Vibration-Induced Nystagmus in Patients with Vestibular Disorders

BACKGROUND AND OBJECTIVES: It has been reported that vibration applied either on the mastoid or the sternocleidomastoid (SCM) muscles induces nystagmus in patients after unilateral vestibular neuritis. The aims of the study were to characterize the vibration-induced nystagmus (VIN) in patients with various vestibular disorders and to compare the results of VIN to unilateral weakness in caloric test. MATERIALS AND METHODS:Fifthy-four patients with Meniere's disease, 58 patients with unilateral vestibular neuritis, 170 patients with migraine-associated dizziness, and 78 patients with chronic recurrent vestibulopathy were included. We recorded eye movements during unilateral 100-Hz vibration on the mastoids and SCM muscles. The bithermal caloric test was also performed. Abnormal criteria of VIN were slow-phase slow-phase velocity (SPV) at 4 all different conditions > or = 2degrees/s with the same directions or mean of SPV at vibration on both mastoids or both SCM muscles > or = 5degrees/s with the same directions. RESULTS: In Meniere's disease, 28 of 57 (49.1%) of patients show pathologic VIN, 21 of 57 (36.8%) show pathologic canal paresis. 14 of 57 (24.6%) show abnormalities in both tests, and 35 of 57 (61.4%) show any abnormalities in either test. In unilateral vestibular neuritis, 43 of 58 (77.6%) showed pathologic VIN, 58 of 58 (100%) show canal paresis. In migraine-associated dizziness, 48 of 170 (28.2%) showed pathologic VIN, 58 of 170 (18.8%) show canal paresis. 15 of 170 (8.8%) showed abnormalities in both tests, and 65 of 170 (38.2%) show any abnormalities in either test. In chronic recurrent vestibulopathy, 23 of 78 (29.5%) of patients show pathologic VIN and 17 of 78 (21.8%) show pathologic canal paresis. Seven of 78 (9.0%) showed abnormalities in both tests, and 33 of 78 (42.3%) show any abnormalities in either test. CONCLUSION: VIN test can increase the sensitivity in detecting vestibular imbalance in vestibular disorders when combined with caloric test.

Recurrent Vestibulopathy: Clinical Characteristics and Efficacy of Combination Therapy

BACKGROUND AND OBJECTIVES: Recurrent vestibulopathy is defined a disease characterized by more than a single episode of vertigo of duration characteristic of endolymphatic hydrops but without auditory or clinical neurological symptoms or signs. To investigate the clinical characteristics and the efficacy of combination therapy, we analyzed the clinical records of the patients diagnosed as recurrent vestibulopathy. MATERIALS AND METHOD: Clinical records of sixty four patients diagnosed as recurrent vestibulopathy were retrospectively reviewed. The data on age, sex distribution, natural history, family history of recurrent vestibulopathy, concurrent headache, caloric response was analyzed. The efficacy of combination therapy for vertigo control in the patients with a minimum 24-month follow-up was also evaluated. RESULTS: Mean onset age of recurrent vestibulopathy was 43 years and there was a female preponderance. Concurrent headache and elevated SP/AP ratio in electrocochleogram was frequently observed in these patients. After the combination medical therapy, patients with severe recurrent vestibulopathy showed significant decrease in the number of vertigo spells with 37.5% of complete control of vertigo. CONCLUSION: As a distinctive clinical disorder with unknown cause, recurrent vestibulopathy should be always considered to the patients complaining recurrent episodic vertigo. Combination therapy individualized to the symptoms and signs of the patients with recurrent vestibulopathy might be effective in reducing the frequency of vertigo attacks. Further case-control studies with large population should be necessary.