Neuropathology of spinocerebellar ataxia type 8: Common features and unique tauopathy.

Spinocerebellar ataxia type 8 (SCA8) is a neurodegenerative condition that presents with several neurological symptoms, such as cerebellar ataxia, parkinsonism, and cognitive impairment. It is caused by a CTA/CTG repeat expansion on chromosome 13q21 (ataxin 8 opposite strand [ATXN8OS]). However, the pathological significance of this expansion remains unclear. Moreover, abnormal CTA/CTG repeat expansions in ATXN8OS have also been reported in other neurodegenerative diseases, including progressive supranuclear palsy. In this study, we analyzed all available autopsy cases in Japan to investigate common pathological features and profiles of tau pathology in each case. Severe neuronal loss in the substantia nigra and prominent loss of Purkinje cells, atrophy of the molecular layer, and proliferation of Bergmann glia in the cerebellum were common features. Regarding tauopathy, one case presented with progressive supranuclear palsy-like 4-repeat tauopathy in addition to mild Alzheimer-type 3- and 4-repeat tauopathy. Another case showed 3- and 4-repeat tauopathy accentuated in the brainstem. The other two cases lacked tauopathy after extensive immunohistochemical studies. The present study confirmed common pathological features of SCA8 as degeneration of the substantia nigra in addition to the cerebellum. Our study also confirmed unique tauopathy in two of four cases, indicating the necessity to further collect autopsy cases. © 2023 Japanese Society of Neuropathology.

Citation

Yuki Yonenobu, Goichi Beck, Kansuke Kido, Norihisa Maeda, Rika Yamashita, Kimiko Inoue, Yuko Saito, Masato Hasegawa, Hidefumi Ito, Kazuko Hasegawa, Eiichi Morii, Toru Iwaki, Shigeo Murayama, Hideki Mochizuki. Neuropathology of spinocerebellar ataxia type 8: Common features and unique tauopathy. Neuropathology : official journal of the Japanese Society of Neuropathology. 2023 Oct;43(5):351-361

Mesh Tags

PMID: 36703300

search → result