THE CEREBELLUM IN CEREBRAL PALSY: A COMMONLY OVERLOOKED BUT FREQUENTLY INVOLVED STRUCTURE

Objectives: Cerebellar injury in children with cerebral palsy (CP) who were survivors of extreme prematurity (<28 weeks and <1000 grams) has only recently been appreciated. To investigate the frequency and extent of cerebellar involvement in this group, we reviewed the records of patients with cerebral palsy enrolled in the Children's Rehabilitation Services clinic (CRS) (a state operated, multi-specialty program for special needs children in which CP is a qualifying condition) in Phoenix.

Methods: Of 1025 children with CP enrolled in CRS, 150 (14.6%) were survivors of extreme premature birth. MRI had been done in 86 patients. Only 48 interpretation reports (56%) mentioned the cerebellum, of these 39 (81%) described various degrees of injury to this structure. We reviewed 50 available MRI scans looking at the degree, distribution and frequency of cerebellar and cerebral injury.

Results: Cerebellar injury was found in 38 (76%). Injury to the inferior cerebellum was the most common with diffuse and focal/unilateral injury occurring in about 10% each. In 15 of the scans reviewed, the interpretation report did not describe the cerebellum. Eleven of those scans showed cerebellar injury on review (11/15 73%). The most common cerebral finding was decreased white matter volume with no or minimal gliosis and thinning of the corpus callosum. The clinical manifestion of the CP in these children was characteristically a mixed motor deficit with components of spasticity, dystonia and ataxia.

Conclusion: 1) Children who survive extreme prematurity account for about 15% (150/1025) of all cases of cerebral palsy in Arizona today and constitute an increasing proportion of children with this condition. 2) The integrity of the cerebellum is frequently not described in MRI reports, possibly, cerebellar findings are overlooked (11/15). 3) Cerebellar injury occurs in the majority of these children (38/50 76%) and the imaging findings are more or less characteristic. 4) The clinical characteristics of the motor disability in these patients are distinct. 5) The imaging findings are presumably due to selective vulnerability of the cerebellum and cerebral white matter between 20 and 28 weeks of gestation.