Etiology and course of cerebellar ataxia: A study from eastern India

Objective: The course of various cerebellar ataxia disorders in our population is relatively unexplored, especially beyond the hereditary spinocerebellar ataxias (SCA). This study was conducted to objectively assess the severity and progression of various disorders causing the cerebellar ataxia. Materials and Methods: This longitudinal prospective study evaluated the etiologies and the corresponding severity and progression of the cerebellar ataxia. Clinical examination and the relevant investigations were performed. The severity of ataxia was assessed using the Scale for Assessment and Rating of Ataxia (SARA) - at initial presentation and another at 6 months of follow-up, and the change in SARA scores were calculated to find the disease progression. Results: Out of 145 patients studied, SCA predominated followed by Autoimmune/paraneoplastic disorders, Multiple System Atrophy-Cerebellar (MSA-C), Wilson's disease, and Multiple sclerosis. On follow-up, human immunodeficiency virus (HIV) associated progressive multifocal leukoencephalopathy was the most rapidly advancing disease, followed by MSA-C, Friedreich's ataxia, and Huntington's disease, all of which progressed faster than SCA. SCA 3 emerged as the most progressive SCA followed by SCA 1, SCA 6, SCA 2, and SCA 12. The autoimmune etiologies showed favorable response to treatment, although with some variability across the different disorders. In the paraneoplastic category, anti Tr associated ataxia improved better than other disorders. Multiple sclerosis and other treatable disorders also responded to treatment. Conclusion: Cerebellar ataxia is the predominant clinical feature in a wide variety of disorders. While some are progressive, others are responsive to treatment, the extent of which differed according to the etiology.