Evaluation of the slopes of cognitive impairment and disability in Alzheimer's disease (AD) patients treated with acetylcholinesterase inhibitors (AChEl).

AD is characterized by a widespread cognitive impairment and deficit in functional competency to perform activities of daily living (ADL). The longitudinal reliability of cognitive and functional performance indices and the strength of relationship between patients cognitive impairment and their functional competence are still open issues. The aim of this study has been to evaluate, in a selected sample of patients with AD treated with AChEl, the slopes of cognitive impairment and disability. Among 249 AD patients, according to DSM-IV criteria, with presence/absence of associated vascular lesions (AD+VD), eligible for AChEl treatment, we selected subjects with mild to moderate cognitive impairment, without high comorbidity and severe psychiatric disease, with caregiver who resided with, or had frequent contact with the patient. Patients that changed treatment shifting from one AChEl to another, that didn't tolerate inhibitors (drop-out), and that presented behavioral and psychological symptoms of dementia (BPSD) requiring neuroleptic treatment during the study period were excluded from the final analysis. A sample of 99 subjects (30 males, 69 females; mean age of 79.4+/-5.0 years), completing a 15 months follow-up was considered. Cognitive performance remained stable after 15 months of treatment, but disability increased. No difference was found due to the AChEl compound used. The same hold true for the subgroups with presence/absence of a vascular components, whereas subgroup with mild cognitive performance showed a cognitive decline, parallel to the functional one. Our data underline the efficacy of AChEl in the treatment of AD with presence/absence of vascular component. Nevertheless, the judgement on the level of efficacy of AChEl could be biased by the level of reliability of the indices considered.