Actigraphic, but not subjective, sleep measures are associated with cognitive impairment in memory clinic patients.

AIM: Sleep disturbances are prevalent in various dementia subtypes but rarely investigated in early clinical stages. Although memory clinics have become an established institution for the early diagnosis of dementia, sleep assessment is not part of their routine diagnostics. This study aimed to examine whether subjective and objective sleep variables are related to cognitive impairment in patients referred to a memory clinic. METHODS: On two consecutive days, patients underwent routine diagnostic procedures, including a neuropsychological examination (consortium to establish a registry for alzheimer's disease), and had their sleep quality evaluated by the Pittsburgh Sleep Quality Index and overnight hand-wrist actigraphy. RESULTS: Data of 31 patients (age, M ± SEM: 74.1 ± 1.5; 18 women, 13 men; Clinical Dementia Rating: 0-1) were analysed. One had been diagnosed with subjective cognitive impairment, 13 with mild cognitive impairment with or without depression, and 17 with dementia syndrome due to Alzheimer's and/or cerebrovascular disease. Compared to patients with subjective or mild cognitive impairment, dementia patients showed a significantly increased nocturnal acceleration magnitude; other differences in subjective and objective sleep measures were not significant. Comparing patients with subjectively poor (Pittsburgh Sleep Quality Index > 5: n = 9) and good sleep (Pittsburgh Sleep Quality Index ≤ 5: n = 22) yielded no differences in any neuropsychological and clinical variables. In contrast, patients with low actigraphically recorded sleep efficiency (<85%: n = 11) exhibited a significantly more impaired cognitive performance than those in the high sleep efficiency group (≥85%: n = 20). Correlation analyses demonstrated that actigraphically assessed disturbed sleep continuity accompanied by increased night-time motor activity was substantially associated with cognitive impairment. CONCLUSION: This study highlights that objectively assessed, but not self-reported, parameters of disturbed sleep are closely related to cognitive dysfunction in the early stages of dementia of different aetiologies. Possible diagnostic and treatment implications are discussed.

[Subjective memory impairments in early detection of dementia: Relation to acceptability of lumbar puncture in memory clinic patients]. / Subjektive Gedächtnisbeeinträchtigungen in der Früherkennung von Demenzen: Beziehung zur Akzeptanz der Lumbalpunktion bei Patienten einer Gedächtnissprechstunde.

BACKGROUND: In memory clinics, biomarker-based diagnostic tools for early detection and differential diagnosis of dementia are increasingly important, even if their acceptance by patients is relatively low. OBJECTIVE: The aim of study was to examine whether sociodemographic and clinical features of memory clinic patients are associated with acceptance of lumbar puncture (LP). Of particular interest was the patients' self-perception of memory decline (subjective memory impairment, SMI) accompanied by related concerns that might affect decision to consent to LP. METHODS: Consecutive patients were examined in a day-care hospital on two consecutive days in order to implement a diagnostic procedure based on the S3 guideline "Dementia" including offer of LP. We assessed demographic and clinical variables such as depression, anxiety, neurocognitive performance and dementia severity (Clinical Dementia Rating, CDR). Furthermore, patients were interviewed about perceived memory decline and were classified on this basis - independent of their neuropsychological results - into three groups: no SMI, SMI without concerns or SMI with concerns. RESULTS: Of 44 patients (73.8 ±â€Š8.3 years; 27 f/17 m; CDR < 1: n = 16, CDR = 1: n = 28), 29 had SMI with concerns. These patients tended to be younger and had a higher level of education than those who did not report SMI (n = 7) and those perceiving SMI without concerns (n = 8). Furthermore, patients without SMI more frequently had a dementia syndrome. Patients who agreed to lumbar puncture (n = 23) were - compared to patients refusing LP (n = 17; 4 patients had to be excluded because of medical contraindication for immediate LP) - more likely male, had significantly more frequent SMI with concerns and performed poorer on declarative memory tasks. Binary regression analysis yielded SMI with concerns, a more impaired memory performance and male sex as significant predictors for consenting to LP. CONCLUSIONS: The study provides evidence that patient characteristics such as subjective and objective memory impairment as well as sex may affect the likelihood to consent to a generally less accepted biomarker-based dementia diagnostic procedure such as LP.