Clinical course of pathologically confirmed corticobasal degeneration and corticobasal syndrome
Authors: Aiba Ikuko , Hayashi Yuichi , Shimohata Takayoshi , Yoshida Mari , Saito Yuko , Wakabayashi Koichi , Komori Takashi , Hasegawa Masato , Ikeuchi Takeshi , Tokumaru Aya M , Sakurai Keita , Murayama Shigeo , Hasegawa Kazuko , Uchihara Toshiki , Toyoshima Yasuko , Saito Yufuko , Yabe Ichiro , Tanikawa Satoshi , Sugaya Keizo , Hayashi Kentaro , Sano Terunori , Takao Masaki , Sakai Motoko , Fujimura Harutoshi , Takigawa Hiroshi , Adachi Tadashi , Hanajima Ritsuko , Yokota Osamu , Miki Tomoko , Iwasaki Yasushi , Kobayashi Michio , Arai Nobutaka , Ohkubo Takuya , Yokota Takanori , Mori Keiko , Ito Masumi , Ishida Chiho , Tanaka Masaharu , Idezuka Jiro , Kanazawa Masato , Aoki Kenju , Aoki Masashi , Hasegawa Takafumi , Watanabe Hirohisa , Hashizume Atsushi , Niwa Hisayoshi , Yasui Keizo , Ito Keita , Washimi Yukihiko , Mukai Eiichiro , Kubota Akatsuki , Toda Tatsushi , Nakashima Kenji ,   J-VAC study group, Hayashi Yuichi , Shimohata Takayoshi , Yoshida Mari , Saito Yuko , Wakabayashi Koichi , Komori Takashi , Hasegawa Masato , Ikeuchi Takeshi , Tokumaru Aya M , Sakurai Keita , Murayama Shigeo , Hasegawa Kazuko , Uchihara Toshiki , Toyoshima Yasuko , Saito Yufuko , Yabe Ichiro , Tanikawa Satoshi , Sugaya Keizo , Hayashi Kentaro , Sano Terunori , Takao Masaki , Sakai Motoko , Fujimura Harutoshi , Takigawa Hiroshi , Adachi Tadashi , Hanajima Ritsuko , Yokota Osamu , Miki Tomoko , Iwasaki Yasushi , Kobayashi Michio , Arai Nobutaka , Ohkubo Takuya , Yokota Takanori , Mori Keiko , Ito Masumi , Ishida Chiho , Tanaka Masaharu , Idezuka Jiro , Kanazawa Masato , Aoki Kenju , Aoki Masashi , Hasegawa Takafumi , Watanabe Hirohisa , Hashizume Atsushi , Niwa Hisayoshi , Yasui Keizo , Ito Keita , Washimi Yukihiko , Mukai Eiichiro , Kubota Akatsuki , Toda Tatsushi , Nakashima Kenji , Tanaka Shinya , Ishikawa Kinya , Sengoku Renpei , Sakashita Yasuhiro , Matsubara Tomoyasu , Inoue Kimiko , Mori Chiaki , Saito Tomoko , Tokuda Takahiko , Kowa Hisanori , Terada Seishi , Nakashima-Yasuda Hanae , Kato-Motozaki Yuko , Komai Kiyonobu , Onodera Osamu , Kakita Akiyoshi , Shimizu Hiroshi , Tada Mari , Matsumoto Arifumi , Kikuchi Akio , Watanabe Mutsufusa , Katsuno Masahisa , Ieda Tosiaki , Maeda Meiko Hashimoto , Aiba Ikuko 
Published: November 2023

Abstract
The clinical presentation of corticobasal degeneration is diverse, while the background pathology of corticobasal syndrome is also heterogeneous. Therefore, predicting the pathological background of corticobasal syndrome is extremely difficult. Herein, we investigated the clinical findings and course in patients with pathologically, genetically and biochemically verified corticobasal degeneration and corticobasal syndrome with background pathology to determine findings suggestive of background disorder. Thirty-two patients were identified as having corticobasal degeneration. The median intervals from the initial symptoms to the onset of key milestones were as follows: gait disturbance, 0.0 year; behavioural changes, 1.0 year; falls, 2.0 years; cognitive impairment, 2.0 years; speech impairment, 2.5 years; supranuclear gaze palsy, 3.0 years; urinary incontinence, 3.0 years; and dysphagia, 5.0 years. The median survival time was 7.0 years; 50% of corticobasal degeneration was diagnosed as corticobasal degeneration/corticobasal syndrome at the final presentation. Background pathologies of corticobasal syndrome (n = 48) included corticobasal degeneration (33.3%), progressive supranuclear palsy (29.2%) and Alzheimer’s disease (12.5%). The common course of corticobasal syndrome was initial gait disturbance and early fall. In addition, corticobasal degeneration–corticobasal syndrome manifested behavioural change (2.5 years) and cognitive impairment (3.0 years), as the patient with progressive supranuclear palsy–corticobasal syndrome developed speech impairment (1.0 years) and supranuclear gaze palsy (6.0 years). The Alzheimer’s disease–corticobasal syndrome patients showed cognitive impairment (1.0 years). The frequency of frozen gait at onset was higher in the corticobasal degeneration–corticobasal syndrome group than in the progressive supranuclear palsy–corticobasal syndrome group [P = 0.005, odds ratio (95% confidence interval): 31.67 (1.46–685.34)]. Dysarthria at presentation was higher in progressive supranuclear palsy–corticobasal syndrome than in corticobasal degeneration–corticobasal syndrome [P = 0.047, 6.75 (1.16–39.20)]. Pyramidal sign at presentation and personality change during the entire course were higher in Alzheimer’s disease–corticobasal syndrome than in progressive supranuclear palsy–corticobasal syndrome [P = 0.011, 27.44 (1.25–601.61), and P = 0.013, 40.00 (1.98–807.14), respectively]. In corticobasal syndrome, decision tree analysis revealed that ‘freezing at onset’ or ‘no dysarthria at presentation and age at onset under 66 years in the case without freezing at onset’ predicted corticobasal degeneration pathology with a sensitivity of 81.3% and specificity of 84.4%. ‘Dysarthria at presentation and age at onset over 61 years’ suggested progressive supranuclear palsy pathology, and ‘pyramidal sign at presentation and personality change during the entire course’ implied Alzheimer’s disease pathology. In conclusion, frozen gait at onset, dysarthria, personality change and pyramidal signs may be useful clinical signs for predicting background pathologies in corticobasal syndrome.