[Mesencephalic artery syndrome]

The authors report a 62-year-old woman, with stroke-like onset of unconsciousness, left oculomotor nerve paresis, slight right-sided paresis with extensor plantar response. On autopsy thombosis at the site of basilar artery bifurcations was found with symmetrical "butterfly type" necrosis of the thalamus, and with necrosis of mesencephalic and pontine midline structures.