Prevalence of Sleep Disturbances in Mild Cognitive Impairment and Dementing Disorders: A Multicenter Italian Clinical Cross-Sectional Study on 431 Patients

TLDR

Sleep disturbances are common among the elderly and individuals with cognitive decline. This study aimed to describe the frequency and characteristics of insomnia, excessive daytime sleepiness, sleep‑disordered breathing, REM behavior disorder, and restless legs syndrome in a large cohort of patients with mild cognitive impairment or dementia. Four hundred thirty‑one consecutive patients from ten Italian neurological centers—204 with Alzheimer’s disease, 138 with mild cognitive impairment, 43 with vascular dementia, 25 with frontotemporal dementia, and 21 with Lewy body or Parkinson’s disease dementia—were evaluated for sleep disorders using standardized questionnaires. Over 60 % of participants had at least one sleep disturbance, with Alzheimer’s disease and mild cognitive impairment showing similar prevalence, vascular dementia exhibiting higher rates of sleep‑disordered breathing, and Lewy body or Parkinson’s disease dementia displaying more REM behavior disorder, underscoring the frequent co‑occurrence of sleep disorders and the need for routine clinical assessment.

Abstract

<i>Background/Aims:</i> Sleep disturbances are common in the elderly and in persons with cognitive decline. The aim of this study was to describe frequency and characteristics of insomnia, excessive daytime sleepiness, sleep-disordered breathing, REM behavior disorder and restless legs syndrome in a large cohort of persons with mild cognitive impairment or dementia. <i>Methods:</i> 431 consecutive patients were enrolled in 10 Italian neurological centers: 204 had Alzheimer’s disease, 138 mild cognitive impairment, 43 vascular dementia, 25 frontotemporal dementia and 21 Lewy body dementia or Parkinson’s disease dementia. Sleep disorders were investigated with a battery of standardized questions and questionnaires. <i>Results:</i> Over 60% of persons had one or more sleep disturbances almost invariably associated one to another without any evident and specific pattern of co-occurrence. Persons with Alzheimer’s disease and those with mild cognitive impairment had the same frequency of any sleep disorder. Sleep-disordered breathing was more frequent in vascular dementia. REM behavior disorder was more represented in Lewy body or Parkinson’s disease dementia. <i>Conclusion:</i> A careful clinical evaluation of sleep disorders should be performed routinely in the clinical setting of persons with cognitive decline. Instrumental supports should be used only in selected patients.