Dementia in middle-aged patients with schizophrenia.
Résumé
Although numerous studies have assessed cognitive dysfunction in patients with schizophrenia, very few have focused on the diagnosis of dementia. Our objectives were to accurately diagnose dementia in a cohort of middle-aged patients with schizophrenia and to assess the type of dementia. 96 patients with schizophrenia (46 inpatients and 50 outpatients), aged 50 to 70 years, underwent a psychiatric, neurological, and neuropsychological evaluation at baseline and after a 20-month follow-up. We established a 3-step procedure: 1) diagnose dementia according to the DSM-IV criteria, using the Mattis Dementia Rating and Activities of Daily Living scales; 2) characterize dementia using brain imaging, perfusion by 99mTc-ECD-SPECT and laboratory tests including Alzheimer's disease cerebrospinal fluid biomarkers; and 3) search for genetic determinants. Fourteen patients fulfilled the diagnostic criteria of dementia. Four were diagnosed with possible or probable behavioral-variant frontotemporal dementia (bvFTD), two with probable Alzheimer's disease, two with probable vascular dementia (including one due to CADASIL), one with CNS inflammatory disease, and six could not be fully characterized. The diagnosis of dementia in middle-aged patients with schizophrenia is challenging but possible, using a multistep procedure. The most frequent condition, bvFTD, could reflect the presence of an evolutive neurodegenerative process in some patients.