Anti-N-methyl-D-aspartate Receptor Encephalitis Magnetic Resonance imaging and Clinical Features: A Case Series

Abstract

Introduction: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a neuro-immunological disease presenting with a variety of neuropsychiatric features and magnetic resonance imaging (MRI) findings. This case series investigates the patterns of MRI features of these patients and their possible correlation with clinical parameters. Methods: Clinical records and brain MRI features of 17 patients diagnosed with anti-NMDAR encephalitis were reviewed retrospectively. Correlation of imaging features with clinical parameters, including demographics, presentation, and clinical outcome, was investigated. Results: Seven patients (41.2%) had abnormal brain MRI findings at presentation. The temporal lobe (excluding the hippocampus) was the commonest site of involvement, followed by the hippocampus and the insula. Normal MRI findings at presentation and hippocampal involvement showed no correlation with the clinical parameters. Interval development of cerebral atrophy (global or localised medial temporal atrophy) on repeat imaging was associated with worse functional outcome measured on the modified Rankin scale (p = 0.008) and with a lower rate of symptom-free recovery (p = 0.045). Conclusion: More than half of our study subjects had normal brain MRI findings at presentation. The temporal lobe (excluding the hippocampus) was the commonest site of abnormal signal. Interval development of cerebral atrophy was associated with worse functional outcome and lower rate of symptom-free recovery.