Abstracts

Rationale:
Autoimmune encephalitis presentation ranges from mild cognitive impairment to severe encephalopathy and refractory seizures. Here we review presentation, treatment and outcome of patients with seizures and autoimmune encephalitis due to antibodies against membrane surface antigens, N-Methyl-D-aspartic acid receptor (NMDAR) and Leucine-rich, glioma inactivated 1 (LGI1) as well as anti-glutamic acid decarboxylase (GAD65) antibodies at our institution over a 5-year period. 
Method:
This is a retrospective study of adults 18 years or older with autoimmune encephalitis due to antibodies against membrane surface antigens (NMDAR and LGI1) as well as anti GAD65 antibodies from the University of Arkansas for Medical Sciences, Little Rock AR. Patients with other antibodies like antibodies against nuclear antigens and nonspecific antibodies were excluded. Hospital presentations and admissions in a 5-year period were reviewed. Duration of admission, treatment, antiepileptic drugs (AED) used and outcome of admissions were reported.
Results:
Autoantibody screening was ordered for 175 patients by the Neurology service between May 2014 and April 2018. Antibody screening was positive in 61 patients with 27 patients presenting with seizures or encephalopathy (the rest had other neurological manifestations). Seven patients had encephalitis and seizures due to antibodies against membrane surface antigens (NMDAR and LGI1) or anti GAD65 antibodies. Three patients had anti-NMDAR antibodies, two had anti-LGI1 antibodies and two had anti-GAD65 antibodies. Patient’s age at presentation ranged from 25 to 81 years. Three patients were males and four were females. The seven patients were followed for a mean of 3 years (range: 1-5 years). They presented to the hospital 25 times during this period and were admitted 19 times. Seizures were the reason for presentation in 14 of their presentations (56%). They were admitted for a total of 301 days with a mean of 43 days per patient and a range of 1 to 62 days per admission.   All the patients were treated with AEDs during these admissions. Patients were on a mean of 3.2 AEDs during each admission (range 1 – 10). Out of a total of 19 admissions, IVIG was used in 10, IV steroids in 11, oral steroids in 12, one other immune suppressant in 7, two other immunosuppressants in 2 and plasma exchange in 3. The other immune suppressants used varied and included azathioprine in one admission, rituximab in 5, Mycophenolate in 2, methotrexate in 2 and cyclophosphamide in one. On the day of discharge of each admission, 12 were independent, 4 required admission to a nursing home and 3 were dependent and required family support at home. Relapses occurred after 9 discharges within 2 weeks to one year. One patient with NMDAR encephalitis was lost to follow up after a single admission.
Conclusion:
Conclusion: Patients with autoimmune encephalitis due to antibodies against membrane surface antigens (NMDAR and LGI1) as well as anti GAD65 antibodies present with different symptoms including seizures and encephalopathy. They tend to present frequently to the hospital and stay for prolonged periods during hospitalization. They require a combination of multiple treatment modalities including AED, steroids, IVIG and other immunosuppressant medications for each relapse. Many patients require further care in nursing homes or by family on discharge and relapses are frequent.
Funding:
:None