Insular cortex epilepsy in Rasmussen Syndrome: a case report

Case presentation: Male patient, 7 years old, first child of a non-consanguineous couple, previously healthy and with normal neuropsychomotor development, presented with recurrent nausea and vomiting associated with facial paresthesia. Neurological examination was initially normal. 3 months after the onset of the condition, he started daily myoclonic seizures and was hospitalized for investigation. During clinical investigation, an electroencephalogram was performed, which showed disorganized basal activity, frequent fronto-temporal epileptiform paroxysms in the right cerebral hemisphere, with propagation to contralateral homologous areas, and magnetic resonance imaging that showed an increase in the signal from the cortex of the right frontal lobe and homolateral insula. On neurological examination, mild left hemiparesis was noted. The patient progressed to drug-resistant epilepsy and control magnetic resonance imaging showed signal alteration and atrophy in the right cerebral hemisphere, compatible with Rasmussen syndrome. He underwent immunoglobulin, pulse therapy with methylprednisolone and nine anti-seizure drugs, but showed no clinical response. A video electroencephalogram was performed, which showed autonomic crises with insular characteristics. Due to poor seizure control and progression of brain atrophy, hemispherectomy surgery was indicated. As he presented recurrence of crises after the first surgery, he was surgically approached twice more. After surgery, the patient presented seizure control and developed behavioral disorder and left hemiparesis.

Discussion: Rasmussen syndrome is a rare disease, with an incidence of 1.7–2.4 per 10 million individuals. Progressive hemispheric atrophy is seen on neuroimaging. The cause of this is unknown, and no causative antibody has been identified. Patients have focal seizures (usually motor seizures, including epilepsia partialis continua), which progress over time in frequency and severity. A progressive contralateral hemiparesis develops. The diagnosis is based on the characteristic clinical presentation and imaging findings.

Final comments: Insular lobe seizures are an under-recognized seizure type and great mimicker of temporal, frontal, and parietal seizure semiology. Understanding seizure semiology is one of the most important and crucial steps in diagnosing a seizure disorder. We present a case of Rasmussen syndrome that started with insular seizures, a clinical presentation rarely reported in the world literature.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
18 September 2023