RT Journal Article SR Electronic T1 Treatment of Anti-GAD65 Autoimmune Encephalitis With Methylprednisolone JF Ochsner Journal JO Ochsner J FD O. P. Jindal Global University SP 312 OP 315 DO 10.31486/toj.20.0096 VO 21 IS 3 A1 Shayan Azizi A1 Diamler L. Vadlamuri A1 Louis A. Cannizzaro YR 2021 UL http://www.ochsnerjournal.org/content/21/3/312.abstract AB Background: Anti-glutamic acid decarboxylase 65 (anti-GAD65) antibody encephalitis is a rare form of autoimmune encephalitis that can lead to severe neurologic impairment, coma, and death.Case Report: We present the case of a 54-year-old male with severely altered mental status and profound neurologic impairment who rapidly progressed to a comatose state. Because of the patient's rapidly deteriorating status, lack of yield with diagnostic testing, and lack of clinical improvement with broad empiric treatments, the clinical decision was made to treat the patient with high-dose methylprednisolone, and the treatment returned the patient to his baseline mental status. After the patient's discharge, the autoimmune encephalitis panel returned positive for anti-GAD65 antibodies.Conclusion: This case illustrates the importance of considering a diagnosis of autoimmune encephalitis for patients with rapidly deteriorating mental status. Unless contraindicated, treatment with high-dose glucocorticoids can be successful for these patients. This case also shows a potential association between hypothyroidism and anti-GAD65 antibodies.