Presentation
Developmental delay and hypotonia since birth.
Patient Data
Abnormal bilateral periventricular white matter hyperintensity in the frontal lobes on the fluid-sensitive sequences. The frontal lobes show a bizarre pattern of shallow sulci oriented parallel to each other with slightly thickened cortices and bumpy grey-white matter interfaces - pachygyria.
There is bilateral temporoparietal polymicrogyria.
The corpus callosum has a bizarre configuration, though not hypoplastic. There is marked pontine and inferior vermian hypoplasia and collicular fusion. The pontine hypoplasia leads to a Z configuration.
Disorganized cerebellar folia with multiple subcentimeter cysts are seen in the posterior and inferior cerebellar hemispheres.
In view of the characteristic distribution of cortical dysplasia, cerebellar abnormalities and relatively preserved general configuration of the brain, a probable diagnosis of Fukuyama congenital muscular dystrophy is considered.
Case Discussion
Fukuyama congenital muscular dystrophy is a congenital muscular dystrophy with an autosomal recessive inheritance pattern, considered to be the second most common muscular dystrophy in Japan 1, after Duchenne muscular dystrophy
The most common and characteristic changes in the central nervous system are brain malformations, which include polymicrogyria, pachygyria and agyria of the cerebrum and cerebellum (cobblestone cortex), which lack neuronal lamination of the normal six-layered cortex 1.
On brain MR examinations, virtually all patients show polymicrogyria and approximately half show pachygyria. These two types of cortical dysplasias are present in characteristic distributions: the former demonstrates frontal lobe involvement in all and parietotemporal lobe involvement in some, whereas the latter involves the temporooccipital lobes.
Traditionally, the diagnosis is based on pathologic evidence of muscular dystrophy in the biopsy specimen obtained in the appropriate clinical context.