Transient upbeat nystagmus due to unilateral focal pontine infarction.
Upbeat nystagmus is known to be caused by an imbalance of the vertical vestibulo-ocular reflex (VOR), favoring downward VOR activity, due to bilateral lesions of the medulla, ventral tegmentum, anterior cerebellar vermis, adjacent brachium conjunctivum and the midbrain. We report on two patients who had transient upbeat nystagmus due to unilateral pontine infarction that may have disrupted bilateral upward VOR pathways running in the ventral tegmental tracts.
Lee
Seung-Chul
SC
Department of Neurology, College of Medicine, Hanyang University, 249-1 Guri Hospital, Gyomun-dong, Guri-si, Gyeonggi-do, 471-701, Korea.
Lee
Seok-Ho
SH
Lee
Kyu-Yong
KY
Lee
Young Joo
YJ
Koh
Seong-Ho
SH
D000368:Aged; D020526:Brain Stem Infarctions / Q000150:complications* / Q000473:pathology*; D004584:Electronystagmography / Q000379:methods; D007839:Functional Laterality; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000209:etiology*; D011149:Pons / Q000473:pathology*