No abstract available.
Functional Neuroimaging ; Neurotology

Vestibular stimulation by air-conducted sound (ACS), bone-conducted vibration (BCV), or electrical currents (galvanic stimulation) elicits vestibular evoked myogenic potentials (VEMPs) that are now widely used to assess otolith function. Conventional cervical VEMPs, which are a manifestation of the vestibulocollic reflex, measure electromyographic activity from surface electrodes placed over the tonically activated sternocleidomastoid muscles. VEMPs can also be recorded from the extraocular muscles using surface electrodes placed over the inferior oblique and inferior rectus muscles, known as ocular VEMPs (oVEMPs). oVEMPs are a manifestation of the vestibulo-ocular pathways. We describe herein the neurophysiological properties of VEMPs obtained in response to ACS and BCV stimulation, and outline the known characteristics of VEMPs in central and peripheral disorders commonly encountered in neuro-otology clinics.
Electrodes ; Muscles ; Neurotology ; Otolithic Membrane ; Reflex ; Saccule and Utricle ; Vestibular Evoked Myogenic Potentials ; Vibration

BACKGROUND AND OBJECTIVES: Chronic recurrent attacks of vertigo, not associated with any auditory or neurological symptoms, are a common reason for referral to our neurotology clinic. Even after an extensive neurotological evaluation, some cases remain undiagnosed. We have performed this study to assess the prevalence of migraine in patients with idiopathic isolated recurrent vertigo as compared with controls, and to identify the clinical features and abnormalities of vestibular testing in patients with isolated recurrent vertigo. MATERIALS AND METHODS: We prospectively evaluated 72 consecutive patients who presented to the clinic with isolated recurrent vertigo of unknown cause. All patients underwent diagnostic evaluation to exclude identifiable causes of isolated recurrent vertigo. We compared the prevalence of migraine, according to the International Headache Society (IHS) criteria, in the isolated recurrent vertigo group, with a sex- and age-matched control group of orthopaedic patients. RESULTS: The prevalence of migraine according to IHS criteria was higher in the isolated recurrent vertigo group (61.1 %) than in the control group (10 %; p<0.01). Only 16.7 % of patients had an abnormal vestibular function test. The most common abnormal finding was a unilateral vestibular weakness to caloric stimulation. CONCLUSIONS: Our results suggest that migraine should be considered in the differential diagnosis of isolated recurrent vertigo of unknown cause.
Diagnosis, Differential ; Headache ; Humans ; Migraine Disorders* ; Neurotology ; Prevalence ; Prospective Studies ; Referral and Consultation ; Vertigo* ; Vestibular Function Tests

This paper presents diagnostic criteria for Meniere's disease jointly formulated by the Classification Committee of the Barany Society, The Japan Society for Equilibrium Research, the European Academy of Otology and Neurotology, the Equilibrium Committee of the American Academy of Otolaryngology-Head and Neck Surgery, and the Korean Balance Society. The classification includes two categories: definite Meniere's disease and probable Meniere's disease. The diagnosis of definite Meniere's disease is based on clinical criteria and requires the observation of an episodic vertigo syndrome associated with low- to medium- frequency sensorineural hearing loss and fluctuating aural symptoms (hearing, tinnitus and/or fullness) in the affected ear. Duration of vertigo episodes is limited to a period between 20 minutes and 12 hours. Probable Meniere's disease is a broader concept defined by episodic vestibular symptoms (vertigo or dizziness) associated with fluctuating aural symptoms occurring in a period from 20 minutes to 24 hours.
Classification ; Diagnosis ; Ear ; Hearing Loss, Sensorineural ; Japan ; Meniere Disease ; Neck ; Neurotology ; Otolaryngology ; Tinnitus ; Vertigo

Patients with recurrent vertigo/dizziness or unsteadiness are a heterogeneous group of complex disorders affecting the peripheral and central vestibular system. They represent a diagnostic challenge for the clinicians, and their genetic basis is largely not known. However, there are some cerebellar and vestibular disorders with a strong genetic background, such as episodic ataxia, spinocerebellar ataxia, vestibular migraine, Meniere's disease, and autosomal dominant nonsyndromic deafness. Furthermore, recent advances in next generation sequencing technique are increasing the number of novel genes associated with cerebellar and vestibular disorders. In this article, we have summarized clinical and molecular genetics findings in neuro-otology.
Ataxia ; Cerebellar Ataxia ; Deafness ; Dizziness ; Humans ; Meniere Disease ; Migraine Disorders ; Molecular Biology ; Neurotology ; Spinocerebellar Ataxias

Cerebellar stroke is a common cause of a vascular vestibular syndrome. Although vertigo ascribed to cerebellar stroke is usually associated with other neurological symptoms or signs, it may mimic acute peripheral vestibulopathy (APV), so called pseudo-APV. The most common pseudo-APV is a cerebellar infarction in the territory of the medial branch of the posterior inferior cerebellar artery (PICA). Recent studies have shown that a normal head impulse result can differentiate acute medial PICA infarction from APV. Therefore, physicians who evaluate stroke patients should be trained to perform and interpret the results of the head impulse test. Cerebellar infarction in the territory of the anterior inferior cerebellar artery (AICA) can produce a unique stroke syndrome in that it is typically accompanied by unilateral hearing loss, which could easily go unnoticed by patients. The low incidence of vertigo associated with infarction involving the superior cerebellar artery distribution may be a useful way of distinguishing it clinically from PICA or AICA cerebellar infarction in patients with acute vertigo and limb ataxia. For the purpose of prompt diagnosis and adequate treatment, it is imperative to recognize the characteristic patterns of the clinical presentation of each cerebellar stroke syndrome. This paper provides a concise review of the key features of cerebellar stroke syndromes from the neuro-otology viewpoint.
Arteries ; Ataxia ; Head ; Hearing Loss ; Hearing Loss, Unilateral ; Humans ; Hydrazines ; Incidence ; Infarction ; Neurotology ; Pica ; Stroke ; Vertigo ; Vestibular Neuronitis

Neuro-otologic symptoms such as dizziness, hearing loss, or tinnitus give rise to peripheral change-induced neuroplasticity or central pathology-induced structural or functional changes. In this regard, functional neuroimaging modalities such as positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), quantitative electroencephalography (qEEG), or functional near infrared spectroscopy have provided researchers with possibility to observe neuro-otologic disease-induced central functional changes. Among these methods, PET and fMRI are advantageous over qEEG or MEG with regard to spatial resolution, while qEEG and MEG are advantageous over PET or fMRI with regard to temporal resolution. Also, fMRI or MEG is not suitable for patients with implanted devices, whereas PET is not ideal for repetitive measures due to radiation hazard. In other words, as these modalities are complementary to one another, researchers should choose optimum imaging modality on a case by case basis. Hereinafter, representative functional neuroimaging modalities and their application to neuro-otologic research will be summarized.
Dizziness ; Electroencephalography ; Functional Neuroimaging ; Hearing Loss ; Humans ; Magnetic Resonance Imaging ; Magnetoencephalography ; Neuronal Plasticity ; Neurotology ; Positron-Emission Tomography ; Spectrum Analysis ; Tinnitus