[Exacerbation of partial seizures in a case with heterotopic gray matter using antiepileptic drugs].

A two-year-old, right-handed girl was admitted to our hospital with a history of partial seizures. The first seizure, conjugated eye movements and head turning to the right, occurred at the age of 24 months. Later, she suffered from several seizures daily at the age of 34 months. At the age of 35 months, she was admitted to our hospital. On admission her neurological examination was normal. EEG showed a left parietal spike focus. A computed tomographic scan showed a small hyperdense area in the left parietal lobe without contrast enhancement. She was treated with carbamazepine (CBZ : 6 mg/kg/day). When seizures occurred several times within an hour, intravenous or rectal administration of diazepam (DZP : 0.3 mg/kg/dose) was added. However, she complained of sleepiness. The seizures occurred more frequently than before, 50 to 80 times daily, and became secondarily generalized. We thought that the exacerbation of the seizures resulted from the somnolence caused by DZP and CBZ. Consequently, these drugs were discontinued, and phenytoin was begun. She has since been free of seizures for two years. Approximately one year after the discontinuance of DZP and CBZ, heterotopic gray matter and abnormal gyri involving the left parieto-temporal lobe were found by magnetic resonance imaging (MRI). MRI is useful for detecting small heterotopic gray matter. To summarize this case, one should consider the possibility that excessive polytherapy induces seizures, particularly in patients with structural brain abnormalities such as heterotopic gray matter.