[Electroencephalographic patterns and their association with functional prognosis in anti-NMDA autoimmune encephalitis].

Abstract

Background: Autoimmune encephalitis is a rare disease with low incidence and prevalence but carries high rates of disability and potential fatality.

Objective: To determine whether the presence of abnormal electroencephalographic patterns in patients with anti-NMDAR autoimmune encephalitis affects functional prognosis at 3 months.

Material and methods: A retrospective, observational, analytical, longitudinal-cross-sectional study was conducted with a retrospective cohort.

Results: Out of a total of 44 patients with anti-NMDAR autoimmune encephalitis, concerning electroencephalographic findings, 19 patients had a normal EEG result (43.2%), 18 had cortical dysfunction (40.9%), 7 had epileptiform reports (15.9%), and only 1 had a Delta Brush report (2.3%). The functional outcome of patients at 3 months measured by the modified Rankin Scale (mRS) was as follows: 3 patients without disability (6.8%), 6 patients with mild disability (13.6%), 17 patients with mild to moderate disability (38.6%), 9 patients with moderate to severe disability (20.5%), 1 patient bedridden (2.3%), and 2 deceased (5.6%).

Conclusion: In our study, no association was found between an abnormal electroencephalographic pattern and a worse functional prognosis at 3 months in patients with autoimmune encephalitis. Although the electroencephalogram analyzed is the initial one, it would be necessary to assess later whether the persistence of abnormalities in the electroencephalogram is related to a greater number of sequelae and disabilities.