Spastic cerebral palsy: possible spinal interneuronal contributions

The author explores the possibility that abnormal and immature spinal interneuronal circuits play a rôle in spastic cerebral palsy. Interneuronal abnormalities could account for a number of characteristic signs: sensitivity to normally innocuous stimuli, hyperreflexia, abnormal and inappropriate co-ordination patterns, and limitations in acquiring, planning, executing and correcting skillful actions. The precise pattern of interneuronal anomalies present will depend on the original site of the lesion, age at onset, and on how central and segmental development were affected. Although the number of relevant studies is very small, there are indications that long-term training can produce changes in segmental response, both by altering descending inhibition and by producing lasting changes in spinal neuronal organisation and responsiveness. Modern recording techniques have introduced the prospect of tracing immature and abnormal segmental components and of establishing their impacts on movement control.