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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.

Electrical impedance myography and quantitative ultrasound are two noninvasive, painless, and effort-independent approaches for assessing neuromuscular disease. Both techniques have potential to serve as useful biomarkers in clinical trials in Duchenne muscular dystrophy. However, their comparative sensitivity to disease status and how they relate to one another are unknown.We performed a cross-sectional analysis of electrical impedance myography and quantitative ultrasound in 24 healthy boys and 24 with Duchenne muscular dystrophy, aged 2 to 14 years with trained research assistants performing all measurements. Three upper and three lower extremity muscles were studied unilaterally in each child, and the data averaged for each individual.Both electrical impedance myography and quantitative ultrasound differentiated healthy boys from those with Duchenne muscular dystrophy (P0.001 for both). Quantitative ultrasound values correlated with age in Duchenne muscular dystrophy boys (rho = 0.45; P = 0.029), whereas electrical impedance myography did not (rho = -0.31; P = 0.14). However, electrical impedance myography phase correlated with age in healthy boys (rho = 0.51; P = 0.012), whereas quantitative ultrasound did not (rho = -0.021; P = 0.92). In Duchenne muscular dystrophy boys, electrical impedance myography phase correlated with the North Star Ambulatory Assessment (rho = 0.65; P = 0.022); quantitative ultrasound revealed a near-significant association (rho = -0.56; P = 0.060). The two technologies trended toward a moderate correlation with one another in the Duchenne muscular dystrophy cohort but not in the healthy group (rho = -0.40; P = 0.054 and rho = -0.32; P = 0.13, respectively).Electrical impedance myography and quantitative ultrasound are complementary modalities for the assessment of boys with Duchenne muscular dystrophy; further study and application of these two modalities alone or in combination in a longitudinal fashion are warranted.

This open-label, multiple ascending-dose study was conducted to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of ISIS-SMNRx (ISIS 396443) in children with Types 2 and 3 SMA. ISIS-SMNRx is an antisense oligonucleotide designed to alter splicing of SMN2 mRNA to increase the amount of functional SMN protein. Results from SMA mouse models indicate ISIS-SMNRx had a significant effect on functional and histological measures of neuromuscular health when delivered to the CNS. A Phase 1 single ascending-dose study in children with SMA had previously been completed, showing acceptable safety/tolerability. Multiple doses of ISIS-SMNRx (3 dose levels) were delivered by intrathecal injection to medically stable SMA patients 2–15 years of age (n = 25). Subjects were dosed 2–3 times over 3 months and then followed for 6 months post-dosing and monitored for drug safety and tolerability, CSF and plasma pharmacokinetics, CSF SMN protein levels, and clinical outcome measures. Overall, no safety or tolerability concerns related to ISIS-SMNRx were identified; the majority of adverse events were mild or moderate in severity and none were related to dose level of ISIS-SMNRx. No drug-related changes in neurological exams, laboratory assessments (including CSF safety), or systemic evaluations were reported. Repeated intrathecal injections were well tolerated in SMA children. CSF and plasma drug levels were dose-dependent predictable, and consistent with expected levels. HFMSE scores indicated an improvement in motor function at all doses levels, with a time and dose dependency. 6MWT and ULM functional tests also indicated improvement, although with limited data. Measurement of SMN protein levels in CSF indicated a significant increase at the highest dose (p = 0.004), indicating biological activity of ISIS-SMNRx in SMA patients. Results from this study support continued development and further examination of ISIS-SMNRx in a Phase 2/3 controlled study.