The Etiologies of Chronic Progressive Cerebellar Ataxia in a Korean Population.

background and purposeThe etiologies and frequencies of cerebellar ataxias vary between countries. Our primary aim was to determine the frequency of each diagnostic group of cerebellar ataxia patients in a Korean population.

methodsWe reviewed the medical records of patients who were being followed up between November 1994 and February 2016. We divided patients with cerebellar ataxias into familial and non-familial groups and analyzed the frequency of each etiology. Finally, we categorized patients into genetic, sporadic, secondary, and suspected genetic, but undetermined ataxia.

resultsA total of 820 patients were included in the study, among whom 136 (16.6%) familial patients and 684 (83.4%) non-familial cases were identified. Genetic diagnoses confirmed 98/136 (72%) familial and 72/684 (11%) nonfamilial patients. The overall etiologies of progressive ataxias comprised 170 (20.7%) genetic, 516 (62.9%) sporadic, 43 (5.2%) secondary, and 91 (11.1%) undetermined ataxia. The most common cause of ataxia was multiple-system atrophy (57.3%). In the genetic group, the most common etiology was spinocerebellar ataxia (152/170, 89.4%) and the most common subtype was spinocerebellar ataxia-3.38 of 136 familial and 53 of 684 sporadic cases (91/820, 11.1%) were undetermined ataxia.

conclusionsThis is the largest epidemiological study to analyze the frequencies of various cerebellar ataxias in a Korean population based on the large database of a tertiary hospital movement-disorders clinic in South Korea. These data would be helpful for clinicians in constructing diagnostic strategies and counseling for patients with cerebellar ataxias.