Magnetic resonance imaging (MRI) findings in children surviving extremely premature delivery and extremely low birthweight with cerebral palsy.

To delineate the frequency, severity, and characteristics of the brain injury occurring in children surviving extremely premature birth, we reviewed brain magnetic resonance images (MRIs) of children with cerebral palsy whose birthweight was less than 1000 g and whose gestational age was less than 28 weeks. The patients were all enrolled in the state Children's Rehabilitative Services clinic, where cerebral palsy is an automatic qualifying condition. We tabulated the MRI findings with respect to the cerebellum, periventricular white matter, and corpus callosum. The inclusion criteria were met by 157 children; 94 had an MRI. The available scans were reviewed by the authors, and the findings were tabulated. Fifty scans were available for review. There were 4 totally normal scans, 18 scans had normal cerebellar imaging, and 8 scans were felt to have normal cerebral findings. The common cerebral abnormalities included decreased white-matter volume without gliosis (n = 36), periventricular leukomalacia (n = 16), and a thin corpus callosum (n = 18). Cerebellar abnormalities were found in 32. The cerebellar findings included destruction of major portions of the cerebellum (usually the inferior vermis and hemispheres) (n = 23) and focal or unilateral loss of cerebellar tissue (n = 4). The high incidence of injury to the cerebellum has not been previously appreciated. The most common cerebral injury is decreased volume of white matter in the periventricular regions without gliosis. The pattern of cerebellar injury suggests a vascular insult, and the deficient white matter without gliosis suggests immaturity of oligodendrogliocytes with limited response to injury. Both lesions are more or less unique to the age at which the insult occurred and represent an emerging, newly recognized type of cerebral palsy.