Three-dimensional analysis of benign paroxysmal positional nystagmus in a patient with anterior semicircular canal variant.
OBJECTIVE
To show the positional nystagmus in a patient who had suffered from benign paroxysmal positional vertigo (BPPV) that was thought to be caused by involvement of the anterior semicircular canal (ASCC) (A-BPPV).


METHODS
Retrospective case report.


METHODS
City hospital.


METHODS
The present study reports a rare case of A-BPPV in a 41-year-old woman.


METHODS
The patient is 41-year-old woman who developed a positional vertigo after playing volleyball on March 22, 2005 and consulted our hospital the next day. When left Dix-Hallpike maneuver was performed, she showed a positional nystagmus of which fast phase direction of the torsional component was clockwise while that of the vertical component was downward. We plotted the slow phase eye velocity of the positional nystagmus during the left Dix-Hallpike maneuver on three-dimensional coordinates that showed the axis of the positional nystagmus to be perpendicular to the plane of the right ASCC.


CONCLUSIONS
These results suggested that the patient was suffering from A-BPPV.
Imai
Takao
T
Department of Otolaryngology, Kansai-Rosai Hospital, Hyogo, and Department of Otolaryngology and Sensory Organ Surgery, Osaka University Graduate School of Medicine, Osaka, Japan. imaitakao@hotmail.com
Takeda
Noriaki
N
Ito
Mahito
M
Nakamae
Koji
K
Sakae
Hideki
H
Fujioka
Hiromu
H
Kubo
Takeshi
T
D000328:Adult; D004584:Electronystagmography; D005133:Eye Movements; D005260:Female; D019416:Head Movements; D006801:Humans; D021621:Imaging, Three-Dimensional; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000503:physiopathology*; D011187:Posture; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000473:pathology* / Q000503:physiopathology; D014717:Vertigo / Q000503:physiopathology*; D014724:Vestibular Function Tests; D014743:Videotape Recording