Prevalence of Tremors in Patients With Multiple Sclerosis: A Cross-Sectional Study in Isfahan, Iran

Background: Multiple Sclerosis (MS) is a demyelinating disorder of the central nervous system. Tremors are a common problem in the patients suffering from MS which is mostly observed in the arms but can also affect the other body parts. There have been few studies on tremors among the MS patients.  Objectives: This study is the first to report the prevalence of tremor in a group of MS patients in Iran. We have also reported the possible associations between the presence of tremor and different forms of ataxia.  Materials & Methods: This study was performed on a group of MS patients in Alzahra hospital, Isfahan, Iran. Patients were interviewed, and a neurologist carried out the neurological examinations, including the evaluation of the type of tremor with the help of Expanded Disability Status Scale (EDSS); ataxia clinical scale for dysmetria, dysdiadochokinesia, dysarthria and gait ataxia. Movement Disorder Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) part 3.15 to 3.17 was also used for tremor classification. Tremor-related disability and handicap were scored by using Disability and Handicap Questionnaires.  Results: Out of the 164 patients, 113 had tremor (69%) of which 23 were males (20%), and 90 were females (80%). A strong correlation between tremor and ataxia was reported while there were no correlations between tremor and patient’s gender, type of MS or the first clinical presentation. Twenty-three of the 164 patients suffered from the incapacitating tremor and had serious problems doing certain tasks. We also reported tremor to greatly affect the daily activities. Conclusion: The frequency of tremor in MS is relatively high. Strong correlation is between tremor and ataxia but not with the gender, the type of MS or the first clinical presentation. The tremor of MS greatly affected the activities of the daily living.