L'objectif de cette étude est d'évaluer les liens entre les dysfonctionnements frontaux et la démotivation chez la personne âgée ; 45 patients âgés (31 femmes : 79,5 6,5 ; 14 hommes : 74,3 10,7) pris en charge en hôpital de jour psychogériatrique ont été sélectionnés pour cette étude. La motivation est évaluée au moyen de l'Échelle d'appréciation de la démotivation (EAD). Durant une période de temps équivalente, les patients sont également testés avec le Mini Mental test (MMS), l'échelle de dépression de Cornell ainsi que l'Échelle d'apathie de Marin. Une batterie d'évaluation du fonctionnement exécutif a aussi été administrée : le Trail Making Test A et B, le test de sélection de cartes de Wisconsin et la Batterie rapide d'évaluation frontale (BREF). Les résultats démontrent que la perte de motivation est corrélée au nombre d'erreurs au test du Wisconsin surtout avec le nombre d'erreurs persévératives. Un bon niveau de motivation est lié avec de bonnes performances à la BREF, surtout pour les sous-items Programmation et Inhibition. En revanche, il n'existe pas de lien entre démotivation et vitesse d'exécution au Trail Making Test . En conclusion, des pertes de motivation sont associées à des troubles des fonctions exécutives. Leur dépistage est ainsi indispensable en vue de l'établissement d'un programme de rééducation cognitive.

Loss of motivation and frontal dysfunction are frequent in old people. Motivation refers to what drives acts and relationships. The loss of motivation has some spécific characteristics from depression : loss of sens of meaning, loss of commitment for others, dysinterest for daily activities. The frontal function is related to speed of acting, emotional system, anticipating of the future. All these points are altered in demotivated patients. For these reasons we assayed to analyse the possible links between loss of motivation and frontal dysfunctions. Methods–The focus of this assay was to determine and to precise the functional links between frontal brain and loss of motivation in old people ; 45 old patients cared in a day care hospital were proposed to participate to neuropsychologic evaluation. After their agreement and their family acceptation if they were demented, they were assessed by a practitioner, then by 2 different psychologists. They were evaluated for cognition (MMS), depression (Cornell's scale), apathy (Marin's scale), age and scolarships level. In a other time, they were tested with different frontal tests : Trail making A and B, Wisconsin, BREF (frontal battery of psychological tests) analyse concerned speeds, number and natures of errors, habilities for matching categories. Loss of demotivation was scored on EAD scale. Statistical analysis was done with Systat 10 and Statview software. Results– It could be notice the significant negative links between EAD scores and the BREF scales, or with the number of categories found with the Wisconsin test. The more motivated the patients are the best results they have with their frontal tests. There are positive and significant links between EAD score and the number of errors at the Wisconsin test, and especially with repetitive errors either with this test or with BREF test. Repetitive errors and the number of errors, pointing some frontal dysfunctions are associated with a loss of motivation. Considering BREF sub-items, it could be shown the negative links between EAD scores and programmation or inhibition sub-items. All these points persist in a statistical model including pathology, cognitive levels, depression level at the Cornell's scale, age or scolarship level. We do not find a link between EAD scores and the time obtained with the Trail making test. Conclusion– Loss of motivation is associated with some frontal impairment responsible for numerous errors in tasks. A good motivation of old people is associated with good frontal habilities especially in complex tasks or in programming capacities of old patients. There is no links between the speeds of tasks and the level of motivation. Motivation could be so related with orbito-frontal brain activities.