Objective:

NA

Background:

LGI-1 is a synaptic protein and the autoantibody target in LG-1 encephalitis. These patients present with high frequency seizures. Acute treatment with high-dose corticosteroids and intravenous immunoglobulin (IVIg) or plasma exchange (PLEX) demonstrate comparative efficacy at disease control.

Design/Methods:

A 40-year-old female with recently diagnosed R frontotemporal epilepsy at an outside hospital was admitted to the epilepsy monitoring unit where she had frequent focal onset seizures controlled on three antiseizure medications. She left before completion of work-up, but returned with breakthrough seizures; prior collected serum paraneoplastic panel resulted positive for LGI-1. She was treated with IV steroids and IVIg without additional seizures and discharged on steroid taper. Shortly after discharge, she represented with new convulsive status epilepticus, requiring intubation and multiple anesthetic drips for control. She underwent PLEX and continued high dose prednisone which allowed for weaning from anesthetic drips. By discharge, seizures were well-controlled with clobazam 10 mg daily, valproate 750 mg BID, levetiracetam 1g BID, and lacosamide 200 mg BID and she continued high dose, prolonged steroid taper.

Results:

This patient had worsening seizure burden despite receiving IV steroids and IVIg for LGI-1 encephalitis, indicating refractory disease. While IVIg reduces autoantibodies by relying on cell-intrinsic mechanisms of antibody breakdown, PLEX provides a prompt mechanism for clearing circulating antibodies via direct filtration. Risks of plasma exchange involve coagulation complications and electrolyte impairments, and most centers require placement of a dialysis catheter, making it more invasive and less preferred for initial treatment. However, in the case of refractory disease with generalized super refractory status epilepticus, PLEX may be necessary for faster seizure control.

Conclusions:

Plasma exchange may be necessary for refractory LGI-1 encephalitis not responsive to IVIg particularly in the setting of super refractory status epilepticus.