Syndrome of the mesencephalic artery: report of a case with CT and necropsy findings.

The syndrome of the mesencephalic artery refers to the clinical constellation of akinetic mutism and third nerve palsy which results from occlusion of one or more of the posterior thalamo-perforating arteries that arise from the proximal posterior cerebral artery. A patient with this syndrome is described in whom a bilateral paramedian midbrain infarct was shown by computed tomography and confirmed pathologically. To our knowledge, this is only the second reported case of mesencephalic infarct shown by computed tomography and the first in which the CT findings have been corroborated by pathological examination.