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Characteristics of locomotor control in children with cerebral palsy
1Department of Neurology, University of Freiburg, Germany. berger@nz11.ukl.uni-freiburg.de
Insights
Children with cerebral palsy (CP) exhibit an immature reflex pattern due to arrested maturation, similar to infants learning to walk. This pattern results from a lack of supraspinal control over muscle reflexes.
Area of Science:
- Neuroscience
- Developmental Biology
- Biomedical Engineering
Background:
- Children with cerebral palsy (CP) often display abnormal muscle activation patterns during locomotion.
- Electromyographical (EMG) recordings reveal characteristic features in CP, including muscle coactivation and altered reflex responses.
Purpose of the Study:
- To investigate the relationship between the electromyographical (EMG) reflex patterns in children with cerebral palsy (CP) and normal motor maturation.
- To determine if the observed reflex patterns in CP reflect an arrested developmental stage.
Main Methods:
- Analysis of electromyographical (EMG) recordings from the leg muscles of children with cerebral palsy (CP) during the stance phase of walking.
- Comparison of EMG patterns in CP children with those observed in infants during the process of learning to walk.
- Examination of reflex excitability and muscle activation patterns.
Main Results:
- CP children exhibit coactivation of antagonistic leg muscles, low tonic extensor EMG activation, and enhanced short-latency stretch reflexes.
- These EMG features in CP strongly resemble the reflex patterns seen in infants (7-10 months) learning to walk.
- Normal maturation involves supraspinal control of afferent pathways, regulating stretch reflexes and polysynaptic responses, a process that appears impaired in CP.
Conclusions:
- The characteristic EMG reflex pattern in children with CP suggests an arrested normal motor maturation.
- This arrested maturation is linked to a failure in the development of supraspinal control over specific afferent pathways.
- Adults with supraspinal lesions may exhibit a similar regression to this early reflex pattern.
Abstract:
The typical features of electromyographical (EMG) recordings from children with cerebral palsy (CP) consist of a coactivation of antagonistic leg muscles during the stance phase, a low and tonic activation of extensor EMG, and enhanced stretch reflex excitability with short latency. This characteristic reflex pattern is suggested to reflect an arrested normal maturation. The strong similarity between the walking pattern of CP children (8-16 years of age) and the reflex pattern during the process of learning to walk (7-10 months of age) lets us draw the following conclusion. During normal maturation a close parallelism exists between the control of group I afferent inhibition with the suppression of mono/oligosynaptic stretch reflexes and group II afferent facilitation with the increase of polysynaptic (mainly extensor) EMG responses. This maturation depends on supraspinal control, and does not occur in CP children. In adult patients with a supraspinal lesion, a regression to this early reflex pattern takes place.