Fukuyama type congenital muscular dystrophy as a natural model of childhood epilepsy.

Fukuyama type Congenital Muscular Dystrophy, inherited autosomal-recessively, is characterized by muscular dystrophy associated with severe mental retardation and epileptic convulsions. By examining 56 cases, followed for more than three years, 75 EEG records from 40 patients and visual evoked potentials from 11 patients with reference to autopsied materials, the authors aimed at clarifying the causative relationship between congenital central nervous system (CNS) lesions and childhood epilepsy. In 36 out of 56 cases diffuse epileptic seizures were observed with onset at 1.64 +/- 1.01 years average. In 32/36 cases seizures developed before 3 years of age. In 51/75 EEGs focal paroxysmal discharges (FPD), fronto-contro-parietal in younger and centro-occipital in older cases, were observed. Abnormal basic activities (ABA), diffuse-alpha-activity and/or abundant or extreme spindles, were observed more often in older than younger cases. The incidence of FPD was similar between convulsive and non-convulsive cases, but ABA predominated in the former, VEP revealed abnormal findings in 64% of 11 cases examined. Of the CNS pathology, consisting of cerebral and cerebellar gyral abnormalities and a hypoplastic corticospinal tract, the gyral lesions (verrucous polymicrogyria with adhesions of adjacent gyri and cellular disarrangement) were thought to be lesions causing epilepsy. Cortical nonprogressive gyral lesions occurring around the second trimester could cause FPD and clinical diffuse epileptic seizures develop with other factors concerned with ABA.