[Relationship of white matter lesions on brain computed tomography and cognitive function in elderly subjects with mild cognitive impairment]. / Relations entre troubles cognitifs et lésions de la substance blanche cérébrale.

ABSTRACT

UNLABELLED White matter lesions (WML) are frequently disclosed on elderly people computed tomography (CT) brain scan. OBJECTIVE: To evaluate the relationship between WML and cognitive functions of patients suffering from Mild Cognitive Impairment (MCI). METHODS: We studied the association between WML on CT brain scan and cognitive functions in 136 consecutive elderly subjects attending a geriatric outpatient clinic, suffering from MCI. The global cognitive assessment was based on Mini Mental State Examination (MMSE), a validated comprehensive battery of neuropsychological tests, the Cognitive Efficiency Profile (CEP), a CT brain scan and a complete biological screening. WML on CT brain scan was evaluated by a blinded investigator. RESULTS: In this population, 75 +/- 8 years of age, (women 60%, and hypertension 54%), 33% of subjects had WML on CT brain scan. Patients with WML were significantly older (OR=1.27; IC 95%=1.04 - 1.22), had more frequently a past history of hypertension (OR=2.71; IC 95%=1.06 - 6.96) and more frequently lacunae associated with WML (OR=4.48; IC 95%=1.18 - 16.99). Subjects with WML had significantly poorer cognitive functions than those without WML (CEP score/100=62.33 +/- 13.58 versus 71.87 +/- 14.19, p<0.01 and MMSE score/30=27.02 +/- 2.34 versus 27.97 +/- 1.89, p<0.01) CONCLUSION: Our results showed a relationship between WML on CT brain scan and the depth of cognitive dysfunction among MCI patients. Further long term prospective studies have to be performed to determinate if WML are involved in transitions between MCI and Alzheimer' s disease.