[Altered identification with relative preservation of emotional prosody production in patients with Alzheimer's disease]. / Altération de l'identification de la prosodie émotionnelle avec relative préservation de la production chez des patients atteints de la maladie d'Alzheimer.

Patients with Alzheimer's disease (AD) show cognitive and behavioral disorders, which they and their caregivers have difficulties to cope with in daily life. Psychological symptoms seem to be increased by impaired emotion processing in patients, this ability being linked to social cognition and thus essential to maintain good interpersonal relationships. Non-verbal emotion processing is a genuine way to communicate, especially so for patients whose language may be rapidly impaired. Many studies focus on emotion identification in AD patients, mostly by means of facial expressions rather than emotional prosody; even fewer consider emotional prosody production, despite its playing a key role in interpersonal exchanges. The literature on this subject is scarce with contradictory results. The present study compares the performances of 14 AD patients (88.4±4.9 yrs; MMSE: 19.9±2.7) to those of 14 control subjects (87.5±5.1 yrs; MMSE: 28.1±1.4) in tasks of emotion identification through faces and voices (non linguistic vocal emotion or emotional prosody) and in a task of emotional prosody production (12 sentences were to be pronounced in a neutral, positive, or negative tone, after a context was read). The Alzheimer's disease patients showed weaker performances than control subjects in all emotional recognition tasks and particularly when identifying emotional prosody. A negative relation between the identification scores and the NPI (professional caregivers) scores was found which underlines their link to psychological and behavioral disorders. The production of emotional prosody seems relatively preserved in a mild to moderate stage of the disease: we found subtle differences regarding acoustic parameters but in a qualitative way judges established that the patients' productions were as good as those of control subjects. These results suggest interesting new directions for improving patients' care.

[Prototypic value of semantic intrusion errors in Alzheimer's disease]. / Valeur prototypique des intrusions sémantiques dans la maladie d'Alzheimer.

Semantic intrusions are inappropriate responses frequently observed in patients with Alzheimer's disease. They belong to the same category as the words to be remembered, but their prototypic value remains largely unexplored. The prototype is the most representative word in a particular lexical category. The prototypic value is measured according to different criteria: written and oral lexical frequency, frequency of use, degree of typicality, degree of familiarity and rank of quotation. The objective of the study was to evaluate the prototypic value of intrusions produced by 17 Alzheimer's patients with mild to severe dementia, during the cued recall of the Grober & Buschke procedure (RL/RI 16 items). The prototypic value was compared to the categorial norms provided by 1) 17 control subjects and 2) the lexical database "Lexique 3". The results show that intrusions had a significantly higher prototypic value than targeted items. The prototypic value increased with the progression of the disease, and according to the evaluation criteria used. Thus with the criteria "frequency of use", "degree of typicality" and "degree of familiarity," the prototypic value increased exponentially with the severity of dementia. In contrast, in spite of the development of the pathology, the prototypic value decreased when assessed by the criteria of "rank of quotation", and "lexical frequency" (oral and written). In conclusion, the qualitative analysis of the prototypic value of intrusion errors in Alzheimers opens up new clinical and methodological considerations.

[Sporadic Creutzfeldt-Jakob disease and isolated dementia. Contribution of brain MRI]. / Maladie de Creutzfeldt-Jakob sporadique et état démentiel isolé

Creutzfeldt-Jakob disease (CJD) is the most frequent transmissible spongiform encephalopathy. Its definite diagnosis is ascertained by cerebral neuropathological exam. However, diagnosis of a probable or possible case of CJD can be evoked on the basis of Masters'classification which is based on the association of different clinical and electroencephalographical criteria. We report the case of a 58-year-old woman who died in a geriatric unit of autopsy proven sporadic CJD. The clinical course over 15 months was rapidly progressive dementia without characteristic clinical and EEG signs. The case presentation did not meet the criteria of probable or possible CJD, according to Masters'classification. However, 4 months after the onset of the disease, t-Flair MRI revealed an increased signal intensity in the right frontal and occipital cortex which could suggest the diagnosis of CJD. This case therefore stresses the contribution of MRI, especially diffusion-weighted imaging, for early diagnosis of CJD. It shows also the short comings of Masters'classification which does not always enable diagnosis of CJD even though control measures would have to be rapidly undertaken, specially the decontamination of medico-surgical equipment. Finally, this case illustrates the great importance of post mortem exam in such context. In light of this clinical observation, we discuss this rare diagnosis which should be considered in geriatrics when confronted with a rapidly progressive dementia