ARE WHITE-MATTER LESIONS DIRECTLY ASSOCIATED WITH COGNITIVE IMPAIRMENT IN PATIENTS WITH LACUNAR INFARCTS

Forty-four patients (mean age 66, SD 8 years) with either clinical evi dence of a focal lacunar syndrome (n = 36) or with disorders of memory or gait (n = 8) in the presence of a lacunar infarct on CT were studi ed for cognitive functioning and for the presence of white matter lesi ons on MRI. MR images were assessed by a neurologist and a neuroradiol ogist blinded to the clinical data. Thirty-six patients had one or mor e lacunar infarcts on CT or MRI (in the thalamus in 5, in the caudate nucleus in 3 and in the internal capsule or corona radiata in the rema ining patients). Twelve patients had multiple infarcts. Severe lesions of the white matter were found in 13 patients, mild to moderate lesio ns in 20 patients. Scores on Digit Span, Digit Symbol and delayed reca ll of the 15-Words test were significantly lower in the group with sev ere lesions, whilst there was a trend in the same direction for the Co gnitive part of the Cambridge Examination of Mental Disorders in the E lderly, the Trailmaking B, Stroop colour interference test and the del ayed visual reproduction of the Wechsler Memory Scale. These findings suggest that diffuse lesions of the white matter are an independent fa ctor in the pathogenesis of intellectual dysfunction, also in patients with lacunar infarcts, but a truly independent analysis is difficult because the most severe involvement of the white matter tended to be a ssociated with the largest number of lacunar infarcts.