Middle Cerebral Artery Pulsatility Index is Associated with Cognitive Impairment in Lacunar Stroke

BACKGROUND AND PURPOSE: Pulsatility index (PI) of the middle cerebral artery is postulated to reflect the vascular resistance in the artery distal of the probe, and has been reported to increase in small vessel disease, diabetes mellitus, ageing, and dementia. Lacunar infarcts are considered to be related to cognitive impairment. We therefore conducted a study to assess the association between cognitive impairment and PI in patients with a lacunar infarct. METHODS: Consecutive patients presenting with an acute lacunar syndrome who were admitted to the stroke unit were enrolled. The patients were examined with Doppler ultrasonography of the intracranial arteries, and the PI of the middle cerebral artery was recorded. Cognitive function was evaluated by mini-mental state examination (MMSE), clock drawing test, and trail making test (TMT) A and B. RESULTS: Among the 113 patients included, 85 patients had an acute lacunar infarct and 28 had one or more nonlacunar infarcts. The mean PI was 1.46 (SD = .33). PI was significantly (P < .05) associated with MMSE, TMT A and TMT B in patients with lacunar infarct, even after adjustment for multiple patient characteristics (age, sex, prestroke hypertension, smoking, previous stroke, and diabetes). CONCLUSIONS: PI was associated with the cognitive performance in patients with lacunar infarcts and a lacunar syndrome. An elevated PI may be related to impairment in several cognitive domains. These findings suggest that transcranial Doppler ultrasonography could be an adjunct tool for early diagnosis of cognitive impairment after stroke.