Turning in Parkinson's disease patients and controls: the effect of auditory cues.

Turning is an impaired activity in persons with Parkinson's disease (PwPD). The current study examines the turning characteristics in PwPD (9 freezers and 10 nonfreezers) and 9 controls, and explores the effect of rhythmic auditory cues while turning. Turning parameters were collected from a 180 degrees left U-turn during a noncued and a cued condition, using a 3D measuring system. Auditory cues were supplied with a metronome at a rhythm equaling the subject's comfortable step frequency during straight line walking. Results showed that in contrast to controls, PwPD used a wider turning-arc and took smaller, narrower steps. In addition, they demonstrated a higher Coefficient of Variation (CV) of step duration (6.92%) compared to controls (4.88%, P < 0.05). The "wide-arc" turning strategy of PwPD was more prominent in freezers than in nonfreezers. Auditory cues reduced the CV of step duration in PwPD (both freezers and nonfreezers) during turning (from 6.92 to 6.00%, P < 0.05). In summary: Cueing reduced the gait-timing variability during turning, but PwPD maintained a wider arc to turn compared with controls.     

Reduced Cross-Sectional Muscle Growth Six Months after Botulinum Toxin Type-A Injection in Children with Spastic Cerebral Palsy

Botulinum Neurotoxin type-A (BoNT-A) injections are widely used as first-line spasticity treatment in spastic cerebral palsy (SCP). Despite improved clinical outcomes, concerns regarding harmful effects on muscle morphology have been raised. Yet, the risk of initiating BoNT-A to reduce muscle growth remains unclear. This study investigated medial gastrocnemius (MG) morphological muscle growth in children with SCP (n = 26, median age of 5.2 years (3.5)), assessed by 3D-freehand ultrasound prior to and six months post-BoNT-A injections. Post-BoNT-A MG muscle growth of BoNT-A naive children (n = 11) was compared to (a) muscle growth of children who remained BoNT-A naive after six months (n = 11) and (b) post-BoNT-A follow-up data of children with a history of BoNT-A treatment (n = 15). Six months after initiating BoNT-A injection, 17% decrease in mid-belly cross-sectional area normalized to skeletal growth and 5% increase in echo-intensity were illustrated. These muscle outcomes were only significantly altered when compared with children who remained BoNT-A naive (+4% and −3%, respectively, p < 0.01). Muscle length growth persevered over time. This study showed reduced cross-sectional growth post-BoNT-A treatment suggesting that re-injections should be postponed at least beyond six months. Future research should extend follow-up periods investigating muscle recovery in the long-term and should include microscopic analysis.     

Botulinum toxin A treatment of the lower extremities in children with cerebral palsy

Objectives

In the last 2 decades, BTX-A is increasingly being used in the management of spasticity in children with Cerebral Palsy (CP) and there is no doubt about its effect on range of motion, spasticity reduction and gait pattern in this patient population. However, in daily practice, there is still an ongoing search for the best way to apply BTX-A. Two studies were set up to evaluate how successful an integrated multilevel treatment approach is in children with CP. The first study identifies crucial factors within the treatment strategy which may predict the outcome. The second study evaluates the efficacy of repeated BTX-A injections.

Methods

Patient selection was based on following criteria: diagnosis of CP, lower limb BTX-A treatment, age at time of treatment <24 years, no combined surgery at the time of BTX-A injections, 3D gait analysis and clinical evaluation pre and 2 months post BTX-A injections. The first study included the last treatment of 577 patients. In the second study, the first and last BTX-A treatment of 222 children were included. The Goal Attainment Scale (GAS) was used to evaluate the functional outcome of each treatment session.

Results

In the first study, the mean GAS score of the total group was 51.7 (±7.5). Considering a converted total score of 50 as cut-off score for successful treatment, 67.1 % of the treatments were successful. Significantly higher GAS scores were found in mildly involved children compared to more involved children (p < 0.0001) and for multilevel injections or injections in the distal muscle groups only compared to injections in the proximal muscles of the lower limb only (p < 0.0001). Other crucial factors for a successful outcome were amount of physical therapy per week (p=0.0026), post injection casting (p=0.005) and frequency of using day and night orthoses after injection (p < 0.0001). In the second study, the mean GAS score of the total group decreased from 54.8 (±6.8) at the first treatment to 50.7 (±6.9) at the last treatment, indicating that on average, repeated BTX-A treatment is successful.

Conclusion

The integrated multilevel BTX-A approach is successful in children with CP. Several factors might help the clinician to select patients that are most likely to benefit from the treatment, to assure the most optimal treatment strategy and to predict the outcome. Each treatment should be carefully planned and goals should be well chosen, because the effectiveness of the BTX-A treatment may decrease with increasing number of treatments in the same patient.     

Kinematic and kinetic evaluation of the ankle after intramuscular injection of botulinum toxin A in children with cerebral palsy

Intramuscular botulinum toxin A (BTA) injection has a role in the conservative management of dynamic equinus deformity in children with cerebral palsy. The effect of BTA injection of the gastrocsoleus muscle during gait was evaluated. Eight children with hemiplegia (median age 4.4 years, range 2 to 8 years) were included in this retrospective study. Assessment included kinematic and kinetic gait analysis before and after (median 57.5 days) treatment. Postinjective kinematics showed significant improvement of ankle range of motion in the stance phase of gait. Ankle kinetics demonstrated a significant decrease of pathological power generation in midstance. The ankle power quotient (APQ) was also significantly improved. Ankle power in terminal stance was improved, although not to a significant level. These results provide evidence of normalization of energy production at the ankle, which is critical for normal gait. The effect of BTA is temporary and can be successfully repeated. This allows deferring the need for surgical intervention until the child is older and recurrence rate is lower.     

A clinical tool to measure trunk control in children with cerebral palsy: the Trunk Control Measurement Scale

In this study the psychometric properties of the Trunk Control Measurement Scale (TCMS) in children with cerebral palsy (CP) were examined. Twenty-six children with spastic CP (mean age 11 years 3 months, range 8-15 years; Gross Motor Function Classification System level I n = 11, level II n = 5, level III n = 10) were included in this study. To determine the discriminant ability of the TCMS, 30 typically developing (TD) children (mean age 10 years 6 months, range 8-15 years) were also included. For inter-rater reliability, two testers scored all children simultaneously. To determine test-retest reliability, participants were reassessed on a second test occasion. For construct validity, the Gross Motor Function Measure (GMFM) was administered. Intraclass correlation coefficients (ICC) ranged from 0.91 to 0.99 for inter-rater and test-retest reliability. Kappa and weighted kappa values ranged for all but one item from 0.45 to 1. The standard error of measurement was 2.9% and 3.4%, and the smallest detectable difference for repeated measurements was 8% and 9.43% between raters and test-retest, respectively. Cronbach's alpha coefficients ranged from 0.82 to 0.94. Spearman rank correlation with the GMFM was 0.88 and increasing coefficients were found from dimension B to E. Subscale and total TCMS scores showed significant differences between children with CP and TD children (p < 0.0001). The results support the reliability and validity of the TCMS in children with spastic CP. The scale gives insight into the strengths and weaknesses of the child's trunk performance and therefore can have valuable clinical use.     

Effect of dynamic orthoses on gait: a retrospective control study in children with hemiplegia

Several positive influences of orthoses on gait in children with cerebral palsy have been documented, as well as some detrimental effects. Most importantly, push-off is decreased in orthoses, compromising a physiological third ankle rocker. The aim of this study was to evaluate the effect of three types of orthosis on gait in a homogeneous group of children. All orthoses aimed at improving push-off and normalizing the pathological plantarflexion-knee extension couple. Thirty-seven children (22 females, 15 males) with hemiplegia, aged 4 to 10 years (30 Gross Motor Function Classification System [GMFCS] Level I, six GMFCS Level II), walked barefoot and with orthoses being either Orteams (orthoses with the dorsal part containing 11 sleeves), posterior leafsprings (PLS), or Dual Carbon Fibre Spring ankle foot orthosis (AFOs; CFO: carbon fibre at the dorsal part of the orthosis). All orthoses were expected to prevent plantarflexion and allow dorsiflexion, thus improving first, second, and third rocker. The orthoses were compared through objective gait analysis, including 3D kinematics and kinetics. All orthoses successfully improved the gait pattern and only small differences were noted between the configurations of the different orthoses. The CFO, however, allowed a more physiological third ankle rocker compared with the Orteam/PLS. Although the PLS ensured the highest correction at the ankle around initial contact, the CFO created a significantly higher maximal hip flexion moment in stance. In general, the results of this study indicated a substantial functional flexibility of the CFO.     

Inter- and intra-observer reliability of masking in plantar pressure measurement analysis

Plantar pressure measurement is an important tool in gait analysis. Manual placement of small masks (masking) is increasingly used to calculate plantar pressure characteristics. Little is known concerning the reliability of manual masking. The aim of this study was to determine the reliability of masking on 2D plantar pressure footprints, in a population with forefoot deformity (i.e. hallux valgus). Using a random repeated-measure design, four observers identified the third metatarsal head on a peak-pressure barefoot footprint, using a small mask. Subsequently, the location of all five metatarsal heads was identified, using the same size of masks and the same protocol. The 2D positional variation of the masks and the peak pressure (PP) and pressure time integral (PTI) values of each mask were calculated. For single-masking the lowest inter-observer reliability was found for the distal-proximal direction, causing a clear, adverse impact on the reliability of the pressure characteristics (PP and PTI). In the medial-lateral direction the inter-observer reliability could be scored as high. Intra-observer reliability was better and could be scored as high or good for both directions, with a correlated improved reliability of the pressure characteristics. Reliability of multi-masking showed a similar pattern, but overall values tended to be lower. Therefore, small sized masking in order to define pressure characteristics in the forefoot should be done with care.     

Observing shadow motions: Resonant activity within the observer's motor system?

Several studies have demonstrated that the human motor cortex is activated by the mere observation of actions performed by others. In the present study, we explored whether the perception of ‘impoverished motion stimuli’, such as shadow animations, is sufficient to activate motor areas. To do so, transcranial magnetic stimulation (TMS) was applied over the hand area of the primary motor cortex (M1) while subjects observed shadow animations depicting finger motions. Data showed that resonant motor responses in M1 were only found when a biological effector was recognized from the observed shadow animation. Interestingly, M1 responses were similar for observing shadow or real motions. Therefore, the loss of ‘pictorial’ movement features in a shadow animation appeared to have no effect on motor resonance in M1. In summary, these findings suggest that the ‘recognition’ of biological motion from sparse visual input is both necessary and sufficient to recruit motor areas. This supports the hypothesis that the motor system is involved in recognizing the actions performed by others.