A Case with Absence Seizures After Neuroimaging Changes of Rasmussen Syndrome

Abstract

Case Report The patient was a 5 year and 5 month‐old boy. A brother had a history of febrile convulsions. The patient was born after 38 weeks of pregnancy, birth weight 3,260 g. The neonatal period was uneventful. His development was normal until 1 year and 3 months of age, after which he suffered generalized tonic seizures 2–3 times per year. Episodes of unconsciousness as often as ten times per day began at 5 years of age. Brain MRI, performed at 2 years of age, was normal. EEG revealed spikes from the right mid‐temporel and right central regions and diffuse irregular spike and waves at 4 years of age. Cryptogenic localization‐related epilepsy was diagnosed and treated with phenobarbital, carhamazepine, valproic acid, and acetazolamide without control of his convulsions. After 5 years of age, he began losing consciousness approximately 10 times per day. At 5 years and 5 months of age, he had fever, cough, rhinorrhea, and 2 generalized tonic‐clonic convulsions for about 2 minutes and subsequently generalized tonicclonic convulsive status epilepticus for 30 minutes. He was admitted to Kagawa Prefectural Central Hospital. At admission, his consciousness score was 200 points (JCS) and he had intermittent clonic convulsions of the right hand and face. He also exhibited right hemiplegia. Partial seizures continued for about 2 weeks, Blood examination revealed CRP of 1.4 mg/dl, with negative antibody titers for herpes simplex and EB virus. CSF findings were normal. At 6 days of admission, T2‐weighted brain MRI studies revealed high density i n the gray matter in the left hemisphere. After 2 months of hospitalization, MRI revealed remarkable left hemispheric atrophy. Two SPECT studies done at an interval of 2 months disclosed hyperperfusion of the left hemisphere. These findings were considered compatible with Rasmussen syndrome. At admission, the EEG revealed left high‐voltage slow wave activity and frequent spikes in the left anterior temporal region. After 4 months of hospitalization, tonic‐clonic convulsions occurred once per month. After 8 months of hospitalization, episodes of unconsciousness occurred 10 times per day. The ictal EEG revealed diffuse right hemisphere dominant 3isecond spike and wave bursts, which were induced by hyperventilation. Ethosuximide completely controlled these episodes and also improved EEG findings. Conclusion: The clinical findings suggested that this patient had RdS‐ mussen syndrome during the course of a cryptogenic localizationrelated epilepsy and subsequently experienced absence seizures. Despite his organic brain damage, his ictal 3/second spike and wave bursts exhibited no preceding focal spikes or slow waves, and ethosuximide markedly improved these absence seizures and EEG abnormalities. The mechanism of these absence seizures was thus not secondary bilateral synchrony and appeared to be the same as that of the primary generalized seizures.