Artery of Percheron infarction.

An 85 year-old woman with normal cognitive function and ability to walk unaided was admitted to hospital in May 2011 because of sudden onset of stupor and a fall at home. She had a history of hypertension, diabetes mellitus, and atrial fibrillation, and was taking aspirin. On physical examination, she was somnolent with Glasgow Coma Scale score of 8/15 (eye 1/4, motor 6/6, verbal response 1/5). Power was grade 3/5 in all four limbs. Plantar reflexes were down going and tendon jerks were not brisk. There was no vertical gaze palsy. Respiratory, cardiovascular, and abdominal examination was unremarkable. The admission random blood glucose level was 7.2 mmol/L. Complete blood picture, routine biochemistry, thyroid function tests, vitamin B12, and