Paul De Cock

The effects of quantitative gait assessment and botulinum toxin a on musculoskeletal surgery in children with cerebral palsy

BACKGROUND The limits of nonoperative treatment for children with cerebral palsy, including physical therapy and orthotics, commonly lead to orthopaedic surgical intervention. The purpose of the present study was to evaluate the influence of gait analysis and botulinum toxin type-A injections on the timing, prevalence, and frequency of orthopaedic surgery. METHODS We performed a retrospective review of 424 children with cerebral palsy who had been born between 1976 and 1994. The children were divided into three groups: Group 1 comprised 122 patients who were managed throughout the entire study period according to best-practice guidelines in orthopaedics, Group 2 comprised 170 patients who were similarly managed but with input from gait analysis, and Group 3 comprised 132 patients who had gait analysis and also received botulinum toxin type-A injections. We analyzed the prevalence of orthopaedic surgical procedures at different ages (three to nine years) and the time to the first surgical procedure. RESULTS The progression to orthopaedic surgery was significantly different among the three groups (p < 0.0001). The proportion of patients who had undergone at least one surgical procedure by the age of seven years was 52% (sixty-four of 122) for Group 1, 27% (forty-six of 170) for Group 2, and 10% (thirteen of 132) for Group 3. There was a delay in surgery in Group 2 as compared with Group 1 (p < 0.00001 at seven, eight, and nine years of age) and a significant decrease in the prevalence of orthopaedic surgical procedures for Group 3 as compared with Group 1 (p < 0.00001 at four to eight years of age) and Group 2 (p < 0.0025 at four to nine years of age). CONCLUSIONS In the treatment of children who have cerebral palsy, the introduction of gait analysis increases the age of the first orthopaedic surgical procedure and botulinum toxin type-A treatment delays and reduces the frequency of surgical procedures.

The pregnancy and long-term neurodevelopmental outcome of monochorionic diamniotic twin gestations: a multicenter prospective cohort study from the first trimester onward

OBJECTIVES We sought to document the pregnancy and neurodevelopmental outcome in monochorionic diamniotic twin pregnancies and to identify risk factors for death and impairment. STUDY DESIGN We conducted a prospective cohort study of 136 monochorionic twins followed up from the first trimester until infancy. RESULTS A total of 122 (90%) pregnancies resulted in 2 survivors, 6 (4%) in 1 survivor and 8 (6%) in no survivor. In all, 230 (92%) of 250 surviving infants were assessed at a mean age of 24 months. Neurodevelopmental impairment was present in 22 (10%) infants. Death or impairment of 1 or both infants occurred in 28 (22%) of 126 pregnancies. Twin-to-twin transfusion syndrome and assisted conception increased the risk of both death and impairment, whereas early-onset discordant growth only increased the risk of death. CONCLUSION The mortality in this prospective series was 8% and neurodevelopmental impairment occurred in 10% of infants.

How do Zimbabweans value health states

BackgroundQuality of life weights based on valuations of health states are often used in cost utility analysis and population health measures. This paper reports on an attempt to develop quality of life weights within the Zimbabwe context.Methods2,384 residents in randomly selected small residential plots of land in a high-density suburb of Harare valued descriptors of 38 health states based on different combinations of the five domains of the EQ-5D (mobility, self-care, usual activities, pain or discomfort and anxiety or depression). The English version of the EQ-5D was used. The time trade-off method was used to determine the values, and 19,020 individual preferences for health states were analysed. A residual maximum likelihood linear mixed model was used to estimate a function for predicting the values of all possible combinations of levels on the five domains. The model was fit to a random subset of two-thirds of the observations, with the remaining observations reserved for analysis of predictive validity. The results were compared to a similar study undertaken in the United Kingdom.ResultsA credible model was developed to predict the values of states that were not valued directly. In the subset of observations reserved for validation, the mean absolute difference between predicted and observed values was 0.045. All domains of the EQ-5D were found to contribute significantly to the model, both at the moderate and severe levels. Severe pain was found to have the largest negative coefficient, followed by the inability to wash and dress oneself.ConclusionDespite a generally lower education level than their European counterparts, urban Zimbabweans appear to value health states in a consistent manner, and the determination of a global method of establishing quality of life weights may be feasible and valid. However, as the relative weightings of the different domains, although correlated, differed from the standard set of weights recommended by the EuroQol Group, the locally determined coefficients should be used within the Zimbabwean context.

Construction of a stereotaxic DTI atlas with full diffusion tensor information for studying white matter maturation from childhood to adolescence using tractography-based segmentations.

Reconstruction of white matter (WM) fiber tracts based on diffusion tensor imaging (DTI) is increasingly being used in clinical and research settings to study normal and pathological WM tissue as well as the maturation of this WM tissue. Such fiber tracking (FT) methodology, however, is highly dependent on the manual delineation of anatomical landmarks and the algorithm settings, often rendering the reproducibility and reliability questionable. Predefining these regions of interest on a fractional anisotropy (FA) atlas in standard space has already been shown to improve the reliability of FT results. In this paper, we constructed a new DTI atlas, which contains the complete diffusion tensor information in ICBM152 coordinates. From this high‐dimensional DTI atlas, and using robust FT protocols, we reconstructed a large number of WM tracts. Subsequently, we created tract masks from these fiber tract bundles and evaluated the atlas framework by comparing the reproducibility of the results obtained from our standardized tract masks with regions‐of‐interest labels from the conventional FA‐based WM atlas. Finally, we assessed laterality and age‐related WM changes in 42 normal subjects aged 0 to 18 years using these tractography‐derived tract segmentations. In agreement with previous literature, we observed an FA increase with age, which was mainly due to the decrease of perpendicular diffusivity. In addition, major functional pathways in the language, motor, and limbic system, showed a significant asymmetry in terms of the observed diffusion metrics. Hum Brain Mapp, 2010.

A Novel Method for the Nonradiological Assessment of Ineffective Swallowing

OBJECTIVES:This validation study evaluates a new manometry impedance-based approach for the objective assessment of pharyngeal function relevant to postswallow bolus residue.METHODS:We studied 23 adult and pediatric dysphagic patients who were all referred for a videofluoroscopy, and compared these patients with 10 adult controls. The pharyngeal phase of swallowing of semisolid boluses was recorded with manometry and impedance. Fluoroscopic evidence of postswallow bolus residue was scored. Pharyngeal pressure impedance profiles were analyzed. Computational algorithms measured peak pressure (Peak P), pressure at nadir impedance (PNadImp), time from nadir impedance to PeakP (PNadImp–PeakP), the duration of impedance drop in the distal pharynx (flow interval), upper esophaghageal sphincter (UES) relaxation interval (UES-RI), nadir UES pressure (NadUESP), UES intrabolus pressure (UES-IBP), and UES resistance. A swallow risk index (SRI) was derived by the formula: SRI=(FI × PNadImp)/(PeakP × (TNadImp-PeakP+1)) × 100.RESULTS:In all, 76 patient swallows (35 with residue) and 39 control swallows (12 with residue) were analyzed. Different functional variables were found to be altered in relation to residue. In both controls and patients, flow interval was longer in relation to residue. In controls, but not patients, residue was associated with an increased PNadImp (suggestive of increased pharyngeal IBP). Controls with residue had increased UES-IBP, NadUESP, and UES resistance compared with patients with residue. Residue in patients was related to a prolonged UES-RI. The SRI was elevated in relation to residue in both controls and patients and an average SRI of 9 was optimally predictive of residue (sensitivity 75% and specificity 80%).CONCLUSIONS:We present novel findings in control subjects and dysphagic patients showing that combined manometry and impedance recordings can be objectively analyzed to derive pressure-flow variables that are altered in relation to the bolus residual and can be combined to predict ineffective pharyngeal swallowing.

Botulinum toxin type A treatment of cerebral palsy: an integrated approach

We have applied a multilevel approach to the management of spasticity associated with cerebral palsy (CP). All of the following factors are important in forming an integrated strategy for botulinum toxin type A (BTX‐A) therapy: the timing of injections, patient selection, multilevel BTX‐A treatment, optimal dosage and injection technique, follow‐up treatment and objective measurements of functional outcome. Data on all these factors are presented here. CP patients had a mean age of 6.5 years (n = 315), and the dose of BTX‐A (BOTOX®) ranged from 2 to 29 U/kg body weight (n= 156). The combination of muscles injected in our multilevel approach differed for patients with diplegia, hemiplegia and quadriplegia: patients with hemiplegia received injections in the gastrocnemius and medial hamstrings; this combination was extended to the adductors for patients with diplegia and quadriplegia (n= 156). For patients with quadriplegia, muscles in a three‐level (gastrocnemius, medial hamstrings, adductors and iliopsoas) or two‐level (excluding the gastrocnemius) combination were also frequently injected. The duration of effect of BTX‐A treatment was mainly determined by follow‐up treatment consisting of: serial casting, day and night orthoses and physiotherapy. No major side effects of BTX‐A were reported. This integrated approach appears to prolong the duration of BTX‐A treatment, resulting in a duration of about 1 year between injections.

Association between visual perceptual deficits and motor deficits in children with developmental coordination disorder

This study explored the relation between a motor-free visual perceptual deficit, different visual-motor integration deficits, and different motor skills in children with developmental coordination disorder (DCD). Thirty-six children (22 males), aged 9 or 10 years, with DCD and a control group (n=36), matched for age and sex, were assessed with the Movement Assessment Battery for Children (MABC), a ball-catching test, a jumping test, a timed response task to a visual moving stimulus, and the Beery-Buktenica Developmental Test of Visual-Motor Integration, incorporating copying, visual discrimination, and tracing tasks. Children with DCD performed significantly worse than the control group on all measures. The visual discrimination task did not correlate significantly with any of the motor tasks. The visual timing task correlated significantly with the ball-catching test in the DCD group. The copying test was significantly correlated with the MABC in the DCD group. The association between visual-perceptual deficits and motor tasks was shown to be task specific.

Integrity of the inferior longitudinal fasciculus and impaired object recognition in children: a diffusion tensor imaging study

Aim  In this study, we explored the integrity of the inferior longitudinal fasciculus (ILF) by means of diffusion tensor imaging tractography in children with visual perceptual impairment, and more specifically, object recognition deficits, compared with typically developing children.

Is There a Common Neuroanatomical Substrate of Language Deficit between Autism Spectrum Disorder and Specific Language Impairment

Discussion of an overlap between specific language impairment (SLI) and autism spectrum disorder (ASD) is on going. The most intriguing overlap between both phenotypes is the similarity in the observed language deficits described in SLI and a subgroup of ASD with co-occurring linguistic impairment, ASD-LI. Examining whether a similar neuroanatomical substrate underlies this phenotypical linguistic overlap, we studied the white matter microstructural properties of the superior longitudinal fascicle (SLF) of 19 ASD-LI adolescents (mean age 13.8 ± 1.6 years) and 21 age-matched controls and compared them with 13 SLI children (mean age 10.1 ± 0.4 years) and 12 age-matched controls. A linguistic profile assessment and a diffusion tensor imaging analysis of the SLF were performed. Linguistic testing revealed a mixed receptive-expressive disorder profile in both groups, confirming their overlap at phenotypical level. At neuroanatomical level, no significant differences in mean SLF fractional anisotropy (FA) and mean SLF apparent diffusion coefficient values between ASD-LI participants and controls were seen. By contrast, the mean SLF FA was significantly reduced in the SLI children as compared with their controls. The observation of structural SLF disturbances in SLI but not in ASD-LI suggests the existence of a different neuroanatomical substrate for the language deficits in both disorders.

Upper limb impairments and their impact on activity measures in children with unilateral cerebral palsy

BACKGROUND Insights in upper limb impairments and their relationship with activity measures in children with unilateral cerebral palsy (CP) are important to optimize treatment interventions. AIMS (1) To investigate upper limb impairments and activity limitations in children with unilateral CP; (2) to compare these according to the Manual Ability Classification System (MACS), timing of lesion (congenital/acquired) and age; (3) to determine the impact of impairments on activity measures. METHODS Eighty-one children with unilateral CP aged 5-15 years (mean 9 years 11 months; congenital N=69, acquired N=12) were recruited. Body function measurements included passive range of motion (PROM), muscle tone, strength and sensibility. At activity level, the Melbourne Assessment, Assisting Hand Assessment (AHA) and Abilhand-Kids were assessed. RESULTS Most PROM limitations were found for elbow extension and supination. Increased tone and weakness were most prominent in distal muscles. Stereognosis and two-point discrimination were mostly affected. Children with a lower MACS level or acquired lesion had significantly more impairments and activity limitations. In children with congenital lesions, best predictors for unimanual capacity (Melbourne Assessment) were wrist strength, stereognosis and proprioception, and for bimanual performance (AHA) wrist strength and grip strength, explaining 76% of the variance. For the Abilhand-Kids, wrist strength and stereognosis predicted 46% of the variance. CONCLUSIONS Classification according to MACS and timing of lesion is important to differentiate within the wide range of impairments and activity limitations. In children with congenital lesions, unimanual capacity and bimanual performance are highly determined by distal strength, supporting the additional use of impairment-based interventions.