An 18-year-old female with a history of mitral clip repair presented with new-onset seizures including right arm clonic movements, then progressing to generalized tonic activity. The patient had stopped Keppra due to side effects. She was then started on zonisamide. MRI was contraindicated due to her mitral clip. Continuous EEG showed left intermittent seizures. She demonstrated left facial twitching. Despite increasing zonisamide, EEG showed left-sided PLEDs and right-sided non-convulsive seizures. This raised concern for partial status epilepticus (possibly due to HSV or autoimmune encephalitis). Acyclovir and fosphenytoin were initially started, with EEG continuing to show seizures. Lumbar puncture was then performed and demonstrated positive GAD65 antibodies.

The patient was diagnosed with partial status epilepticus secondary to anti-GAD65 autoimmune encephalitis. She was transferred to the ICU, intubated, and started on a versed drip. She was treated with multiple anti-epileptic drugs, IVIG, and later rituximab. Seven sessions of plasma exchange (PLEX) were then completed. Patient started to show improvement after rituximab, and especially after PLEX. After extubation, she quickly returned to baseline and her medications were tapered. She was discharged on fycompa, vimpat, and a prednisone taper with outpatient follow-up.