Ngaire Stott

Botulinum toxin assessment, intervention and follow‐up for paediatric upper limb hypertonicity: international consensus statement

The primary objective of this paper was to evaluate the published evidence of efficacy and safety of botulinum neurotoxin (BoNT) injections in paediatric upper limb hypertonia (PULH). Secondary objectives included the provision of clinical context, based on evidence and expert opinion, in the areas of assessment, child and muscle selection, dosing, and adjunctive treatment. A multidisciplinary panel of authors systematically reviewed, abstracted, and classified relevant literature. Recommendations were based on the American Academy of Neurology (AAN) evidence classification. Following a literature search, 186 potential articles were screened for inclusion, and 15 of these met the criteria and were reviewed. Grade A evidence was found to support the use of BoNT to reach individualized therapeutic goals for PULH. There is grade B evidence (probably effective) for tone reduction following BoNT injections and grade U evidence (inconclusive) for improvement in upper limb (UL) activity and function. BoNT injections were generally found to be safe and well tolerated with the most common side effect identified as a transient decrease in grip strength.

Reliability and validity of an activity monitor (IDEEA) in the determination of temporal–spatial gait parameters in individuals with cerebral palsy

This study evaluated within- and between-session reliability and validity of temporal-spatial gait parameters derived from the intelligent device for energy expenditure and activity (IDEEA) activity monitor (Minisun, Fresno, CA) in subjects with cerebral palsy, using three-dimensional gait analysis (3-DGA) as the criterion standard. Twenty-five subjects with cerebral palsy (mean age 14.1 years, range 8-23) and 30 control subjects (mean age 14.2 years, range 7-24) completed two 3-DGA, 1 week apart with simultaneous IDEEA data collection. The IDEEA had lower within-session reliability than the 3-DGA for both groups, indicated by greater measurement errors and wider repeatability values for all temporal-spatial parameters. Between-session reliability of 3-DGA was high for both groups with intra-class correlation coefficients (ICC) >0.80. The IDEEA monitor showed high between-session reliability for control subjects (ICC 0.71-0.89), but lower reliability in subjects with cerebral palsy, particularly for walking velocity and stride length (ICC 0.53 and 0.62, respectively). Validity comparison between IDEEA and 3-DGA measures using Bland Altman 95% limits of agreement showed a measurement bias, with the IDEEA over-estimating step and stride length and underestimating cadence in both subject groups compared to 3-DGA. The 95% limits of agreement were smaller in controls (step +/-0.20 m; stride +/-0.27 m; walking velocity +/-0.28 m/s) than in subjects with cerebral palsy (step +/-0.36 m; stride +/-0.37 m; velocity +/-0.58 m/s). Modifications may be necessary to improve the reliability and validity of the IDEEA in children, particularly for use in neurological conditions.

Use of three‐dimensional kinematic analysis following upper limb botulinum toxin A for children with hemiplegia

Background and purpose:  To examine whether three‐dimensional (3‐D) kinematic analysis can detect changes in upper limb tasks (reach and hand‐to‐mouth) in children with hemiplegia, following upper limb botulinum toxin A injections.

Anatomically-based musculoskeletal modeling: prediction and validation of muscle deformation during walking

Accurate modeling of the musculoskeletal system during motion is a challenging task that has not yet been solved. In this paper, we outline and validate a free-form deformation method called the Host Mesh Fitting (HMF) technique for predicting muscle deformation during walking of a subject-specific musculoskeletal model. 20 lower limb muscles were deformed according to the HMF solution of a surrounding host mesh that resembled the skin boundary, resulting in a realistic walking simulation of the anatomically-based model. The shape changes of five muscles were further validated by comparing the predicted deformations with magnetic resonance image data in two lower limb positions.

Reported outcomes of lower limb orthopaedic surgery in children and adolescents with cerebral palsy: A mapping review

Lower limb surgery is often performed in ambulatory children with cerebral palsy (CP) to improve walking ability. This mapping review reports on outcome measures used in the published literature to assess surgical results, determine range and frequency of use, and map each measure to the International Classification of Functioning, Disability and Health.

Radiological outcome of reconstructive hip surgery in children with gross motor function classification system IV and V cerebral palsy.

Hip subluxation is common in children with cerebral palsy (CP). The aim of this study was to describe the radiological outcome of reconstructive hip surgery in children with CP, gross motor function classification system (GMFCS) level IV and V, and determine whether the GMFCS level plays a predictive role in outcome. This was a retrospective cohort study conducted at a tertiary-level pediatric hospital with a CP hip surveillance program. Of 110 children with GMFCS IV and V CP registered for hip surveillance, 45 underwent reconstructive hip surgery between 1997 and 2009, defined as varus derotational proximal femoral osteotomy with or without additional pelvic osteotomy. Eleven children were excluded because of lack of 12-month follow-up (n=10) or missing clinical records (n=1). Thus, 21 GMFCS IV children (median age 6 years at surgery) and 13 GMFCS V children (median age 5 years at surgery), who underwent 58 index surgeries, were included in the study. Clinical records and radiology were reviewed. The two surgical groups were femoral osteotomy (varus derotational femoral osteotomy with an AO blade plate or femoral locking plate fixation), or femoral ostetotomy with additional pelvic osteotomy. Reimer’s migration percentage (MP) was calculated from anteroposterior pelvis radiographs to determine the outcome for each hip independently. Failure was defined as MP of greater than 60% or further operation on the hip. Reconstructive surgeries were performed for 58 hips with a median preoperative MP of 55%. There were 15 failures at a median of 62 months, including nine failures in 35 GMFCS IV hips and six failures in 23 GMFCS V hips. Overall, GMFCS V hips tended to fail earlier, (hazard ratio 2.3) with a median time to failure of 78 and 39 months for GMFCS IV and V hips, respectively. Combined femoral and pelvic osteotomies had the lowest failure rates in both groups of patients. The GMFCS classification may have some predictive value for outcomes following reconstructive hip surgery, with surgery for GMFCS V hips tending to fail earlier.

Toward modeling locomotion using electromyography-informed 3D models: application to cerebral palsy

This position paper proposes a modeling pipeline to develop clinically relevant neuromusculoskeletal models to understand and treat complex neurological disorders. Although applicable to a variety of neurological conditions, we provide direct pipeline applicative examples in the context of cerebral palsy (CP). This paper highlights technologies in: (1) patient‐specific segmental rigid body models developed from magnetic resonance imaging for use in inverse kinematics and inverse dynamics pipelines; (2) efficient population‐based approaches to derive skeletal models and muscle origins/insertions that are useful for population statistics and consistent creation of continuum models; (3) continuum muscle descriptions to account for complex muscle architecture including spatially varying material properties with muscle wrapping; (4) muscle and tendon properties specific to CP; and (5) neural‐based electromyography‐informed methods for muscle force prediction. This represents a novel modeling pipeline that couples for the first time electromyography extracted features of disrupted neuromuscular behavior with advanced numerical methods for modeling CP‐specific musculoskeletal morphology and function. The translation of such pipeline to the clinical level will provide a new class of biomarkers that objectively describe the neuromusculoskeletal determinants of pathological locomotion and complement current clinical assessment techniques, which often rely on subjective judgment. WIREs Syst Biol Med 2017, 9:e1368. doi: 10.1002/wsbm.1368

Soleus muscle weakness in Cerebral Palsy: muscle architecture revealed with Diffusion Tensor Imaging

Cerebral palsy (CP) is associated with movement disorders and reduced muscle size. This latter phenomenon has been observed by computing muscle volumes from conventional MRI, with most studies reporting significantly reduced volumes in leg muscles. This indicates impaired muscle growth, but without knowing muscle fiber orientation, it is not clear whether muscle growth in CP is impaired in the along-fiber direction (indicating shortened muscles and limited range of motion) or the cross-fiber direction (indicating weak muscles and impaired strength). Using Diffusion Tensor Imaging (DTI) we can determine muscle fiber orientation and construct 3D muscle architectures to examine along-fiber length and cross-sectional area separately. Such an approach has not been undertaken in CP. Here, we use advanced DTI sequences with fast imaging times to capture fiber orientations in the soleus muscle of children with CP and age-matched, able-bodied controls. Physiological cross sectional areas (PCSA) were reduced (37 ± 11%) in children with CP compared to controls, indicating impaired muscle strength. Along-fiber muscle lengths were not different between groups, but we observed large variance in length within CP group. This study is the first to demonstrate functional strength deficits using DTI and implicates impaired cross-sectional muscle growth in children with cerebral palsy.

The effect of a non‐surgical orthopaedic physician on wait times to see a paediatric orthopaedic surgeon

High referral volumes to paediatric orthopaedic surgeons create long clinic waiting lists. The use of extended scope roles for doctors and health professionals is one strategy to address these wait times. We completed a 6‐month trial of a non‐surgical paediatric orthopaedic physician role (NSP) to help manage non‐urgent referrals to our service from local general practitioners (GPs).