracranial) and C5/C6 segments. The Chi-square test showed that the severity and allocation of calcifications are not influenced by gender; it also showed that their severity increases with age (P < .05). In the cohort studied, the incidence of calcifications increased throughout the C1, C5/C6, and C4 segments. More severe calcifications were found at the C4, C1, and C5/C6 segments in decreasing order but increased with age, regardless of gender. Copyright © 2016 Elsevier Inc. All rights reserved.

The round window region and contiguous areas: endoscopic anatomy and surgical implications.

PubMed

Marchioni, Daniele; Alicandri-Ciufelli, Matteo; Pothier, David D; Rubini, Alessia; Presutti, Livio

2015-05-01

The round window region is a critical area of the middle ear; the aim of this paper is to describe its anatomy from an endoscopic perspective, emphasizing some structures, the knowledge of which could have important implications during surgery, as well as to evaluate what involvement cholesteatoma may have with these structures. Retrospective review of video recordings of endoscopic ear surgeries and retrospective database review were conducted in Tertiary university referral center. Videos from endoscopic middle ear procedures carried out between June 2010 and September 2012 and stored in a shared database were reviewed retrospectively. Surgeries in which an endoscopic magnification of the round window region and the inferior retrotympanum area was performed intraoperatively were included in the study. Involvement by cholesteatoma of those regions was also documented based on information obtained from the surgical database. Conformation of the tegmen of the round window niche may influence the surgical view of round window membrane. A structure connecting the round window area to the petrous apex, named the subcochlear canaliculus, is described. Cholesteatoma can invade the round window areas in some patients. Endoscopic approaches can guarantee a very detailed view and allow the exploration of the round window region. Exact anatomical knowledge of this region can have important advantages during surgery, since some pathology can invade inside cavities or tunnels otherwise not seen by instrumentation that produces a straight-line view (e.g. microscope).

Microsurgical Resection of Glomus Jugulare Tumors With Facial Nerve Reconstruction: 3-Dimensional Operative Video.

PubMed

Cândido, Duarte N C; de Oliveira, Jean Gonçalves; Borba, Luis A B

2018-05-08

Paragangliomas are tumors originating from the paraganglionic system (autonomic nervous system), mostly found at the region around the jugular bulb, for which reason they are also termed glomus jugulare tumors (GJT). Although these lesions appear to be histologically benign, clinically they present with great morbidity, especially due to invasion of nearby structures such as the lower cranial nerves. These are challenging tumors, as they need complex approaches and great knowledge of the skull base. We present the case of a 31-year-old woman, operated by the senior author, with a 1-year history of tinnitus, vertigo, and progressive hearing loss, that evolved with facial nerve palsy (House-Brackmann IV) 2 months before surgery. Magnetic resonance imaging and computed tomography scans demonstrated a typical lesion with intense flow voids at the jugular foramen region with invasion of the petrous and tympanic bone, carotid canal, and middle ear, and extending to the infratemporal fossa (type C2 of Fisch's classification for GJT). During the procedure the mastoid part of the facial nerve was identified involved by tumor and needed to be resected. We also describe the technique for nerve reconstruction, using an interposition graft from the great auricular nerve, harvested at the beginning of the surgery. We achieved total tumor resection with a remarkable postoperative course. The patient also presented with facial function after 6 months. The patient consented with publication of her images.

Case analysis of temporal bone lesions with facial paralysis as main manifestation and literature review.

PubMed

Chen, Wen-Jing; Ye, Jing-Ying; Li, Xin; Xu, Jia; Yi, Hai-Jin

2017-08-23

This study aims to discuss clinical characteristics, image manifestation and treatment methods of temporal bone lesions with facial paralysis as the main manifestation for deepening the understanding of such type of lesions and reducing erroneous and missed diagnosis. The clinical data of 16 patients with temporal bone lesions and facial paralysis as main manifestation, who were diagnosed and treated from 2009 to 2016, were retrospectively analyzed. Among these patients, six patients had congenital petrous bone cholesteatoma (PBC), nine patients had facial nerve schwannoma, and one patient had facial nerve hemangioma. All the patients had an experience of long-term erroneous diagnosis. The lesions were completely excised by surgery. PBC and primary facial nerve tumors were pathologically confirmed. Facial-hypoglossal nerve anastomosis was performed on two patients. HB grade VI was recovered to HB grade V in one patient. The anastomosis failed due to severe facial nerve fibrosis in one patient. Hence, HB remained at grade VI. Postoperative recovery was good for all patients. No lesion recurrence was observed after 1-6 years of follow-up. For the patients with progressive or complete facial paralysis, imaging examination should be perfected in a timely manner. Furthermore, PBC, primary facial nerve tumors and other temporal bone space-occupying lesions should be eliminated. Lesions should be timely detected and proper intervention should be conducted, in order to reduce operation difficulty and complications, and increase the opportunity of facial nerve function reconstruction.

Radiological Study of the Carotid-Clival Window and Its Application in Endoscopic Endonasal Expanded Approaches.

PubMed

Pérez de San Román-Mena, Laila; Simal-Julián, Juan Antonio; Miranda-Lloret, Pablo; Sanromán-Álvarez, Pablo; Botella-Asunción, Carlos

2017-08-01

The surgical approach to the petrous apex (PA) and petroclival junction (PCJ) remains a challenge. The carotid-clival window (CCW) represents the widest window available to approach the PCJ from a mediolateral endoscopic route. Here we define the CCW radiologically in nonpathological conditions, to establish the anatomic variability of the PCJ, relate this variability to pneumatization patterns, and evaluate some technical concerns conditioned by the CCW. This was an analytical study of 10 multislice computed tomography scans from patients without SB pathology. Bilateral measures were taken at the roof and floor levels of the lacerum canal (LC) and its posterior projection over the PCJ (segments DE and QR). All measures were compared across different pneumatization patterns. The DE and QR lengths were found to be the most important measures affecting the width of the CCW. Wide variability was observed, with a mean DE length of 8.52 mm (range, 2.4-12.8 mm) at the LC floor level and a mean QR length of 9.11 mm (range, 4.3-13.1 mm) at the LC roof level. The presence of retrocarotid pneumatization was statistically significantly associated with longer DE and QR segments. No differences were found among other pneumatization patterns. The CCW varies widely among individuals. The presence of pneumatization behind the paraclival carotid represents an advantageous characteristic when planning an endoscopic approach to the PCJ. Copyright © 2017 Elsevier Inc. All rights reserved.

Climbing fibers mediate vestibular modulation of both "complex" and "simple spikes" in Purkinje cells.

PubMed

Barmack, N H; Yakhnitsa, V

2015-10-01

Climbing and mossy fibers comprise two distinct afferent paths to the cerebellum. Climbing fibers directly evoke a large multispiked action potential in Purkinje cells termed a "complex spike" (CS). By logical exclusion, the other class of Purkinje cell action potential, termed "simple spike" (SS), has often been attributed to activity conveyed by mossy fibers and relayed to Purkinje cells through granule cells. Here, we investigate the relative importance of climbing and mossy fiber pathways in modulating neuronal activity by recording extracellularly from Purkinje cells, as well as from mossy fiber terminals and interneurons in folia 8-10. Sinusoidal roll-tilt vestibular stimulation vigorously modulates the discharge of climbing and mossy fiber afferents, Purkinje cells, and interneurons in folia 9-10 in anesthetized mice. Roll-tilt onto the side ipsilateral to the recording site increases the discharge of both climbing fibers (CSs) and mossy fibers. However, the discharges of SSs decrease during ipsilateral roll-tilt. Unilateral microlesions of the beta nucleus (β-nucleus) of the inferior olive blocks vestibular modulation of both CSs and SSs in contralateral Purkinje cells. The blockage of SSs occurs even though primary and secondary vestibular mossy fibers remain intact. When mossy fiber afferents are damaged by a unilateral labyrinthectomy (UL), vestibular modulation of SSs in Purkinje cells ipsilateral to the UL remains intact. Two inhibitory interneurons, Golgi and stellate cells, could potentially contribute to climbing fiber-induced modulation of SSs. However, during sinusoidal roll-tilt, only stellate cells discharge appropriately out of phase with the discharge of SSs. Golgi cells discharge in phase with SSs. When the vestibularly modulated discharge is blocked by a microlesion of the inferior olive, the modulated discharge of CSs and SSs is also blocked. When the vestibular mossy fiber pathway is destroyed, vestibular modulation of ipsilateral CSs and

Nicergoline in the treatment of dizziness in elderly patients. A review.

PubMed

Felisati, G; Pignataro, O; Di Girolamo, A; Bruno, E; Alessandrini, M; Guidetti, G; Monzani, D; Beldi, A M; Mira, E; Benazzo, M; Pallestrini, E; Caligo, G; Casani, A; Battaglia, A

2004-01-01

In elderly patients, dizziness occurs very frequently with significant effects on the patient's life. Its frequency increases with age, and may arise from a variety of causes. Chronic dysequilibrium in elderly patients is most probably related to disturbances within the central nervous system, due either to altered neuronal functions or to an underlying vascular disease. Nicergoline, a drug used in the treatment of cognitive disturbances in geriatric patients, improves dizziness in elderly demented and non-demented patients. In a double blind,placebo controlled trial the drug improved (i) the severity of symptoms, measured by the dizziness assessment rating scale (DARS), (ii) the overall clinical conditions revealed by global impression scale, and (iii) the perceived quality of life estimated by the dizziness handicap inventory (DHI). These results indicate a possible positive effect also on posturographic measures. Moreover, the improvement occurred at no expense of the established strategy of postural control suggesting that the effect is mediated by a substitute compensatory mechanism allowing the patient to preserve consolidated postural strategies. The results of previous open clinical studies in about 3000 patients are in agreement with those findings. Overall, severity of symptoms decreased by 68 % (57 % in the control study). Globally, the results indicate a beneficial effect of nicergoline on symptoms related to balance disorders of central origin. Animal studies show that the drug displays a broad spectrum of actions on cellular and molecular mechanisms. Moreover, animal research specifically aimed at vestibular pathophysiology has revealed that nicergoline improves vestibular compensation in models of vestibular lesion. Chronic treatment with nicergoline improved the time-course of behavioral recovery in old rats after hemi-labyrinthectomy and counteracted the regulation of cholinergic receptors observed after lesion in old rats. Nicergoline interacts at

Role of skeletal muscle in ear development.

PubMed

Rot, Irena; Baguma-Nibasheka, Mark; Costain, Willard J; Hong, Paul; Tafra, Robert; Mardesic-Brakus, Snjezana; Mrduljas-Djujic, Natasa; Saraga-Babic, Mirna; Kablar, Boris

2017-10-01

The current paper is a continuation of our work described in Rot and Kablar, 2010. Here, we show lists of 10 up- and 87 down-regulated genes obtained by a cDNA microarray analysis that compared developing Myf5-/-:Myod-/- (and Mrf4-/-) petrous part of the temporal bone, containing middle and inner ear, to the control, at embryonic day 18.5. Myf5-/-:Myod-/- fetuses entirely lack skeletal myoblasts and muscles. They are unable to move their head, which interferes with the perception of angular acceleration. Previously, we showed that the inner ear areas most affected in Myf5-/-:Myod-/- fetuses were the vestibular cristae ampullaris, sensitive to angular acceleration. Our finding that the type I hair cells were absent in the mutants' cristae was further used here to identify a profile of genes specific to the lacking cell type. Microarrays followed by a detailed consultation of web-accessible mouse databases allowed us to identify 6 candidate genes with a possible role in the development of the inner ear sensory organs: Actc1, Pgam2, Ldb3, Eno3, Hspb7 and Smpx. Additionally, we searched for human homologues of the candidate genes since a number of syndromes in humans have associated inner ear abnormalities. Mutations in one of our candidate genes, Smpx, have been reported as the cause of X-linked deafness in humans. Our current study suggests an epigenetic role that mechanical, and potentially other, stimuli originating from muscle, play in organogenesis, and offers an approach to finding novel genes responsible for altered inner ear phenotypes.

Severe skull base osteomyelitis caused by Pseudomonas aeruginosa with successful outcome after prolonged outpatient therapy with continuous infusion of ceftazidime and oral ciprofloxacin: a case report.

PubMed

Conde-Díaz, Cristina; Llenas-García, Jara; Parra Grande, Mónica; Terol Esclapez, Gertrudis; Masiá, Mar; Gutiérrez, Félix

2017-02-21

Skull base osteomyelitis is an uncommon disease that usually complicates a malignant external otitis with temporal bone involvement. It affects predominantly diabetic and immunocompromised males and has a high mortality rate. Pseudomonas aeruginosa is the most common causative organism. Currently, there is no consensus about the best therapeutic option. Here we describe a case of severe skull base osteomyelitis caused by Pseudomonas aeruginosa with progressive palsy of cranial nerves that was successfully managed with prolonged outpatient continuous infusion of ceftazidime plus oral ciprofloxacin. A 69-year-old Caucasian man presented with dysphagia, headache, and weight loss. He complained of left earache and purulent otorrhea. Over the following weeks he developed progressive palsy of IX, X, VI, and XII cranial nerves and papilledema. A petrous bone computed tomography scan showed a mass in the left jugular foramen with a strong lytic component that expanded to the cavum. A biopsy was then performed and microbiological cultures grew Pseudomonas aeruginosa. After 6 weeks of parenteral antibiotic treatment, our patient was discharged and treatment was continued with a domiciliary continuous infusion of a beta-lactam through a peripherally inserted central catheter, along with an oral fluoroquinolone for 10 months. Both radiological and clinical responses were excellent. Skull base osteomyelitis is a life-threating condition; clinical suspicion and correct microbiological identification are key to achieve an accurate and timely diagnosis. Due to the poor outcome of Pseudomonas aeruginosa skull base osteomyelitis, prolonged outpatient parenteral antibiotic therapy administered by continuous infusion could be a valuable option for these patients.

Comparison of virtual monoenergetic and polyenergetic images reconstructed from dual-layer detector CT angiography of the head and neck.

PubMed

Neuhaus, Victor; Große Hokamp, Nils; Abdullayev, Nuran; Maus, Volker; Kabbasch, Christoph; Mpotsaris, Anastasios; Maintz, David; Borggrefe, Jan

2018-03-01

To compare the image quality of virtual monoenergetic images and polyenergetic images reconstructed from dual-layer detector CT angiography (DLCTA). Thirty patients who underwent DLCTA of the head and neck were retrospectively identified and polyenergetic as well as virtual monoenergetic images (40 to 120 keV) were reconstructed. Signals (± SD) of the cervical and cerebral vessels as well as lateral pterygoid muscle and the air surrounding the head were measured to calculate the CNR and SNR. In addition, subjective image quality was assessed using a 5-point Likert scale. Student's t-test and Wilcoxon test were used to determine statistical significance. Compared to polyenergetic images, although noise increased with lower keV, CNR (p < 0.02) and SNR (p > 0.05) of the cervical, petrous and intracranial vessels were improved in virtual monoenergetic images at 40 keV and virtual monoenergetic images at 45 keV were also rated superior regarding vascular contrast, assessment of arteries close to the skull base and small arterial branches (p < 0.0001 each). Compared to polyenergetic images, virtual monoenergetic images reconstructed from DLCTA at low keV ranging from 40 to 45 keV improve the objective and subjective image quality of extra- and intracranial vessels and facilitate assessment of vessels close to the skull base and of small arterial branches. • Virtual monoenergetic images greatly improve attenuation, while noise only slightly increases. • Virtual monoenergetic images show superior contrast-to-noise ratios compared to polyenergetic images. • Virtual monoenergetic images significantly improve image quality at low keV.

Closure of the middle ear with special reference to the development of the tegmen tympani of the temporal bone

PubMed Central

Rodríguez-Vázquez, José Francisco; Murakami, Gen; Verdugo-López, Samuel; Abe, Shin-ichi; Fujimiya, Mineko

2011-01-01

Closure of the middle ear is believed to be closely related to the evolutionary development of the mammalian jaw. However, few comprehensive descriptions are available on fetal development. We examined paraffin-embedded specimens of 20 mid-term human fetuses at 8–25 weeks of ovulation age (crown-rump length or CRL, 38–220 mm). After 9 weeks, the tympanic bone and the squamous part of the temporal bone, each of which was cranial or caudal to Meckel's cartilage, grew to close the lateral part of the tympanosquamosal fissure. At the same time, the cartilaginous tegmen tympani appeared independently of the petrous part of the temporal bone and resulted in the petrosquamosal fissure. Subsequently, the medial part of the tympanosquamosal fissure was closed by the descent of a cartilaginous inferior process of the tegmen tympani. When Meckel's cartilage changed into the sphenomandibular ligament and the anterior ligament of the malleus, the inferior process of the tegmen tympani interposed between the tympanic bone and the squamous part of the temporal bone, forming the petrotympanic fissure for the chorda tympani nerve and the discomalleolar ligament. Therefore, we hypothesize that, in accordance with the regression of Meckel's cartilage, the rapidly growing temporomandibular joint provided mechanical stress that accelerated the growth and descent of the inferior process of the tegmen tympani via the discomalleolar ligament. The usual diagram showing bony fissures around the tegmen tympani may overestimate the role of the tympanic bone in the fetal middle-ear closure. PMID:21477146

Middle infratemporal fossa less invasive approach for radical resection of parapharyngeal tumors: surgical microanatomy and clinical application.

PubMed

Nonaka, Yoichi; Fukushima, Takanori; Watanabe, Kentaro; Sakai, Jun; Friedman, Allan H; Zomorodi, Ali R

2016-01-01

Surgery of the infratemporal fossa (ITF) and parapharyngeal area presents a formidable challenge to the surgeon due to its anatomical complexity and limited access. Conventional surgical approaches to these regions were often too invasive and necessitate sacrifice of normal function and anatomy. To describe a less invasive transcranial extradural approach to ITF parapharyngeal lesions and to determine its advantages, 17 patients with ITF parapharyngeal neoplasms who underwent tumor resection via this approach were enrolled in the study. All lesions located in the ITF precarotid parapharyngeal space were resected through a small operative corridor between the trigeminal nerve third branch (V3) and the temporomandibular joint (TMJ). Surgical outcomes and postoperative complications were evaluated. Pathological diagnosis included schwannoma in eight cases, paraganglioma in two cases, gangliocytoma in two cases, carcinosarcoma in one case, giant cell tumor in one case, pleomorphic adenoma in one case, chondroblastoma in one case, and juvenile angiofibroma in one case. Gross total resection was achieved in 12 cases, near-total and subtotal resection were in 3 and 2 cases, respectively. The most common postoperative complication was dysphagia. Surgical exposure can be customized from minimal (drilling of retrotrigeminal area) to maximal (full skeletonization of V3, removal of all structures lying lateral to the petrous segment of internal carotid artery) according to tumor size and location. Since the space between the V3 and TMJ is the main corridor of this approach, the key maneuver is the anterior translocation of V3 to obtain an acceptable surgical field.

Microsurgical and Endoscopic Anatomy for Intradural Temporal Bone Drilling and Applications of the Electromagnetic Navigation System: Various Extensions of the Retrosigmoid Approach.

PubMed

Matsushima, Ken; Komune, Noritaka; Matsuo, Satoshi; Kohno, Michihiro

2017-07-01

The use of the retrosigmoid approach has recently been expanded by several modifications, including the suprameatal, transmeatal, suprajugular, and inframeatal extensions. Intradural temporal bone drilling without damaging vital structures inside or beside the bone, such as the internal carotid artery and jugular bulb, is a key step for these extensions. This study aimed to examine the microsurgical and endoscopic anatomy of the extensions of the retrosigmoid approach and to evaluate the clinical feasibility of an electromagnetic navigation system during intradural temporal bone drilling. Five temporal bones and 8 cadaveric cerebellopontine angles were examined to clarify the anatomy of retrosigmoid intradural temporal bone drilling. Twenty additional cerebellopontine angles were dissected in a clinical setting with an electromagnetic navigation system while measuring the target registration errors at 8 surgical landmarks on and inside the temporal bone. Retrosigmoid intradural temporal bone drilling expanded the surgical exposure to allow access to the petroclival and parasellar regions (suprameatal), internal acoustic meatus (transmeatal), upper jugular foramen (suprajugular), and petrous apex (inframeatal). The electromagnetic navigation continuously guided the drilling without line of sight limitation, and its small devices were easily manipulated in the deep and narrow surgical field in the posterior fossa. Mean target registration error was less than 0.50 mm during these procedures. The combination of endoscopic and microsurgical techniques aids in achieving optimal exposure for retrosigmoid intradural temporal bone drilling. The electromagnetic navigation system had clear advantages with acceptable accuracy including the usability of small devices without line of sight limitation. Copyright © 2017 Elsevier Inc. All rights reserved.

The accuracy of an electromagnetic navigation system in lateral skull base approaches.

PubMed

Komune, Noritaka; Matsushima, Ken; Matsuo, Satoshi; Safavi-Abbasi, Sam; Matsumoto, Nozomu; Rhoton, Albert L

2017-02-01

Image-guided optical tracking systems are being used with increased frequency in lateral skull base surgery. Recently, electromagnetic tracking systems have become available for use in this region. However, the clinical accuracy of the electromagnetic tracking system has not been examined in lateral skull base surgery. This study evaluates the accuracy of electromagnetic navigation in lateral skull base surgery. Cadaveric and radiographic study. Twenty cadaveric temporal bones were dissected in a surgical setting under a commercially available, electromagnetic surgical navigation system. The target registration error (TRE) was measured at 28 surgical landmarks during and after performing the standard translabyrinthine and middle cranial fossa surgical approaches to the internal acoustic canal. In addition, three demonstrative procedures that necessitate navigation with high accuracy were performed; that is, canalostomy of the superior semicircular canal from the middle cranial fossa, 1 cochleostomy from the middle cranial fossa, 2 and infralabyrinthine approach to the petrous apex. 3 RESULTS: Eleven of 17 (65%) of the targets in the translabyrinthine approach and five of 11 (45%) of the targets in the middle fossa approach could be identified in the navigation system with TRE of less than 0.5 mm. Three accuracy-dependent procedures were completed without anatomical injury of important anatomical structures. The electromagnetic navigation system had sufficient accuracy to be used in the surgical setting. It was possible to perform complex procedures in the lateral skull base under the guidance of the electromagnetically tracked navigation system. N/A. Laryngoscope, 2016 127:450-459, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Human bony labyrinth is an indicator of population history and dispersal from Africa

PubMed Central

Ponce de León, Marcia S.; Koesbardiati, Toetik; Weissmann, John David; Milella, Marco; Reyna-Blanco, Carlos S.; Suwa, Gen; Kondo, Osamu; Malaspinas, Anna-Sapfo; White, Tim D.; Zollikofer, Christoph P. E.

2018-01-01

The dispersal of modern humans from Africa is now well documented with genetic data that track population history, as well as gene flow between populations. Phenetic skeletal data, such as cranial and pelvic morphologies, also exhibit a dispersal-from-Africa signal, which, however, tends to be blurred by the effects of local adaptation and in vivo phenotypic plasticity, and that is often deteriorated by postmortem damage to skeletal remains. These complexities raise the question of which skeletal structures most effectively track neutral population history. The cavity system of the inner ear (the so-called bony labyrinth) is a good candidate structure for such analyses. It is already fully formed by birth, which minimizes postnatal phenotypic plasticity, and it is generally well preserved in archaeological samples. Here we use morphometric data of the bony labyrinth to show that it is a surprisingly good marker of the global dispersal of modern humans from Africa. Labyrinthine morphology tracks genetic distances and geography in accordance with an isolation-by-distance model with dispersal from Africa. Our data further indicate that the neutral-like pattern of variation is compatible with stabilizing selection on labyrinth morphology. Given the increasingly important role of the petrous bone for ancient DNA recovery from archaeological specimens, we encourage researchers to acquire 3D morphological data of the inner ear structures before any invasive sampling. Such data will constitute an important archive of phenotypic variation in present and past populations, and will permit individual-based genotype–phenotype comparisons. PMID:29610337

Human bony labyrinth is an indicator of population history and dispersal from Africa.

PubMed

Ponce de León, Marcia S; Koesbardiati, Toetik; Weissmann, John David; Milella, Marco; Reyna-Blanco, Carlos S; Suwa, Gen; Kondo, Osamu; Malaspinas, Anna-Sapfo; White, Tim D; Zollikofer, Christoph P E

2018-04-17

The dispersal of modern humans from Africa is now well documented with genetic data that track population history, as well as gene flow between populations. Phenetic skeletal data, such as cranial and pelvic morphologies, also exhibit a dispersal-from-Africa signal, which, however, tends to be blurred by the effects of local adaptation and in vivo phenotypic plasticity, and that is often deteriorated by postmortem damage to skeletal remains. These complexities raise the question of which skeletal structures most effectively track neutral population history. The cavity system of the inner ear (the so-called bony labyrinth) is a good candidate structure for such analyses. It is already fully formed by birth, which minimizes postnatal phenotypic plasticity, and it is generally well preserved in archaeological samples. Here we use morphometric data of the bony labyrinth to show that it is a surprisingly good marker of the global dispersal of modern humans from Africa. Labyrinthine morphology tracks genetic distances and geography in accordance with an isolation-by-distance model with dispersal from Africa. Our data further indicate that the neutral-like pattern of variation is compatible with stabilizing selection on labyrinth morphology. Given the increasingly important role of the petrous bone for ancient DNA recovery from archaeological specimens, we encourage researchers to acquire 3D morphological data of the inner ear structures before any invasive sampling. Such data will constitute an important archive of phenotypic variation in present and past populations, and will permit individual-based genotype-phenotype comparisons. Copyright © 2018 the Author(s). Published by PNAS.

Derivation of new diagnostic reference levels for neuro-paediatric computed tomography examinations in Switzerland.

PubMed

Wagner, Franca; Bize, Julie; Racine, Damien; Le Coultre, Regis; Francis, Verdun; Trueb, Philipp; Treier, Reto

2018-05-22

Definition of new national diagnostic reference levels (DRLs) for volume computed tomography dose index (CTDIvol) and dose length product (DLP) for neuro-paediatric CT examinations depending on the medical indication. Methods: Paediatric cranial CT data sets acquired between January 2013 and December 2016 were retrospectively collected between July 2016 and March 2017 from the eight largest university and cantonal hospitals that perform most of the neuro-paediatric CTs in Switzerland. A consensus review of CTDIvol and DLP was undertaken for the three defined anatomical regions: brain, facial bone and petrous bone; each with and without contrast medium application. All indications for cranial CT imaging in paediatrics were assigned to one of these three regions. Descriptive statistical analysis of the distribution of the median values for CTDIvol and DLP yielded minimum, maximum, 25th percentile (1st quartile), median (2nd quartile) and 75th percentile (3rd quartile). New DRLs for neuro-paediatric CT examinations in Switzerland were based on the 75th percentiles of the distributions of the median values of all eight centres. Where appropriate, values were rounded such that the DRLs increase or at least remain constant as the age of the patient increases. Results: Our results revealed DRLs for CTDIvol and DLP up to 20% lower than the DRLs used so far in Switzerland and elsewhere in Europe. Conclusions: This study provides Swiss neuro-paediatric CT DRL values to establish optimum conditions for paediatric cranial CT examinations. Periodic national updates of DRLs, following international comparisons, are essential. . Creative Commons Attribution license.

Pre-reconstruction of cervical-to-petrous internal carotid artery: An improved technique for treatment of vascular lesions involving internal carotid artery at the lateral skull base.

PubMed

Li, Fang-Da; Gao, Zhi-Qiang; Ren, Hua-Liang; Liu, Chang-Wei; Song, Xiao-Jun; Li, Yan-Feng; Zheng, Yue-Hong

2016-04-01

Reconstruction of the internal carotid artery (ICA) is an operative challenge for lesions involving the lateral skull base because of excessive blood loss, intraoperative cranial nerve injury, and difficulties in cerebral protection. Between January 2010 and October 2014, 9 patients with vascular lesions at the lateral skull base were treated with a "pre-reconstruction" technique, which means reconstruction of the ICA in advance of excising the lesions. All operations were technically successful with no mortality or strokes. The mean blood loss was 921 ± 210 mL. The mean total clamping time was 18 ± 5 minutes. Among the 5 patients without invasion of specific cranial nerves, no long-term sequelae occurred during the follow-up period ranging from 11 to 54 months. With less blood loss, slighter cranial nerve injuries, and shorter clamping time, the "pre-reconstruction" technique was safe and effective for the treatment of vascular lesions at the lateral skull base. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1562-E1567, 2016. © 2016 Wiley Periodicals, Inc.

Surgical considerations and safety of cochlear implantation in otitis media with effusion.

PubMed

Cevizci, Rasit; Dilci, Alper; Celenk, Fatih; Karamert, Recep; Bayazit, Yildirim

2018-06-01

To evaluate the effects of otitis media with effusion on surgical parameters, patient safety, perioperative and postoperative complications. Total 890 children who underwent cochlear implantation between 2006 and 2015 were included. The ages ranged from 12 months to 63 months (mean: 32 months). The patients were divided into two groups according to the presence or absence of otitis media with effusion; otitis media with effusion group and non-otitis media group. Of 890 children, 105 had otitis media with effusion prior to surgery. In non-otitis media with group, there were 785 children. The average duration of surgery was 60min (ranged from 28 to 75min) in non-otitis media group, and 90min (ranged from 50 to 135min) in otitis media with effusion group (p<0.05). Granulation tissue and edematous middle ear and mastoid mucosa were observed in all cases of otitis media with effusion during the surgery. There was no significant difference between the complications of groups with or without otitis media with effusion (p>0.05). In 5 of 105 patients, there was a ventilation tube inserted before cochlear implantation, which did not change the outcome of implantation. There is no need for surgical treatment for otitis media with effusion before implantation since otitis media with effusion does not increase the risks associated with cochlear implantation. Operation duration is longer in the presence of otitis media with effusion. However, otitis media with effusion leads to intraoperative difficulties like longer operation duration, bleeding, visualization of the round window membrane, cleansing the middle ear granulations as well as mastoid and petrous air cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Cost effective use of audiograms after pediatric temporal bone fractures.

PubMed

Frisenda, Julia L; Schroeder, James W; Ryan, Maura E; Valika, Taher S; Billings, Kathleen R

2015-11-01

To identify the relationship of pediatric temporal fractures to the incidence and type of hearing loss present. To analyze the timing and utility of audiometric testing in children with temporal bone fractures. Retrospective case series of 50 pediatric patients with temporal bone fractures who were treated at an urban, tertiary care children's hospital from 2008 to 2014. A statistical analysis of predictors of hearing loss after temporal bone fracture was performed. Fifty-three fractures (69.7%) in 50 patients involved the petrous portion of the temporal bone. The mean age of patients was 7.13 years, and 39 (73.6%) were male. A fall was the most common mechanism of injury in 28 (52.8%) patients, followed by crush injury (n=14, 26.2%), and vehicular trauma (n=10, 18.9%). All otic capsule violating fractures were associated with a sensorineural hearing loss (n=4, 7.5%, p=0.002). Three of four otic capsule sparing fractures were associated with ossicular dislocation, with a corresponding mixed or conductive hearing loss on follow up audiometric testing. The majority of otic capsule sparing fracture patients (n=19/43, 44.2%) who had follow up audiograms had normal hearing, and those with otic capsule violating fractures were statistically more likely to have persistent hearing loss than those with otic capsule sparing fractures (p=0.01). Patients with otic capsule violating fractures or those with ossicular disruption are at higher risk for persistent hearing loss. Cost-saving may be accrued by selecting only those patients at high risk for persistent hearing loss for audiometric testing after temporal bone fractures. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Lateral transzygomatic middle fossa approach and its extensions: surgical technique and 3D anatomy.

PubMed

Chotai, Silky; Kshettry, Varun R; Petrak, Alex; Ammirati, Mario

2015-03-01

Various approaches to lesions involving the middle fossa and cavernous sinus (CS), with and without posterior fossa extension have been described. In the present study, we describe the surgical technique for the extradural lateral tranzygomatic middle fossa approach and its extensions, highlight relevant 3D anatomy. Simulations of the lateral transzygomatic middle fossa approach and its extensions were performed in four silicon-injected formalin fixed cadaveric heads. The step-by-step description and relevant anatomy was documented with 3D photographs. The lateral transzygomatic middle fossa approach is particularly useful for lesions involving the middle fossa with and without CS invasion, extending to the posterior fossa and involving the clinoidal region. This approach incorporates direct lateral positioning of patient, frontotemporal craniotomy with zygomatic arch osteotomy, extradural elevation of the temporal lobe, and delamination of the outer layer of the lateral CS wall. Extradural drilling of the sphenoid wing and anterior clinoid process allows entry into the CS through the superior wall and exposure of the clinoidal segment of the ICA. Posteriorly, drilling the petrous apex allows exposure of the ventral brainstem from trigeminal to facial nerve and can be extended to the interpeduncular fossa by division of the superior petrosal sinus. The present study illustrates 3D anatomical relationships of the lateral transzygomatic middle fossa approach with its extensions. This approach allows wide access to different topographic areas (clinoidal region and clinoidal ICA, the entire CS, and the posterior fossa from the interpeduncular fossa to the facial nerve) via a lateral trajectory. Precise knowledge of technique and anatomy is necessary to properly execute this approach. Copyright © 2014 Elsevier B.V. All rights reserved.

Pathological Location of Cranial Nerves in Petroclival Lesions: How to Avoid Their Injury during Anterior Petrosal Approach.

PubMed

Borghei-Razavi, Hamid; Tomio, Ryosuke; Fereshtehnejad, Seyed-Mohammad; Shibao, Shunsuke; Schick, Uta; Toda, Masahiro; Yoshida, Kazunari; Kawase, Takeshi

2016-02-01

Objectives  Numerous surgical approaches have been developed to access the petroclival region. The Kawase approach, through the middle fossa, is a well-described option for addressing cranial base lesions of the petroclival region. Our aim was to gather data about the variation of cranial nerve locations in diverse petroclival pathologies and clarify the most common pathologic variations confirmed during the anterior petrosal approach. Method  A retrospective analysis was made of both videos and operative and histologic records of 40 petroclival tumors from January 2009 to September 2013 in which the Kawase approach was used. The anatomical variations of cranial nerves IV-VI related to the tumor were divided into several location categories: superior lateral (SL), inferior lateral (IL), superior medial (SM), inferior medial (IM), and encased (E). These data were then analyzed taking into consideration pathologic subgroups of meningioma, epidermoid, and schwannoma. Results  In 41% of meningiomas, the trigeminal nerve is encased by the tumor. In 38% of the meningiomas, the trigeminal nerve is in the SL part of the tumor, and it is in 20% of the IL portion of the tumor. In 38% of the meningiomas, the trochlear nerve is encased by the tumor. The abducens nerve is not always visible (35%). The pathologic nerve pattern differs from that of meningiomas for epidermoid and trigeminal schwannomas. Conclusion  The pattern of cranial nerves IV-VI is linked to the type of petroclival tumor. In a meningioma, tumor origin (cavernous, upper clival, tentorial, and petrous apex) is the most important predictor of the location of cranial nerves IV-VI. Classification of four subtypes of petroclival meningiomas using magnetic resonance imaging is very useful to predict the location of deviated cranial nerves IV-VI intraoperatively.

Bilateral tympanokeratomas (cholesteatomas) with bilateral otitis media, unilateral otitis interna and acoustic neuritis in a dog.

PubMed

Østevik, Liv; Rudlang, Kathrine; Holt Jahr, Tuva; Valheim, Mette; Njaa, Bradley Lyndon

2018-05-22

An aural cholesteatoma, more appropriately named tympanokeratoma, is an epidermoid cyst of the middle ear described in several species, including dogs, humans and Mongolian gerbils. The cyst lining consists of stratified, keratinizing squamous epithelium with central accumulation of a keratin debris. This case report describes vestibular ganglioneuritis and perineuritis in a dog with chronic otitis, bilateral tympanokeratomas and presumed extension of otic infection to the central nervous system. An 11-year-old intact male Dalmatian dog with chronic bilateral otitis externa and sudden development of symptoms of vestibular disease was examined. Due to the dog's old age the owner opted for euthanasia without any further examination or treatment and the dog was submitted for necropsy. Transection of the ears revealed grey soft material in the external ear canals and pearly white, dry material consistent with keratin in the tympanic bullae bilaterally. The brain and meninges were grossly unremarkable. Microscopical findings included bilateral otitis externa and media, unilateral otitis interna, ganglioneuritis and perineuritis of the spiral ganglion of the vestibulocochlear nerve and multifocal to coalescing, purulent meningitis. A keratinizing squamous epithelial layer continuous with the external acoustic meatus lined the middle ear compartments, consistent with bilateral tympanokeratomas. Focal bony erosion of the petrous portion of the temporal bone and squamous epithelium and Gram-positive bacterial cocci were evident in the left cochlea. The findings suggest that meningitis developed secondary to erosion of the temporal bone and ganglioneuritis and/or perineuritis of the vestibulocochlear nerve. Middle ear tympanokeratoma is an important and potentially life-threatening otic condition in the dog. Once a tympanokeratoma has developed expansion of the cyst can lead to erosion of bone and extension of otic infection to the inner ear, vestibulocochlear ganglion and

Transarterial Onyx embolization of intracranial dural arteriovenous fistulas: a single center experience.

PubMed

Luo, Chao-Bao; Chang, Feng-Chi; Mu-Huo Teng, Michael; Lin, Chung-Jung; Wu, Hsiu-Mei; Guo, Wan-Yuo; Chang, Cheng-Yen

2014-04-01

Transarterial embolization of intracranial dural arteriovenous fistulas (DAVFs) is usually associated with inadequate embolization. The purpose of this study was to report our experience of transarterial Onyx embolization of intracranial DAVFs with an emphasis on treatment outcome with this new embolic agent in different types of DAVFs. In the past 3 years, a total of 14 intracranial DAVFs have been treated by transarterial Onyx embolization. Among these, there were nine males and five females, aged from 30 years to 82 years (mean = 62 years). We retrospectively analyzed the injection volume and time of Onyx embolization as well as outcomes in different types of DAVFs. The locations of the DAVFs were sigmoid sinus (n = 6), tentorium (n = 3), sinus confluence (n = 2), transverse-sigmoid sinus (n = 1), sigmoid sinus-jugular bulb (n = 1) and the superior petrous sinus (n = 1). The mean volume and time of Onyx injection were 3.4 mL and 28 minutes, respectively (Cognard type I: 4.9 mL, 40 minutes; type II: 4.5 mL, 34 minutes; type III: 2.2 mL, 21 minutes; type IV: 2 mL, 22 minutes). Total fistula occlusion was achieved in six out of seven patients of type III and type IV DAVFs, and in four out of seven patients of type I and type II DAVFs. Nine patients had total resolution of their symptoms, whereas partial regression occurred in five patients. No significant periprocedural complication was found. Mean clinical follow-up period was 16 months. Transarterial Onyx embolization of intracranial DAVFs is safe and effective. This technique is particularly useful in type III and type IV DAVFs with a high cure rate, and lower volume of Onyx as well as a short injection time. Copyright © 2014. Published by Elsevier B.V.

Adaptive fractionated stereotactic Gamma Knife radiotherapy of meningioma using integrated stereotactic cone-beam-CT and adaptive re-planning (a-gkFSRT).

PubMed

Stieler, F; Wenz, F; Abo-Madyan, Y; Schweizer, B; Polednik, M; Herskind, C; Giordano, F A; Mai, S

2016-11-01

The Gamma Knife Icon (Elekta AB, Stockholm, Sweden) allows frameless stereotactic treatment using a combination of cone beam computer tomography (CBCT), a thermoplastic mask system, and an infrared-based high-definition motion management (HDMM) camera system for patient tracking during treatment. We report on the first patient with meningioma at the left petrous bone treated with adaptive fractionated stereotactic radiotherapy (a-gkFSRT). The first patient treated with Gamma Knife Icon at our institute received MR imaging for preplanning before treatment. For each treatment fraction, a daily CBCT was performed to verify the actual scull/tumor position. The system automatically adapted the planned shot positions to the daily position and recalculated the dose distribution (online adaptive planning). During treatment, the HDMM system recorded the intrafractional patient motion. Furthermore, the required times were recorded to define a clinical treatment slot. Total treatment time was around 20 min. Patient positioning needed 0.8 min, CBCT positioning plus acquisition 1.65 min, CT data processing and adaptive planning 2.66 min, and treatment 15.6 min. The differences for the five daily CBCTs compared to the reference are for rotation: -0.59 ± 0.49°/0.18 ± 0.20°/0.05 ± 0.36° and for translation: 0.94 ± 0.52 mm/-0.08 ± 0.08 mm/-1.13 ± 0.89 mm. Over all fractions, an intrafractional movement of 0.13 ± 0.04 mm was observed. The Gamma Knife Icon allows combining the accuracy of the stereotactic Gamma Knife system with the flexibility of fractionated treatment with the mask system and CBCT. Furthermore, the Icon system introduces a new online patient tracking system to the clinical routine. The interfractional accuracy of patient positioning was controlled with a thermoplastic mask and CBCT.

Enhanced, rapid occlusion of carotid and vertebral arteries using the AMPLATZER Vascular Plug II device: the Duke Cerebrovascular Center experience in 8 patients with 22 AMPLATZER Vascular Plug II devices.

PubMed

Mihlon, Frank; Agrawal, Abishek; Nimjee, Shahid M; Ferrell, Andrew; Zomorodi, Ali R; Smith, Tony P; Britz, Gavin W

2015-01-01

Therapeutic embolization of the common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA) is necessary in the treatment of a subset of chronic arteriovenous fistulas (AVFs), hemorrhages, highly vascularized neoplasms before resection, and giant aneurysms. There are currently no reports of the use of the AMPLATZER Vascular Plug II (AVP II) device to occlude the CCA, ICA, or VA. The objective of this article is to present the Duke Cerebrovascular Center experience using the AVP II device in neurointerventional applications. This case series is a retrospective review of all of the cases at Duke University Hospital in which an AVP II device was used in the CCA, ICA, or VA up to September 2012. The AVP II device was often used in conjunction with embolization coils or as multiple AVP II devices deployed in tandem. During 2010-2012, 8 cases meeting criteria were performed. These included 2 chronic VA to internal jugular AVFs, 1 hemorrhagic CCA to internal jugular AVF secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to trauma, 1 ruptured ICA aneurysm, 1 giant petrous ICA aneurysm, and 1 case of cervical vertebral sarcoma requiring preoperative VA embolization. Successful occlusion of the target vessel was achieved in all 8 cases. There was 1 major complication that consisted of a watershed distribution cerebral infarct; however, this was related to emergent occlusion of the ICA in the setting of intracranial hemorrhage and was not a problem intrinsic to the AVP II device. The AVP II device is relatively large, self-expanding vascular occlusion device that safely allows enhanced, rapid take-down of the CCA, ICA, and VA with low risk of distal migration. Copyright © 2015 Elsevier Inc. All rights reserved.

CT Scan of Thirteen Natural Mummies Dating Back to the XVI-XVIII Centuries: An Emerging Tool to Investigate Living Conditions and Diseases in History.

PubMed

Petrella, Enrico; Piciucchi, Sara; Feletti, Francesco; Barone, Domenico; Piraccini, Antonella; Minghetti, Caterina; Gruppioni, Giorgio; Poletti, Venerino; Bertocco, Mauro; Traversari, Mirko

2016-01-01

To correlate the radiologic findings detected with computed tomography scan with anthropological data in 13 naturally mummified bodies discovered during works of recovery of an ancient church in a crypt in Roccapelago, in the Italian Apennines. From a group of about sixty not-intentionally mummified bodies, thirteen were selected to be investigated with volumetric computed tomography (CT). Once CT scan was performed, axial images were processed to gather MPR and Volume Rendering reconstructions. Elaborations of these images provided anthropometric measurements and a non-invasive analysis of the residual anatomical structures. For each body the grade of preservation and the eventual pathological changes were recorded. Furthermore, in order to identify nutritional and occupational markers, radiologic signs of bone tropism and degenerative changes were analysed and graded. Mummies included seven females and six males, with an estimated age ranging from 20 to 60 years. The first relevant finding identified was a general low grade of preservation, due to the lack of anatomic tissues different from bones, tendons and dehydrated skin. The low grade of preservation was related to the natural process of mummification. Analysing bone degenerative changes on CT scan, the majority of the bodies had significant occupational markers consisting of arthritis in the spine, lower limbs and shoulders even in young age. Few were the pathological findings identified. Among these, the most relevant included a severe bilateral congenital hip dysplasia and a wide osteolytic lesion involving left orbit and petrous bone that was likely the cause of death. Although the low grade of preservation of these mummies, the multidisciplinary approach of anthropologists and radiologists allowed several important advances in knowledge for the epidemiology of Roccapelago. First of all, a profile of living conditions was delineated. It included occupational and nutritional conditions. Moreover

Horizontal vestibuloocular reflex evoked by high-acceleration rotations in the squirrel monkey. I. Normal responses

NASA Technical Reports Server (NTRS)

Minor, L. B.; Lasker, D. M.; Backous, D. D.; Hullar, T. E.; Shelhamer, M. J. (Principal Investigator)

1999-01-01

The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in five squirrel monkeys with intact vestibular function. The VOR evoked by steps of acceleration in darkness (3,000 degrees /s(2) reaching a velocity of 150 degrees /s) began after a latency of 7.3 +/- 1.5 ms (mean +/- SD). Gain of the reflex during the acceleration was 14.2 +/- 5.2% greater than that measured once the plateau head velocity had been reached. A polynomial regression was used to analyze the trajectory of the responses to steps of acceleration. A better representation of the data was obtained from a polynomial that included a cubic term in contrast to an exclusively linear fit. For sinusoidal rotations of 0.5-15 Hz with a peak velocity of 20 degrees /s, the VOR gain measured 0.83 +/- 0.06 and did not vary across frequencies or animals. The phase of these responses was close to compensatory except at 15 Hz where a lag of 5.0 +/- 0.9 degrees was noted. The VOR gain did not vary with head velocity at 0.5 Hz but increased with velocity for rotations at frequencies of >/=4 Hz (0. 85 +/- 0.04 at 4 Hz, 20 degrees /s; 1.01 +/- 0.05 at 100 degrees /s, P < 0.0001). No responses to these rotations were noted in two animals that had undergone bilateral labyrinthectomy indicating that inertia of the eye had a negligible effect for these stimuli. We developed a mathematical model of VOR dynamics to account for these findings. The inputs to the reflex come from linear and nonlinear pathways. The linear pathway is responsible for the constant gain across frequencies at peak head velocity of 20 degrees /s and also for the phase lag at higher frequencies being less than that expected based on the reflex delay. The frequency- and velocity-dependent nonlinearity in VOR gain is accounted for by the dynamics of the nonlinear pathway. A transfer function that increases the gain of this pathway with frequency and a term related to the third power of head

Magnetic resonance imaging of the inner ear by using a hybrid radiofrequency coil at 7 T

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Nam; Heo, Phil; Kim, Young-Bo; Han, Gyu-Cheol

2015-01-01

Visualization of the membranous structures of the inner ear has been limited to the detection of the normal fluid signal intensity within the bony labyrinth by using magnetic resonance imaging (MRI) equipped with a 1.5 Tesla (T) magnet. High-field (HF) MRI has been available for more than a decade, and numerous studies have documented its significant advantages over conventional MRI with regards to its use in basic scientific research and routine clinical assessments. No previous studies of the inner ear by using HF MRI have been reported, in part because high-quality resolution of mastoid pneumatization is challenging due to artifacts generated in the HF environment and insufficient performance of radiofrequency (RF) coils. Therefore, a hybrid RF coil with integrated circuitry was developed at 7 T and was targeted for anatomical imaging to achieve a high resolution image of the structure of the human inner ear, excluding the bony portion. The inner-ear's structure is composed of soft tissues containing hydrogen ions and includes the membranous labyrinth, endolymphatic space, perilymphatic space, and cochlear-vestibular nerves. Visualization of the inner-ear's anatomy was performed in-vivo with a custom-designed hybrid RF coil and a specific imaging protocol based on an interpolated breath-held examination sequence. The comparative signal intensity value at 30-mm away from the phantom side was 88% higher for the hybrid RF coil and 24% higher for the 8-channel transmit/receive (Tx/Rx) coil than for the commercial birdcage coil. The optimized MRI protocol employed a hybrid RF coil because it enabled high-resolution imaging of the inner-ear's anatomy and accurate mapping of structures including the cochlea and the semicircular canals. These results indicate that 7 T MRI achieves high spatial resolution visualization of the inner-ear's anatomy. Therefore, MRI imaging using a hybrid RF coil at 7 T could provide a powerful tool for clinical investigations of petrous

The pterygoclival ligament: a novel landmark for localization of the internal carotid artery during the endoscopic endonasal approach.

PubMed

Tayebi Meybodi, Ali; Little, Andrew S; Vigo, Vera; Benet, Arnau; Kakaizada, Sofia; Lawton, Michael T

2018-05-18

OBJECTIVE The transpterygoid extension of the endoscopic endonasal approach provides exposure of the petrous apex, Meckel's cave, paraclival area, and the infratemporal fossa. Safe and efficient localization of the lacerum segment of the internal carotid artery (ICA) is a crucial part of such exposure. The aim of this study is to introduce a novel landmark for localization of the lacerum ICA. METHODS Ten cadaveric heads were prepared for transnasal endoscopic dissection. The floor of the sphenoid sinus was drilled to expose an extension of the pharyngobasilar fascia between the sphenoid floor and the pterygoid process (the pterygoclival ligament). Several features of the pterygoclival ligament were assessed. In addition, 31 dry skulls were studied to assess features of the bony groove harboring the pterygoclival ligament. RESULTS The pterygoclival ligament was identified bilaterally during drilling of the sphenoid floor in all specimens. The ligament started a few millimeters posterior to the posterior end of the vomer alae and invariably extended posterolaterally and superiorly to blend into the fibrous tissue around the lacerum ICA. The mean length of the ligament was 10.5 ± 1.7 mm. The mean distance between the anterior end of the ligament and midline was 5.2 ± 1.2 mm. The mean distance between the posterior end of the ligament and midline was 12.3 ± 1.4 mm. The bony pterygoclival groove was identified at the confluence of the vomer, pterygoid process of the sphenoid, and basilar part of the occipital bone, running from posterolateral to anteromedial. The mean length of the groove was 7.7 ± 1.8 mm. Its posterolateral end faced the anteromedial aspect of the foramen lacerum medial to the posterior end of the vidian canal. A clinical case illustration is also provided. CONCLUSIONS The pterygoclival ligament is a consistent landmark for localization of the lacerum ICA. It may be used as an adjunct or alternative to the vidian nerve to localize the ICA during

Degradation of the Bragg peak due to inhomogeneities.

PubMed

Urie, M; Goitein, M; Holley, W R; Chen, G T

1986-01-01

The rapid fall-off of dose at the end of range of heavy charged particle beams has the potential in therapeutic applications of sparing critical structures just distal to the target volume. Here we explored the effects of highly inhomogeneous regions on this desirable depth-dose characteristic. The proton depth-dose distribution behind a lucite-air interface parallel to the beam was bimodal, indicating the presence of two groups of protons with different residual ranges, creating a step-like depth-dose distribution at the end of range. The residual ranges became more spread out as the interface was angled at 3 degrees, and still more at 6 degrees, to the direction of the beam. A second experiment showed little significant effect on the distal depth-dose of protons having passed through a mosaic of teflon and lucite. Anatomic studies demonstrated significant effects of complex fine inhomogeneities on the end of range characteristics. Monoenergetic protons passing through the petrous ridges and mastoid air cells in the base of skull showed a dramatic degradation of the distal Bragg peak. In beams with spread out Bragg peaks passing through regions of the base of skull, the distal fall-off from 90 to 20% dose was increased from its nominal 6 to well over 32 mm. Heavy ions showed a corresponding degradation in their ends of range. In the worst case in the base of skull region, a monoenergetic neon beam showed a broadening of the full width at half maximum of the Bragg peak to over 15 mm (compared with 4 mm in a homogeneous unit density medium). A similar effect was found with carbon ions in the abdomen, where the full width at half maximum of the Bragg peak (nominally 5.5 mm) was found to be greater than 25 mm behind gas-soft-tissue interfaces. We address the implications of these data for dose computation with heavy charged particles.

Cladistic analysis of extant and fossil African papionins using craniodental data.

PubMed

Gilbert, Christopher C

2013-05-01

This study examines African papionin phylogenetic history through a comprehensive cladistic analysis of extant and fossil craniodental morphology using both quantitative and qualitative characters. To account for the well-documented influence of allometry on the papionin skull, the general allometric coding method was applied to characters determined to be significantly affected by allometry. Results of the analyses suggest that Parapapio, Pliopapio, and Papio izodi are stem African papionin taxa. Crown Plio-Pleistocene African papionin taxa include Gorgopithecus, Lophocebus cf. albigena, Procercocebus, Soromandrillus (new genus defined herein) quadratirostris, and, most likely, Dinopithecus. Furthermore, S. quadratirostris is a member of a clade also containing Mandrillus, Cercocebus, and Procercocebus; ?Theropithecus baringensis is strongly supported as a primitive member of the genus Theropithecus; Gorgopithecus is closely related to Papio and Lophocebus; and Theropithecus is possibly the most primitive crown African papionin taxon. Finally, character transformation analyses identify a series of morphological transformations during the course of papionin evolution. The origin of crown African papionins is diagnosed, at least in part, by the appearance of definitive and well-developed male maxillary ridges and maxillary fossae. Among crown African papionins, Papio, Lophocebus, and Gorgopithecus are further united by the most extensive development of the maxillary fossae. The Soromandrillus/Mandrillus/Cercocebus/Procercocebus clade is diagnosed by upturned nuchal crests (especially in males), widely divergent temporal lines (especially in males), medially oriented maxillary ridges in males, medially oriented inferior petrous processes, and a tendency to enlarge the premolars as an adaptation for hard-object food processing. The adaptive origins of the genus Theropithecus appear associated with a diet requiring an increase in size of the temporalis, the optimal

Hearing loss in pediatric temporal bone fractures: Evaluating two radiographic classification systems as prognosticators.

PubMed

Bhindi, A; Carpineta, L; Al Qassabi, B; Waissbluth, S; Ywakim, R; Manoukian, J J; Nguyen, L H P

2018-06-01

Temporal bone fractures (TBF) are traditionally classified by their angle of fracture relative to the petrous ridge, and more recently by whether or not they violate the otic-capsule. This study compared rates of hearing loss (HL) and signs of otologic dysfunction among fracture types of both classification systems, within the pediatric population. Pediatric patients were retrospectively characterized from a previously identified cohort of TBF patients, diagnosed from 2000 to 2014. CT scans were reviewed and TBFs were classified first as longitudinal (L), transverse (T) or mixed (M), and then as otic-capsule sparing (OCS) or otic-capsule violating (OCV). Medical records were reviewed, and rates of HL and presenting signs were compared among L, T and M fractures, and OCS and OCV fractures. Forty-three patients with 47 TBFs met the inclusion criteria. Eighteen, 4 and 25 TBFs were classified as L, T and M fractures, respectively. Thirty-three and 9 were classified as OCS, and OCV, respectively. Among 24 cases of HL: 20, 3, and 1 were conductive HL (CHL), sensorineural HL (SNHL) and mixed HL, respectively. Two cases of SNHL were found among OCV fractures, with none in OCS fractures (estimated difference 0.22; 95% confidence interval 0.01-0.60). Similar rates of CHL were found across L, T and M fractures (range 36-50%), and across OCV and OCS fractures (range 42-44%). Hemotympanum was the most common presenting sign, found in 68% of TBFs and 80% of CHL cases. There were no significant differences in the incidence of signs or symptoms between fracture types. In our cohort, both the traditional and otic-capsule radiographic classification systems failed to predict the incidence of CHL and other otologic signs in the pediatric population. Though OCV fractures conferred an increased risk for developing SNHL, we found a lower incidence than anticipated given violation to the bony labyrinth. Copyright © 2018. Published by Elsevier B.V.

The cranial base of Australopithecus afarensis: new insights from the female skull

PubMed Central

Kimbel, William H.; Rak, Yoel

2010-01-01

Cranial base morphology differs among hominoids in ways that are usually attributed to some combination of an enlarged brain, retracted face and upright locomotion in humans. The human foramen magnum is anteriorly inclined and, with the occipital condyles, is forwardly located on a broad, short and flexed basicranium; the petrous elements are coronally rotated; the glenoid region is topographically complex; the nuchal lines are low; and the nuchal plane is horizontal. Australopithecus afarensis (3.7–3.0 Ma) is the earliest known species of the australopith grade in which the adult cranial base can be assessed comprehensively. This region of the adult skull was known from fragments in the 1970s, but renewed fieldwork beginning in the 1990s at the Hadar site, Ethiopia (3.4–3.0 Ma), recovered two nearly complete crania and major portions of a third, each associated with a mandible. These new specimens confirm that in small-brained, bipedal Australopithecus the foramen magnum and occipital condyles were anteriorly sited, as in humans, but without the foramen's forward inclination. In the large male A.L. 444-2 this is associated with a short basal axis, a bilateral expansion of the base, and an inferiorly rotated, flexed occipital squama—all derived characters shared by later australopiths and humans. However, in A.L. 822-1 (a female) a more primitive morphology is present: although the foramen and condyles reside anteriorly on a short base, the nuchal lines are very high, the nuchal plane is very steep, and the base is as relatively narrow centrally. A.L. 822-1 illuminates fragmentary specimens in the 1970s Hadar collection that hint at aspects of this primitive suite, suggesting that it is a common pattern in the A. afarensis hypodigm. We explore the implications of these specimens for sexual dimorphism and evolutionary scenarios of functional integration in the hominin cranial base. PMID:20855310

CT Scan of Thirteen Natural Mummies Dating Back to the XVI-XVIII Centuries: An Emerging Tool to Investigate Living Conditions and Diseases in History

PubMed Central

Petrella, Enrico; Piciucchi, Sara; Feletti, Francesco; Barone, Domenico; Piraccini, Antonella; Minghetti, Caterina; Gruppioni, Giorgio; Poletti, Venerino; Bertocco, Mauro; Traversari, Mirko

2016-01-01

Objectives To correlate the radiologic findings detected with computed tomography scan with anthropological data in 13 naturally mummified bodies discovered during works of recovery of an ancient church in a crypt in Roccapelago, in the Italian Apennines. Methods From a group of about sixty not-intentionally mummified bodies, thirteen were selected to be investigated with volumetric computed tomography (CT). Once CT scan was performed, axial images were processed to gather MPR and Volume Rendering reconstructions. Elaborations of these images provided anthropometric measurements and a non-invasive analysis of the residual anatomical structures. For each body the grade of preservation and the eventual pathological changes were recorded. Furthermore, in order to identify nutritional and occupational markers, radiologic signs of bone tropism and degenerative changes were analysed and graded. Results Mummies included seven females and six males, with an estimated age ranging from 20 to 60 years. The first relevant finding identified was a general low grade of preservation, due to the lack of anatomic tissues different from bones, tendons and dehydrated skin. The low grade of preservation was related to the natural process of mummification. Analysing bone degenerative changes on CT scan, the majority of the bodies had significant occupational markers consisting of arthritis in the spine, lower limbs and shoulders even in young age. Few were the pathological findings identified. Among these, the most relevant included a severe bilateral congenital hip dysplasia and a wide osteolytic lesion involving left orbit and petrous bone that was likely the cause of death. Conclusions Although the low grade of preservation of these mummies, the multidisciplinary approach of anthropologists and radiologists allowed several important advances in knowledge for the epidemiology of Roccapelago. First of all, a profile of living conditions was delineated. It included occupational and

Observations on the bony bridging of the jugular foramen in man.

PubMed

Dodo, Y

1986-02-01

The anatomical nature and pattern of incidence of bony bridging of the jugular foramen was investigated using 64 fetal crania aged nine months to term and 222 adult crania of Japanese. In addition, the region of the jugular foramen of an adult cadaver was carefully dissected in order to clarify the relationship between the cranial nerves passing through the jugular foramen and the intrajugular processes of the jugular foramen. The general conclusions concerning the anatomical nature of the bony bridging of the jugular foramen were as follows. (1) The intrajugular process of the temporal bone is situated posterior to the triangular depression (as described in Gray's Anatomy) of the petrous part. (2) The bony bridging of the jugular foramen is established by the contact of the intrajugular process of the temporal bone with the bony process of the occipital bone projecting either from just above the hypoglossal canal (Type I) or from posterior to the hypoglossal canal (Type III). (3) If both the processes of the occipital bone reach the intrajugular process of the temporal bone simultaneously, the jugular foramen is divided into three compartments. (4) In the case of Type I bridging, the anteromedial compartment transmits the glossopharyngeal nerve, while the posterolateral compartment gives passage to the vagus nerve, the accessory nerve and the internal jugular vein. (5) In the case of Type II bridging, the anteromedial compartment contains the glossopharyngeal, vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. (6) When tripartite division of the jugular foramen occurs, the anteromedial compartment transmits the glossopharyngeal nerve, the middle compartment contains the vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. Concerning the pattern of incidence of jugular foramen bridging in the Japanese fetal and adult cranial series, this is similar to that of the bony

Observations on the bony bridging of the jugular foramen in man.

PubMed Central

Dodo, Y

1986-01-01

The anatomical nature and pattern of incidence of bony bridging of the jugular foramen was investigated using 64 fetal crania aged nine months to term and 222 adult crania of Japanese. In addition, the region of the jugular foramen of an adult cadaver was carefully dissected in order to clarify the relationship between the cranial nerves passing through the jugular foramen and the intrajugular processes of the jugular foramen. The general conclusions concerning the anatomical nature of the bony bridging of the jugular foramen were as follows. (1) The intrajugular process of the temporal bone is situated posterior to the triangular depression (as described in Gray's Anatomy) of the petrous part. (2) The bony bridging of the jugular foramen is established by the contact of the intrajugular process of the temporal bone with the bony process of the occipital bone projecting either from just above the hypoglossal canal (Type I) or from posterior to the hypoglossal canal (Type III). (3) If both the processes of the occipital bone reach the intrajugular process of the temporal bone simultaneously, the jugular foramen is divided into three compartments. (4) In the case of Type I bridging, the anteromedial compartment transmits the glossopharyngeal nerve, while the posterolateral compartment gives passage to the vagus nerve, the accessory nerve and the internal jugular vein. (5) In the case of Type II bridging, the anteromedial compartment contains the glossopharyngeal, vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. (6) When tripartite division of the jugular foramen occurs, the anteromedial compartment transmits the glossopharyngeal nerve, the middle compartment contains the vagus and accessory nerves, and the posterolateral compartment transmits the internal jugular vein. Concerning the pattern of incidence of jugular foramen bridging in the Japanese fetal and adult cranial series, this is similar to that of the bony

Posterior inferior cerebellar artery aneurysms: Anatomical variations and surgical strategies

PubMed Central

Singh, Rohit K.; Behari, Sanjay; Kumar, Vijendra; Jaiswal, Awadhesh K.; Jain, Vijendra K.

2012-01-01

Context: Posterior inferior cerebellar artery (PICA) aneurysms are associated with multiple anatomical variations of the parent vessel. Complexities in their surgical clipping relate to narrow corridors limited by brain-stem, petrous-occipital bones, and multiple neurovascular structures occupying the cerebellomedullary and cerebellopontine cisterns. Aims: The present study focuses on surgical considerations during clipping of saccular PICA aneurysms. Setting and Design: Tertiary care, retrospective study. Materials and Methods: In 20 patients with PICA aneurysms, CT angiogram/digital substraction angiogram was used to correlate the site and anatomical variations of aneurysms located on different segments of PICA with the approach selected, the difficulties encountered and the final outcome. Statistical Analysis: Comparison of means and percentages. Results: Aneurysms were located on PICA at: vertebral artery/basilar artery (VA/BA)-PICA (n=5); anterior medullary (n=4); lateral medullary (n=3); tonsillomedullary (n=4); and, telovelotonsillar (n=4) segments. The Hunt and Hess grade distribution was I in 15; II in 2; and, III in 3 patients (mean ictus-surgery interval: 23.5 days; range: 3-150 days). Eight patients had hydrocephalus. Anatomical variations included giant, thrombosed aneurysms; 2 PICA aneurysms proximal to an arteriovenous malformation; bilobed or multiple aneurysms; low PICA situated at the foramen magnum with a hypoplastic VA; and fenestrated PICA. The approaches included a retromastoid suboccipital craniectomy (n=9); midline suboccipital craniectomy (n=6); and far-lateral approach (n=5). At a follow-up (range 6 months-2.5 years), 13 patients had no deficits (modified Rankin score (mRS) 0); 2 were symptomatic with no significant disability (mRS1); 1 had mild disability (mRS2); 1 had moderately severe disability (mRS4); and 3 died (mRS6). Three mortalities were caused by vasospasm (2) and, rupture of unclipped second VA-BA junctional aneurysm (1

Gamma Knife radiosurgery for posterior fossa meningiomas: a multicenter study.

PubMed

Sheehan, Jason P; Starke, Robert M; Kano, Hideyuki; Barnett, Gene H; Mathieu, David; Chiang, Veronica; Yu, James B; Hess, Judith; McBride, Heyoung L; Honea, Norissa; Nakaji, Peter; Lee, John Y K; Rahmathulla, Gazanfar; Evanoff, Wendi A; Alonso-Basanta, Michelle; Lunsford, L Dade

2015-06-01

Posterior fossa meningiomas represent a common yet challenging clinical entity. They are often associated with neurovascular structures and adjacent to the brainstem. Resection can be undertaken for posterior fossa meningiomas, but residual or recurrent tumor is frequent. Stereotactic radiosurgery (SRS) has been used to treat meningiomas, and this study evaluates the outcome of this approach for those located in the posterior fossa. At 7 medical centers participating in the North American Gamma Knife Consortium, 675 patients undergoing SRS for a posterior fossa meningioma were identified, and clinical and radiological data were obtained for these cases. Females outnumbered males at a ratio of 3.8 to 1, and the median patient age was 57.6 years (range 12-89 years). Prior resection was performed in 43.3% of the patient sample. The mean tumor volume was 6.5 cm(3), and a median margin dose of 13.6 Gy (range 8-40 Gy) was delivered to the tumor. At a mean follow-up of 60.1 months, tumor control was achieved in 91.2% of cases. Actuarial tumor control was 95%, 92%, and 81% at 3, 5, and 10 years after radiosurgery. Factors predictive of tumor progression included age greater than 65 years (hazard ratio [HR] 2.36, 95% CI 1.30-4.29, p = 0.005), prior history of radiotherapy (HR 5.19, 95% CI 1.69-15.94, p = 0.004), and increasing tumor volume (HR 1.05, 95% CI 1.01-1.08, p = 0.005). Clinical stability or improvement was achieved in 92.3% of patients. Increasing tumor volume (odds ratio [OR] 1.06, 95% CI 1.01-1.10, p = 0.009) and clival, petrous, or cerebellopontine angle location as compared with petroclival, tentorial, and foramen magnum location (OR 1.95, 95% CI 1.05-3.65, p = 0.036) were predictive of neurological decline after radiosurgery. After radiosurgery, ventriculoperitoneal shunt placement, resection, and radiation therapy were performed in 1.6%, 3.6%, and 1.5%, respectively. Stereotactic radiosurgery affords a high rate of tumor control and neurological preservation

Neuroimaging Evidence of a Bilateral Representation for Visually Presented Numbers.

PubMed

Grotheer, Mareike; Herrmann, Karl-Heinz; Kovács, Gyula

2016-01-06

The clustered architecture of the brain for different visual stimulus categories is one of the most fascinating topics in the cognitive neurosciences. Interestingly, recent research suggests the existence of additional regions for newly acquired stimuli such as letters (letter form area; LFA; Thesen et al., 2012) and numbers (visual number form area; NFA; Shum et al., 2013). However, neuroimaging methods thus far have failed to visualize the NFA in healthy participants, likely due to fMRI signal dropout caused by the air/bone interface of the petrous bone (Shum et al., 2013). In the current study, we combined a 64-channel head coil with high spatial resolution, localized shimming, and liberal smoothing, thereby decreasing the signal dropout and increasing the temporal signal-to-noise ratio in the neighborhood of the NFA. We presented subjects with numbers, letters, false numbers, false letters, objects and their Fourier randomized versions. A group analysis showed significant activations in the inferior temporal gyrus at the previously proposed location of the NFA. Crucially, we found the NFA to be present in both hemispheres. Further, we could identify the NFA on the single-subject level in most of our participants. A detailed analysis of the response profile of the NFA in two separate experiments confirmed the whole-brain results since responses to numbers were significantly higher than to any other presented stimulus in both hemispheres. Our results show for the first time the existence and stimulus selectivity of the NFA in the healthy human brain. This fMRI study shows for the first time a cluster of neurons selective for visually presented numbers in healthy human adults. This visual number form area (NFA) was found in both hemispheres. Crucially, numbers have gained importance for humans too recently for neuronal specialization to be established by evolution. Therefore, investigations of this region will greatly advance our understanding of learning and

[Squirrel monkey--an ideal primate (correction of prmate) model of space physiology].

PubMed

Matsunami, K

1997-06-01

to elucidate functions of the peripheral vestibular system. A transfer function was proposed to explain the behaviors of regular and irregular unit activity of vestibular nerve fibers. The physiologic characteristics of the second order vestibular neuron was investigated in combination of electrophysiological and micro-morphological way, with using WGA-HRP methods, in relation to somato-motor and eye movements. Interconnections between vestibular neurons and cerebellum, interstitial nucleus of Cajal, oculomotor nuclear complex, superior colliculus and cervical spinal cord were elucidated. In physiological field of the vestibular system, the vestibulo-ocular reflex is well studied and results obtained from the squirrel monkey experiments were reviewed. The squirrel monkey, particularly the Bolivian, is a unique animal in that it is vulnerable to motion sickness induced by visual-motion stimulation with phase mismatch of the two stimuli. Experimental results of labyrinthectomy or bilateral ablation of the maculae staticae led to the conclusion that both semicircular and otolith organs are involved in the genesis of space motion sickness. On the other hand, destruction of the area postrema, acknowledged as the vomiting center to chemical stimulants, produced controversial results. However, it must be pointed out that the a human subject underwent to resection of the area postrema, became insensitive to administration of apomorphine, a well known chemical stimulant of vomiting. Finally the experiments in space revealed the presence of at least two origins of caloric nystagmus, that is, attributable to convection and non-convection current of the endolymphatic fluid.

Procedures for restoring vestibular disorders

PubMed Central

Walther, Leif Erik

2005-01-01

This paper will discuss therapeutic possibilities for disorders of the vestibular organs and the neurons involved, which confront ENT clinicians in everyday practice. Treatment of such disorders can be tackled either symptomatically or causally. The possible strategies for restoring the body's vestibular sense, visual function and co-ordination include medication, as well as physical and surgical procedures. Prophylactic or preventive measures are possible in some disorders which involve vertigo (bilateral vestibulopathy, kinetosis, height vertigo, vestibular disorders when diving (Tables 1 (Tab. 1) and 2 (Tab. 2)). Glucocorticoid and training therapy encourage the compensation of unilateral vestibular loss. In the case of a bilateral vestibular loss, it is important to treat the underlying disease (e.g. Cogan's disease). Although balance training does improve the patient's sense of balance, it will not restore it completely. In the case of Meniere's disease, there are a number of medications available to either treat bouts or to act as a prophylactic (e.g. dimenhydrinate or betahistine). In addition, there are non-ablative (sacculotomy) as well as ablative surgical procedures (e.g. labyrinthectomy, neurectomy of the vestibular nerve). In everyday practice, it has become common to proceed with low risk therapies initially. The physical treatment of mild postural vertigo can be carried out quickly and easily in outpatients (repositioning or liberatory maneuvers). In very rare cases it may be necessary to carry out a semicircular canal occlusion. Isolated disturbances of the otolith function or an involvement of the otolith can be found in roughly 50% of labyrinth disturbances. A specific surgical procedure to selectively block the otolith organs is currently being studied. When an external perilymph fistula involving loss of perilymph is suspected, an exploratory tympanotomy involving also the round and oval window niches must be carried out. A traumatic rupture of

The bony labyrinth of the middle Pleistocene Sima de los Huesos hominins (Sierra de Atapuerca, Spain).

PubMed

Quam, Rolf; Lorenzo, Carlos; Martínez, Ignacio; Gracia-Téllez, Ana; Arsuaga, Juan Luis

2016-01-01

We performed 3D virtual reconstructions based on CT scans to study the bony labyrinth morphology in 14 individuals from the large middle Pleistocene hominin sample from the site of the Sima de los Huesos (SH) in the Sierra de Atapuerca in northern Spain. The Atapuerca (SH) hominins represent early members of the Neandertal clade and provide an opportunity to compare the data with the later in time Neandertals, as well as Pleistocene and recent humans more broadly. The Atapuerca (SH) hominins do not differ from the Neandertals in any of the variables related to the absolute and relative sizes and shape of the semicircular canals. Indeed, the entire Neandertal clade seems to be characterized by a derived pattern of canal proportions, including a relatively small posterior canal and a relatively large lateral canal. In contrast, one of the most distinctive features observed in Neandertals, the low placement of the posterior canal (i.e., high sagittal labyrinthine index), is generally not present in the Atapuerca (SH) hominins. This low placement is considered a derived feature in Neandertals and is correlated with a more vertical orientation of the ampullar line (LSCm < APA), posterior surface of the petrous pyramid (LSCm > PPp), and third part of the facial canal (LSCm < FC3). Some variation is present within the Atapuerca (SH) sample, however, with a few individuals approaching the Neandertal condition more closely. In addition, the cochlear shape index in the Atapuerca (SH) hominins is low, indicating a reduction in the height of the cochlea. Although the phylogenetic polarity of this feature is less clear, the low shape index in the Atapuerca (SH) hominins may be a derived feature. Regardless, cochlear height subsequently increased in Neandertals. In contrast to previous suggestions, the expanded data in the present study indicate no difference across the genus Homo in the angle of inclination of the cochlear basal turn (COs < LSCm). Principal components

Pediatric blunt cerebrovascular injury: the McGovern screening score.

PubMed

Herbert, Joseph P; Venkataraman, Sidish S; Turkmani, Ali H; Zhu, Liang; Kerr, Marcia L; Patel, Rajan P; Ugalde, Irma T; Fletcher, Stephen A; Sandberg, David I; Cox, Charles S; Kitagawa, Ryan S; Day, Arthur L; Shah, Manish N

2018-03-16

OBJECTIVE The objective of this study was to assess the incidence, diagnosis, and treatment of pediatric blunt cerebrovascular injury (BCVI) at a busy Level 1 trauma center and to develop a tool for accurately predicting pediatric BCVI and the need for diagnostic testing. METHODS This is a retrospective cohort study of a prospectively collected database of pediatric patients who had sustained blunt trauma (patient age range 0-15 years) and were treated at a Level 1 trauma center between 2005 and 2015. Digital subtraction angiography, MR angiography, or CT angiography was used to confirm BCVI. Recently, the Utah score has emerged as a screening tool specifically targeted toward evaluating BCVI risk in the pediatric population. Using logistical regression and adding mechanism of injury as a logit, the McGovern score was able to use the Utah score as a starting point to create a more sensitive screening tool to identify which pediatric trauma patients should receive angiographic imaging due to a high risk for BCVI. RESULTS A total of 12,614 patients (mean age 6.6 years) were admitted with blunt trauma and prospectively registered in the trauma database. Of these, 460 (3.6%) patients underwent angiography after blunt trauma: 295 (64.1%), 107 (23.3%), 6 (1.3%), and 52 (11.3%) patients underwent CT angiography, MR angiography, digital subtraction angiography, and a combination of imaging modalities, respectively. The BCVI incidence (n = 21; 0.17%) was lower than that in a comparable adult group (p < 0.05). The mean patient was age 10.4 years with a mean follow-up of 7.5 months. Eleven patients (52.4%) were involved in a motor vehicle collision, with a mean Glasgow Coma Scale score of 8.6. There were 8 patients (38.1%) with carotid canal fracture, 6 patients (28.6%) with petrous bone fracture, and 2 patients (9.5%) with infarction on initial presentation. Eight patients (38.1%) were managed with observation alone. The Denver, modified Memphis, Eastern Association for the

MS Non-Pharmacological Countermeasure to Decrease Landing Sickness and Improve Functional Performance While Disorientad

NASA Technical Reports Server (NTRS)

Rosenberg, M. J. F.; Kreutzberg, G. A.; Galvan-Garza, R. C.; Mulavara, A. P.; Reschke, M. F.

2017-01-01

Upon return from spaceflight, a majority of crewmembers experience motion sickness (MS) symptoms. The interactions between crewmembers' adaptation to a gravitational transition, the performance decrements resulting from MS and/or use of promethazine (PMZ), and the constraints imposed by mission task demands could significantly challenge and limit an astronaut's ability to perform functional tasks during gravitational transitions. No operational countermeasure currently exists to mitigate the risks associated with these sensorimotor disturbances. Stochastic resonance (SR) can be thought of simply as "noise benefit" or an increase in information transfer by a system when in the presence of a non-zero level of noise. We have shown that low levels of stochastic vestibular stimulation (SVS) improve balance and locomotor performance due to SR (Goel et al. 2015, Mulavara et al. 2011, 2015). Additionally, a study in a 6-hydroxydopamine (6-OHDA) hemi-lesioned rat model of Parkinson's disease demonstrated improvements in locomotor activity after low-level SVS delivery possibly due to an increase in nigral gamma-aminobutyric acid (GABA) release in a dopamine independent way (Samoudi et al. 2012). SVS specifically increased GABA release on the lesioned, but not the intact side. These results suggest that SVS can cause targeted alterations of GABA release to affect performance of functional tasks. Activation of the GABA pathway is important in modulating MS and promoting adaptability (Cohen 2008). Magnusson et al. (2000) supported this finding by showing that the administration of a GABAB agonist caused a reversal of the symptoms that is normally seen after unilateral labyrinthectomy. Thus, GABA could play a significant role in reducing MS and promoting adaptability. We have taken advantage of the SR mechanism as a modulator of neurotransmitters to develop a unique SVS countermeasure system to mitigate MS symptoms and improve functional performance after landing. Healthy

Adaptive Changes In Postural Equilibrium And Motion Sickness Following Repeated Exposures To Virtual Environments

NASA Technical Reports Server (NTRS)

Harm, D. L.; Taylor, L. C.

2006-01-01

Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Changes in the environmental sensory stimulus conditions and the way we interact with the new stimuli may result in motion sickness, and perceptual, spatial orientation and sensorimotor disturbances. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. Adaptation is revealed by aftereffects including perceptual disturbances and sensorimotor control disturbances. The purpose of the current study was to compare disturbances in postural control produced by dome and head-mounted virtual environment displays, and to examine the effects of exposure duration, and repeated exposures to VR systems. Forty-one subjects (21 men, 20 women) participated in the study with an age range of 21-49 years old. One training session was completed in order to achieve stable performance on the posture and VR tasks before participating in the experimental sessions. Three experimental sessions were performed each separated by one day. The subjects performed a navigation and pick and place task in either a dome or head-mounted display