L’approche diagnostique de la maladie d’Alzheimer (MA) repose sur la présence de l’atrophie cérébrale associée à la note du mini-examen de l’état mental. Dans ce contexte, cette étude est menée afin d’évaluer la corrélation entre l’imagerie et les tests neuropsychologiques des cas atteints de la MA d’apparition précoce et d’apparition tardive.

Une analyse des aspects cliniques et paracliniques des cas marocains atteints de la MA.

Vingt-cinq patients (17 cas sporadiques et 8 cas familiaux) vus à la consultation mémoire du service de neurologie au CHU Ibn Rochd de Casablanca ont bénéficié d’un examen neurologique somatique standard, d’une évaluation des fonctions cognitives, d’une imagerie cérébrale et d’un bilan biologique.

Une discrète prédominance féminine (56 % versus 44 %). Quarante-huit pour cent des cas que ce soient de formes familiales ou sporadiques ont un score (MMSE) inférieur à 10 et sont touchés par une démence sévère, 28 % par une démence modérément sévère et 24 % sont déments légers à modérés. Les patients qui ont des formes sévères ont une atrophie qui est d’autant plus marquée que la maladie est plus sévère. Ce dysfonctionnement est responsable de troubles de mémoire, du langage et de l’altération des fonctions exécutives.

Une forte corrélation entre l’imagerie et les tests neuropsychologiques. Plus l’atrophie cérébrale est importante plus les performances neuropsychologiques sont diminuées.

The diagnostic approach for Alzheimer's disease is based on the presence of cerebral atrophy combined with the score of the mini-examination of the mental state. In this context, this study was conducted to assess the correlation between imaging and neuropsychological testing for cases of early-onset and late-onset Alzheimer's disease.

Analysis of the clinical and paraclinical aspects of Moroccan cases with Alzheimer's disease.

Seventeen sporadic cases and 8 family cases were seen at the memory clinic of the Neurology Department of the University of Casablanca Ibn Rochd Hospital. A family history was obtained through a clinical interview of the patient and a yes or no self-reporting questionnaire from the guardian or other family member. The disease was considered familial if at least one additional first degree relative suffered from early-onset AD-type dementia. All patients underwent standard somatic neurological examination, cognitive function assessment, brain imaging and laboratory tests. Written consent was obtained from the patients and their guardians prior to the study.

In our study of 25 individuals, the observed mean age of AD patients was 64.52±9.30 and we observed a slight female predominance (56% versus 44%). In addition, we found a prevalence of AD of approximately 20%, increasing with age, in the population below 60 years of age. Approximately half of our patients (48%) had a score lower than 10 and were affected by severe insanity, while 28% were affected by moderate severe insanity and 24% were light to moderately insane. Twenty-five patients underwent neuroimaging, 18 of whom were assessed by MRI, while 7 were assessed by CT. All patients had hippocampal atrophy, which progressed to affect others brain regions. The blood tests showed no abnormalities in the 25 enrolled AD cases.

Age is undoubtedly the main risk factor for AD; this is also the true for our cases where advanced age was responsible for the exponential increase of the disease's frequency; it reached a peak in the age group of 60–69 years. The AD diagnosis approach is based on the presence of cerebral atrophy combined with the score of the mini-examination of the mental state (MMSE). In our study, in addition to the MMSE, depending on the level of education, the clinician used other tests that do not necessarily require a level of education such as the BEC96, visual short-term or digital memory assessment, work memory assessment, language assessment test (DO80) and apraxia. Neuropsychological examination of the cases with a score of less than 10 showed severe cognitive impairment. The cases presented memory and language impairments, aphasia, visual spatial disorientation, decreased autonomy, executive dysfunction and praxis deficits, all major causes of severe dementia. Neuroimaging revealed hippocampal and cortical atrophy. Correlated with the other studies that aimed to establish links between brain alterations and neuropsychological disorders, we can conclude that a higher level of atrophy reflects a decrease in neuropsychological performance.