Background: Our magnetoencephalographic (MEG) brain imaging studies have shown that youth with cerebral palsy (CP) demonstrate altered sensorimotor beta (18-24Hz) cortical oscillations when controlling their leg motor actions and these anomalous cortical oscillations are linked with the extent of their mobility impairments. Current therapeutic trends for improving mobility have shifted from strength training to high-velocity power training, which has shown improvements in isokinetic strength, power production and mobility of youth with CP. However, no studies have assessed whether these clinically relevant improvements are linked with changes in the sensorimotor cortical oscillations. The objective of this study was to utilize MEG brain imaging to examine the potential changes in sensorimotor cortical oscillations following power training.
Methods: Youth with CP (N=11; Age=15.9 ±1.1yrs; GMFCS I-III) and neurotypical controls (NT) (N=16; Age=14.6 ±0.8yrs) were recruited to participate in this study. The youth with CP underwent 24 high-velocity leg press power training sessions that were performed on a Total Gym® sled. Pre-Post bilateral leg press 1-repetition maximum (1RM) and peak power production were used to assess the muscular performance changes. The 1-minute walk was used to assess mobility changes. During MEG recordings, participants used their right leg to complete a goal-directed isometric target-matching task. Advanced beamforming methods were subsequently used to image the strength of the sensorimotor beta oscillatory power. The NTs only underwent the baseline MEG assessment.
Results: Youth with CP increased their 1RM (Pre=158.3 ±24.7kg, Post=247.5 ±41.5kg, p\u3c0.01), and peak power production (Pre=509.9 ±64.7W, Post=677.1 ±113.3W, p=0.04). Participants with CP also improved their 1-minute walk (Pre=77.4 ±9.2m, Post=80.8 ±8.4m, p = 0.02). The beta sensorimotor cortical oscillations in the leg region were stronger in the youth with CP prior to training compared with the NTs (CP=-25.9±1.8%; NT=-17.2±3.6%, p=0.04). However, the youth with CP had a reduction in the strength of the beta oscillations after undergoing the power training (pre=-25.9 ±1.8%, post=-14.8 ±3.6%, p=0.02), and the strength of the oscillations was not significantly different from the NTs after training (p=0.68). Lastly, the peak power production after training was tightly linked with the strength of the post-therapy sensorimotor cortical oscillations (r=0.79, p=0.03).
Conclusion: Power training appears to improve the neural generators that control the leg motor actions, and these neuroplastic changes partly contribute to improvements in the peak power production of youth with CP. Potentially, power training might provide the key therapeutic ingredients for complementary muscular and neurological plastic change.https://digitalcommons.unmc.edu/chri_forum/1001/thumbnail.jp
