Current Journal of Neurology

Association between chronic tobacco smoking and cognitive function in persons with multiple sclerosis

Articles in Press

Document Type : Original Article

Authors

Turhan Kahraman 1
Irem Kara 2
Gozde Deniz Unal 2
Yasemin Simsek 2
Ela Simay Zengin 2
Serkan Ozakbas 3

1 Department of Physiotherapy and Rehabilitation, Faculty of Health Sciences, Izmir Katip Celebi University, Izmir, Turkey

2 Center for Treatment and Research of Neuroimmunological Disorders, Izmir University of Economics, Medical Point Hospital, Izmir, Turkey

3 Center for Treatment and Research of Neuroimmunological Disorders, Izmir University of Economics, Medical Point Hospital, Izmir, Turkey Department of Neurology, Faculty of Medicine, Izmir University of Economics, Izmir, Turkey Multiple Sclerosis Research Association, Izmir, Turkey

Abstract
Background: Cognitive impairment is common in multiple sclerosis (MS) and can markedly influence individuals’ quality of life (QOL). Understanding the factors influencing cognitive dysfunction in MS is essential for developing targeted interventions. Smoking, a modifiable risk factor linked to numerous adverse outcomes in MS, has an unclear relationship with cognitive function. This comparative study with cross-sectional data collection aimed to examine the association between smoking and cognitive performance in persons with MS.
Methods: A total of 152 participants with MS were recruited, comprising 76 smokers and 76 non-smokers. Cognitive function was assessed using the Brief International Cognitive Assessment for MS (BICAMS), which includes the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II), and Brief Visuospatial Memory Test-Revised (BVMT-R). Cognitive impairment was defined as scores below 1.5 standard deviations (SDs) from the mean, and tobacco exposure was quantified in terms of pack-years. Analyses controlled for potential confounders such as age, education, and Expanded Disability Status Scale (EDSS) scores.
Results: Smokers performed significantly worse on the CVLT-II and BVMT-R (P < 0.05), while no differences were observed on the SDMT. After adjusting for confounders, only BVMT-R performance remained significantly associated with smoking status (P = 0.009, η²p  = 0.049). Smokers had higher odds of cognitive impairment on the BVMT-R [odds ratio (OR) = 11.8, P = 0.002]. Additionally, pack-year exposure correlated with declines in BVMT-R and CVLT-II scores (P < 0.05).
Conclusion: These findings indicate an association between smoking and cognitive performance in MS, particularly in visuospatial and verbal memory domains. Further research is needed to explore underlying mechanisms and inform clinical strategies.
 

Keywords

Multiple Sclerosis
Smoking
Cognition
Memory
Function
Subjects
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Current Journal of Neurology

Articles in Press, Accepted Manuscript
Available Online from 24 March 2026

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