Dissociated unilateral convergence paralysis in a patient with thalamotectal haemorrhage.

A 47 year old male was admitted in a comatose state. CT scan showed a haemorrhage in the right pulvinar thalamus descending into the right part of the lamina quadrigemina. He presented with anisocoria, prompt bilateral pupillary light reaction, and unilateral convergence paralysis contralateral to the lesion in combination with upward gaze palsy. During an observation period of two months, the convergence reaction returned to normal. MRI showed a lacunar lesion ventral to superior right colliculus. Angiography revealed an arteriovenous malformation (right posterior cerebral artery--sinus rectus) as the possible cause of the haemorrhage.