Head position dependency of induced nystagmus to ice-water irrigation in peripheral vestibulopathy.
OBJECTIVE
Evaluation of head-position dependency during the ice-water test is essential when the test is indicated. Because ice-water irrigation (IWI) in the prone position is frequently skipped in many laboratories, we investigated the importance of evaluating position dependency in an ice-water test.


METHODS
Twenty-five unilateral peripheral vestibulopathy patients showing no nystagmus during warm irrigation were included. IWI was performed in supine and prone positions, and maximum slow-phase velocity and direction of nystagmus were assessed by using video nystagmography.


RESULTS
Eleven cases showed head-position dependency and were interpreted as hypofunctional. Fourteen cases showed no dependency, suggesting the absence of end organ function. In the latter group, 6 patients showing definite nystagmus in supine position could have been misinterpreted as hypofunctional, had it not been for prone-position results.


CONCLUSIONS
Evaluation of head position dependency by using IWI is important in the determination of lateral semicircular canal function.
Choi
Byung Yoon
BY
Department of Otolaryngology, Seoul National University College of Medicine, Korea.
Koo
Ja-Won
JW
Oh
Seung Ha
SH
Chang
Sun O
SO
Kim
Chong-Sun
CS
D000328:Adult; D000368:Aged; D004584:Electronystagmography; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006257:Head; D006801:Humans; D007053:Ice; D008297:Male; D008875:Middle Aged; D009760:Nystagmus, Physiologic; D011187:Posture; D007507:Therapeutic Irrigation; D015837:Vestibular Diseases / Q000209:etiology / Q000503:physiopathology*; D014743:Videotape Recording; D014867:Water
D007053:Ice; D014867:Water