Abstract Details

Up to 50% of MRIs in NMDARE are reportedly abnormal. However, data is limited on range and types of abnormalities, and also how abnormal MRIs associate with outcomes in pNMDARE.

To correlate MRI brain lesions with clinical outcomes in pediatric anti-NMDA receptor encephalitis (pNMDARE).

This was a multi-center retrospective cohort study with ten institutions. NMDARE was defined as positive CSF NMDA-receptor antibody and at least one neuropsychiatric symptom. Patients with prior HSV encephalitis were excluded. Outcomes were assessed by the modified Rankin Score (mRS) at 1 year with good (mRS ≤ 2) and poor (mRS ≥ 3) outcomes and also for full recovery (mRS=0) versus incomplete recovery (mRS>0). Statistical analyses were performed using SAS 16.0 (Cary, NC). 

A total of 169 patients with pNMDARE were included, with one-year mRS available in 134/169 (79%). Abnormal MRIs were found in 59/169 (35%), and were associated with an increased likelihood of intubation and ICU admission (chi-square, p = 0.038 and p=0.045, respectively). The most common T2 FLAIR lesion locations were frontal (29/59, 49%), temporal (28/59, 47%), parietal (19/59, 32%), and hippocampal lesions (11/59, 19%). MRI enhancement was seen in 34/165 (21%) and MRI brain atrophy was seen in 4% (6/168). MRI features that predicted incomplete recovery at one year (mRS > 0) was the presence of T2 frontal lobe lesions (chi-square, p = 0.0427). G-tube placement and intubation also predicted incomplete recovery. On multivariable logistic regression analysis using backward selection, one-year mRS was associated with: intubation (OR 0.232, 95%CI 0.103-0.526) and T2 frontal lesions on MRI (OR 0.373, 95% 0.148-0.938).

Abnormal frontal lesions on MRI along with intubation may associate with one-year mRS in pNMDARE. MRIs may be a helpful tool for prognostication, which will be examined in future studies.