Motor control testing of upper limb function after botulinum toxin injection: a case study

To evaluate changes in upper extremity function in a hemiparetic patient after treatment with botulinum toxin (BTX) using motor-control testing (MCT) techniques.

Interventional with longitudinal study, open label.

A children's hospital and a motor-control laboratory at a major academic center.

A 16-year-old male with right hemiparetic cerebral palsy and a healthy 12-year-old control subject.

BTX injections to the elbow and wrist flexors.

MCT was used to examine 4 upper extremity movements: forward reach, bilateral rhythmic movements (both muscle homologous and direction homologous), isometric pinch, and hand tapping. The patient was tested before treatment and at 2, 4, 6, 12, 18, and 24 weeks after treatment. In addition, range of motion (ROM), the Ashworth scale of spasticity, Functional Independence Measure, and the mobility and activities of daily living (ADL) sections of the Pediatric Evaluation of the Disability Inventory were performed.

Forward reach demonstrated little change initially despite patient reports of "feeling looser." Improvement was noted after 18 weeks, but returned to baseline level at 24 weeks. Bilateral rhythmic movements also showed slight improvement at 18 weeks. Pinch force increased significantly after 2 weeks, but declined again at 6 weeks. Improvements occurred in ROM and the Ashworth rating of spasticity, but were not temporally associated with each other or with MCT results. Functional assessment data did not change during the study period.

Improvements in more complex motor tasks were noted after significant delay from the time of treatment, while simpler tasks demonstrated a more rapid improvement, followed by a rapid return to baseline levels. This case suggests that MCT techniques can provide quantitative and qualitative data, which can add new information about upper extremity motor disability and the outcome of treatment.