COGNITIVE DYSFUNCTION FOLLOWING SUBCORTICAL INFARCTION

Objective: To determine the association between computed tomographic s can findings of subcortical infarction, peri-ventricular lucency, and ventricular enlargement and a patient's performance on a range of neur opsychological tests. Design: Prospective study of patients in whom co mputed tomographic scanning identified discrete areas of subcortical l ucency that were consistent with multiple subcortical infarcts and in whom there was no evidence for additional cerebral computer tomographi c pathology. Setting: Hospital practice that included both inpatients and ambulatory patients. Patients: One hundred forty-seven consecutive appropriate computed tomographic scans were identified. Sixty-two pat ients were excluded because of concomitant medical disorders, and eigh t refused participation. We describe 77 patients.Main Outcome Measures : Performance on a battery of neuropsychological tests. Results: The n umber of infarcts but not the volume of infarction, periventricular lu cency, and cerebral ventricular enlargement but not cortical atrophy w ere significantly associated with impaired performance on neuropsychol ogical tests. The number of infarcts correlated with impaired performa nce on tests, and this impaired performance was thought to be dependen t on the function of frontal systems, while periventricular lucency an d ventricular enlargement correlated with impaired performance on a wi der range of tests, including tests that depended on memory and langua ge. Conclusions: The number of infarcts, periventricular lucency, and ventricular enlargement are the computed tomographic head scan paramet ers that correlated with severity of impaired performance on neuropsyc hological tests in patients with subcortical infarction. Cognitive imp airment is presumed to be the result of cortical disconnection followi ng disruption of the connections between the subcortical regions and t he frontal cortex.