[A case report of childhood multiple sclerosis with periodic synchronous discharge on EEG].

A 12-year-old girl with multiple sclerosis (MS) with periodic synchronous discharge (PSD) on electroencephalogram (EEG) is reported. The patient developed clonic seizure of both arms at the age of 10. The muscle strength of left hand and both legs were decreased and her school records were declined at the age of 12. On neurological examination, the patient showed mild intellectual disturbance, mild weakness of face and extremities and bilateral decreased DTRs. Her gait was slightly ataxic. Cerebrospinal fluid (CSF) revealed an oligoclonal band. Serial CT scans disclosed ring enhancements in the regions corresponding to clinical symptoms (right central gyrus on Sep. '85, right lower and middle temporal gyri, and mesial site of occipital lobe on Oct. '85, right cerebellum on Jan. '86). The same lesions were visualized as a high signal intensity on T2 weight images and as a low signal intensity on T1 weight images on MRI. The attack of seizure occurs more frequently in children with than adults with MS. However, as far as we know in the cases of children with MS, there were no reports of PSD which was usually seen in the cases of subacute sclerosing panencephalitis. The pathomechanism of PSD is speculated to be suffered from subcortical damage.