Area Postrema Syndrome in Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy: A Case Series and Literature Review.

Background and objectives: To report the frequency of area postrema syndrome (APS) in glial fibrillary acidic protein-immunoglobulin G (GFAP-IgG)-positive patients and emphasize the importance of APS among the phenotypes in autoimmune GFAP astrocytopathy.

Methods: Eight GFAP-IgG-positive cases with APS were retrospectively identified during 2015-2021. The APS phenotypes were described. A literature review of 8 previously reported cases was also included in analysis.

Results: A total of 8 patients (11%) (1 woman, 7 men; mean age: 52.4 ± 18.4 years) presented with APS in a cohort of 74 GFAP-IgG-positive patients, 3 of whom (4%) had disease onset with APS. All patients had hiccups, and hiccups was the unique symptom of APS in 5 patients. The median time from disease onset to APS occurrence was 2 days (range 0-20), and the mean duration of APS episodes was 23.6 ± 11.4 days. No patient had isolated APS attack. All episodes were completely resolved with a mean duration of 9.3 ± 5.4 days after immunotherapy. APS manifestations of 8 cases in previous studies showed similar features with our cases. In total, coexisting aquaporin-4-IgG was only detected in one of the 16 cases.

Discussion: APS could be an early, but not isolated clinical manifestation of autoimmune GFAP astrocytopathy. Hiccups was the predominant symptom of APS in this disorder. APS attacks of autoimmune GFAP astrocytopathy have good response to immunotherapy.