In this irreversible surgical procedure, selected dorsal (sensory) nerve roots in the spinal cord are cut to prevent them from stimulating the spastic muscles (see figure below), hence it is also termed selective dorsal rhizotomy. Usually administered when a child with cerebral palsy is between 2 and 6 years of age, it may permanently reduce sensory inputs to the brain and spasticity, leading to improvements in the ability to sit, stand and walk. In non-human animal research, dorsal rhizotomy has been used as a model to examine the effects of removing somatic sensation. One striking finding is that the monkeys were able to use their forelimbs, even when they were unable to view them, but that movements in performing a number of tasks were executed clumsily.
