Clinical study of childhood acute disseminated encephalomyelitis, multiple sclerosis, and acute transverse myelitis in Fukuoka Prefecture, Japan.

Acute disseminated encephalomyelitis (ADEM) has recently been studied in several countries owing to the development and wide spread use of imaging technology, but few epidemiological studies of childhood ADEM have been undertaken in Asian countries. To perform a comprehensive survey of ADEM and related diseases in Japanese children, we conducted a multicenter, population-based study on childhood ADEM, multiple sclerosis, and acute isolated transverse myelitis in Fukuoka Prefecture, Japan. We identified 26 children with ADEM, 8 with multiple sclerosis, and 4 with acute transverse myelitis during 5 years between September 1998 and August 2003. The incidence of childhood ADEM under the age of 15 years was 0.64 per 100,000 person-years, mean age at onset was 5.7 years, and male-female ratio was 2.3:1. The prevalence of childhood multiple sclerosis was 1.3 per 100,000 persons. The mean age at onset of multiple sclerosis, 9.3 years, was significantly higher than that of ADEM. Nineteen (73%) and four (15%) patients with ADEM experienced antecedent infectious illnesses and vaccinations, respectively, within 1 month before the onset. Clinical and radiological findings of ADEM revealed that the frequency of seizures, mean white blood cell counts in cerebrospinal fluid, and the frequency of subcortical lesions in Fukuoka study, seemed to be higher than those in previous non-Asian studies. These findings suggest that there are ethnic or geographical differences in the incidence and clinical features of ADEM, and that there might be potent genetic or environmental risk factors for ADEM distinct from those for multiple sclerosis.

[A case of parietal lobe epilepsy with ictal laughter].

We report here about an 8-year-old boy with parietal lobe epilepsy (PLE) and ictal laughter. At the age of 6, he began to experience drop seizures, followed by sensory fits. Interictal EEG showed frequent spikes at C3, C4, P3 and Cz. Despite treatment with antiepileptic drugs, he often fell down in seizures after feeling abnormal sensations in the right shoulder. On ictal video EEG at the age of 7 years, (1) he became motionless and complained of fear and pain in the right hand, (2) he had clonic seizures of the right upper limb and fell down to his left, (3) he laughed though he did not feel funny. Ictal EEG showed spikes which originated in Pz and then were generalized. In many of the previously reported cases, ictal laughter is associated with hypothalamic hamartomas, infantile spasms,. complex partial seizures of frontal, temporal, or parietal origin. We diagnosed the present case as having PLE. However, other localization could not be roled out because the spikes were generalized quickly. To date, there are two reported cases of ictal laughter with PLE, but ictal EEG is lacking in these patients. Ictal laughter is rare in non-lesional cryptogenic PLE, but it may imply PLE's pathogenesis.