Hypertonia in childhood secondary dystonia due to cerebral palsy is associated with reflex muscle activation

Children with secondary dystonia due to cerebral palsy exhibit abnormal upper extremity postures and slow voluntary movement. However, the interaction between abnormal postures and abnormal movement in dystonia is still unclear. Some mechanisms by which postures are maintained in dystonia include stretch reflexes, overflow of muscle activation to other muscles, and direct coactivation of antagonist muscles. This study explored the independent contributions of each of these postural mechanisms to abnormal biceps brachii (antagonist) activity during elbow extension, which slows movement. A linear model of biceps activation as a function of velocity-dependent reflexes, triceps-dependent overflow, and direct drive to the biceps was fitted to experimental data from 11 children and young adults with secondary dystonia due to cerebral palsy and 11 age-matched control subjects. Subjects performed elbow extension movements against each of four levels of resistance without perturbations or in each of two perturbation conditions. Results show that biceps activity in children with dystonia consists of significant contributions of reflex activation, overflow from triceps, and direct muscular drive. Additionally, stretch reflexes during movement are shown to be elevated at three latencies after stretch. These findings suggest that there are postural mechanisms involved in stabilizing the elbow along its slow trajectory during movement and provide a quantitative basis for the selection of treatments targeting specific impairments in children with secondary dystonia due to cerebral palsy.

Download Full-text

Deep anterior cerebellar stimulation reduces symptoms of secondary dystonia in patients with cerebral palsy treated due to spasticity

Clinical Neurology and Neurosurgery ◽

10.1016/j.clineuro.2015.05.017 ◽

2015 ◽

Vol 135 ◽

pp. 62-68 ◽

Cited By ~ 25

Author(s):

Paweł Sokal ◽

Marcin Rudaś ◽

Marek Harat ◽

Łukasz Szylberg ◽

Piotr Zieliński

Keyword(s):

Cerebral Palsy ◽

Secondary Dystonia ◽

Cerebellar Stimulation

Download Full-text

Prospective Open-Label Clinical Trial of Trihexyphenidyl in Children With Secondary Dystonia due to Cerebral Palsy

Journal of Child Neurology ◽

10.1177/0883073807302601 ◽

2007 ◽

Vol 22 (5) ◽

pp. 530-537 ◽

Cited By ~ 62

Author(s):

Terence D. Sanger ◽

Amy Bastian ◽

Jan Brunstrom ◽

Diane Damiano ◽

Mauricio Delgado ◽

...

Keyword(s):

Clinical Trial ◽

Cerebral Palsy ◽

Open Label ◽

Secondary Dystonia

Download Full-text

Backward walking highlights gait asymmetries in children with cerebral palsy

Journal of Neurophysiology ◽

10.1152/jn.00679.2017 ◽

2018 ◽

Vol 119 (3) ◽

pp. 1153-1165 ◽

Cited By ~ 12

Author(s):

Germana Cappellini ◽

Francesca Sylos-Labini ◽

Michael J. MacLellan ◽

Annalisa Sacco ◽

Daniela Morelli ◽

...

Keyword(s):

Cerebral Palsy ◽

Muscle Activation ◽

Pattern Generation ◽

Comprehensive Assessment ◽

Emg Activity ◽

Backward Walking ◽

Spinal Circuitry ◽

Children With Cerebral Palsy ◽

Control Circuits ◽

The Brain

To investigate how early injuries to developing motor regions of the brain affect different forms of gait, we compared the spatiotemporal locomotor patterns during forward (FW) and backward (BW) walking in children with cerebral palsy (CP). Bilateral gait kinematics and EMG activity of 11 pairs of leg muscles were recorded in 14 children with CP (9 diplegic, 5 hemiplegic; 3.0–11.1 yr) and 14 typically developing (TD) children (3.3–11.8 yr). During BW, children with CP showed a significant increase of gait asymmetry in foot trajectory characteristics and limb intersegmental coordination. Furthermore, gait asymmetries, which were not evident during FW in diplegic children, became evident during BW. Factorization of the EMG signals revealed a comparable structure of the motor output during FW and BW in all groups of children, but we found differences in the basic temporal activation patterns. Overall, the results are consistent with the idea that both forms of gait share pattern generation control circuits providing similar (though reversed) kinematic patterns. However, BW requires different muscle activation timings associated with muscle modules, highlighting subtle gait asymmetries in diplegic children, and thus provides a more comprehensive assessment of gait pathology in children with CP. The findings suggest that spatiotemporal asymmetry assessments during BW might reflect an impaired state and/or descending control of the spinal locomotor circuitry and can be used for diagnostic purposes and as complementary markers of gait recovery.NEW & NOTEWORTHY Early injuries to developing motor regions of the brain affect both forward progression and other forms of gait. In particular, backward walking highlights prominent gait asymmetries in children with hemiplegia and diplegia from cerebral palsy and can give a more comprehensive assessment of gait pathology. The observed spatiotemporal asymmetry assessments may reflect both impaired supraspinal control and impaired state of the spinal circuitry.

Download Full-text

Early Development of Locomotor Patterns and Motor Control in Very Young Children at High Risk of Cerebral Palsy, a Longitudinal Case Series

Frontiers in Human Neuroscience ◽

10.3389/fnhum.2021.659415 ◽

2021 ◽

Vol 15 ◽

Author(s):

Annike Bekius ◽

Margit M. Bach ◽

Laura A. van de Pol ◽

Jaap Harlaar ◽

Andreas Daffertshofer ◽

...

Keyword(s):

Cerebral Palsy ◽

High Risk ◽

Young Children ◽

Early Development ◽

Muscle Activation ◽

Brain Lesions ◽

Very Young Children ◽

Gait Parameters ◽

Locomotor Patterns ◽

Over Time

The first years of life might be critical for encouraging independent walking in children with cerebral palsy (CP). We sought to identify mechanisms that may underlie the impaired development of walking in three young children with early brain lesions, at high risk of CP, via comprehensive instrumented longitudinal assessments of locomotor patterns and muscle activation during walking. We followed three children (P1–P3) with early brain lesions, at high risk of CP, during five consecutive gait analysis sessions covering a period of 1 to 2 years, starting before the onset of independent walking, and including the session during the first independent steps. In the course of the study, P1 did not develop CP, P2 was diagnosed with unilateral and P3 with bilateral CP. We monitored the early development of locomotor patterns over time via spatiotemporal gait parameters, intersegmental coordination (estimated via principal component analysis), electromyography activity, and muscle synergies (determined from 11 bilateral muscles via nonnegative matrix factorization). P1 and P2 started to walk independently at the corrected age of 14 and 22 months, respectively. In both of them, spatiotemporal gait parameters, intersegmental coordination, muscle activation patterns, and muscle synergy structure changed from supported to independent walking, although to a lesser extent when unilateral CP was diagnosed (P2), especially for the most affected leg. The child with bilateral CP (P3) did not develop independent walking, and all the parameters did not change over time. Our exploratory longitudinal study revealed differences in maturation of locomotor patterns between children with divergent developmental trajectories. We succeeded in identifying mechanisms that may underlie impaired walking development in very young children at high risk of CP. When verified in larger sample sizes, our approach may be considered a means to improve prognosis and to pinpoint possible targets for early intervention.

Download Full-text

Alleviation of Motor Impairments in Patients with Cerebral Palsy: Acute Effects of Whole-body Vibration on Stretch Reflex Response, Voluntary Muscle Activation and Mobility

Frontiers in Neurology ◽

10.3389/fneur.2017.00416 ◽

2017 ◽

Vol 8 ◽

Cited By ~ 12

Author(s):

Anne Krause ◽

Eckhard Schönau ◽

Albert Gollhofer ◽

Ibrahim Duran ◽

Anja Ferrari-Malik ◽

...

Keyword(s):

Cerebral Palsy ◽

Stretch Reflex ◽

Muscle Activation ◽

Whole Body Vibration ◽

Reflex Response ◽

Whole Body ◽

Acute Effects ◽

Motor Impairments ◽

Body Vibration ◽

Voluntary Muscle

Download Full-text

Modeling of Muscle Activation from Electromyography Recordings in Patients with Cerebral Palsy

Applied Sciences ◽

10.3390/app8122345 ◽

2018 ◽

Vol 8 (12) ◽

pp. 2345

Author(s):

Susmita Roy ◽

Ana Alves-Pinto ◽

Renée Lampe

Keyword(s):

Cerebral Palsy ◽

Reference Values ◽

Muscle Activation ◽

Muscle Force ◽

Rectus Femoris ◽

Biceps Femoris ◽

Force Modeling ◽

Lower Extremity Muscle ◽

Musculus Gastrocnemius ◽

Parameter Dependent

The present study estimated muscle activation from electromyographic (EMG) recordings in patients with cerebral palsy (CP) during cycling on an ergometer. This could be used as an input to the modeling of muscle force following the neuromusculoskeletal modeling technique which can help to understand the alterations in neuromotor processes underlying disabilities in CP. EMG signals of lower extremity muscle activity from 14 adult patients with CP and 10 adult healthy participants were used here to derive muscle activation. With a self developed EMG system, signals from the following muscles were recorded: Musculus tibialis anterior, Musculus gastrocnemius, Musculus rectus femoris, and Musculus biceps femoris. Collected EMG signals were mathematically transformed into muscle activation following a parameter dependent and a nonlinear transformation. Muscle activation values from patients with CP were compared to equivalent reference values obtained from healthy controls. Muscle activation calculated at specific foot positions deviated clearly from reference values. The deviation was larger for patients with higher degree of spasticity. Observations underline the need of muscle force modeling during cycling for individualized cycling training for rehabilitation strategy.

Download Full-text