Vertical gaze palsy and thalamic dementia: Syndrome of the posterior thalamo-subthalamic paramedian artery

Abstract

Predominant downgaze palsy in combination with thalamic dementia were the presenting symptoms in two patients, in whom a bilateral thalamic infarct could be demonstrated on CT scan. Fourteen similar cases of vascular origin have been reported with postmortem examination. Besides a symmetrical butterfly-shaped thalamic infarct an additional bilateral paramedian mesodiencephalic involvement of the lesion including the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF) could be revealed in all cases.

This unique oculomotor/psychobehavioral syndrome is diagnostic of an ischemia in the distribution of a small thalamo-perforating artery frequently arising as one midline pedicle between the bifurcation of the basilar artery and the origin of the posterior communicating artery, thus supplying the paramedian subthalamo-thalamic region on both sides.

Key Words:

• vertical gaze palsy
• thalamic dementia