Neuronal migration disorders in cerebral palsy

Abstract

We retrospectively analyzed 58 autopsy cases of cerebral palsy which were clinically diagnosed at the Aichi Prefecture Colony Hospital. Most of the cases of cerebral palsy had brainweights that were 60-70% of the normal brainweight for their ages. However, approximately 20% of the brains were not small, especially in cases over 20 years of age. The brains of cerebral palsy cases showed wide morphological variation, and were classified into thinned cerebral mantle type (10 cases), hydrocephalus type (three cases) and microgyria-pachygyria type (45 cases). Macroscopic morphometric analysis was performed in the brains of the microgyria-pachygyria type using the coronal whole brain sections through the mammillary bodies stained with Klüver-Barerra (KB) stain, and compared with the brains of four cases of the Fukuyama type congenital muscular dystrophy (FCMD), two cases of lissencephaly, and nine cases of non-neural diseases as controls. The morphometric values of the coronal sections in the cerebral palsy cases showed diminished white matter with more dilatated ventricles compared with the control brains. This tendency was stronger in the brains of spastic cerebral palsy cases than in the brain of athetotic cerebral palsy cases. Cerebral palsy, in terms of the morphological complexity of the cerebrum as determined by the morphometric analysis, was situated between FCMD and lissencephaly. Although microscopic analysis of cerebral palsy brains was limited to 19 cases, there were four brains with heterotopic gray matter, three brains with cortical folding, a sign of cortical dysplasia, and three brains with neuronal cytomegaly. In addition, more than half of the brains showed disorganization of lamination in the cortex with disorientation of neurons. These findings suggest that some cases of cerebral palsy may result from disrupted neuronal migration during cortical development.