Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an autoimmune process that can cause both meningitis/encephalitis pictures.1,2,3 Clinical manifestations of this disease include but are not limited to headache (60%), ataxia (40%), tremor (40%), autonomic dysfunction (20%), and seizures (20%).4 Though not predictive of cancer, up to 22% of cases go on to develop cancers, ranging from adenocarcinomas to gliomas.5,6 Diagnosis of this autoimmune encephalitis is of utmost importance as it is responsive to steroids which can alter treatment and outcome significantly.

This is a 69 year-old with a history of diabetes mellitus and hypertension. In 2016, she had an episode of dizziness while driving and found herself in an accident with no recollection of what had occurred. She was diagnosed with vasovagal syncope, with unremarkable cardiac workup, but continued to have similar episodes. During her first epilepsy workup in 2019, she was found to have epileptiform discharges in the right frontotemporal region. Her brain MRI revealed a right frontotemporal meningioma, later resected. During this time, she developed worsening cognition, tremors, and gastrointestinal discomfort, initially attributed to her anti-seizure medications. Ultimately, she continued to progress despite medication adjustments and was readmitted for further workup. Her lumbar puncture showed protein 102, glucose 72, lymphocytes 77 (negative cytology and flow), and the neural autoantibody panel revealed GFAP antibodies. Patient was treated with a 12-week course of intravenous steroids with prominent improvement. Comprehensive cancer screening revealed invasive ductal carcinoma of the breast and upper lobe lung adenocarcinoma for which she was treated with surgical resection with good outcome.

This is a less typical presentation of GFAP mediated encephalitis given absence of the typical imaging findings, such as linear perivascular radial enhancement patterns. CSF studies revealed pleocytosis and she was clinically steroid responsive.