The role of sleep on cognition and functional connectivity in patients with multiple sclerosis

Quinten Van Geest,Y D Van Der Werf,B Westerik,H E Hulst,J J G Geurts

doi:10.1007/s00415-016-8318-6

Quinten Van Geest, Y D Van Der Werf + Show 3 more

Open Access

https://doi.org/10.1007/s00415-016-8318-6

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Abstract

Sleep disturbances are common in multiple sclerosis (MS), but its impact on cognition and functional connectivity (FC) of the hippocampus and thalamus is unknown. Therefore, we investigated the relationship between sleep disturbances, cognitive functioning and resting-state (RS) FC of the hippocampus and thalamus in MS. 71 MS patients and 40 healthy controls underwent neuropsychological testing and filled out self-report questionnaires (anxiety, depression, fatigue, and subjective cognitive problems). Sleep disturbances were assed with the five-item version of the Athens Insomnia Scale. Hippocampal and thalamic volume and RS FC of these regions were determined. Twenty-three patients were categorized as sleep disturbed and 48 as normal sleeping. No differences were found between disturbed and normal sleeping patients concerning cognition and structural MRI. Sleep disturbed patients reported more subjective cognitive problems, and displayed decreased FC between the thalamus and middle and superior frontal gyrus, inferior frontal operculum, anterior cingulate cortex, inferior parietal gyrus, precuneus, and angular gyrus compared to normal sleeping patients. We conclude that sleep disturbances in MS are not (directly) related to objective cognitive functioning, but rather to subjective cognitive problems. In addition, sleep disturbances in MS seem to coincide with a specific pattern of decreased thalamic FC.

Highlights

Up to 65 % of multiple sclerosis (MS) patients suffer from cognitive problems [1], resulting in a reduced quality of life [2]
No significant relationship was found between Athens Insomnia Scale (AIS) score, fatigue, and subjective cognitive problems in all MS patients
In healthy controls (HCs), higher AIS score was correlated with worse Letter Digit Substitution Task (LDST) performance (Spearman’s q = -0.35, p = 0.026)

Summary

Introduction

Up to 65 % of multiple sclerosis (MS) patients suffer from cognitive problems [1], resulting in a reduced quality of life [2]. Several factors are thought to negatively influence cognition in MS patients, such as depression [3], fatigue [4], and sleep disturbances [5]. In healthy controls (HCs), proper sleep is important for memory consolidation [7] and sleep deprivation has been related to impaired functioning in various cognitive domains [8]. The literature on sleep disturbances and cognition in MS is scarce. One study showed an association between sleep disturbances and a decline in sustained attention [9], whereas another study related reduced sleep efficiency to problems with information processing and executive function [5]

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