Central Positional Nystagmus Lasting over 17 Years ; a Case Report
Clinical and MRI Study
1992 Volume 51 Issue 4 Pages 454-459
Details
1992 Volume 51 Issue 4 Pages 454-459
Our patient had had positional nystagmus of the central type for 17 years. At the age of 52, he had a sudden onset of vertigo and gait disturbance. Since then, we had the chance to examine him once every two weeks. Horizontal and rotatory nystagmus directed to the left was always observed when his head was turned or hung down and twisted to the left. The nystagmus was provoked without latency and lasted as long as these positions were kept and neither decreased or habituated. At the onset of his disease, optokinetic nystagmus (OKN) was provoked poorly and the eye tracking test (ETT) showed a saccadic pattern. As his course progressed, OKN was easily provoked, and ETT showed a normal pattern. CT-scans showed no abnormality, while MRI revealed ischemia of the left cerebellar hemisphere including the fastigial nucleus, and the middle cerebellar penduncle including the juxtarestiform body. Considering the hypothesis of the mechanism of positional nystagmus of central origin, the pathogenesis of his nystagmus could be the ischemic degeneration of the fastigial nucleus and juxtarestiform body.
