Mental status changes and stroke

A retrospective analysis at a tertiary referred center was done to determine the frequency with which an acute confusional state is caused by a stroke and to evaluate the usefulness of performing computed tomography in this setting. We reviewed 127 neurology consultations requested for patients presenting with acute and apparently isolated mental status changes. The mean age was 62. Nine of 127 (7%) were thought to have suffered mental status changes as a result of an acute stroke: one subarachnoid hemorrhage and eight ischemic strokes. There was no intracerebral hemorrhage. The locations of the infarcts were right frontoparietal (four patients), bilateral occipital (two patients), bilateral frontal (two patients), and right pontine (one patient, in whom the causality of the stroke was uncertain). Of those nine strokes presenting with isolated mental symptoms, six (66%) had some focal abnormality on neurological examination. Only three of the 109 patients (2.7%) with no focal findings were ultimately diagnosed as strokes, and one of these had a subarachnoid hemorrhage. Stroke was a relatively rare cause of acute confusional syndrome. The neurological examination had a very high negative predictive value (97%) and was reliable in selecting patients who should undergo an imaging study.