Marilynn P. Wyatt

Double-blind study of botulinum A toxin injections into the gastrocnemius muscle in patients with cerebral palsy

The purpose of this study was to quantify the gait of subjects receiving two injections of either botulinum A toxin or saline vehicle into the gastrocnemius muscle(s). The study group consisted of cerebral palsy patients who walked with an equinus gait pattern. This study was a randomized, double-blinded, parallel clinical trial of 20 subjects. All were studied by gait analysis before and after the injections. There were no adverse effects. Peak ankle dorsiflexion in stance and swing significantly improved in subjects who received the drug and not in controls. Results of this double blind study give support to the short term efficacy of botulinum toxin A to improve gait in selected patients with cerebral palsy.

Injection of botulinum A toxin into the gastrocnemius muscle of patients with cerebral palsy: a 3-dimensional motion analysis study

Abstract Botulinum A toxin (BOTOX ® ) was injected into the gastrocnemius muscle of 26 cerebral palsy subjects with equinus gait. All subjects were equinus walkers without fixed contracture of the triceps-surae muscle. Injections were performed at 3 month intervals, if needed, as determined by the treating clinician. There were 14 subjects with spastic hemiplegia, 11 subjects with spastic diplegia and 1 subject with spastic quadriplegia. In the case of those subjects with bilateral equinus gait the dose was divided and given into both the right and left gastrocnemius muscle. Gait analysis data was collected prior to the first injection and subsequently at 3 month intervals for 1 year. Kinematic and electromyographic data was obtained. This data was analyzed to provide objective information about the outcome of treatment. Four subjects moved away and were lost to follow-up. Seven subjects left the study to have surgery. The data collected revealed statistically significant improvements in dynamic ankle dorsiflexion in both stance and swing phases, stride length, and electromyography of the tibialis anterior. There were no complications. While the results of this study are promising, additional prospective studies are needed to determine the feasibility of preventing muscle contractures over a longer time period. Furthermore, there is a need for inclusion of other muscles in future research. Future research should also compare BOTOX ® treatment with alternative methods of dealing with muscle spasticity such as: casting, orthotic devices, physical therapy, selective dorsal rhizotomy, and surgical lengthening.

Psoas release at the pelvic brim in ambulatory patients with cerebral palsy: Operative technique and functional outcome

Seventeen patients with cerebral palsy (29 hips) underwent psoas recession at the pelvic brim. The operative technique was a direct anterior approach, lateral to the femoral sheath. There were no infections or nerve or arterial injuries. After surgery, clinical examination revealed that fixed hip-flexion contractures decreased significantly in all patients. All of the subjects retained the ability to flex the hip against gravity and against manual resistance. All of the subjects underwent pre- and postoperative gait analysis. Stance-phase dynamic minimum hip flexion decreased significantly. Dynamic pelvic tilt improved to a statistically significant level for the younger children but did not for the group as a whole. There was less improvement with increasing age. Step length was significantly increased and cadence significantly decreased in all patients. We conclude that psoas recession at the pelvic brim, by using the anterior approach, lateral to the femoral sheath, is a safe, reliable, and effective procedure for children with cerebral palsy who have excessive anterior pelvic tilt and excessive dynamic hip flexion or hip-flexion contracture.

Vibratory response in idiopathic scoliosis

Recent clinical studies have suggested that a neurological lesion may be a cause of adolescent idiopathic scoliosis and animal experiments have implicated the posterior column pathway. We have tried to determine if differences in neurological response could be detected and measured clinically, and have compared the threshold of detection of vibratory sensation in 20 girls with adolescent idiopathic scoliosis with that in 20 clinically normal age-matched controls. A highly significant reduction of the threshold of detection of vibration was seen in the scoliotic group compared to the controls (p less than 0.001). Curve magnitude did not correlate with this threshold for either the upper (r = 0.172) or lower extremity (r = 0.126). Significant asymmetry between right- and left-sided thresholds to vibration was demonstrated in the scoliotic group. Our study supports the concept that an aberration in the function of the posterior column pathway of the cord may be of primary importance in the aetiology of idiopathic scoliosis. A clinically practical test to measure this function is presented.

CLINICAL USE OF prédiction REGIONS FOR MOTION ANALYSIS

This study assesses the diagnostic capability of statistically defined prédiction regions, developed by a ‘bootstrap’ method, for assessing the curves of angular rotation of joints in children as they walk. The prédiction regions had been previously developed in the authors laboratory from a study of 309 normal children. The goal of the present study was to determine whether these computer‐generated prédiction regions could be used as a screen in clinical gait analysis, to determine whether a movement falls outside the normal range of variability. Kinematic analysis of 38 consecutive children referred to the motion analysis laboratory for clinical gait assessment provided 912 curves of lower‐extremity joint angle dynamics. An experienced observer first inspected the patients curves with mean normal curves superimposed and designated the curves as normal or abnormal. The performance of the computer‐generated prédiction regions was judged by comparison with the experienced observers designations. The prédiction regions were found to have a high sensitivity (81%), indicating that they can be used as an initial screen to identify deficits in lower limb function.