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.Electronic supplementary materialThe online version of this article (doi:10.1007/s00415-016-8318-6) contains supplementary material, which is available to authorized users.

Background: Cognitive deficits affect up to 70% of all patients with Multiple Sclerosis (MS) and have a significant impact on quality of life. Cognitive assessments need to be performed by a neuropsychologist and are often timeconsuming, hampering timely identification and adequate monitoring of cognitive decline in MS. Objective: To develop a time-efficient, unsupervised, digital tool to screen for cognitive deficits in MS. Methods: A digital (adjusted) version of the Brief International Cognitive Assessment for MS, including the Symbol Digit Modalities Test (SDMT, information processing speed), the California Verbal Learning Test (CVLT-II, verbal memory) and the Spatial Recall Test (SPART, visuospatial memory) was developed: Multiple Screener (intellectual property of Sanofi Genzyme). Firstly, the clarity and feasibility of the tool was confirmed by 16 patients with MS (mean age 50.9 years (SD 9.4, range 37-68). Next, in 60 healthy controls (HCs, mean age 44.5 years (SD 14.0, range 18-67), intraclass correlation coefficients (ICC) were calculated to describe how strongly the digital version resembled the paper and pencil-based assessment. Finally, 236 HCs (mean age 42.8 years (SD 12.8, range 18-69) were included to obtain norm scores for each test. Results: ICCs between digital and paper and pencil-based assessment were excellent to good (SDMT (ICC 0.79, confidence interval (CI) 0.67-0.87); CVLT-II (ICC 0.77, CI 0.64-0.85); SPART (ICC 0.61, CI 0.42-0.75)). For each test, a regression-based correction for the effect of age was applied on the raw scores before converting them to norm Z-scores. Additionally, the SDMT scores needed correction for education and the CVLT-II for education and sex (subgroups were created). Conclusions: Performance on an adjusted, digital version of the BICAMS correlates highly with the standard paper-and-pencil based test scores in HCs. Multiple Screener is an unsupervised, digital tool, with available norm scores, ultimately allowing for easy monitoring of cognitive decline in patients with MS.