Absence of transcallosal inhibition in adolescents with diplegic cerebral palsy

The role of intracortical organization in the pathophysiology of cerebral p alsy (CP) is not clear. We used transcranial magnetic stimulation to invest igate the paradigm of transcallosal inhibition (TI) in a group of adolescen t patients with diplegic CP (n = 4), hereditary spastic paraplegia (n = 2), and healthy control adolescents (n = 4). None of the patients with CP show ed TI, whereas all other subjects had normal TI. These findings indicate a lack of inhibitory control of the motor cortex in CP. (C) 1999 John Wiley & Sons, Inc.