[Loss of motivation and frontal dysfunction. Role of the white matter change]

Since the recognition of white matter changes on computed tomography, researches were done to investigate a possible relation with ageing and cognition. This study examined whether computed tomography evidence of cerebrovascular disease in the form of white matter changes was associated with decreased implicit performance of frontal tests and with a loss of motivation in a group of 10 elderly volunteers with a mild cognitive impairment and in a group of 29 demented patients; 39 old patients (28 females: 82.4 +/- 7.1; 10 males: 75.5 +/- 11.3) cared in a psycho-geriatric day care hospital were enrolled for this essay. Motivation was evaluated with a specific scale: EAD. Patients were tested during the same period with MMSE for cognition, Cornell's scale for depression, Marin's scale for apathy. There were also assessed with a battery of frontal tests: BREF test. A brain scan was used to determinate the presence of leukoaraïosis. Table 1 give a description of the population according to the pathology. Cognitive disorder, but also apathy and loss motivation, frontal evaluation significantly differ in the two studied groups. The presence of a leukoaraïosis is associated with older people, a weaker cognitive status, a more important apathy or loss of motivation, and weaker results with frontal evaluation (table 2). Similar results were obtained considering only the frontal lesions (table 3). Age related changes of the white matter observed on computed tomography were associated with a decreased cognitive status. Leukoaraïosis is associated with loss of motivation and related with a poor results on frontal assessment. Loss of motivation is associated with certain frontal dysfunctions and with brain abnormal scan anomalies.