Cerebral palsy, a neurological disease of the young developing brain, is accompanied by a plethora of side effects. As an extension of general poverty of motor control, those with cerebral palsy show deficient hand function. Patients also present with various cognitive deficits, including reduced intellectual ability, and linguistic deficits, such as impaired language comprehension. There are concomitant sensory deficits, especially concerning tactile sensibility. Additionally, people with cerebral palsy often have impairments related to oral processes, such as swallowing. Other comorbid conditions include mental retardation and epilepsy.
HAND FUNCTION
At a specific level of impaired motor control, those with cerebral palsy experience deficient hand function. Sufferers have limited manual dexterity in the hand or hands affected by the disease, and even to an extent in the non-affected hand (in the case of unilateral, or hemiplegic, cerebral palsy). In particular, cerebral palsy patients have trouble with reaching for and gripping objects, as well as replacing and releasing objects. Such actions as carried out by cerebral palsy patients feature uncoordinated and non-fluid movements accompanied by slow speed and low accuracy. Research indicates that such deficiencies in manual ability are due primarily to faulty processing of sensory input, which prevents the execution of desired motor outputs.
1. An investigation of the factors affecting handwriting performance in children with hemiplegic cerebral palsy
Purpose. This study investigated the effects of sensory - perceptual - motor and cognitive functions on handwriting performance in primary-school children with left-hemiplegic cerebral palsy, compared with that of their healthy peers. Methods. The study included 26 children aged 8 - 12 years with left-hemiplegic cerebral palsy and 32 typically developing children of similar age with dominant right hand. The Minnesota Handwriting Assessment was used to evaluate handwriting ability. The Bruininks - Oseretsky Test of Motor Proficiency was used to assess motor performance. Cognitive function was assessed by the Loewenstein Occupational Therapy Cognitive Assessment. The Ayres Southern California Sensory Integration Tests were used to assess visual perception, kinaesthesia, and graphesthesia. Results. Statistically significant differences were found between the two groups in sensory-perceptual-motor and cognitive function and in handwriting ability (p < 0.05). There were also significant correlations between handwriting parameters and upper-extremity speed and dexterity, proprioception, bilateral coordination, visual and spatial perception and, visual-motor organisation in children with cerebral palsy (p < 0.05). Conclusions. The results showed that left-hemiplegic children with cerebral palsy whose right sides were dominant were significantly less competent at handwriting than their right-dominant, healthy peers. It was found that the impairment in proprioception seen in the non-hemiplegic side in children with cerebral palsy, and also the impairment in bilateral coordination, speed and dexterity of the upper extremities, visual and spatial perception, visual-motor organization, and tactile-sensory impairments negatively affected their handwriting skills. In the treatment approaches for children with hemiplegic cerebral palsy, comprehensive sensory - perceptual - motor assessments that involve both extremities must be performed in detail at the earliest possible stage, in order to minimize the existing problems with early-treatment policies. Developing the sensory - perceptual - motor and cognitive function of hemiplegic children would thus be possible, and they would be able to adapt to the same primary-school curriculum as their healthy peers.
[Bumin, G. & Kavak, S. T. (2008). An investigation of the factors affecting handwriting performance in children with hemiplegic cerebral palsy. Disability and Rehabilitation,19, 1-12 [epublication ahead of print].]
2. Hand impairments and their relationship with manual ability in children with cerebral palsy
OBJECTIVE: To study hand impairments and their relationship with manual ability in children with cerebral palsy. DESIGN: Cross-sectional survey. PATIENTS: A total of 101 children with cerebral palsy (mean age 10 years, age range 6-15 years) were assessed. METHODS: Three motor and 3 sensory impairments were measured on both hands. Motor impairments included grip strength (Jamar dynamometer), gross manual dexterity(Box and Block Test) and fine finger dexterity (Purdue Peg-board Test). Sensory impairments included tactile pressure detection (Semmes-Weinstein aesthesiometer), stereognosis(Manual Form Perception Test) and proprioception (passive mobilization of the metacarpophalangeal joints). Manual ability was measured with the ABILHAND-Kids questionnaire.The relationship between hand impairments and manual ability was studied through correlation coefficients and a multiple linear forward stepwise regression analysis. RESULTS: Motor impairments were markedly more prevalent than sensory ones. Gross manual dexterity on the dominant hand and grip strength on the non-dominant hand were the best independent predictors of the children's manual ability,predicting 58% of its variance. CONCLUSION: Hand impairments and manual ability are not related in a predictable straightforward relationship. It is important that, besides hand impairments, manual ability is also measured and treated, as it is not simply the integration of hand functions in daily activities.
[Arnould, C., Penta, M. & Thonnard, J. L. (2007). Hand impairments and their relationship with manual ability in children with cerebral palsy. Journal of Rehabilitation Medicine, 39(9), 708-14.]
3. Kinematic analysis of unimanual reaching and grasping movements in children with hemiplegic cerebral palsy
BACKGROUND: Kinematic investigations of prehension movements made by children with cerebral palsy are few and mainly focus on the reaching phase. To increase understandings of how both reaching and grasping movements are organized in these children, the aim was to investigate their spatiotemporal characteristics and additionally, how different kinematic parameters are related to the level of hand functions. METHODS: Eleven children with hemiplegic cerebral palsy; categorized as "mild" and "moderate", in their age of 5.8-12 years and eleven typically developing, "control" children participated. Reaching and grasping made with both the affected/non-preferred and unaffected/preferred sides were recorded and several kinematic parameters investigated. FINDINGS: In comparison to the control and the mild hemiplegic children, the moderate children exhibited more segmented reaches, longer reach- and grasp durations, and with no anticipatory shaping of the fingers when grasping with the affected hand. Their reaching path with the "unaffected" hand was also more segmented. The mild hemiplegic children showed ability for anticipatory hand closure and performed reaches with similar duration and trajectory as controls. The velocity at hand-object-contact and the quality of their grasping was however affected in comparison to the controls. INTERPRETATION: Findings from the investigated kinematics provide evidence of how spatiotemporal organization of reaching and grasping are affected in children with hemiplegia and related to the level of impaired hand functions. The outcomes clearly show that if these children are treated as one homogeneous group much information about their prehension capacity described from the kinematics will be concealed. Thus, observations of importance for developing effective, individual interventions adjusted to different level of impairments.
[Ronnqvist, L. & Rosblad, B. (2007). Kinematic analysis of unimanual reaching and grasping movements in children with hemiplegic cerebral palsy. Clinical Biomechanics (Bristol, Avon), 22(2), 165-75.]
4. Development of hand function among children with cerebral palsy: Growth curve analysis for ages 16 to 70 months
This study documents the development of hand and upper-extremity function in young children who have cerebral palsy (CP) with upper-extremity involvement using longitudinal data. Assessments of hand function and the quality of upper-extremity movement were conducted on 29 males and 22 females (mean age 36.2 months, SD 10.6; age range 16 to 60 months at baseline) and on four other occasions over 10 months. Linear mixed effects modeling was used to estimate average developmental curves and the degree of individual differences in the patterns of development which were conditional on the body-site distribution of CP and severity of impairments. Results indicate that hand function in this clinical population develops differently from overall upper-extremity skills with declines in function in upper-extremity skills being more common and pronounced among older children. However, there is substantial interindividual variation. Distribution of CP and severity of impairments were significant predictors of development. Results are discussed in terms of their clinical implications.
[Hanna, S. E., Law, M. C., Rosenbaum, P. L., King, G. A., Walter, S. D., Pollock, N. & Russell, D. J. (2003). Development of hand function among children with cerebral palsy: Growth curve analysis for ages 16 to 70 months. Developmental Medicine and Child Neurology, 45(7), 448-55.]
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5. Object release under varying task constraints in children with hemiplegic cerebral palsy
Considerable attention has been given in recent years to fingertip force coordination during grasping and lifting small objects in children with cerebral palsy (CP). However, little is known about the children's ability to replace and release an object from grasp. The present study examined the coordination of fingertip forces during replacement and release of an object from grasp under varying task constraints in the involved hand of 15 children (10 males, five females, age range 7 to 14 years) with hemiplegic CP and in the non-dominant hand of 15 age-matched, typically-developing children (seven males, eight females). Participants released an object, instrumented with force transducers and held with a precision grip, onto a stable surface and onto an unstable surface (requiring higher accuracy) at self-paced and fast-as-possible speeds. Temporal and force measures were recorded and the dependent measures were tested using analyses of variance. Results showed that force coordination was impaired in children with hemiplegia, resulting in prolonged and uncoordinated replacement and release of the object (p<0.05). Differences between controls and children with hemiplegia were greater when speed and accuracy constraints were imposed (i.e. task performance was affected by these constraints to a greater extent in the children with CP, p<0.05). Impairments in temporal coordination of object release were also observed in the non-involved hand under all conditions (p<0.05). These results provide additional information about impaired hand function in children with hemiplegic CP. Clinical implications of these findings are discussed.
[Gordon, A. M., Lewis, S. R., Eliasson, A. C. & Duff, S. V. (2003). Object release under varying task constraints in children with hemiplegic cerebral palsy. Developmental Medicine and Child Neurology, 45(4), 240-8.]
6. Relation between clinical measures and fine manipulative control in children with hemiplegic cerebral palsy
The present investigation examines the relation between various clinical measures and the performance of a functional precision grip-lift task. Fifteen children with hemiplegic cerebral palsy (CP), aged 8 to 14 years, and 15 age-matched control children grasped and lifted an object whose surface texture was varied while their fingertip forces were recorded. The force coordination was compared with tactile sensibility, grip strength, manual dexterity, and spasticity using correlational and regression analyses. The findings highlight the importance of tactile sensibility in this task. However, the manner in which sensibility was related varied for the sensory adaptation of fingertip forces, the anticipatory scaling of the force increase, and the smooth transitions between the temporal phases comprising the grip-lift task. The findings also indicate that spasticity affects some measures of the task, but not others, suggesting that the relation between spasticity and motor performance may not be absolute. The results further suggest that the impairments in grasping in children with hemiplegic CP are largely but not exclusively due to disturbed sensory mechanisms which may have direct implications for therapeutic intervention.
[Gordon, A. M. & Duff, S. V. (1999). Relation between clinical measures and fine manipulative control in children with hemiplegic cerebral palsy. Developmental Medicine and Child Neurology, 41(9), 586-91.]
7. Grip strength parameters and functional activities in young adults with unilateral cerebral palsy compared with healthy subjects
OBJECTIVE: To determine reliability of maximal grip strength, muscle coordination and muscle endurance. To compare these parameters in young adults with unilateral cerebral palsy and healthy subjects. To evaluate the correlation of these variables with functional activities. SUBJECTS: Twenty-six healthy subjects and 26 young adults with unilateral cerebral palsy recruited from a cohort study in young adults with cerebral palsy. METHODS: Maximal grip strength, muscle coordination and muscle endurance were measured in both hands of all subjects. In the healthy subjects test-retest reliability was established. In the young adults with cerebral palsy, the Melbourne assessment and Abilhand Questionnaire were used to determine functional activities. RESULTS: For the dominant and non-dominant hand the intraclass correlation coefficients for the maximal grip strength were 0.93 and 0.91, for the muscle coordination 0.81 and 0.86, and for the muscle endurance 0.59 for both sides. Maximal grip strength of the involved hand of patients was reduced compared with the uninvolved hand and compared with healthy subjects. There was no difference in muscle coordination and muscle endurance between the involved and uninvolved hands. These parameters, however, were significantly reduced in both hands compared with healthy subjects. Correlations between grip strength parameters and activity limitations were relatively weak and non-linear. CONCLUSION: Performance of activity is not directly related to grip strength parameters. The uninvolved hand of young adults with unilateral cerebral palsy also has impaired function.
[van Meeteren, J., van Rijn, R. M., Selles, R. W., Roebroeck, M. E. & Stam, H. J. (2007). Grip strength parameters and functional activities in young adults with unilateral cerebral palsy compared with healthy subjects. Journal of Rehabilitation Medicine, 39(8), 598-604.]
8. Fingertip force planning during grasp is disrupted by impaired sensorimotor integration in children with hemiplegic cerebral palsy
In the present study we examine the ability of children with hemiplegic cerebral palsy (CP) to use anticipatory control of fingertip forces during grasping, and whether anticipatory control is facilitated by lifts with the contralateral hand. Eight children with CP (age 4-13) were asked to perform several lifts of either a 250-g or 500-g object instrumented with force transducers with one hand, followed immediately by several lifts with the contralateral hand. This was repeated for each combination of weight and starting (involved or non-involved) hand. Similar to previous studies, the rate of load force development showed impaired anticipatory control during lifts with the involved hand, intact anticipatory control in the non-involved hand, and transfer of anticipatory control from the non-involved to the involved hand. Surprisingly, however, we also found a transfer from the involved hand to the non-involved hand. The results suggest that the impaired anticipatory control in the involved hand is not purely a sensory or motor problem, and instead is due to an inability to appropriately integrate sensory information with subsequent motor output of the same hand. These results provide important information about the mechanisms underlying impaired anticipatory control, and may have important clinical implications.
[Gordon, A. M., Charles, J. & Steenbergen, B. (2006). Fingertip force planning during grasp is disrupted by impaired sensorimotor integration in children with hemiplegic cerebral palsy. Pediatric Research, 60(5), 587-91.]
9. Fingertip forces during object manipulation in children with hemiplegic cerebral palsy. II: Bilateral coordination
The present study examines the coordination of fingertip forces during object manipulation in both the involved and non-involved hand of 14 children with hemiplegic cerebral palsy (CP) aged between 8 and 14 years. While no impairment could be observed in the non-involved hand, subtle deficits in the sequencing of the grip-lift movement were observed in all children tested in this hand. However, they were able to scale the fingertip force output of the non-involved hand in advance (use anticipatory control) based on the object's weight. In the second experiment in this paper, we tested whether the anticipatory control can be generalized across hands. The results indicate that sensory information from the non-involved hand can be used for anticipatory scaling of isometric force increase during subsequent lifts with the contralateral involved hand. These findings suggest that the initial lack of anticipatory control usually observed in the involved hand of children with hemiplegic CP is likely to be based on disturbed sensory input.
[Gordon, A. M., Charles, J. & Duff, S. V. (1999). Fingertip forces during object manipulation in children with hemiplegic cerebral palsy. II: Bilateral coordination. Developmental Medicine and Child Neurology, 41(3), 176-85.]
10. Impaired force coordination during object release in children with hemiplegic cerebral palsy
Recent studies on hand motor control in children with cerebral palsy (CP) have focused on the coordination of fingertip forces during the grasping and lifting of objects. However, little is known about the ability to replace and release an object from grasp, a function that is just as important for fine dexterity. The present study examines the coordination of fingertip forces during the replacement and release of an object (either 200 g or 400 g) from grasp in 14 children (aged between 7 and 13 years) with hemiplegic CP and in 14 age-matched typically developing children. The results indicate that children with hemiplegic CP abruptly replaced the object but had a prolonged and uncoordinated release of the grasp. Unlike what was seen in the control children, the grip and load forces decreased sequentially in the children with CP. However, all the children could appropriately scale the rate of force decrease based on somatosensory weight-related information from the ongoing lift. The results provide further information about the impaired hand skills in children with hemiplegic CP.
[Eliasson, A. C. & Gordon, A. M. (2000). Impaired force coordination during object release in children with hemiplegic cerebral palsy. Developmental Medicine and Child Neurology, 42(4), 228-34.]
11. Development of hand function and precision grip control in individuals with cerebral palsy: A 13-year follow-up study
OBJECTIVE: Although children with cerebral palsy display large developmental differences in hand function from that of typically developing children by the age of 6 to 10 years, little is known about the developmental processes underlying hand function during subsequent development. In this study we investigated the development of manual dexterity in a timed motor task, the timing and amplitude of fingertip-force application during a precision grasping task, and the relationship between changes in these measures. We applied highly quantitative analytical approaches to determine if the fingertip-force application pattern and trial-to-trial variation of fingertip-force application change during development. METHODS: Twelve subjects with cerebral palsy (aged 6-8 years) participated in the first data-collection session conducted between 1989 and 1990. Ten of these subjects (5 with hemiplegia and 5 with diplegia, aged 19-21 years) returned between 2002 and 2003. Manual dexterity was measured by using timed tasks of the Jebsen-Taylor test of hand function. Subjects also lifted an object instrumented with force transducers while we measured the temporal coordination of fingertip coordination and the path ratio between the grip and vertical load-force trajectory (straightness). We used generalized procrustes analysis to determine if there were changes in shape of the force trajectory and intertrial variability. RESULTS: The Jebsen-Taylor test times decreased 45% from the first to the second data session. The overall time to complete the grip-lift task decreased 22%, mainly because of a faster transition from grasp to lift. The grip-force/load-force path ratios decreased from 1.7 to 1.35 (1 = straight line). Generalized procrustes analysis indicated a change in the shape and a decrease in variability in shape of the force-ratio path. CONCLUSIONS: Our results demonstrate that the efficiency in grasping had developed during a 13-year period for this small group of participants with cerebral palsy, which suggests that improvement in hand function occurs over a longer time frame than commonly would be expected.
[Eliasson, A. C., Forssberg, H., Hung, Y. C. & Gordon, A. M. (2006). Development of hand function and precision grip control in individuals with cerebral palsy: A 13-year follow-up study. Pediatrics, 118(4), e1226-36.]