Cerebellar dysgenesis in infants and children: an experience of 22 cases.

There were a total of 22 cases of cerebellar dysgenesis documented by brain sonogram, and/or brain computer-tomography scan, and/or brain magnetic resonance imaging (MRI) in our department over the past 10 years. There were ten males and twelve females. The mean age at diagnosis was 5.79 months. The follow-up period ranged from 2 days to 132 months. Seven cases were suspected upon prenatal examination. Three cases presented with isolated cerebellar hypoplasia, one with Dandy- Walker malformation and three with Joubert syndrome. Seven cases presented with cerebellar dysgenesis complicated with supratentorial brain dysgenesis. Among them, three had vermis hypoplasia with hypoplasia of the corpus callosum, 1 had vermis hypoplasia with holoprosencephaly, 1 had cerebellar hypoplasia with lissencephaly and hypoplasia of corpus callosum, 1 had vermis hypoplasia, agenesis of the corpus callosum and pachygyria, and 1 had cerebellar hypoplasia, hypoplasia of corpus callosum and midline cystic malformation. They all showed severe psychomotor retardation. Six cases showed chromosome anomalies. The neurological outcome for cases with isolated cerebellar hypoplasia was better than the outcome of the complicated cases. MRI is recommended for patients with microcephaly to check for the possibility of combined supratentorial brain dysgenesis. When performing MRI, a median sagittal view should be included. A classification for clinical approach was presented at the same time. In this retrospective study, this classification seemed to have benefits in prediction of clinical outcomes.