Catatonic Schizophrenia Associated With Cerebrospinal GAD65 Autoantibodies: Case Report and Literature Review

BackgroundGAD65 autoimmunity is reported to be associated with schizophrenia and bipolar disorder. However, there has been no evidence that glutamic acid decarboxylase 65 (GAD65) autoantibodies in cerebrospinal fluid (CSF) are associated with akinetic catatonia in schizophrenia patients. MethodsWe report the case of a 28-year-old man who underwent diagnostics including brain MRI, neuropsychological testing, and electroencephalography (EEG) as well as a tumor search via CT of the abdomen and thorax, as well as colonoscopy and gastroscopy. For clinical characterization, his patient files were retrospectively examined. ResultsOur patient presented catatonia that responded somewhat to benzodiazepines in combination with previously taken antipsychotics such as risperidone for prediagnosed paranoid schizophrenia. Diagnostics revealed GAD65 autoantibodies in his serum and CSF. MRI revealed no brain lesion, and the tumor search had no malignancy. We diagnosed catatonic schizophrenia. Furthermore, as he had not fully recovered, he was given immunotherapy entailing two cycles of intravenous immunoglobulins. Subsequent neuropsychological testing due to subjective cognitive complaints after immunotherapy revealed no objective cognitive deficits. ConclusionsWe present the novel finding of an association between GAD65 autoantibodies in the serum and CSF with catatonia in a patient suffering from prediagnosed chronic schizophrenia. Due to the presence of CSF GAD65 antibodies and the catatonia factor in prediagnosed schizophrenia, we suspect that his catatonia has an autoimmune origin. Immunotherapy stabilized the catatonia that had initially responded to lorazepam treatment. Further research should be done to characterize patients' responses to immunotherapy and standard treatment in a large cohort of patients with GAD65 antibody-associated catatonia and schizophrenia.

Automated summary

This study provides evidence of an association between GAD65 autoantibodies in serum and cerebrospinal fluid and catatonia in patients with schizophrenia. Immunotherapy helped stabilize the catatonia symptoms in the patient. Further research is needed to investigate the response to treatment in a larger cohort of patients with GAD65 antibody-associated catatonia and schizophrenia.