Postural mechanisms in moderate-to-severe cerebral palsy

How Does Postural Control of Children with CP Deal with Manipulations on Base of Support and Support Surface? A Systematic Review

AIMS

Systematically review literature addressing the effects of changes in base of support (BoS) configuration and characteristics of support surface (SS) on postural control of children with cerebral palsy (CP).

METHODS

We conducted a tailored electronic database search in PubMed/Web of Science/SCOPUS/Embase.

RESULTS

We identified 15 studies meeting inclusion criteria.

CONCLUSION

The extant literature suggests that when children with CP experience changes in BoS and SS, they engage in fewer adaptive postural control responses than typically developing children. Documented response patterns of children with CP in the literature might guide the selection and development of rehabilitation strategies to appropriately facilitate or challenge postural control in children with CP.

Quantifying States and Transitions of Emerging Postural Control for Children Not Yet Able to Sit Independently

Objective, quantitative postural data is limited for individuals who are non-ambulatory, especially for those who have not yet developed trunk control for sitting. There are no gold standard measurements to monitor the emergence of upright trunk control. Quantification of intermediate levels of postural control is critically needed to improve research and intervention for these individuals. Accelerometers and video were used to record postural alignment and stability for eight children with severe cerebral palsy aged 2 to 13 years, under two conditions, seated on a bench with only pelvic support and with additional thoracic support. This study developed an algorithm to classify vertical alignment and states of upright control; Stable, Wobble, Collapse, Rise and Fall from accelerometer data. Next, a Markov chain model was created to calculate a normative score for postural state and transition for each participant with each level of support. This tool allowed quantification of behaviors previously not captured in adult-based postural sway measures. Histogram and video recordings were used to confirm the output of the algorithm. Together, this tool revealed that providing external support allowed all participants: (1) to increase their time spent in the Stable state, and (2) to reduce the frequency of transitions between states. Furthermore, all participants except one showed improved state and transition scores when given external support.

The Effects of Trunk Impairment on Fatigue and Balance in Children with Cerebral Palsy

Cerebral palsy (CP) involves trunk impairment, leading to decreased postural control that is an important contributor to problems maintaining daily activities without undue fatigue. Our aim in this research was to determine the effects of trunk impairment on fatigue and balance in children with hemiplegic CP. We included 65 ambulatory children with CP in this cross-sectional study, and we grouped them into those with greater trunk impairment (Group 1, n = 33) and lesser trunk impairment (Group 2, n = 32) according to their scores on the Trunk Imparment Scale (TIS). We assessed their fatique level using the Pediatric Quality of Life Inventory™ Version 4.0 Multidimensional Fatigue Scale (PedsQL-MFS), and their balance ability using the Pediatric Balance Scale (PBS). We found that the PedsQL-MFS parameters, except the general and cognitive fatigue scores, were significantly better for participants in Group 2 than in Group 1; however Group 2 showed significantly higher scores for balance ability than did Group 1 (p < .001). All of the TIS parameters were significantly correlated with sleep/rest fatigue, and PBS scores and trunk coordination were also significantly correlated with general fatigue (p = .013) and cognitive fatigue (p = .003) which are subparameters of the PedsQL-MFS and PBS (p < .001). However static balance was highly and negatively correlated with cognitive fatigue (p < .037).Increased trunk impairment contributed to the exacerbation of fatigue and balance problems in children with hemiplegic CP. Inadequate trunk control was associated with poor sleep and poor resting quality rather than perceived general and cognitive fatigue.

Deficits of Sensory Integration and Balance as Well as Scoliotic Changes in Young Schoolgirls

The aim of this study was to assess the relationship between sensory integration and balance deficits as well as scoliotic changes in young schoolgirls. The study comprised 54 girls aged 11 years with scoliotic changes. The Clinical Test of Sensory Integration and Balance of the Biodex Balance System platform were used to analyze the deficits in sensory integration and balance. Scoliotic changes were assessed using the Diers Formetric III 4D optoelectronic method. In the present study, there was a significant relationship between sensory integration and balance deficits as well as spine curvature angle (°) (p = 0.01), vertebral surface rotation (°) (p = 0.03), pelvic tilt (°) (p = 0.02), and lateral deviation (mm) (p = 0.04). The integration of the sensory systems has a positive effect on the structure of the intended and controlled movement as well as body posture and the development of the spine. In the treatment of scoliotic changes, one should also consider exercises that improve sensory integration as well as position and balance reactions.

Rapid assessment of hand reaching using virtual reality and application in cerebellar stroke

The acquisition of sensory information about the world is a dynamic and interactive experience, yet the majority of sensory research focuses on perception without action and is conducted with participants who are passive observers with very limited control over their environment. This approach allows for highly controlled, repeatable experiments and has led to major advances in our understanding of basic sensory processing. Typical human perceptual experiences, however, are far more complex than conventional action-perception experiments and often involve bi-directional interactions between perception and action. Innovations in virtual reality (VR) technology offer an approach to close this notable disconnect between perceptual experiences and experiments. VR experiments can be conducted with a high level of empirical control while also allowing for movement and agency as well as controlled naturalistic environments. New VR technology also permits tracking of fine hand movements, allowing for seamless empirical integration of perception and action. Here, we used VR to assess how multisensory information and cognitive demands affect hand movements while reaching for virtual targets. First, we manipulated the visibility of the reaching hand to uncouple vision and proprioception in a task measuring accuracy while reaching toward a virtual target (n = 20, healthy young adults). The results, which as expected revealed multisensory facilitation, provided a rapid and a highly sensitive measure of isolated proprioceptive accuracy. In the second experiment, we presented the virtual target only briefly and showed that VR can be used as an efficient and robust measurement of spatial memory (n = 18, healthy young adults). Finally, to assess the feasibility of using VR to study perception and action in populations with physical disabilities, we showed that the results from the visual-proprioceptive task generalize to two patients with recent cerebellar stroke. Overall, we show that VR coupled with hand-tracking offers an efficient and adaptable way to study human perception and action.

Objective measurement of sitting - Application in children with cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) and a severe motor impairment, have limited ability to perform volitional movements due to spasticity, involuntary postures and movements and reduced ability to maintain antigravity head and trunk control. A stable sitting position is a prerequisite for participation in daily life, but there is a lack of objective measurement methods for this population.

RESEARCH QUESTION

Is it feasible to measure a stable sitting position with pressure mapping and 2D motion analysis, and can it detect differences to a) a reference group, b) between subgroups of CP and c) before and after treatment with intrathecal baclofen (ITB)?

METHODS

Pressure mapping, and a 2D motion analysis system, were used to capture movements of centre of pressure (CoP), and movements of head, hand and leg, sitting on a bench for 90 s. Twenty-two children with dyskinetic or bilateral spastic CP, GMFCS III-V, mean age 9.0, and 30 children with typical development (TD) mean age 10.7, were recruited between 2010 and 2019. Seventeen children were treated with ITB. Parents were interviewed regarding aspect of sitting. Non-parametric methods were used for statistical analysis.

RESULTS

Differences in CoP and kinematics were detected with more movements in children with CP compared to children with TD (p < 0.001). There were more movements in children with dyskinetic CP compared to children with bilateral spastic CP as captured with the pressure mapping system (CoP distance p = .005 and Anterio-Posterior sway p = .014). After treatment with ITB, involuntary movements had decreased (CoP p = 0.006-0.035, kinematics p = 0.002-0.020). Parents reported improvement in sitting. The two measurement systems showed consistent results (rho 0.500-0.771, p = <0.001-0.049).

SIGNIFICANCE

It was feasible to objectively measure sitting position in children with a moderate-to-severe motor impairment with differences to a reference group and after an intervention. CoP and head movements were the variables that were easiest to capture.