Cortical potentials evoked by horizontal rotatory stimulation: the effects of angular acceleration.
OBJECTIVE
To examine the potentials evoked by rotatory stimulation, which we consider the optimal means of invoking angular acceleration and which may lead to clinical applications in patients with vertigo.


METHODS
Horizontal rotatory stimulation using a trapezoidal waveform was performed with 3 different angular accelerations (20, 15 and 10 degrees/s2) used sequentially, with alternating clockwise and counterclockwise stimulation, to normal subjects and a patient with bilateral loss of vestibular function.


RESULTS
It is likely that angular accelerations of < 20 degrees/s2 produce minor somatosensory effects. Clear potentials were evoked in 13/18 ears (72%) of the normal subjects with stimulation at an angular acceleration of 15 degrees/s2. No response was recorded in the patient with stimulation at 15 degrees/s2.


CONCLUSIONS
We suggest that an angular acceleration of 15 degrees/s2 is optimal for clinical examinations.
Kenmochi
Mutsumi
M
Department of Otolaryngology, St. Marianna School of Medicine, Yokohama City Seibu Hospital, Japan. mkenmochi@marianna-u.ac.jp
Ohashi
Toru
T
Nishino
Hirohito
H
Sato
Shigeki
S
D000054:Acceleration; D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials; D006801:Humans; D008297:Male; D009760:Nystagmus, Physiologic / Q000502:physiology*; D011187:Posture / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012399:Rotation; D014717:Vertigo / Q000503:physiopathology; D014722:Vestibule, Labyrinth / Q000503:physiopathology*