Clinical features of autoimmune cerebellar ataxia related to neuronal antibodies

Yun Cai Zhijuan Hua Yanan Chen Xue Chen Na Liu Ting Liu Qianwen Zhou Jinghua Li Weiying Di ^*

• Affiliated Hospital of Hebei University, Baoding, China

Objective:To investigate the clinical features of neuronal antibodies related to autoimmune cerebellar ataxia(ACA),and provide guidance for the diagnosis and treatment of this disease.Methods:Demographic and clinical data were collected from the antibody-positive patients with ACA who were admitted to the Department of Neurology, Affiliated Hospital of Hebei University, from January 2018 to February 2023. Aretrospective analysis was performed for the clinical manifestations,laboratory examinations,imaging data, treatment, and prognosis.Results:A total of six patients, including one male and five female patients,with a median age of 52.5 years, were enrolled in this study. All patients presented with dizziness and gait abnormalities with or without dysarthria.No tumor was found in these patients. Three patients were at the prodromal stage of infection, and one patient exhibited post-ACA fever symptoms and aggravated disease phenotypes.Three patients were positive for anti-glutamate decarboxylase (GAD), and one patient was positive for each of the anti-Tr,anti-mGluR1, and anti-Homer-3 antibodies.The white blood cell (WBC) count and protein levels of cerebrospinal fluid (CSF) were increased in four patients, which was in agreement with predominant lymphocytic inflammation.One patient displayed positive signals for CSF-specific oligoclonal proteins. Out of six patients, two were diagnosed with bilateral cerebellar atrophy, and two had non-specific white matter changes. All the patients received immunotherapy and rehabilitation treatment. Except for the Homer-3-positive patient, the rest of the patients showed good prognoses. One patient relapsed.Conclusion:ACA can be induced or aggravated by infection. The detection of neuronal antibodies is crucial for a precise diagnosis of ACA. The cerebellar system symptoms,such as dizziness, unsteady walking, nystagmus, and dysarthria, are the first and main manifestations of ACA. Head magnetic resonance imaging(MRI) in patients with ACA may be normal or may exhibit abnormalities including cerebellar atrophy and non-specific white matter changes. Immunotherapy could be effective in most ACA patients.