Quantitative Evaluation of Lower Extremity Joint Contractures in Spinal Muscular Atrophy: Implications for Motor Function.

PURPOSE: To quantitatively describe passive lower extremity range of motion in participants with spinal muscular atrophy (SMA) types 2 and 3, and to establish preliminary thresholds to identify individuals at risk for performing poorly on disease-specific motor function outcome measures. METHODS: Eighty participants with SMA types 2 and 3, enrolled in an international multicenter natural history study, were evaluated with lower extremity range of motion testing and the Hammersmith Functional Motor Scale-Expanded. RESULTS: A hip extension joint angle of -7.5° or less for SMA type 2 and 0° or less for SMA type 3 identified diminished motor ability with good sensitivity. For knee extension, a joint angle of -9.0° or less for SMA type 2 or 0° or less for SMA type 3 was similarly sensitive. CONCLUSIONS: Minimal hip and knee joint contractures were associated with diminished motor ability. Clinical trial designs should consider the effect of contractures on motor function.

Longitudinal Patterns of Thalidomide Neuropathy in Children and Adolescents.

OBJECTIVE: To characterize the longitudinal clinical and electrophysiological patterns of thalidomide neuropathy in children and adolescents. STUDY DESIGN: Retrospective analysis of clinical records at a tertiary care children's hospital, including serial electrophysiological studies. RESULTS: Sixteen patients aged 6-24 years received thalidomide to treat Crohn's disease from 2002 to 2012. Nine subjects had electrophysiological evidence of sensorimotor axonal polyneuropathy, 8 of whom had sensory and/or motor symptoms. The patients with polyneuropathy received thalidomide for 5 weeks to 52 months, with cumulative doses ranging from 1.4 to 207.7 g. All subjects with cumulative doses greater than 60 g developed polyneuropathy, and 4 of the 5 subjects who received thalidomide for more than 20 months developed polyneuropathy. The 7 subjects who had normal neurophysiological studies received therapy for 1 week to 25 months, with cumulative doses ranging from 0.7 to 47 g. In contrast to some previous reports, several patients had sensorimotor polyneuropathies, rather than pure sensory neuropathies. In patients with neuropathy who received therapy for more than 24 months and had 3 or more electromyography studies, the severity of the neuropathy plateaued. CONCLUSIONS: Factors in addition to the total dose may contribute to the risk profile for thalidomide neuropathy, including pharmacogenetic susceptibilities. The severity of the neuropathy does not worsen relentlessly. Children, adolescents, and young adults receiving thalidomide should undergo regular neurophysiological studies to monitor for neuropathy.