To determine the presence of cerebral atrophy by a retrospective review of brain MRIs in pediatric patients with anti-N-methyl-D-aspartate receptor encephalitis (NMDARE).

NMDARE is an autoimmune encephalitis first identified in 2007. Despite the high morbidity and mortality, many patients have good outcomes with treatment. MRI findings are nonspecific and may be normal. However, prior case reports have described diffuse cerebral atrophy and other abnormalities following the acute phase of the disease. To date, observations of diffuse brain atrophy in NMDARE have been qualitative and the number of cases in the literature remains small.

This is a retrospective case series children admitted to Barrow Neurological Institute between 2006 and 2019. We identified 15 pediatric patients diagnosed with NMDARE, confirmed by positive antibody titers. Relevant clinical data was reviewed. A board-certified neuroradiologist performed qualitative analysis of MRIs looking for brain atrophy and other signal abnormalities.

Brain imaging was abnormal in 7 out of 15 patients, and of those, 4 patients demonstrated qualitative bilateral cerebral hemispheric volume loss. Clinical features were overall similar between the patients with atrophy and those without, except for a lack of hemiparesis in the atrophy group. Dyskinesias and psychiatric symptoms were present in all patients.

Four out of 15 NMDARE patients had brain atrophy with no major difference in clinical manifestation compared to patients without brain volume loss. Despite receiving first line therapy within 3 months of symptom onset, there was progression of brain volume loss on repeat MRIs. Although this study is limited by its retrospective nature and lack of quantitative brain volume measurements, it adds to the existing literature evidence of global cerebral atrophy associated with NMDARE.