Tremor in Patients with Relapsing-Remitting Multiple Sclerosis: Clinical Characteristics and Impact on Quality of Life

Background: Little is known about the prevalence and clinical characteristics of tremors in patients with multiple sclerosis (MS), their associated clinical disability, and their impact on quality of life (QoL). Objective: This study aimed to investigate the frequency and types of tremors in patients with relapsing remitting MS (RRMS) in remission, and their impact on patients’ QoL. Methods: A total of 250 patients with RRMS in remission were examined for tremors. All patients were assessed using the Expanded Disability Status Scale (EDSS). Patients with tremors underwent further assessment using the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTRS), the Beck Depression Inventory (BDI), the Montreal Cognitive Assessment (MoCA) scale, and the Short Form 36 Health Survey Questionnaire (SF-36). Brain MRI was obtained for a subgroup of patients. Results: Tremors were detected in 36 patients (14.4%) and were associated with significantly worse EDSS scores, BDI (P = 0.021), MoCA, most SF-36 domains, higher total and last year relapses (P < 0.001) and longer disease duration (P = 0.027). Patients with tremors showed higher lesion load (P = 0.007), more infratentorial (P ≤ 0.001), cerebellar and diencephalic lesions (P = 0.024), and cortical atrophy (P = 0.012). Total FTMTRS was significantly correlated to age, EDSS, and physical functioning. Dystonia was associated with tremors in 17 patients (6.8% of total RRMS patients and 47.2% of patients with tremors). Conclusion: The current study confirms the common occurrence of tremors and their subtypes among patients with RRMS with mild disability and demonstrates their association with increased disability and impaired QoL.