Autoimmune glial fibrillary acidic protein astrocytopathy presented as ataxia, myoclonus and bulbar syndrome: a case report and review of the literature

OBJECTIVE: To describe an atypical case of autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy. RESULTS: A patient in his 60s presented with 6 months of progressive ataxia, proximal myoclonus and bulbar symptomatology. Cerebrospinal fluid (CSF) analysis showed monocytic pleocytosis, elevated protein level and elevated adenosine deaminase (ADA) level. CSF microbiological studies were negative and brain and cervical MRI showed no significant findings. We tested for nuclear, cytoplasmatic and synaptic neural autoantibodies as well as anti-GFAP antibodies. While awaiting these results, the patient was commenced on methylprednisolone boluses (1 g/day for 5 days), noting rapid neurological improvement. Eventually, CSF tests were positive for anti-GFAP antibodies. CONCLUSION: We report atypical manifestations of GFAP astrocytopathy. Further research is needed to fully understand the spectrum of neurological manifestations of this autoimmune disease and facilitate timely diagnosis.