Chronic inflammatory demyelinating polyneuropathy: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials.

PURPOSE: To investigate the possibility of vestibular damage in a group of patients suffering from chronic inflammatory demyelinating polyneuropathy (CIDP) using a diagnostic protocol including the caloric test, C-VEMPs and O-VEMPs. METHODS: Twenty patients suffering from CIDP (mean age 58.5 years, range 33-80 years; 4 women and 16 men) were investigated. To assess any eventual audio-vestibular involvement, all patients of the study underwent pure tone audiometry, Fitzgerald-Hallpike caloric vestibular test, C-VEMPs and O-VEMPs. RESULTS: In 11 patients with CIDP values of both O-VEMPs and C-VEMPs were either absent or abnormal. An absent trace at O-VEMPs testing occurred in 36% of these pathological patients, whereas an increase of n10 latency and amplitude was present in the other 64% . CONCLUSIONS: A specific diagnostic protocol including the caloric test, C-VEMPS, O-VEMPS, could be useful when employed for identifying vestibular damage in CIDP patients.

A 1-year follow-up study with C-VEMPs, O-VEMPs and video head impulse testing in vestibular neuritis.

The aim of this paper was to evaluate prospectively, in a group of patients affected by VN, a diagnostic protocol employing C-VEMPs, O-VEMPs and vHIT together. The diagnosis of vestibular neurolabyrinthitis was based on the clinical history, absence of associated auditory or neurological symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function using the Fitzgerald-Hallpike caloric vestibular test and ice test. Our series revealed an incidence of 55% of superior and inferior vestibular neurolabyrinthitis, 40% of superior vestibular neurolabyrinthitis and 5% of inferior vestibular neurolabyrinthitis. These data, however, comprised different degrees of vestibular involvement considering the evaluation of each single vestibular end-organ with potential different prognosis. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves. The implementation of C-VEMPs, O-VEMPs and vHIT in a vestibular diagnostic protocol has made possible to observe patients with ampullary VN, unidentifiable with other types of vestibular exams. The effect of age seems to have some impact on the recovery. When recovery firstly involves the utricular and saccular nerves and subsequently the ampullary nerves, it may be reasonable to expect a more favorable and successful outcome.

Vestibular neurolabyrinthitis: a follow-up study with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test.

OBJECTIVES: The aim of this study was to evaluate prospectively, in a group of patients affected by vestibular neurolabyrinthitis (VN), a diagnostic protocol including cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and the video head impulse test (vHIT). METHODS: The diagnosis of VN was based on the patient's clinical history, an absence of associated auditory or neurologic symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function by use of the Fitzgerald-Hallpike caloric vestibular test and the ice test. RESULTS: In our series, 55% of the cases were superior and inferior VN, 40% were superior VN, and 5% were inferior VN. These cases, however, comprised different degrees of vestibular involvement, as the individual vestibular end organs have different prognoses. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves. CONCLUSIONS: The implementation of C-VEMPs, O-VEMPs, and the vHIT in a vestibular diagnostic protocol has made it possible to observe patients with ampullary VN in a way that has not been feasible with other types of vestibular examinations. The age of the patient seems to have some impact on recovery from VN. When recovery occurs in the utricular and saccular nerves first and in the ampullary nerves subsequently, it may be reasonable to expect a more favorable outcome.

Selective vestibular neurolabyrinthitis of the lateral and superior semicircular canal ampulla and ampullary nerves.

OBJECTIVES: The diagnosis of vestibular neurolabyrinthitis is based on the sudden appearance of vertigo that lasts for hours or days without associated cochlear or central nervous system signs or symptoms. The advent of the video head impulse test, cervical vestibular evoked myogenic potential testing, and ocular vestibular evoked myogenic potential testing has provided interesting clinical evidence for evaluating and monitoring the damage to specific compartments of the vestibular apparatus. These various methods of testing individual end-organ functions may have a clinical impact on the vestibular workup of neurolabyrinthitis. METHODS: This report describes 3 patients with acute vestibular neurolabyrinthitis in whom caloric tests, cervical vestibular evoked myogenic potentials, ocular vestibular evoked myogenic potentials, and the video head impulse test led to a suspicion of peripheral vestibular deficits of the lateral or superior semicircular canal ampulla or ampullary nerves. RESULTS: In our patients, the examination results (normal hearing, absence of responses on caloric testing, and bilateral preservation of cervical and ocular vestibular evoked myogenic potentials) disclosed an acute partial superior vestibular neurolabyrinthitis. CONCLUSIONS: To our knowledge, these are the first reported cases in which selective damage to the lateral and superior semicircular canals and their nerves caused by neurolabyrinthitis was demonstrated clinically. Our clinical results indicate that the damage can be selective for specific vestibular end organs.

Focal epileptic seizure induced by transient hypoglycaemia in insulin-treated diabetes.

Hypoglycaemia, common in diabetic patients treated with insulin, can induce various neurological disturbances. Of these, seizures are the most common acute symptom, mainly of the generalised tonic-clonic type, with focal events only exceptionally being reported and documented. Hypoglycaemia can modify cortical excitability by determining an imbalance between excitation and inhibition; some brain structures, such as the temporal lobe and hippocampus, appear to be particularly susceptible to this insult. We describe a case of a 61-year-old diabetic patient in whom insulin-induced transient hypoglycaemia triggered a focal seizure of temporal origin that was well documented by EEG during 24-hour ambulatory monitoring. This is, to our knowledge, one of the few, well-documented cases of this type of seizure.

Vestibular evoked periocular potentials in Meniere's disease after glycerol testing.

OBJECTIVES: The present investigation was specifically designed to evaluate the clinical application of vestibular evoked periocular potentials (VEPPs) in the diagnosis of endolymphatic hydrops. METHODS: We compared the results of the traditional pure tone audiometry glycerol test with those of the vestibular evoked myogenic potential (VEMP) glycerol test and the VEPP glycerol test in 22 patients affected by unilateral endolymphatic hydrops. RESULTS: Some patients had positive depletive tests with both VEMPs and VEPPs, and other patients had positive tests with either VEMPs or VEPPs. CONCLUSIONS: Our outcomes confirmed that vestibular evoked potentials represent a useful additional diagnostic tool in the diagnosis of endolymphatic hydrops. The role of VEPPs in this particular issue was not inferior to that of VEMPs. The outcomes also suggested that not only the saccule, but also the utriculus, may be involved in the genesis of VEPPs.

Usher's Syndrome Type II: A Comparative Study of Genetic Mutations and Vestibular System Evaluation.

Objective Usher's syndrome type II (USH2) is characterized by moderate to profound congenital hearing loss, later onset of retinitis pigmentosa, and normal vestibular function. Recently, a study investigating the vestibular function of USH2 patients demonstrated a pathologic response to vestibular tests. In this cross-sectional study we performed vestibular tests of a group patients with genetic diagnosis of USH2 syndrome to demonstrate if vestibular damage is present in USH2 patients. Study Design Cross-sectional study. Setting Tertiary referral center. Subjects and Methods Mutated genes of 7 patients with a clinical diagnosis of USH2 were evaluated. Vestibular function was investigated by audiometry, Fitzgerald-Hallpike caloric vestibular testing, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT). Results Genetic tests confirmed the USH2 diagnosis in 5 of 7 patients examined, with 1 patient reporting a unique mutation on genetic tests. Four (80%) of the 5 patients with a genetic diagnosis of USH2 showed pathological O-VEMPs. Two patients (40%) reported bilateral absent or abnormal values of C-VEMPs. The superior semicircular canal presented a significant deficit in 2 (40%) patients. The same 2 cases showed a pathologic response of the v-HIT of the horizontal semicircular canal. Finally, the posterior semicircular canal presented a significant deficit in 4 (40.0%) patients. Conclusion A vestibular evaluation with vestibular evoked myogenic potentials and v-HIT seems to identify latent damage to the vestibular receptors of USH2 patients.

Retinitis pigmentosa: evaluation of the vestibular system with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test.

OBJECTIVE: Retinitis pigmentosa (RP) represents a group of inherited disorders in which abnormalities of the photoreceptors lead to progressive visual loss. Night blindness, peripheral visual field loss, and eventual total blindness represent typical visual damage of such disease. No study has previously evaluated the presence of a "latent" vestibular deficit in patients with RP. STUDY DESIGN: Prospective study with caloric test, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT). SETTING: Tertiary referral center. PATIENTS: 16 patients suffering from RP. INTERVENTION: Evaluation of vestibular dysfunction with caloric test, C-VEMPs, O-VEMPs, and the measurement of the vestibular-ocular reflex (VOR) using the v-HIT. RESULTS: Only five patients with RP showed normal values in all the vestibular tests performed. Three patients had an evident deficit at the caloric test, whereas eight (50%) of them had a normal caloric test but a pathological response in at least one of the other vestibular tests performed. No patient of the study showed a bilateral otolith or ampullary dysfunction. CONCLUSION: Our patients with RP unexpectedly showed pathological responses in at least one of the vestibular tests performed. Nowadays, in patients affected by RP, a vestibular diagnostic protocol must include VEMPs and v-HIT to confirm the vestibular damage and to identify selective damage of the vestibular nerve.

Usher's Syndrome: Evaluation of the Vestibular System with Cervical and Ocular Vestibular Evoked Myogenic Potentials and the Video Head Impulse Test.

OBJECTIVE: The Usher's syndrome (USH) is composed of a group of inherited disorders characterized by a dual sensory impairment of the audiovestibular and visual systems. Despite the established hearing loss, few authors have investigated vestibular dysfunction in these patients.The aim of this article is to investigate otolith or ampullary dysfunction in a group of patients affected by USH by means of a diagnostic protocol using caloric vestibular tests, cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and video head impulse test (v-HIT) to show any selective damage of the vestibular nerve and also to identify if it is present in patients with a previous diagnosis of USH Type II. STUDY DESIGN: Prospective study with C-VEMPs, O-VEMPs, and v-HIT. SETTING: Tertiary referral center. PATIENTS: Fifteen patients with USH. INTERVENTION: Evaluation of otolith dysfunction with caloric test, C-VEMPs, and O-VEMPs and the measurement of the vestibular-ocular reflex using the v-HIT. RESULTS: Only three cases showed normal values of all the vestibular tests performed. O-VEMPs and C-VEMPs appeared pathologic in nine and seven cases, respectively. V-HITs showed ampullary dysfunction in 10 patients. In our study, eight of the 11 patients belonging to the group of USH Type II showed a pathologic response to at least one of the vestibular tests performed. CONCLUSION: Today, in patients affected by USH, any vestibular diagnostic protocol must include VEMPs and v-HIT to confirm the vestibular damage, identify selective deficit of the vestibular nerve, and provide useful information for a correct classification of USH.