# Anti-α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid (AMPA) Receptor Antibody Encephalitis in an Immunosuppressed Patient With Myasthenia Gravis Post-thymoma Treatment

## TL;DR

A rare autoimmune brain condition called AMPA receptor encephalitis occurred in a patient with a weakened immune system after thymoma treatment, and she fully recovered.

## Contribution

This is the first reported case of AMPA receptor encephalitis in an immunosuppressed patient.

## Key findings

- The patient had positive AMPA receptor antibodies in cerebrospinal fluid.
- The patient achieved full recovery after treatment.
- This case highlights the importance of early diagnosis in autoimmune encephalitis.

## Abstract

Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor encephalitis is a rare form of autoimmune encephalitis. We report a case of a patient with myasthenia gravis post-thymoma treatment who presented with deteriorating mental status. She was found to have positive AMPA receptor titers in her cerebrospinal fluid and subsequently attained full recovery. Of the limited number of cases that were documented, we report the only case of a patient who was previously immunocompromised to develop the condition. Even though autoimmune encephalitis is an emerging condition, its early differentiation from other causes of encephalitis is crucial in the prognosis of the patient.