Amnestic syndrome and vertical gaze palsy: early detection of bilateral thalamic infarction by CT and NMR.

A 27 year old woman with mitral valve prolapse presented with somnolence, bilateral Babinski signs, and grasp reflexes. As somnolence cleared, vertical gaze palsy and Korsakoffian memory deficit were apparent. Initial CT scan was normal, but NMR scan 24 hours after the onset of symptoms revealed prolonged T2 relaxation in medial thalami bilaterally, facilitating diagnosis of bithalamic infarction. Subsequent CT scans delineated infarction in the vascular territory of the paramedian thalamic arteries. Previous clinical reports and the neuro- and vascular anatomy underlying this syndrome are reviewed, including cases that suggest a relationship to the syndrome of transient global amnesia.