Evaluation of Various Movement Disorders in Patients of Genetically Proven Spinocerebellar Ataxia: A Study from a Tertiary Care Center in Northern India

BACKGROUND: Movement disorders are one of the prominent nonataxic symptoms in patients of spinocerebellar ataxia (SCA). The type of movement disorder may provide clinical clue to the type of SCA. OBJECTIVE: The objective of this study is to evaluate various movement disorders in patients of genetically proven SCAs and to establish a probable clinico-genetic correlation. METHODS: Ninety-Five patients of genetically proven SCAs were assessed for the presence of various movement disorders. RESULTS: Patients with SCA (75.8% males) with at least one movement disorder contributed 43.16%. Age for onset of movement disorder was 43.39 ± 13.43 years. SCA-12 (38.95%) was the most common subtype. Among the patients with at least one movement disorder, action tremor of hands contributed majority (90.2%). Dystonia and parkinsonism were present in 17.07% and 12.2% of patients (with movement disorder), respectively. Action tremor of hands was present in 34 patients with SCA-12 (91.89%), and 20 patients (54.05%) had onset of hand tremor preceding the onset of ataxia. Majority of patients with SCA-12 (81%) were of the same ethnic origin belonging to Agrawal community. Patients with movement disorder had a later onset (45 ± 13.88 years) of ataxic symptoms compared to those without a movement disorder (32.8 ± 11.92) (P = <0.0005). There was no significant association between severity of ataxia and presence of movement disorder. CONCLUSION: Movement disorders are present in about 43% of patients with SCA and can precede or succeed the onset of ataxia. Tremor onset SCA predicted SCA-12, especially in Agrawal community.