Temporal but not spatial variability during gait is reduced after selective dorsal rhizotomy in children with cerebral palsy

Can developmental trajectories in gait variability provide prognostic clues in motor adaptation among children with mild cerebral palsy? A retrospective observational cohort study

Aim

To investigate whether multiple domains of gait variability change during motor maturation and if this change over time could differentiate children with a typical development (TDC) from those with cerebral palsy (CwCP).

Methods

This cross-sectional retrospective study included 42 TDC and 129 CwCP, of which 99 and 30 exhibited GMFCS level I and II, respectively. Participants underwent barefoot 3D gait analysis. Age and parameters of gait variability (coefficient of variation of stride-time, stride length, single limb support time, walking speed, and cadence; as well as meanSD for hip flexion, knee flexion, and ankle dorsiflexion) were used to fit linear models, where the slope of the models could differ between groups to test the hypotheses.

Results

Motor-developmental trajectories of gait variability were able to distinguish between TDC and CwCP for all parameters, except the variability of joint angles. CwCP with GMFCS II also showed significantly higher levels of gait variability compared to those with GMFCS I, these levels were maintained across different ages.

Interpretation

This study showed the potential of gait variability to identify and detect the motor characteristics of high functioning CwCP. In future, such trajectories could provide functional biomarkers for identifying children with mild movement related disorders and support the management of expectations.

Reliability and discriminant validity of the quantitative timed up and go in typically developing children and children with cerebral palsy GMFCS levels I-II

PURPOSE

The purpose of this study was to examine the reliability, and discriminant validity of the Quantitative Timed up and Go (QTUG) in typically developing (TD) children and children with cerebral palsy (CP).

METHODS

Twenty-eight TD children and 8 with CP (GMFCS I-II) completed 3 TUG trials while wearing QTUG sensors. Test-retest reliability and discriminative ability were examined for the 57 constituent parameters of the TUG. Relationships between age and these parameters were also examined.

RESULTS

Forty-four of the parameters demonstrated moderate to excellent test-retest reliability, with measures of angular velocity being the most reliable. Twenty-six parameters were different between TD children and those with CP, and twenty-eight gait parameters demonstrated correlations with age, further supporting its discriminative ability.

CONCLUSION

The QTUG is a clinically feasible tool that is capable of both reliably measuring and discriminating many of the movement parameters with the TUG mobility task in TD children and those with CP GMFCS I-II. The results of the present study provide preliminary evidence that the QTUG can discriminate between children on several of the gait parameters within the TUG.

Gait variability is affected more by peripheral artery disease than by vascular occlusion

Background

Patients with peripheral artery disease with intermittent claudication (PAD-IC) have altered gait variability from the first step they take, well before the onset of claudication pain. The mechanisms underlying these gait alterations are poorly understood.

Aims

To determine the effect of reduced blood flow on gait variability by comparing healthy older controls and patients with PAD-IC. We also determined the diagnostic value of gait variability parameters to identify the presence of PAD.

Methods

A cross-sectional cohort design was used. Thirty healthy older controls and thirty patients with PAD-IC walked on a treadmill at their self-selected speed in pain free walking (normal walking for healthy older controls; prior to claudication onset for PAD) and reduced blood flow (post vascular occlusion with thigh tourniquet for healthy older controls; pain for PAD) conditions. Gait variability was assessed using the largest Lyapunov exponent, approximate entropy, standard deviation, and coefficient of variation of ankle, knee, and hip joints range of motion. Receiver operating characteristics curve analyses of the pain free walking condition were performed to determine the optimal cut-off values for separating individuals with PAD-IC from those without PAD-IC.

Results and discussion

Patients with PAD-IC have increased amount of variability for knee and hip ranges of motion compared with the healthy older control group. Regarding the main effect of condition, reduced blood flow demonstrated increased amount of variability compared with pain free walking. Significant interactions between group and condition at the ankle show increased values for temporal structure of variability, but a similar amount of variability in the reduced blood flow condition. This demonstrates subtle interactions in the movement patterns remain distinct between PAD-IC versus healthy older controls during the reduced blood flow condition. A combination of gait variability parameters correctly identifies PAD-IC disease 70% of the time or more.

Conclusions

Gait variability is affected both by PAD and by the mechanical induction of reduced blood flow. Gait variability parameters have potential diagnostic ability, as some measures had 90.0% probability of correctly identifying patients with PAD-IC.

Intraoperative neurophysiological monitoring in selective dorsal rhizotomy (SDR)

For decades, intraoperative neurophysiological monitoring (IONM) has been used to guide selective dorsal rhizotomy (SDR) for the treatment of spastic cerebral palsy (CP). Electromyography (EMG) interpretation methods, which are the core of IONM, have never been fully discussed and addressed, and their importance and necessity in SDR have been questioned for years. However, outcomes of CP patients who have undergone IONM-guided SDR have been favorable, and surgery-related complications are extremely minimal. In this paper, we review the history of evolving EMG interpretation methods as well as their neuroelectrophysiological basis.

Gait deficits and dynamic stability in children and adolescents with cerebral palsy: A systematic review and meta-analysis

BACKGROUND

Studies have demonstrated that ambulatory children and adolescents with cerebral palsy demonstrate atypical gait patterns. Out of numerous gait variables, identification of the most deteriorated gait parameters is important for targeted and effective gait rehabilitation. Therefore, this study aimed to identify the gait parameters with the most discriminating nature to distinguish cerebral palsy gait from normal gait.

METHODS

Multiple databases were searched to include studies on ambulatory children and adolescents with cerebral palsy that included gait (spatio-temporal, kinematic, and kinetic) and dynamic stability variables.

FINDINGS

Of 68 studies that met the inclusion criteria, 35 studies were included in the meta analysis. Effect size was used to assess the discriminative strength of each variable. A large effect (≥ 0.8) of cerebral palsy on double limb support time (Standardized Mean Difference = 0.98), step length (Standardized Mean Difference = 1.65), step width (Standardized Mean Difference = 1.21), stride length (Standardized Mean Difference = 1.75), and velocity (Standardized Mean Difference = 1.42) was observed at preferred-walking speed. At fast-walking speed, some gait variables (i.e. velocity and stride length) exhibited larger effect size compared to preferred-walking speed. For some kinematic variables (e.g. range of motion of pelvis), the effect size varied across the body planes.

INTERPRETATION

Our systematic review detects the most discriminative features of cerebral palsy gait. Non-uniform effects on joint kinematics across the anatomical planes support the importance of 3D gait analysis. Differential effects at fast versus preferred speeds emphasize the importance of measuring gait at a range of speeds.

The influence of the use of ankle-foot orthoses on thorax, spine, and pelvis kinematics during walking in children with cerebral palsy

BACKGROUND

To improve gait function in children with cerebral palsy, ankle-foot orthoses are often prescribed. However, until now, little attention has been devoted to the effect of ankle-foot orthoses on the postural control during walking in children with cerebral palsy.

OBJECTIVES

The aim was to compare the differences in thorax, spine, and pelvis movements in children with cerebral palsy during walking barefoot and walking with ankle-foot orthoses.

STUDY DESIGN

Clinical study with an intra subject design.

METHODS

A total of 15 children (12 boys and 3 girls; mean age, 8 ± 2 years) with bilateral spastic cerebral palsy (12 with Gross Motor Function Classification System I and 3 with Gross Motor Function Classification System II) performed a full-body three-dimensional gait analysis. Differences in the range of motion of the thorax, spine, and pelvis during walking barefoot and walking with bilateral ankle-foot orthoses were analyzed (SPSS v20, paired-samples t-test).

RESULTS

Children with cerebral palsy showed a significantly larger range of motion of the thorax (flexion/extension, lateral bending, and rotation) and the spine (lateral bending) during walking with ankle-foot orthoses compared to walking barefoot. No significant differences were found in the range of motion of the pelvis between these two conditions.

CONCLUSION

It can be concluded that wearing ankle-foot orthoses influences the postural control during walking in children with bilateral spastic cerebral palsy. Due to the increased range of motions, the movement pattern of the trunk diverges from the typically developing children. Clinical relevance Wearing ankle-foot orthoses not only gives more stability at the pelvis and ankle joint but also influences trunk motion. In order of the level of core stability of the child, compensations can be either seen in the lower back or the upper trunk. Clinicians should be aware of these compensations and should evaluate postural control in a more detailed evaluation.

The Effects of Selective Dorsal Rhizotomy on Balance and Symmetry of Gait in Children with Cerebral Palsy

Aim

Cerebral palsy (CP) is associated with dysfunction of the upper motor neuron and results in balance problems and asymmetry during locomotion. Selective dorsal rhizotomy (SDR) is a surgical procedure that results in reduced afferent neuromotor signals from the lower extremities with the aim of improving gait. Its influence on balance and symmetry has not been assessed. The aim of this prospective cohort study was to evaluate the impact of SDR on balance and symmetry during walking.

Methods

18 children (10 girls, 8 boys; age 6 years (y) 3 months (m), SD 1y 8m) with bilateral spastic CP and Gross Motor Function Classification System levels I to II underwent gait analysis before and 6 to 12 months after SDR. Results were compared to 11 typically developing children (TDC; 6 girls, 5 boys; age 6y 6m, SD 1y 11m). To analyse balance, sway velocity, radial displacement and frequency were calculated. Symmetry ratios were calculated for balance measures and spatio-temporal parameters during walking.

Results

Most spatio-temporal parameters of gait, as well as all parameters of balance, improved significantly after SDR. Preoperative values of symmetry did not vary considerably between CP and TDC group and significant postoperative improvement did not occur.

Interpretation

The reduction of afferent signalling through SDR improves gait by reducing balance problems rather than enhancing movement symmetry.

Gait analysis to guide a selective dorsal rhizotomy program

Selective dorsal rhizotomy is a valuable surgical option to manage spasticity in children with bilateral cerebral palsy with the objective of improving function. Choosing the correct patient for rhizotomy requires considerable effort and a comprehensive evaluation. Instrumented three-dimensional gait analysis provides supporting evidence in the selection of the ideal child for SDR as well as enabling quantitative monitoring of outcome and post-operative management up to skeletal maturity.

Towards the importance of minimum toe clearance in level ground walking in a healthy elderly population

Tripping is presumed to be the principal cause for falls during walking. At minimum toe clearance, the potential for trip-related falls is considered to be highest. Thus, controlling minimum toe clearance is essential for walking without tripping. In theory, the central nervous system should therefore give priority to accurate control of the variability in minimum toe clearance, as compared to other gait parameters, since people tend to only modify variability in any given task if it interferes with the task performance. The aim of this study was to determine whether elderly individuals show less increase in variability of minimum toe clearance during a dual-task condition (where an increase of gait variability is provoked), while allowing a larger range of variability in the other gait parameters. Forty elderly participants walked back and forth on a 25 m long track for five minutes. They then walked a second time performing an additional cognitive task. The variability in stride time, stride length and minimum toe clearance as well as dual-task costs of each gait parameter were calculated for each walk. The variability in minimum toe clearance did not change during dual task-walking, whereas the variability of stride length and stride time increased, showing dual-task costs of about 66% and 84%, respectively. To avoid additional detrimental load on the central nervous system, the modification of task-irrelevant variability may be tolerated during dual-task conditions, whereas minimum toe clearance is controlled with high priority.