Avaliação de parâmetros actimétricos em idosos saudáveis e com declínio cognitivo

Abstract

Introduction: Sleep problems are common in dementia, especially in severe cases. Actigraphy has emerged as a valuable method for measuring sleep patterns and has been applied for assessing the rest-activity rhythm in Alzheimer’s disease (AD). A direct comparison between AD and Minimal Cognitive Impairment (MCI) patients, as well as with normal elders, is lacking in the literature concerning actigraphical patters. Methods: This transversal study included 82 ambulatory participants (27 cognitively intact elders, 28 patients with MCI, and 27 patients with late-onset AD with). Subjects with stage 2 or 3 MCI in Clinical Dementia Rating (CDR), use of medications for sleep disturbances, diagnosis of other neurological disease (including non-AD dementias), symptoms suggestive of untreated obstructive sleep apnea or restless leg syndrome, and score higher than 5 in Geriatric Depression Scale (GDS) were excluded. The study was approved by the local Ethical Committee and consisted on the uninterrupted use of a wrist actigraph device for at least 7 days. Demographic and clinical data were collected, including results from cognitive Results: Mini-mental, CDR, AD Assessment Scale – cognitive subscale (ADAS-Cog), Verbal Fluency Test (VFT), clock drawing test, and GDS. Actigraphical records related to rest-activity rhythm were analyzed by an appropriate program, regarding mean intradaily variability (mIV); interdaily stability (IS); mean of the 10 hours of higher activity (M10); mean of the 5 hours of lower activity (L5); relative amplitude (RA). Results: AD group had higher L5 figures (mean and standard deviation: 114.7 ± 124.7 vs. 57.1 ± 48.7; p=0.011) and a trend to higher mIV (0.73 ± 0.15 vs. 0.64 ± 0.15; p=0.055) than the MCI patients. Conversely, RA figures was lower in AD patients (0.94 ± 0.04 vs. 0.97 ± 0.02; p=0.011). Normal subjects showed a trend to lower L5 figures in comparison to AD group (79.7 ± 50.5 vs. 114.7 ± 124.7; p=0.067). As expected, the Alzheimer group exhibited worse performance in all cognitive tests in comparison to the others (Minimental score 18.2 ± 4.8 vs. 24.7 ± 2.5 [MCI] and vs. 27.6 ± 2.4 [normal]; VFT score 9.4 ± 3.0 vs. 15.7 ± 5.0 [MCI] and vs. 19.3 ± 5.1 [normal]; ADAS-Cog score 23.2 ± 10.2 vs. 10.0 ± 2.7 [MCI] and vs. 5.6 ± 2.3 [normal]; p<0.001 for all comparisons). MCI patients also were cognitively worse than normal subjects (Minimental score 24.7 ± 2.5 vs. 27.6 ± 2.4 [p=0.001]; VFT score 15.7 ± 5.0 vs. 19.3 ± 5.1 [p=0.010]; ADAS-Cog score 10.0 ± 2.7 vs. 5.6 ± 2.3 [p=0.032]).Conclusions: AD group exhibited disrupted rest-activity rhythm in comparison to MCI patients and normal elderly. There was no difference in actigraphical patterns between MCI patients and normal subjects.