Cognitive dysfunction following subcortical infarction
A. Corbett, H. Bennett and S. Kos
Neurology Department, Concord Repatriation General Hospital, New South Wales, Australia.
OBJECTIVE: To determine the association between computed tomographic scan
findings of subcortical infarction, periventricular lucency, and
ventricular enlargement and a patient's performance on a range of
neuropsychological tests. DESIGN: Prospective study of patients in whom
computed tomographic scanning identified discrete areas of subcortical
lucency that were consistent with multiple subcortical infarcts and in whom
there was no evidence for additional cerebral computer tomographic
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 patients
were excluded because of concomitant medical disorders, and eight refused
participation. We describe 77 patients. MAIN OUTCOME MEASURES: Performance
on a battery of neuropsychological tests. RESULTS: The number of infarcts
but not the volume of infarction, periventricular lucency, and cerebral
ventricular enlargement but not cortical atrophy were significantly
associated with impaired performance on neuropsychological tests. The
number of infarcts correlated with impaired performance on tests, and this
impaired performance was thought to be dependent on the function of frontal
systems, while periventricular lucency and ventricular enlargement
correlated with impaired performance on a wider range of tests, including
tests that depended on memory and language. CONCLUSIONS: The number of
infarcts, periventricular lucency, and ventricular enlargement are the
computed tomographic head scan parameters that correlated with severity of
impaired performance on neuropsychological tests in patients with
subcortical infarction. Cognitive impairment is presumed to be the result
of cortical disconnection following disruption of the connections between
the subcortical regions and the frontal cortex.
