Search results for "Cochlear Nerve"
showing 10 items of 15 documents
MRI and neurophysiology in vestibular paroxysmia: contradiction and correlation
2013
Background Vestibular paroxysmia (VP) is defined as neurovascular compression (NVC) syndrome of the eighth cranial nerve (N.VIII). The aim was to assess the sensitivity and specificity of MRI and the significance of audiovestibular testing in the diagnosis of VP. Methods 20 VP patients and, for control, 20 subjects with trigeminal neuralgia (TN) were included and underwent MRI (constructive interference in steady-state, time-of-flight MR angiography) for detection of a NVC between N.VIII and vessels. All VP patients received detailed audiovestibular testing. Results A NVC of N.VIII could be detected in all VP patients rendering a sensitivity of 100% and a specificity of 65% for the diagnosi…
Seventh nerve palsies may be the only clinical sign of small pontine infarctions in diabetic and hypertensive patients
2002
Backgroud: Small brainstem infarctions are increasingly recognized as a cause of isolated ocular motor and vestibular nerve palsies in diabetic and/or hypertensive patients. This raises the question whether there are also isolated 7th nerve palsies due to pontine infarctions in patients with such risk factors for the development of cerebrovascular diseases. Methods: Over an 11-year-period, we retrospectively identified 10 diabetic and/or hypertensive patients with isolated 7th nerve palsies and electrophysiological abnormalities indicating pontine dysfunction. All patients had examinations of masseter and blink reflexes, brainstem auditory evoked potentials, direct current electro-oculograp…
The location by early auditory evoked potentials (EAEP) of acoustic nerve and brainstem demyelination in multiple sclerosis (MS).
1980
Tone pips of suprathreshold intensities elicit an acoustic nerve response (I) and six low amplitude brainstem potentials (II-VII) during the initial 10 ms. Seven waves were studied in 40 control subjects and 5 waves (I-V) in 47 patients with MS. The results suggest involvement of the auditory pathway of 24 of 27 patients in the clinically "definite", of 5 of 9 cases in the "probable" and in none of 5 patients in the "possible" MS groups. EAEPs were normal in 6 cases with a spinal form with one exception where changes of potential were indicative of a midbrain lesion. Dysfunction within the acoustic pathway was observed at the level of the acoustic nerve and in the medulla oblongata, pons an…
Radiosurgery as Treatment for Acoustic Neuroma. Ten Years’ Experience
2013
The acoustic neuroma is a benign tumour that usually affects the vestibular portion of the vestibulocochlear nerve. It represents 8% of all intracranial tumours and 80% of those arising at the cerebellopontine angle. There are 3 treatment options: microsurgery (the technique of choice), radiosurgery and observation. The objective of the study was to evaluate the results and side effects obtained using radiosurgery as treatment for acoustic neuroma.We performed a review of all patients treated with radiosurgery (Gamma Knife and linear accelerator) at doses of 1200-1300 cGy for unilateral acoustic neuroma in our hospital from January 1999 until January 2010. In all patients we evaluated the o…
The brainstem efferent acoustic chiasm in pigmented and albino rats
2015
Abstract The present study examined whether structural peculiarities in the brain-efferent pathway to the organ of Corti may underlie functional differences in hearing between pigmented and albino individuals of the same mammalian species. Pigmented Brown-Norway rats and albino Wistar rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani of the cochlea to identify olivocochlear neurons (OCN) in the brainstem superior olivary complex. After five days, brains were perfusion-fixed and brainstem sections were cut and analyzed with respect to retrogradely labeled neurons. Intrinsic neurons of the lateral system were lo…
Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.
2009
OBJECTIVE: We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. METHODS: 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…
Mathematical Model Predicts Clinical Ocular Motor Syndromes
2003
: Clinical ocular motor syndromes were compared with ocular motor syndromes simulated by a mathematical model of the vestibuloocular reflex. The mathematical sensorimotor feedforward model of otolith control of three-dimensional binocular eye position is based on relevant anatomical connections of the vestibuloocular reflex from the utricles to extraocular eye muscles. This is the first attempt to simulate static ocular motor syndromes for unilateral utricular or vestibular nerve failure, lesions of the vestibular nucleus, and lesions of the ascending vestibuloocular reflex pathways. Comparison of the predicted syndromes with those found in patients with unilateral disorders of the vestibul…
Auditory Neuropathy in Children
2001
Auditory neuropathy is a sensorineural disorder characterized by absent or abnormal auditory brainstem evoked potentials and normal cochlear outer hair cell function. A variety of processes is thought to be involved in its pathophysiology and their influence on hearing may be different. We present here the diagnostic sequence and management of two new cases of auditory neuropathy in breastfeeding children.
E-ABR in Patients with Cochlear Implant: A Comparison between Patients with Malformed Cochlea and Normal Cochlea
2019
Objectives This study aims to compare the electrical auditory brainstem response (EABR) following cochlear implant (CI) surgery in pediatric subjects with cochlear malformation and a normal cochlea, in order to assess the sensitivity of EABR and to evaluate the surgery outcome. Materials and methods A total of 26 pediatric subjects who were deaf and scheduled for CI surgery were enrolled into this case control study. Group A (n=20) included subjects with a normo-conformed cochlea. Group B (n=6) included subjects with cochlear malformation. Subjects were evaluated with EABR immediately (T0) and 6 months (T1) post-CI surgery. The EABR Waves III and V average amplitude and latency were compare…
Tinnitus e ipertensione neurogena da conflitto neurovascolare: descrizione di un caso
2008
The term neurovascular conflict (NVC) has been introduced to describe the anatomic situation where a nerve makes contact with a blood vessel, artery or vein, at the exit zone from the brain’s trunk. The NVC between the VIII nerve and a blood vessel is clinically associated with tinnitus, vertigo (disabling positional vertigo, DPV), and unilateral sensorineural hearing loss. The blood vessels which most frequently make contact with the VIII nerve are the anterior-inferior cerebellar artery, then the posterior-inferior cerebellar artery and the basilar artery. The authors present an unusual case in which both vertebral arteries (one of which crosses the midline) create a NVC with left acousti…