The Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis

The Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article The Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis Anastasiia Revurko, Eliza Babych, Yuliia Solodovnikova This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6276602/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Cognitive impairments (CI) affect 30-70% of patients with multiple sclerosis (MS) and can occur even in the absence of other deficits. CI are among the most debilitating manifestations, significantly impacting patients' quality of life, hindering their social activity and employment. The article discusses the possible role of sleep disturbances on cognitive performance in patients with MS considering the role of glymphatic system and its activity during sleep. Methods The study included 32 patients with MS without disease-modifying therapy experiencing exacerbations. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), while sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Statistical analyses were conducted using Jamovi (version 2.3.28). Mann-Whitney U test and Spearman correlation analysis were employed, with p<0.05 considered statistically significant. Results MoCA total scores, executive functions, short term memory, attention, concentration, and working memory were significantly lower in the CI group compared to the normal cognitive function group. Attention, concentration and working memory decline significantly correlated with later falling asleep time and existence of sleep disturbances. Short term memory component has a significant negative correlation with falling asleep time, sleep duration and sleep efficiency. Spearman test showed significant negative correlation between PSQI total score and MoCA total score, attention concentration and working memory as well as short memory components. Conclusion A moderate negative correlation exists between sleep quality scores and cognitive performance, suggesting that poorer sleep may be associated with reduced cognitive function in patients with MS. Health sciences/Neurology Health sciences/Neurology/Neurological disorders/Multiple sclerosis Health sciences/Neurology/Neurological disorders/Sleep disorders Health sciences/Neurology Health sciences/Neurology/Neurological disorders/Multiple sclerosis Health sciences/Neurology/Neurological disorders/Sleep disorders multiple sclerosis cognitive impairment sleep quality glymphatic system Figures Figure 1 Introduction Multiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease and a leading cause of severe disability in young adults [ 1 ]. MS has a wide range of manifestations which depend on the loci of demyelination lesions in the central nervous system (CNS) and include sensory, motor, visual disturbances, balance disorders, pelvic organ dysfunction, as well as cognitive and emotional impairments. Cognitive impairments (CI) affect 30–70% of patients with MS and can occur even in the absence of other deficits. CI are among the most debilitating manifestations of MS, significantly impacting patients' quality of life, hindering their social activity and employment [ 2 , 3 ]. Disease-related unemployment can result in social and psychological consequences, such as depression, loneliness, anxiety, restricted community participation, and persistent stress [ 4 ]. In 2018, a systematic review asessed the relationship between employment status and CI in patients with MS. The findings demonstrated that CI led to difficulties with employment and reduced working hours [ 5 ]. The global prevalence of MS is estimated to range from 50 to 300 per 100,000 people, affecting 2–3 million individuals worldwide [ 3 ]. Regular evaluation of cognitive function in patients with MS is crucial to detect changes and initiate timely interventions [ 2 ]. Assessment includes evaluating information processing speed, episodic memory, language, and visuospatial skills [ 4 ]. The relationship between brain atrophy and cognitive deficits in MS remains unclear. Clinical observations show instances where CI precedes the detection of cortical atrophy on neuroimaging. Conversely, early cortical atrophy may develop without noticeable CI. However, most cases demonstrate an association between gray matter atrophy and cognitive decline [ 6 ]. In 2012, two-photon in vivo imaging revealed the flow of cerebrospinal fluid (CSF) through the brain’s interstitial space. This system, reliant on glial water transport and waste clearance akin to lymphatic systems, was termed the glymphatic system (GS). In rodent studies, brain clearance of soluble metabolites via the GS involved: 1) CSF flow from basal cisterns to the subarachnoid space and perivascular areas; 2) CSF entry into interstitial fluid (ISF) spaces mediated by aquaporin-4 (AQP4) water channels in astrocytes; 3) transport of the CSF-ISF-metabolite complex to perivenous spaces, exiting through lymphatic vessels and systemic circulation [ 7 , 8 ]. Dysfunction of the GS is linked to aging and neurodegenerative diseases [ 9 , 10 ]. Studies have shown that GS function declines due to astrocytic gliosis, AQP4 polarization loss, and reduced clearance of amyloid-beta and other metabolites in Alzheimer’s disease. [ 9 , 11 ]. Reduced perivascular localization of AQP4 was observed in the frontal cortical gray matter in patients with CI in comparison to subjects without. Similarly, the analysis of diffusion along perivascular space index in multiple sclerosis patients and healthy controls displayed an overall glymphatic impairment in first ones, with more severe affection in primary progressive MS. The reduced glymphatic fluid flow in the perivenous spaces may cause the accumulation of neuroinflammatory triggers in the white matter, thus leading to demyelinating processes [ 12 ]. Considering the abovementioned, the GS dysfunction might be involved into the pathogenesis of CI in both neurodegenerative and neuroinflammatory disorders. Recent studies revealed that amyloid-beta accumulates in the brain of healthy individuals after a single night of sleep deprivation, suggesting the GS dysfunction being a result of decreased sleep quality [ 13 ]. Given these findings, we hypothesized a potential relationship between sleep quality and CI in patients with MS. Methods Data The study included 32 patients with MS without disease-modifying therapy experiencing exacerbations, treated at a tertiary care facility in Odesa, Ukraine. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), while sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Data collected included patients' sex, age, MoCA total scores, and subscores for memory, visuospatial skills, executive function, attention, language, and orientation, as well as PSQI total scores and components (e.g., sleep quality, sleep duration, disturbances). Outcome Assessment MoCA is a widely accepted tool for assessing CI in MS, covering domains such as memory, executive function, attention, and language. A score of ≤ 25 was used to classify CI [ 17 ]. PSQI, a subjective measure of sleep quality over the past month, comprises seven components scored up to 3 points each, with higher scores indicating worse sleep quality [ 14 ]. Statistical Analysis Statistical analyses were conducted using Jamovi (version 2.3.28). Mann-Whitney U test and Spearman correlation analysis were employed, with p < 0.05 considered statistically significant. Results Population Characteristics The study included 20 women (mean age 34.8 ± 7.36) and 12 men (mean age 34.6 ± 10.9). Mann-Whitney U revealed that sex influenced executive function (p = 0.013), but other cognitive and sleep quality measures showed no significant sex differences (p > 0.05). Patients were divided into two groups: 1) normal cognitive function (n = 16); 2) cognitive deficit (n = 16), (Table 1 ). Table 1 Mann-Whitney U test results for MoCA and PSQI parameters between sex groups (male/female). Independent Samples T-Test Mann-Whitney U p-value MoCA total score 105.5 0.581 Visuospatial abilities 106.0 0.571 Executive functions 59.5 0.013 Attention, concentration and working memory 116.0 0.868 Language 108.0 0.605 Short term memory 91.5 0.264 Orientation to time and place 94.5 0.090 Sleep quality 114.0 0.816 Falling asleep time 112.0 0.762 Sleep duration 98.5 0.378 Sleep efficiency 119.5 1.000 Sleep disturbance 117.0 0.914 Hypnotic use 98.5 0.230 Daytime disfunction 105.5 0.570 PSQI Total Score 120.0 1.000 Note: Hₐ µM ≠ µF MoCA parameters across groups MoCA total scores, executive functions, short term memory, attention, concentration, and working memory were significantly lower in the CI group compared to the normal cognitive function group (p 0.05), (Table 2 ). Table 2 Mann-Whitney U test results for MoCA parameters across groups with and without CI. Independent Samples T-Test Mann-Whitney U p-value MoCA total score 0.0 < .001 Visuospatial abilities 103.0 0.160 Executive functions 87.0 0.051 Attention, concentration and working memory 74.0 0.007 Language 114.0 0.279 Short term memory 41.0 < .001 Orientation to time and place 127.0 0.487 Note: Hₐ µ 1 ˃ µ 2 PSQI Parameters Across Groups PSQI total score, falling asleep time, sleep duration and sleep efficiency were significantly higher in the group with CI (p 0.05), (Table 3 ). Table 3 Mann-Whitney U test results for PSQI parameters across groups with and without CI. Independent Samples t-Test Mann-Whitney U p-value Sleep quality 112.0 0.262 Falling asleep time 62.0 0.005 Sleep duration 44.5 < .001 Sleep efficiency 75.5 0.014 Sleep disturbance 95.0 0.087 Hypnotic use 114.0 0.789 Daytime disfunction 123.0 0.430 PSQI Total Score 61.5 0.006 Note: Hₐ µ 1 < µ 2 PSQI and MoCA Correlation Spearman test showed significant negative correlation between PSQI total score and MoCA total score (Spearman’s rho = -0.392, df = 30, p = 0.013), attention concentration and working memory (Spearman’s rho = -0.381, df = 30, p = 0.016) as well as short memory components (Spearman’s rho = -0.414, df = 30, p = 0.009). Attention, concentration and working memory decline significantly correlated with later falling asleep time (Spearman’s rho = -0.332, df = 30, p = 0.032) and existence of sleep disturbances (Spearman’s rho = -0.431, df = 30, p = 0.007). Short term memory component has a significant negative correlation with falling asleep time (Spearman’s rho = -0.474, df = 30, p = 0.03), sleep duration (Spearman’s rho = -0.371, df = 30, p = 0.018) and sleep efficiency (Spearman’s rho = -0.306, df = 30, p = 0.044). The results are presented in Fig. 1 . PSQI T.: Pittsburgh Sleep Quality Index total score; MoCA T.: Montreal Cognitive Assessment total score; STM: short term memory; SD: sleep duration; ACWM: attention, concentration and working memory; SE: sleep efficiency; FAT: falling asleep time. Discussion Our study aimed to investigate the potential relationship between sleep quality and CI in patients with MS. To evaluate cognitive function, we used the MoCA scale, where a score of ≤ 25 indicated cognitive impairment. Sleep quality was assessed using the PSQI, with higher scores reflecting poorer sleep quality. Based on the abovementioned results, it can be hypothesized that there is a weak to moderate negative correlation between sleep quality and cognitive performance in patients with MS, given that the GS is primarily active during sleep. The GS is especially active during slow-wave sleep. This activity is associated with a decrease in norepinephrine levels during sleep, leading to a significant increase in interstitial space. Conversely, during wakefulness, CSF flow and the clearance of soluble metabolites are inhibited due to high norepinephrine levels, which reduce interstitial space volume [ 16 ]. A study found that nurses who worked night shifts for over 20 years had an 80% higher risk of developing MS compared to those who worked daytime shifts [ 17 ]. Disruption of the circadian rhythm, which triggers the release of cellular and molecular inflammatory mediators, potentially leading to neuroimmune dysregulation, was proposed as a possible cause of this increased risk. Sleep disturbances affect the expression of genes involved in the synthesis and maintenance of myelin proteins. Additionally, sleep problems reduce the expression of genes necessary for the differentiation of oligodendrocyte precursor cells, which are essential for forming new myelin components in both healthy and damaged brains. Evidence also suggests that sleep disorders increase the expression of apoptotic genes and those responsible for cellular stress, which hinders nerve regeneration in MS [ 18 ]. Shokri-Kojori et al. studied the effects of a single night of sleep deprivation on the clearance of Aβ in the human brain using PET scans. They found that one night of sleep loss significantly increased Aβ burden in the right hippocampus and thalamus, areas critical for cognitive function [ 19 ]. Buratti et al. examined the relationship between sleep quality and clinical manifestations of MS. Patients with relapsing-remitting MS and a PSQI score ≥ 5 in the past month showed a significantly higher likelihood of adverse disease outcomes, including longer and more frequent relapses. This supports the hypothesis that poor sleep quality may impair the ability to recover from MS relapses, possibly due to defects in myelin regeneration [ 20 ]. The correlation between attention, concentration and working memory components and sleep duration was found to be the strongest one and therefore might be a subject of future research. Our study has its limitations in the form of a small group of participants and subjectivity of PSQI results. Conclusions A moderate negative correlation exists between sleep quality scores and cognitive performance, suggesting that poorer sleep may be associated with reduced cognitive function in patients with MS. Declarations Financial Support and Sponsorship None. Conflict of Interest : The authors declare no conflict of interest. Ethics Approval : The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Odesa National Medical University (protocol No. 3, dated March 12, 2025). Patient Consent Informed patient consent was waived by the Ethics Committee of Odesa National Medical University due to the retrospective nature of the study. Ethics and Integrity Statement We were committed to maintaining the highest ethical standards in our research with human participants. Our study received appropriate ethical approval and followed the principles of the Declaration of Helsinki. We prioritized transparency, avoided conflict of interest, and ensured data confidentiality to maintain the integrity of our research. Author Contribution A. Revurko and E. Babych: Data Collection, Methodology, Formal Analysis, Writing – Original Draft, Preparing Figures, Writing – Review & Editing.Y. Solodovnikova: Project Administration, Conceptualization, Methodology, Formal Analysis, Writing – Original Draft, Writing – Review & Editing. Data Availability The datasets generated and analysed during the current study are not publicly available to preserve individuals’ privacy under the European General Data Protection Regulation, but are available from the corresponding author on reasonable request. References Marisa, P. M. G., Carolyn, H., Goldschmidt, A. D. & Rae-Grant Diagnosis and Treatment of Multiple Sclerosis: A Review. JAMA. 2021;325(8):765–779. (2021). https://doi.org/10.1001/jama.2020.26858 Hsu, W. Y. et al. Assessing Cognitive Function in Multiple Sclerosis With Digital Tools: Observational Study. J. Med. Internet Res. e25748. https://doi.org/10.2196/25748 (2021). Alina Ivaniuk, Y., Solodovnikova, T., Marusich, A. & Son The impairment of the functional system and fatigue at the onset of the disease predict reaching disability milestones in relapsing–remitting multiple sclerosis diferently in female and male patients. Acta Neurol. Belgica . https://doi.org/10.1007/s13760-020-01478-0 (2020). Agland, J. L. S. S., Allan, M., Darby, D., Diamond, K. & van der Merlo, D. Walt Managing cognitive impairment and its impact in multiple sclerosis: An Australian multidisciplinary perspective. Multiple Sclerosis and Related Disoders 79 (2023) 104952. (2023). https://doi.org/10.1016/j.msard.2023.104952 Clemens, L. & Langdon, D. How does cognition relate to employment in multiple sclerosis? A systematic review. Mult Scler. Relat. Disord . https://doi.org/10.1016/j.msard.2018.09.018 (2018). Benedict, R. H. B., Amato, M. P., DeLuca, J. & Geurts, J. J. G. Cognitive impairment in multiple sclerosis: clinical management, MRI, and therapeutic avenues. Lancet Neurol. 19 (10), 860–871. https://doi.org/10.1016/S1474-4422(20)30277-5 (2020). Iliff, J. J. et al. A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid. Sci. Transl. Med. 4 (147), 147ra111–147ra111. https://doi.org/10.1126/scitranslmed.3003748 (2012). Iliff, J. & Simon, M. CrossTalk proposal: the glymphatic system supports convective exchange of cerebrospinal fluid and brain interstitial fluid that is mediated by perivascular aquaporin-4. J. Physiol. 597 , 4417–4419. https://doi.org/10.1113/JP277635 (2019). Kress, B. T. et al. Impairment of paravascular clearance pathways in the aging brain. Ann. Neurol. 76 (6), 845–861. https://doi.org/10.1002/ana.24271 (2014). Peng, W. et al. Suppression of glymphatic fluid transport in a mouse model of Alzheimer’s disease. Neurobiol. Dis. 93 , 215–225. https://doi.org/10.1016/j.nbd.2016.05.015 (2016). Szlufik, S., Kopeć, K., Szleszkowski, S. & Koziorowski, D. Glymphatic System Pathology and Neuroinflammation as Two Risk Factors of Neurodegeneration. Cells 13 (3), 286. https://doi.org/10.3390/cells13030286 (2024). Antonio Carotenuto, L. et al. Glymphatic system impairment in multiple sclerosis: relation with brain damage and disability, Brain, 145, Issue 8, August 2022, Pages 2785–2795. https://doi.org/10.1093/brain/awab454 Rasmussen, M. K., Mestre, H. & Nedergaard, M. The glymphatic pathway in neurological disorders. Lancet Neurol. 17 (11), 1016–1024. https://doi.org/10.1016/S1474-4422(18)30318-1 (2018). Nasreddine, Z. S., Phillips, N. A., Bedirian, V., Charbonneau, S., Whitehead, V.,Collin, I., … Chertkow, H. (2005). The Montreal Cognitive Assessment, MoCA: A Brief Screening Tool For Mild Cognitive Impairment. Journal of the American Geriatrics Society,53(4), 695–699. https://doi.org/10.1111/j.1532-5415.2005.53221.x. Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R. & Kupfer, D. J. The Pittsburgh sleep quality index: A new instrument for psychiatric practice and research. Psychiatry Res. 28 (2), 193–213. https://doi.org/10.1016/0165-1781(89)90047-4 (1989). Alaa Alghanimy, L. M., Work, W. M. & Holmes The glymphatic system and multiple sclerosis: An evolving connection. Multiple Sclerosis and Related Disoders 83 (2024) 105456. (2024). https://doi.org/10.1016/j.msard.2024.105456 Papantoniou, K. et al. Rotating night shift work and risk of multiple sclerosis in the Nurses’ Health Studies (Occupational and Environmental Medicine, 2019). https://doi.org/10.1136/oemed-2019-106016 oemed–2019–106016. Bishir, M. et al. Sleep Deprivation and Neurological Disorders. BioMed Research International, 2020, 1–19. (2020). https://doi.org/10.1155/2020/5764017 Shokri-Kojori, E., Wang, G.-J., Wiers, C. E., Demiral, S. B., Guo, M., Kim, S. W.,… Volkow, N. D. (2018). β-Amyloid accumulation in the human brain after one night of sleep deprivation. Proceedings of the National Academy of Sciences, 115(17), 4483–4488. https://doi.org/10.1073/pnas.1721694115. Buratti, L. et al. Sleep quality can influence the outcome of patients with multiple sclerosis. Sleep Med. 58 , 56–60. https://doi.org/10.1016/j.sleep.2019.02.020 (2019). Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6276602","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":484495453,"identity":"0bb8fc14-1af5-4460-b6e4-e7a3e7014c4e","order_by":0,"name":"Anastasiia Revurko","email":"","orcid":"","institution":"Odesa National Medical University","correspondingAuthor":false,"prefix":"","firstName":"Anastasiia","middleName":"","lastName":"Revurko","suffix":""},{"id":484495454,"identity":"73f9ee05-659d-4be7-93ce-ac629cab121a","order_by":1,"name":"Eliza Babych","email":"data:image/png;base64,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","orcid":"","institution":"Odesa National Medical University","correspondingAuthor":true,"prefix":"","firstName":"Eliza","middleName":"","lastName":"Babych","suffix":""},{"id":484495455,"identity":"7bcede23-1bed-4fed-a5aa-a3758fb5f540","order_by":2,"name":"Yuliia Solodovnikova","email":"","orcid":"","institution":"Odesa National Medical University","correspondingAuthor":false,"prefix":"","firstName":"Yuliia","middleName":"","lastName":"Solodovnikova","suffix":""}],"badges":[],"createdAt":"2025-03-21 10:23:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6276602/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6276602/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":86675472,"identity":"3001c54b-c3aa-4a4c-997c-e8d2e11cf446","added_by":"auto","created_at":"2025-07-14 11:59:14","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":107895,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSpearman correlation between PSQI and MoCA Parameters\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-6276602/v1/4223be1ba3d340906198ca1a.png"},{"id":103741091,"identity":"0a95fa51-3d7a-4128-b364-052ae727998a","added_by":"auto","created_at":"2026-03-02 10:57:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":702833,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6276602/v1/c8141c96-9510-4f26-b6e1-e91276eeb097.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eThe Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMultiple sclerosis (MS) is a chronic inflammatory neurodegenerative disease and a leading cause of severe disability in young adults [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. MS has a wide range of manifestations which depend on the loci of demyelination lesions in the central nervous system (CNS) and include sensory, motor, visual disturbances, balance disorders, pelvic organ dysfunction, as well as cognitive and emotional impairments. Cognitive impairments (CI) affect 30\u0026ndash;70% of patients with MS and can occur even in the absence of other deficits. CI are among the most debilitating manifestations of MS, significantly impacting patients' quality of life, hindering their social activity and employment [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Disease-related unemployment can result in social and psychological consequences, such as depression, loneliness, anxiety, restricted community participation, and persistent stress [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn 2018, a systematic review asessed the relationship between employment status and CI in patients with MS. The findings demonstrated that CI led to difficulties with employment and reduced working hours [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The global prevalence of MS is estimated to range from 50 to 300 per 100,000 people, affecting 2\u0026ndash;3\u0026nbsp;million individuals worldwide [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Regular evaluation of cognitive function in patients with MS is crucial to detect changes and initiate timely interventions [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Assessment includes evaluating information processing speed, episodic memory, language, and visuospatial skills [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe relationship between brain atrophy and cognitive deficits in MS remains unclear. Clinical observations show instances where CI precedes the detection of cortical atrophy on neuroimaging. Conversely, early cortical atrophy may develop without noticeable CI. However, most cases demonstrate an association between gray matter atrophy and cognitive decline [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn 2012, two-photon in vivo imaging revealed the flow of cerebrospinal fluid (CSF) through the brain\u0026rsquo;s interstitial space. This system, reliant on glial water transport and waste clearance akin to lymphatic systems, was termed the glymphatic system (GS). In rodent studies, brain clearance of soluble metabolites via the GS involved: 1) CSF flow from basal cisterns to the subarachnoid space and perivascular areas; 2) CSF entry into interstitial fluid (ISF) spaces mediated by aquaporin-4 (AQP4) water channels in astrocytes; 3) transport of the CSF-ISF-metabolite complex to perivenous spaces, exiting through lymphatic vessels and systemic circulation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Dysfunction of the GS is linked to aging and neurodegenerative diseases [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Studies have shown that GS function declines due to astrocytic gliosis, AQP4 polarization loss, and reduced clearance of amyloid-beta and other metabolites in Alzheimer\u0026rsquo;s disease. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Reduced perivascular localization of AQP4 was observed in the frontal cortical gray matter in patients with CI in comparison to subjects without. Similarly, the analysis of diffusion along perivascular space index in multiple sclerosis patients and healthy controls displayed an overall glymphatic impairment in first ones, with more severe affection in primary progressive MS. The reduced glymphatic fluid flow in the perivenous spaces may cause the accumulation of neuroinflammatory triggers in the white matter, thus leading to demyelinating processes [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Considering the abovementioned, the GS dysfunction might be involved into the pathogenesis of CI in both neurodegenerative and neuroinflammatory disorders. Recent studies revealed that amyloid-beta accumulates in the brain of healthy individuals after a single night of sleep deprivation, suggesting the GS dysfunction being a result of decreased sleep quality [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Given these findings, we hypothesized a potential relationship between sleep quality and CI in patients with MS.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eData\u003c/h2\u003e\u003cp\u003eThe study included 32 patients with MS without disease-modifying therapy experiencing exacerbations, treated at a tertiary care facility in Odesa, Ukraine. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), while sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Data collected included patients' sex, age, MoCA total scores, and subscores for memory, visuospatial skills, executive function, attention, language, and orientation, as well as PSQI total scores and components (e.g., sleep quality, sleep duration, disturbances).\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eOutcome Assessment\u003c/h3\u003e\n\u003cp\u003eMoCA is a widely accepted tool for assessing CI in MS, covering domains such as memory, executive function, attention, and language. A score of \u0026le;\u0026thinsp;25 was used to classify CI [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. PSQI, a subjective measure of sleep quality over the past month, comprises seven components scored up to 3 points each, with higher scores indicating worse sleep quality [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eStatistical analyses were conducted using Jamovi (version 2.3.28). Mann-Whitney U test and Spearman correlation analysis were employed, with p\u0026thinsp;\u0026lt;\u0026thinsp;0.05 considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003ePopulation Characteristics\u003c/h2\u003e\u003cp\u003eThe study included 20 women (mean age 34.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.36) and 12 men (mean age 34.6\u0026thinsp;\u0026plusmn;\u0026thinsp;10.9). Mann-Whitney U revealed that sex influenced executive function (p\u0026thinsp;=\u0026thinsp;0.013), but other cognitive and sleep quality measures showed no significant sex differences (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05). Patients were divided into two groups: 1) normal cognitive function (n\u0026thinsp;=\u0026thinsp;16); 2) cognitive deficit (n\u0026thinsp;=\u0026thinsp;16), (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMann-Whitney U test results for MoCA and PSQI parameters between sex groups (male/female).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eIndependent Samples T-Test\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMann-Whitney U\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003ep-value\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMoCA total score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e105.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.581\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVisuospatial abilities\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e106.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.571\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eExecutive functions\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e59.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.013\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAttention, concentration and working memory\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e116.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.868\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLanguage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e108.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.605\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eShort term memory\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e91.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.264\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOrientation to time and place\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e94.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.090\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep quality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e114.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.816\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFalling asleep time\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e112.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.762\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep duration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e98.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.378\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep efficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e119.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep disturbance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e117.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.914\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypnotic use\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e98.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.230\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDaytime disfunction\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e105.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.570\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePSQI Total Score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e120.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1.000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eNote: Hₐ \u0026micro;M\u0026thinsp;\u0026ne;\u0026thinsp;\u0026micro;F\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003eMoCA parameters across groups\u003c/h2\u003e\u003cp\u003eMoCA total scores, executive functions, short term memory, attention, concentration, and working memory were significantly lower in the CI group compared to the normal cognitive function group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). No significant differences were observed for visuospatial skills, language, or orientation (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05), (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMann-Whitney U test results for MoCA parameters across groups with and without CI.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eIndependent Samples T-Test\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMann-Whitney U\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003ep-value\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMoCA total score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVisuospatial abilities\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e103.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.160\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eExecutive functions\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e87.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.051\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAttention, concentration and working memory\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e74.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.007\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLanguage\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e114.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.279\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eShort term memory\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e41.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOrientation to time and place\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e127.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.487\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eNote: Hₐ \u0026micro;\u0026thinsp;\u003csub\u003e1\u003c/sub\u003e ˃ \u0026micro;\u0026thinsp;\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003ePSQI Parameters Across Groups\u003c/h3\u003e\n\u003cp\u003ePSQI total score, falling asleep time, sleep duration and sleep efficiency were significantly higher in the group with CI (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05). Other PSQI individual components did not showed differences between the two groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05), (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMann-Whitney U test results for PSQI parameters across groups with and without CI.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eIndependent Samples t-Test\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eMann-Whitney U\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u003cb\u003ep-value\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep quality\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e112.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.262\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFalling asleep time\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e62.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep duration\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e44.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep efficiency\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e75.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.014\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep disturbance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e95.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.087\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypnotic use\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e114.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.789\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDaytime disfunction\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e123.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.430\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePSQI Total Score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e61.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0.006\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e\u003cp\u003eNote: Hₐ \u0026micro;\u0026thinsp;\u003csub\u003e1\u003c/sub\u003e \u0026lt; \u0026micro;\u0026thinsp;\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\n\u003ch3\u003ePSQI and MoCA Correlation\u003c/h3\u003e\n\u003cp\u003eSpearman test showed significant negative correlation between PSQI total score and MoCA total score (Spearman\u0026rsquo;s rho = -0.392, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.013), attention concentration and working memory (Spearman\u0026rsquo;s rho = -0.381, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.016) as well as short memory components (Spearman\u0026rsquo;s rho = -0.414, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.009).\u003c/p\u003e\u003cp\u003eAttention, concentration and working memory decline significantly correlated with later falling asleep time (Spearman\u0026rsquo;s rho = -0.332, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.032) and existence of sleep disturbances (Spearman\u0026rsquo;s rho = -0.431, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.007).\u003c/p\u003e\u003cp\u003eShort term memory component has a significant negative correlation with falling asleep time (Spearman\u0026rsquo;s rho = -0.474, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.03), sleep duration (Spearman\u0026rsquo;s rho = -0.371, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.018) and sleep efficiency (Spearman\u0026rsquo;s rho = -0.306, df\u0026thinsp;=\u0026thinsp;30, p\u0026thinsp;=\u0026thinsp;0.044). The results are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003ePSQI T.: Pittsburgh Sleep Quality Index total score; MoCA T.: Montreal Cognitive Assessment total score; STM: short term memory; SD: sleep duration; ACWM: attention, concentration and working memory; SE: sleep efficiency; FAT: falling asleep time.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur study aimed to investigate the potential relationship between sleep quality and CI in patients with MS. To evaluate cognitive function, we used the MoCA scale, where a score of \u0026le;\u0026thinsp;25 indicated cognitive impairment. Sleep quality was assessed using the PSQI, with higher scores reflecting poorer sleep quality.\u003c/p\u003e\u003cp\u003eBased on the abovementioned results, it can be hypothesized that there is a weak to moderate negative correlation between sleep quality and cognitive performance in patients with MS, given that the GS is primarily active during sleep.\u003c/p\u003e\u003cp\u003eThe GS is especially active during slow-wave sleep. This activity is associated with a decrease in norepinephrine levels during sleep, leading to a significant increase in interstitial space. Conversely, during wakefulness, CSF flow and the clearance of soluble metabolites are inhibited due to high norepinephrine levels, which reduce interstitial space volume [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA study found that nurses who worked night shifts for over 20 years had an 80% higher risk of developing MS compared to those who worked daytime shifts [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Disruption of the circadian rhythm, which triggers the release of cellular and molecular inflammatory mediators, potentially leading to neuroimmune dysregulation, was proposed as a possible cause of this increased risk. Sleep disturbances affect the expression of genes involved in the synthesis and maintenance of myelin proteins. Additionally, sleep problems reduce the expression of genes necessary for the differentiation of oligodendrocyte precursor cells, which are essential for forming new myelin components in both healthy and damaged brains. Evidence also suggests that sleep disorders increase the expression of apoptotic genes and those responsible for cellular stress, which hinders nerve regeneration in MS [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eShokri-Kojori et al. studied the effects of a single night of sleep deprivation on the clearance of Aβ in the human brain using PET scans. They found that one night of sleep loss significantly increased Aβ burden in the right hippocampus and thalamus, areas critical for cognitive function [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eBuratti et al. examined the relationship between sleep quality and clinical manifestations of MS. Patients with relapsing-remitting MS and a PSQI score\u0026thinsp;\u0026ge;\u0026thinsp;5 in the past month showed a significantly higher likelihood of adverse disease outcomes, including longer and more frequent relapses. This supports the hypothesis that poor sleep quality may impair the ability to recover from MS relapses, possibly due to defects in myelin regeneration [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe correlation between attention, concentration and working memory components and sleep duration was found to be the strongest one and therefore might be a subject of future research.\u003c/p\u003e\u003cp\u003eOur study has its limitations in the form of a small group of participants and subjectivity of PSQI results.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eA moderate negative correlation exists between sleep quality scores and cognitive performance, suggesting that poorer sleep may be associated with reduced cognitive function in patients with MS.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFinancial Support and Sponsorship\u003c/strong\u003e\u003cp\u003eNone.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003ch2\u003e\u003cb\u003eConflict of Interest\u003c/b\u003e:\u003c/h2\u003e\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u003cb\u003eEthics Approval\u003c/b\u003e:\u003c/strong\u003e\u003cp\u003e The study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of Odesa National Medical University (protocol No. 3, dated March 12, 2025).\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ePatient Consent\u003c/strong\u003e\u003cp\u003e Informed patient consent was waived by the Ethics Committee of Odesa National Medical University due to the retrospective nature of the study.\u003c/p\u003e\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eEthics and Integrity Statement\u003c/strong\u003e\u003cp\u003e We were committed to maintaining the highest ethical standards in our research with human participants. Our study received appropriate ethical approval and followed the principles of the Declaration of Helsinki. We prioritized transparency, avoided conflict of interest, and ensured data confidentiality to maintain the integrity of our research.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eA. Revurko and E. Babych: Data Collection, Methodology, Formal Analysis, Writing \u0026ndash; Original Draft, Preparing Figures, Writing \u0026ndash; Review \u0026amp; Editing.Y. Solodovnikova: Project Administration, Conceptualization, Methodology, Formal Analysis, Writing \u0026ndash; Original Draft, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and analysed during the current study are not publicly available to preserve individuals\u0026rsquo; privacy under the European General Data Protection Regulation, but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eMarisa, P. M. G., Carolyn, H., Goldschmidt, A. D. \u0026amp; Rae-Grant Diagnosis and Treatment of Multiple Sclerosis: A Review. JAMA. 2021;325(8):765\u0026ndash;779. (2021). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1001/jama.2020.26858\u003c/span\u003e\u003cspan address=\"10.1001/jama.2020.26858\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHsu, W. Y. et al. Assessing Cognitive Function in Multiple Sclerosis With Digital Tools: Observational Study. \u003cem\u003eJ. Med. Internet Res.\u003c/em\u003e e25748. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2196/25748\u003c/span\u003e\u003cspan address=\"10.2196/25748\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlina Ivaniuk, Y., Solodovnikova, T., Marusich, A. \u0026amp; Son The impairment of the functional system and fatigue at the onset of the disease predict reaching disability milestones in relapsing\u0026ndash;remitting multiple sclerosis diferently in female and male patients. \u003cem\u003eActa Neurol. Belgica\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s13760-020-01478-0\u003c/span\u003e\u003cspan address=\"10.1007/s13760-020-01478-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAgland, J. L. S. S., Allan, M., Darby, D., Diamond, K. \u0026amp; van der Merlo, D. Walt Managing cognitive impairment and its impact in multiple sclerosis: An Australian multidisciplinary perspective. Multiple Sclerosis and Related Disoders 79 (2023) 104952. (2023). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.msard.2023.104952\u003c/span\u003e\u003cspan address=\"10.1016/j.msard.2023.104952\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eClemens, L. \u0026amp; Langdon, D. How does cognition relate to employment in multiple sclerosis? A systematic review. \u003cem\u003eMult Scler. Relat. Disord\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.msard.2018.09.018\u003c/span\u003e\u003cspan address=\"10.1016/j.msard.2018.09.018\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBenedict, R. H. B., Amato, M. P., DeLuca, J. \u0026amp; Geurts, J. J. G. Cognitive impairment in multiple sclerosis: clinical management, MRI, and therapeutic avenues. \u003cem\u003eLancet Neurol.\u003c/em\u003e \u003cb\u003e19\u003c/b\u003e (10), 860\u0026ndash;871. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S1474-4422(20)30277-5\u003c/span\u003e\u003cspan address=\"10.1016/S1474-4422(20)30277-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIliff, J. J. et al. A Paravascular Pathway Facilitates CSF Flow Through the Brain Parenchyma and the Clearance of Interstitial Solutes, Including Amyloid. \u003cem\u003eSci. Transl. Med.\u003c/em\u003e \u003cb\u003e4\u003c/b\u003e (147), 147ra111\u0026ndash;147ra111. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1126/scitranslmed.3003748\u003c/span\u003e\u003cspan address=\"10.1126/scitranslmed.3003748\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIliff, J. \u0026amp; Simon, M. CrossTalk proposal: the glymphatic system supports convective exchange of cerebrospinal fluid and brain interstitial fluid that is mediated by perivascular aquaporin-4. \u003cem\u003eJ. Physiol.\u003c/em\u003e \u003cb\u003e597\u003c/b\u003e, 4417\u0026ndash;4419. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1113/JP277635\u003c/span\u003e\u003cspan address=\"10.1113/JP277635\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKress, B. T. et al. Impairment of paravascular clearance pathways in the aging brain. \u003cem\u003eAnn. Neurol.\u003c/em\u003e \u003cb\u003e76\u003c/b\u003e (6), 845\u0026ndash;861. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/ana.24271\u003c/span\u003e\u003cspan address=\"10.1002/ana.24271\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2014).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng, W. et al. Suppression of glymphatic fluid transport in a mouse model of Alzheimer\u0026rsquo;s disease. \u003cem\u003eNeurobiol. Dis.\u003c/em\u003e \u003cb\u003e93\u003c/b\u003e, 215\u0026ndash;225. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.nbd.2016.05.015\u003c/span\u003e\u003cspan address=\"10.1016/j.nbd.2016.05.015\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSzlufik, S., Kopeć, K., Szleszkowski, S. \u0026amp; Koziorowski, D. Glymphatic System Pathology and Neuroinflammation as Two Risk Factors of Neurodegeneration. \u003cem\u003eCells\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e (3), 286. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/cells13030286\u003c/span\u003e\u003cspan address=\"10.3390/cells13030286\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2024).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAntonio Carotenuto, L. et al. Glymphatic system impairment in multiple sclerosis: relation with brain damage and disability, Brain, 145, Issue 8, August 2022, Pages 2785\u0026ndash;2795. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1093/brain/awab454\u003c/span\u003e\u003cspan address=\"10.1093/brain/awab454\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRasmussen, M. K., Mestre, H. \u0026amp; Nedergaard, M. The glymphatic pathway in neurological disorders. \u003cem\u003eLancet Neurol.\u003c/em\u003e \u003cb\u003e17\u003c/b\u003e (11), 1016\u0026ndash;1024. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S1474-4422(18)30318-1\u003c/span\u003e\u003cspan address=\"10.1016/S1474-4422(18)30318-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNasreddine, Z. S., Phillips, N. A., Bedirian, V., Charbonneau, S., Whitehead, V.,Collin, I., \u0026hellip; Chertkow, H. (2005). The Montreal Cognitive Assessment, MoCA: A Brief Screening Tool For Mild Cognitive Impairment. Journal of the American Geriatrics Society,53(4), 695\u0026ndash;699. https://doi.org/10.1111/j.1532-5415.2005.53221.x.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBuysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R. \u0026amp; Kupfer, D. J. The Pittsburgh sleep quality index: A new instrument for psychiatric practice and research. \u003cem\u003ePsychiatry Res.\u003c/em\u003e \u003cb\u003e28\u003c/b\u003e (2), 193\u0026ndash;213. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/0165-1781(89)90047-4\u003c/span\u003e\u003cspan address=\"10.1016/0165-1781(89)90047-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1989).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlaa Alghanimy, L. M., Work, W. M. \u0026amp; Holmes The glymphatic system and multiple sclerosis: An evolving connection. Multiple Sclerosis and Related Disoders 83 (2024) 105456. (2024). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.msard.2024.105456\u003c/span\u003e\u003cspan address=\"10.1016/j.msard.2024.105456\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePapantoniou, K. et al. \u003cem\u003eRotating night shift work and risk of multiple sclerosis in the Nurses\u0026rsquo; Health Studies\u003c/em\u003e (Occupational and Environmental Medicine, 2019). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1136/oemed-2019-106016\u003c/span\u003e\u003cspan address=\"10.1136/oemed-2019-106016\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003eoemed\u0026ndash;2019\u0026ndash;106016.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBishir, M. et al. Sleep Deprivation and Neurological Disorders. BioMed Research International, 2020, 1\u0026ndash;19. (2020). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/2020/5764017\u003c/span\u003e\u003cspan address=\"10.1155/2020/5764017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShokri-Kojori, E., Wang, G.-J., Wiers, C. E., Demiral, S. B., Guo, M., Kim, S. W.,\u0026hellip; Volkow, N. D. (2018). β-Amyloid accumulation in the human brain after one night of sleep deprivation. Proceedings of the National Academy of Sciences, 115(17), 4483\u0026ndash;4488. https://doi.org/10.1073/pnas.1721694115.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBuratti, L. et al. Sleep quality can influence the outcome of patients with multiple sclerosis. \u003cem\u003eSleep Med.\u003c/em\u003e \u003cb\u003e58\u003c/b\u003e, 56\u0026ndash;60. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.sleep.2019.02.020\u003c/span\u003e\u003cspan address=\"10.1016/j.sleep.2019.02.020\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2019).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"multiple sclerosis, cognitive impairment, sleep quality, glymphatic system","lastPublishedDoi":"10.21203/rs.3.rs-6276602/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6276602/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCognitive impairments (CI) affect 30-70% of patients with multiple sclerosis (MS) and can occur even in the absence of other deficits. CI are among the most debilitating manifestations, significantly impacting patients' quality of life, hindering their social activity and employment. The article discusses the possible role of sleep disturbances on cognitive performance in patients with MS considering the role of glymphatic system and its activity during sleep.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study included 32 patients with MS without disease-modifying therapy experiencing exacerbations. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), while sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI). Statistical analyses were conducted using Jamovi (version 2.3.28). Mann-Whitney U test and Spearman correlation analysis were employed, with p\u0026lt;0.05 considered statistically significant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMoCA total scores, executive functions, short term memory, attention, concentration, and working memory were significantly lower in the CI group compared to the normal cognitive function group. Attention, concentration and working memory decline significantly correlated with later falling asleep time and existence of sleep disturbances. Short term memory component has a significant negative correlation with falling asleep time, sleep duration and sleep efficiency. Spearman test showed significant negative correlation between PSQI total score and MoCA total score, attention concentration and working memory as well as short memory components.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA moderate negative correlation exists between sleep quality scores and cognitive performance, suggesting that poorer sleep may be associated with reduced cognitive function in patients with MS.\u003c/p\u003e","manuscriptTitle":"The Influence of Sleep Quality on Cognitive Performance in Patients With Multiple Sclerosis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-14 11:51:10","doi":"10.21203/rs.3.rs-6276602/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bf00dd55-e49b-461a-a80d-b1cf6cad88b7","owner":[],"postedDate":"July 14th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":51491138,"name":"Health sciences/Neurology"},{"id":51491139,"name":"Health sciences/Neurology/Neurological disorders/Multiple sclerosis"},{"id":51491140,"name":"Health sciences/Neurology/Neurological disorders/Sleep disorders"},{"id":51491141,"name":"Health sciences/Neurology"},{"id":51491142,"name":"Health sciences/Neurology/Neurological disorders/Multiple sclerosis"},{"id":51491143,"name":"Health sciences/Neurology/Neurological disorders/Sleep disorders"}],"tags":[],"updatedAt":"2026-03-02T10:56:48+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-14 11:51:10","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6276602","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6276602","identity":"rs-6276602","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}