Abstract
Objectives Adult-onset Rasmussen’s encephalitis (A-RE) continues to present significant diagnostic and therapeutic challenges to clinicians, resulting in extensive investigations and an invariably long gap from presentation to diagnosis, which may subsequently correlate with poorer clinical outcomes. An increased awareness of the condition and a low threshold for suspicion are paramount to bridging this gap.
Methods/Results Here we present a case of a 36-year-old man with a prodrome of right sided sensory symptoms and subsequent right focal motor seizures, myoclonus/polyminimyoclonus and neurological deficits. Paraneoplastic, autoimmune and neuroinflammatory screen were all unrevealing. The initial electroencephalogram (EEG) was normal; however, the repeat EEG showed focal slowing. Magnetic resonance imaging showed progressive T2 hyperintensity and volume loss predominantly over the left frontoparietal lobes, but also involved the right frontal lobe. Brain biopsy showed features of a T-cell predominant encephalitis. Rasmussen’s encephalitis was suspected and immunotherapy with steroids and intravenous immunoglobulin were initiated, but he continued to deteriorate. He is now started on cyclophosphamide.
Conclusions Our case adds to the accumulating number of cases of A-RE reported in the literature. The rarity of the condition and overlap in clinical phenotype with other central nervous system diseases lead to delayed diagnosis in almost all reported cases. In our patient, the bilateral MRI changes and delayed recognition of seizures compounded to the diagnostic uncertainty. The main therapeutic options in adults are anti-epileptic and immunomodulatory agents, and whilst there is no cure, early and aggressive therapy may result in improved patient outcomes.
