Marij E. Roebroeck

The epidemiology of cerebral palsy: Incidence, impairments and risk factors

Purpose. Describing the epidemiology of cerebral palsy (CP), its impairments and risk factors. Method. Literature review 1965 – 2004. Search terms: Cerebral palsy, incidence, prevalence, impairments, risk factors. Results. In the last 40 years the prevalence of CP has risen to well above 2.0 per 1000 life births. In this time span the proportion of low-birthweight infants rose, the proportion of diplegia decreased, while the proportion of hemiplegia increased. CP is more prevalent in more deprived socio-economic populations. The majority of people with CP have the spastic syndrome of which the diplegic group is the smallest. Dependent on the subgroup of CP, 25 – 80% have additional impairments. A large proportion has some kind of cognitive impairment; the prevalence varies with the type of CP and especially increases when epilepsy is present. Epilepsy is present in 20 – 40%; it is most common among the hemi- and tetraplegics. Sensibility of the hands is impaired in about half. Chronic pain is reported by more than a quarter of the adults. Up to 80% have at least some impairment of speech. Low visual acuity is reported in almost three-quarters of all children. Half of all children have gastrointestinal and feeding problems. Stunted growth occurs in a quarter, while under- or overweight problems are present in half of the children. Almost 70% of people with spastic CP have abnormal brain CT findings; abnormal cranial ultrasounds is most strongly associated with hemiplegia, normal cranial ultrasounds with diplegia. The most important risk factors for CP are low birthweight, intrauterine infections and multiple gestation.

Smallest real difference, a link between reproducibility and responsiveness.

The aim of this study is to show the relationship between test-retest reproducibility and responsiveness and to introduce the smallest real difference (SRD) approach, using the sickness impact profile (SIP) in chronic stroke patients as an example. Forty chronic stroke patients were interviewed twice by the same examiner, with a 1-week interval. All patients were interviewed during the qualification period preceding a randomized clinical trial. Test-retest reproducibility has been quantified by the intraclass correlation coefficient (ICC), the standard error of measurement (SEM) and the related smallest real difference (SRD). Responsiveness was defined as the ratio of the clinically relevant change to the SD of the within-stable-subject test-retest differences. The ICC for the total SIP was 0.92, whereas the ICCs for the specified SIP categories varied from 0.63 for the category ‘recreation and pastime’ to 0.88 for the category ‘work’. However, both the SEM and the SRD far more capture the essence of the reproducibility of a measurement instrument. For instance, a total SIP score of an individual patient of 28.3% (which is taken as an example, being the mean score in the study population) should decrease by at least 9.26% or approximately 13 items, before any improvement beyond reproducibility noise can be detected. The responsiveness to change of a health status measurement instrument is closely related to its test-retest reproducibility. This relationship becomes more evident when the SEM and the SRD are used to quantify reproducibility, than when ICC or other correlation coefficients are used.

TWO STRATEGIES OF TRANSFERRING FROM SIT-TO-STAND ; THE ACTIVATION OF MONOARTICULAR AND BIARTICULAR MUSCLES

In this study, two different strategies of rising from a chair were compared, using integrated biomechanical and electromyographic analyses. Nine healthy subjects were instructed to rise using two different strategies: natural sit-to-stand transfer (NSTS) and a sit-to-stand transfer with full flexion of the trunk (FSTS). Sagittal kinematics and ground reaction forces were registered. Muscle activity of nine muscles of the right leg were recorded by means of surface EMG. All signals were synchronized at seat-off. The results show that no differences occur between the kinematics of knee and ankle, whereas the hip flexion is, as expected, higher during FSTS. The higher moment about the knee during NSTS is shifted to proportionally higher moments about the hip and ankle during FSTS. It is mainly the differences in the EMG-levels of the biarticular hip and knee muscles which might explain the differences in net moment. These results are in accordance with a theory about a particular role of biarticular muscles. On the other hand, the shift from knee to ankle cannot be associated with a particular increase in activity of the biarticular m.gastrocnemius. It is hypothesized that about the ankle, control of stability is preferred over movement control. An important conclusion for rehabilitation medicine is that a lower net moment about the knee in FSTS does not automatically imply that this reduces the load on the knee extensors.

Adult outcomes and lifespan issues for people with childhood‐onset physical disability

This paper aimed to discuss functioning, quality of life, (QoL) and lifespan care issues of adolescents and young adults with childhood‐onset physical disability from a clinical, scientific, and personal perspective. We present a résumé of results of recently performed studies in rehabilitation‐based samples of (young) adults with childhood‐onset conditions such as cerebral palsy (CP) and spina bifida (SB), and different models of transition and lifespan care. The studies showed that many young adults with a childhood‐onset disability experience health‐related problems such as functional deterioration, pain or fatigue, and an inactive lifestyle. A significant number are restricted in participation in work, housing, and intimate relationships. They perceive a lower health‐related and global QoL compared with a reference group. In some centres in the UK and the Netherlands specialized outpatient services are available or being developed. In conclusion, transition to adulthood is a critical phase for reaching autonomous participation in adult life. There is an international challenge to incorporate a lifespan perspective in paediatric, transition, and adult health care services for persons with a childhood‐onset disability.

Determinants of functioning of adolescents and young adults with cerebral palsy

Purpose. To describe the level of functioning of adolescents and young adults with cerebral palsy (CP) and study determinants of their level of functioning. Method. In the CP Transition study, adolescents and young adults aged 16 – 20 years, diagnosed with CP without severe learning disabilities (n = 103) participated. In this group we assessed subject characteristics, i.e., age, type of CP, gross motor function (GMFCS), level of education as well as outcome measures on functioning in daily activities and social participation (Life Habits questionnaire, Vineland Adaptive Behavior Scale, Functional Independence Measure). Multivariate regression analyses were performed. Results. About 20 – 30% of the participants encountered restrictions in daily activities (mobility, self-care, nutrition) and social participation (taking responsibility, community living, leisure activities and employment). The GMFCS level, level of education, and age proved to be important determinants of functioning in daily activities and social participation, explaining 70% and 66% of the variance in outcome respectively. Conclusion. A significant number of adolescents and young adults with CP without severe learning disabilities are restricted in daily activities and social participation. These problems are mainly attributable to restricted gross motor functioning, a low level of education and younger age.

Health issues in young adults with cerebral palsy: Towards a life-span perspective

OBJECTIVE To obtain better insight into the health issues of young adults with cerebral palsy. DESIGN Cross-sectional. SUBJECTS Two data sources were used: 54 adults with cerebral palsy (age range 25-36 years) and 48 physicians (members of the Netherlands Society of Physical and Rehabilitation Medicine). METHODS Adults with cerebral palsy participated in a physical examination and a semi-structured interview assessing several health issues and utilization of healthcare. Rehabilitation physicians completed a questionnaire on impairments they recognized as being related to cerebral palsy. RESULTS In the patient sample, pain (59%) and joint deformities (19-57%) were observed most frequently. Evidence of a decrease in the utilization of healthcare services at adult age emerged. Lower gross motor function and cognitive level appeared to be determinants of motor and speech impairments and of the utilization of 3 allied healthcare services. Rehabilitation physicians reported pain (88%), joint deformities (86%) and fatigue (76%) as being cerebral palsy-related health problems in adults. CONCLUSION Based on the high prevalence of pain and joint deformities and the decrease in the utilization of healthcare services, systematic follow-up in adults with cerebral palsy seems warranted. Cerebral palsy needs to be considered as a life-long condition, requiring a life-span perspective in order to better organize optimal care.

Triad of physical activity, aerobic fitness and obesity in adolescents and young adults with myelomeningocele.

OBJECTIVE Comprehensively and objectively assess physical activity, aerobic fitness and body fat in adolescents and young adults with myelomeningocele and to investigate their relationships. DESIGN Cross-sectional study. SUBJECTS Fifty-one persons (26 males) with myelomeningocele aged 21.1 (standard deviation) 4.5) years. METHODS Physical activity was measured with an accelerometry-based activity monitor. Aerobic fitness was defined as the maximum oxygen uptake during the last minute of a maximal exercise test. Body fat was assessed using sum of 4 skin-folds and body mass index. Correlations were studied using multiple regression analyses. RESULTS Thirty-nine percent of the participants were inactive and another 37% were extremely inactive. Aerobic fitness was 42% lower than normative values and 35% were obese. Ambulatory status was related to daily physical activity (beta = 0.541), aerobic fitness (beta = 0.397) and body fat (beta = -0.243). Gender was related to aerobic fitness (beta = -0.529) and body fat (beta = 0.610). Physical activity was related to aerobic fitness in non-ambulatory persons with myelomeningocele (beta = 0.398), but not in ambulatory persons. CONCLUSION Adolescents and young adults with myelomeningocele were physically inactive, had poor aerobic fitness and high body fat. Differences exist between subgroups regarding gender and ambulatory status.

Test-retest reliability in isokinetic muscle strength measurements of the shoulder

Test-retest reliability is important for long-term follow-up; however, data on the reliability of isokinetic dynamometry of the shoulder are scarce. Twenty subjects (50% male) were measured; 10 with asymmetrical use of the arms (mean age 27 years) and 10 used their arms symmetrically (mean age 32 years). A Biodex dynamometer (Multi joint system 2) was used. Abduction/adduction and external/internal rotation were measured following a standardized protocol. Performed scheme: two sessions with a 2-week interval, all measurements were done with 60 degrees/second (5 repetitions) and respectively 120 degrees/second and 180 degrees/second (10 repetitions). Differences in the mean peak torques, split for muscle group and gender were significant. Intraclass correlation coefficients ranged from 0.69 to 0.92. This implies good to excellent reliability in research on groups. To determine test-retest reliability of two consecutive individual measurements smallest detectable differences (SDD) were computed and ranged from 21% to 43%. It is questionable whether the SDDs are small enough to detect real changes in muscle strength.

Reliability assessment of isometric knee extension measurements with a computer-assisted hand-held dynamometer

OBJECTIVE To assess clinically relevant indexes of measurement error of hand-held dynamometer measurements using a computer-assisted hand-held dynamometer (CAHN-DY). DESIGN In separate sessions, different physical therapists performed repeated measurements of maximal isometric knee extension. SETTING Four physical therapy practices and outpatient departments. PATIENTS Consecutive samples of 30 male and 28 female patients aged 13 to 77 years, with isolated orthopedic knee disorders participated in this study. MAIN OUTCOME MEASURES For intrarater and interrater applications, the standard error of measurement (SEM) and related 95% confidence intervals and minimal detectable changes were assessed. RESULTS Sixty percent of the patients performed within the therapists upper force limit. Variance between sessions performed by the same or different therapists accounted for a large percentage of the measurement error (70% to 81%). For single measurements, the standard error of measurement was assessed not to exceed 10N x m. Minimal detectable changes for different designs varied from 13.8 to 28.2N x m. CONCLUSIONS The CAHN-DY facilitated standardization of test performance in a satisfactory manner, resulting in less measurement error compared with simple hand-held dynamometry.

BODY FAT, FITNESS AND LEVEL OF EVERYDAY PHYSICAL ACTIVITY IN ADOLESCENTS AND YOUNG ADULTS WITH MENINGOMYELOCELE

OBJECTIVE Data on body fat and fitness in adolescents and young adults with meningomyelocele are scarce. The aim of this study was to assess body fat and fitness in this patient group. In addition, we explored whether the level of everyday physical activity is related to body fat and fitness. SUBJECTS AND METHODS Body fat (skinfold thickness), fitness (VO2peak), and everyday physical activity (Activity Monitor, based on accelerometry) were measured in 14 patients with meningomyelocele (8 men, 6 women; age range 14-26 years). RESULTS Peak VO2 was 20-30% lower than reference values and 4 patients were obese. Level of everyday activity was related to fitness (rs = 0.65, p = 0.01) but not to body fat. CONCLUSION Young patients with meningomyelocele are at risk for developing obesity and have a distinctly subnormal fitness. Level of everyday physical activity is related to fitness in this patient group.