Bilateral paramedian thalamic infarction: a distinct but poorly recognized stroke syndrome.

Six patients with bilateral paramedian thalamic infarction were seen in a general hospital over a 4 year period. This distinct stroke syndrome was recognized by the features of disturbed vigilance, often episodic, with vertical gaze disorder. Other signs included an amnesic syndrome, convergence difficulty, third nerve palsies, eyelid retraction, dysarthria, ataxia and involuntary limb movements. Diagnosis was confirmed by CT brain scan or magnetic resonance imaging. A variety of risk factors for stroke were present. All patients improved but two had significant residual disabilities.