113. Unusual spinal epidural cyst mimicking Hirayama disease

Introduction: Spinocerebellar ataxia type 7 (SCA7) is an autosomal-dominant, late-onset and slowly progressive neurodegenerative disorder, primarily characterized by gradual loss of motor coordination, resulting from dysfunction and degeneration of the cerebellum, basal ganglia, brainstem, cerebral cortex, and their connecting pathways. The authors sought to describe SCA7 observed in a family. Case reports: Case 1: An 8-year-old boy showed progressive ataxia, tremor, visual impairment, mental retardation, and decreased physical endurance. Brain magnetic resonance imaging (MRI) displayed severe atrophy involving cerebellar hemispheres, vermis, and brainstem. His CAG repeat of ataxin 7 (ATXN7) was abnormal (81 repeats). After rehabilitation management, ataxia and tremor improved slightly, but remained. The family pedigree of these patients showed that some family members of the paternal line presented progressive ataxia. Case 2: A 38-year-old man showed decreased visual acuity, intention tremor, ataxia, and weakness of both lower extremities for 4 years. Brain MRI revealed atrophy involving brain stem, both cerebellar hemispheres and vermis. His CAG repeat of ATXN7 was abnormal (46 repeats). He did not show any significant aggravation of symptoms during the admission period. Conclusion: SCA7 was diagnosed by confirming abnormal expansion of CAG in the ATXN7 gene. It was also determined that SCA7 patients have a broad spectrum of phenotypic abnormalities depending on the number of CAG repeats even in a family. The authors report two cases of SCA7 observed in a family, which is very rare. * This abstract was presented at 38th National Congress Meeting of the Korean Academy of Rehabilitation Medicine.