Clinical characteristics, treatment and long-term prognosis in patients with anti-NMDAR encephalitis

We aimed to (i) analyse the clinical characteristics, treatment outcome and long-term prognosis of anti-NMDAR encephalitis and (ii) study the differences between paediatric and adult patients.

This was a chart review of all patients with anti-NMDAR encephalitis.

There were 28 patients with 18 patients belonging to the paediatric (<18 years) age group. There was female (94%) preponderance in the paediatric age group, while in adult patients, there was no gender predilection (p=0.006). There was no significant difference in clinical feature, outcome or number of relapses between paediatric and adult population groups. MRI brain was abnormal in 53% of patients. Among the 15 patients with MRI abnormalities at the onset, 53% had poor functional outcome at 1 year, while in 12 patients with normal initial MRI brain, only 8% had poor functional outcome at 1 year (p =0.01). Nearly 53% of patients with abnormal MRI at presentation had at least one clinical relapse within 2 years while in patients with normal MRI at presentation, 15% had a clinical relapse (p=0.037). EEG abnormalities were noticed in 71% of patients; among them, 40 and 15% had poor functional outcome at 1 and 2 years respectively. In comparison, those with normal first EEG at onset, 12% had poor functional outcome at 2 years (p=0.57).

Both paediatric and adult patients presented with similar clinical features but the paediatric population had female preponderance. The functional outcome and number of relapse were comparable in both the paediatric and adult groups. Patients with parenchymal changes on MRI and abnormal EEG showed poorer response compared to those with normal MRI and/or EEG at the onset. Patients have lesser severity of symptoms at relapse than in the first episode. An early diagnosis and treatment are essential for better long-term functional outcome.