Rationale:
Adult-onset Rasmussen encephalitis (A-RE) is a rare immune-mediated epileptic encephalopathy. As most diagnostic criteria are derived from pediatric cohorts, recognition in adults is often delayed, leading to irreversible neurological decline. We present the five-year longitudinal course of a 43-year-old woman with progressive drug-resistant epilepsy, unilateral hemispheric atrophy, and an evolving movement disorder who achieved partial clinical remission with intravenous immunoglobulin (IVIG). This case delineates the adult phenotype and highlights actionable therapeutic windows.Methods:
Case Report and Literature ReviewResults:
A 43-year-old woman with a history of postpartum depression and heavy alcohol use presented to the neurology outpatient clinic for evaluation of drug-resistant epilepsy. Her first seizure occurred six months prior to presentation, followed by recurrent episodes of generalized tonic-clonic seizures resulting in status epilepticus. At the same time, she experienced a progressive decline in communication and memory. Physical examination at that time was unremarkable. Brain MRI revealed asymmetric left hemispheric atrophy and hippocampal sclerosis, while EEG demonstrated focal spike-wave activity in the left occipital-parietal region. Her antiseizure regimen was escalated to include levetiracetam 1000 mg three times daily, lacosamide 200 mg twice daily, and divalproex 500 mg three times daily.
Over the following five years, she developed aphasia, right-sided dystonia, choreoathetosis, bilateral tremors, parkinsonian features, and vertical nystagmus. Lacosamide was replaced by Oxcarbazepine 600 mg twice daily, but she continued to experience 4–5 generalized tonic-clonic seizures every three months. Extensive workup - including genetic testing for Huntington’s disease and an autoimmune encephalitis panel, both in serum and CSF - was unrevealing. Serial MRIs showed progressive atrophy confined to the left hemisphere.
A trial of IVIG infusions was discussed and initiated with the patient’s agreement. She demonstrated notable improvements in seizure frequency, recovery time, language skills, mobility, and cognitive function.
Given the progressive unilateral cerebral atrophy, drug-resistant focal seizures, emerging movement disorder, and partial response to IVIG in the absence of other identifiable causes, we diagnosed her with adult-onset Rasmussen encephalitis. There have been no other hospital admissions for breakthrough seizures. She continues to receive IVIG every 12 weeks and remains on multiple antiseizure medications. Further escalation of immunotherapy may be considered if seizures recur or functional decline progresses.
Conclusions:
Adult-onset Rasmussen encephalitis should be considered in adults presenting with progressive unilateral cortical atrophy, drug-resistant focal seizures, and emerging movement or cognitive deficits. Timely initiation of treatment may provide meaningful clinical improvement and significantly enhance quality of life.
Funding: None