Immature Spinal Locomotor Output in Children with Cerebral Palsy.
Detailed descriptions of gait impairments have been reported in cerebral palsy (CP), but it is still unclear how maturation of the spinal motoneuron output is affected. Spatiotemporal alpha-motoneuron activation during walking can be assessed by mapping the electromyographic activity profiles from several, simultaneously recorded muscles onto the anatomical rostrocaudal location of the motoneuron pools in the spinal cord, and by means of factor analysis of the muscle activity profiles. Here, we analyzed gait kinematics and EMG activity of 11 pairs of bilateral muscles with lumbosacral innervation in 35 children with CP (19 diplegic, 16 hemiplegic, 2-12 years) and 33 typically developing (TD) children (1-12 years). TD children showed a progressive reduction of EMG burst durations and a gradual reorganization of the spatiotemporal motoneuron output with increasing age. By contrast, children with CP showed very limited age-related changes of EMG durations and motoneuron output, as well as of limb intersegmental coordination and foot trajectory control (on both sides for diplegic children and the affected side for hemiplegic children). Factorization of the EMG signals revealed a comparable structure of the motor output in children with CP and TD children, but significantly wider temporal activation patterns in children with CP, resembling the patterns of much younger TD infants. A similar picture emerged when considering the spatiotemporal maps of alpha-motoneuron activation. Overall, the results are consistent with the idea that early injuries to developing motor regions of the brain substantially affect the maturation of the spinal locomotor output and consequently the future locomotor behavior.
Centre of Space Bio-medicine, University of Rome Tor Vergata Rome, Italy.
Germana
G
Cappellini
Laboratory of Neuromotor Physiology, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia Foundation Rome, Italy.
Yury P
YP
Ivanenko
Centre of Space Bio-medicine, University of Rome Tor Vergata Rome, Italy.
Giovanni
G
Martino
School of Kinesiology, Louisiana State University, Baton Rouge LA, USA.
Michael J
MJ
MacLellan
Department of Pediatric Neurorehabilitation, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia Foundation Rome, Italy.
Annalisa
A
Sacco
Department of Pediatric Neurorehabilitation, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia Foundation Rome, Italy.
Daniela
D
Morelli
Centre of Space Bio-medicine, University of Rome Tor VergataRome, Italy; Laboratory of Neuromotor Physiology, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia FoundationRome, Italy; Department of Systems Medicine, University of Rome Tor VergataRome, Italy.
Francesco
F
Lacquaniti
abnormal development; basic muscle activation patterns; cerebral palsy; gait; spinal locomotor output