Hyperactive Stretch Reflexes as a Prognostic Factor of Ambulation in the Children with Spastic Diplegia

Lee, Sang Heon; Kim, Woo Sub; Lee, Eun Hwa; Kim, Sei Joo

Abstract

OBJECTIVE
The purpose of this study was to investigate the influence of hyperactive stretch reflexes and contralateral adductor spread on the prognosis of gait in cerebral palsy with spastic diplegia and to investigate the reflex characteristics of spastic patients according to motor development. METHOD: Thirty three children with spastic diplegia were examined. Compound muscle action potentials elicited by electrical hammer were used for quantification of stretch reflexes. Clinical spasticity was evaluated with the modified Ashworth scale and re-evaluation was done at least for 18 months. The patients were classified as 3 groups according to the stage of motor development: Group I consisted of children who were unable to sit; Group II children were able to pull to stand but unable to walk independently; Group III children could walk independently more than ten steps. Reflex irradiation, amplitudes of compound muscle action potentials, amplitude ratios, and Ashworth scores were analyzed and compared between the groups. Twenty four normal infants and 18 children were examined as control.
RESULTS
Contralateral adductor responses were elicited with patellar tendon tap stimulation in all spastic diplegic children. The amplitudes of contralateral adductor were 2.41 mV in group I, 1.75 mV in group II, and 1.21 mV in group III. The amplitude ratio of contralateral adductor to rectus femoris were 0.53 in group I, 0.40 in group II, and 0.26 in group III, respectively, and correlated with the degree of spasticity.
CONCLUSION
The stretch reflex responses in children with cerebral palsy with spastic diplegia were highly exaggerated, and correlated with motor development. Spread of reflexes to contralateral adductor muscle would be in clinical and electrophysiological value.