JEWELFISH: 24-month results from an open-label study in non-treatment-naïve patients with SMA receiving treatment with risdiplam

Risdiplam is a once-daily oral, survival of motor neuron 2 (SMN2) splicing modifier approved for the treatment of spinal muscular atrophy (SMA). JEWELFISH (NCT03032172) investigated the safety, tolerability, pharmacokinetics (PK), and PK/pharmacodynamic (PD) relationship of risdiplam in non-treatment-naïve patients with SMA. JEWELFISH enrolled adult and pediatric patients (N = 174) with confirmed diagnosis of 5q-autosomal recessive SMA who had previously received treatment with nusinersen (n = 76), onasemnogene abeparvovec (n = 14), olesoxime (n = 71), or were enrolled in the MOONFISH study (NCT02240355) of the splicing modifier RG7800 (n = 13). JEWELFISH was an open-label study with all participants scheduled to receive risdiplam. The most common adverse event (AE) was pyrexia (42 patients, 24%) and the most common serious AE (SAE) was pneumonia (5 patients, 3%). The rate of AEs and SAEs decreased by > 50% from the first to the second year of treatment, and there were no treatment-related AEs that led to withdrawal from treatment. An increase in SMN protein in blood was observed following risdiplam treatment and sustained over 24 months of treatment irrespective of previous treatment. Exploratory efficacy assessments of motor function showed an overall stabilization in mean total scores as assessed by the 32-item Motor Function Measure, Hammersmith Functional Motor Scale-Expanded, and Revised Upper Limb Module. The safety profile of risdiplam in JEWELFISH was consistent with previous clinical trials of risdiplam in treatment-naïve patients. Exploratory efficacy outcomes are reported but it should be noted that the main aim of JEWELFISH was to assess safety and PK/PD, and the study was not designed for efficacy analysis. TRIAL REGISTRATION: The study was registered (NCT03032172) on ClinicalTrials.gov on January 24, 2017; First patient enrolled: March 3, 2017.

Digital measures of respiratory and upper limb function in spinal muscular atrophy: design, feasibility, reliability, and preliminary validity of a smartphone sensor-based assessment suite

Spinal muscular atrophy (SMA) is characterized by progressive muscle weakness and paralysis. Motor function is monitored in the clinical setting using assessments including the 32-item Motor Function Measure (MFM-32), but changes in disease severity between clinical visits may be missed. Digital health technologies may assist evaluation of disease severity by bridging gaps between clinical visits. We developed a smartphone sensor-based assessment suite, comprising nine tasks, to assess motor and muscle function in people with SMA. We used data from the risdiplam phase 2 JEWELFISH trial to assess the test-retest reliability and convergent validity of each task. In the first 6 weeks, 116 eligible participants completed assessments on a median of 6.3 days per week. Eight of the nine tasks demonstrated good or excellent test-retest reliability (intraclass correlation coefficients >0.75 and >0.9, respectively). Seven tasks showed a significant association (P < 0.05) with related clinical measures of motor function (individual items from the MFM-32 or Revised Upper Limb Module scales) and seven showed significant association (P < 0.05) with disease severity measured using the MFM-32 total score. This cross-sectional study supports the feasibility, reliability, and validity of using smartphone-based digital assessments to measure function in people living with SMA.

Risdiplam in Patients Previously Treated with Other Therapies for Spinal Muscular Atrophy: An Interim Analysis from the JEWELFISH Study

INTRODUCTION

Risdiplam is a survival of motor neuron 2 (SMN2) splicing modifier for the treatment of patients with spinal muscular atrophy (SMA). The JEWELFISH study (NCT03032172) was designed to assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of risdiplam in previously treated pediatric and adult patients with types 1-3 SMA. Here, an analysis was performed after all patients had received at least 1 year of treatment with risdiplam.

METHODS

Patients with a confirmed diagnosis of 5q-autosomal recessive SMA between the ages of 6 months and 60 years were eligible for enrollment. Patients were previously enrolled in the MOONFISH study (NCT02240355) with splicing modifier RG7800 or treated with olesoxime, nusinersen, or onasemnogene abeparvovec. The primary objectives of the JEWELFISH study were to evaluate the safety and tolerability of risdiplam and investigate the PK after 2 years of treatment.

RESULTS

A total of 174 patients enrolled: MOONFISH study (n = 13), olesoxime (n = 71 patients), nusinersen (n = 76), onasemnogene abeparvovec (n = 14). Most patients (78%) had three SMN2 copies. The median age and weight of patients at enrollment was 14.0 years (1-60 years) and 39.1 kg (9.2-108.9 kg), respectively. About 63% of patients aged 2-60 years had a baseline total score of less than 10 on the Hammersmith Functional Motor Scale-Expanded and 83% had scoliosis. The most common adverse event (AE) was upper respiratory tract infection and pyrexia (30 patients each; 17%). Pneumonia (four patients; 2%) was the most frequently reported serious AE (SAE). The rates of AEs and SAEs per 100 patient-years were lower in the second 6-month period compared with the first. An increase in SMN protein was observed in blood after risdiplam treatment and was comparable across all ages and body weight quartiles.

CONCLUSIONS

The safety and PD of risdiplam in patients who were previously treated were consistent with those of treatment-naïve patients.

Pharmacotherapy for Spinal Muscular Atrophy in Babies and Children: A Review of Approved and Experimental Therapies

Spinal muscular atrophy (SMA) is an autosomal recessive degenerative neuromuscular disorder characterized by loss of spinal motor neurons leading to muscle weakness and atrophy that is caused by survival motor neuron (SMN) protein deficiency resulting from the biallelic loss of the SMN1 gene. The SMN2 gene modulates the SMA phenotype, as a small fraction of its transcripts are alternatively spliced to produce full-length SMN (fSMN) protein. SMN-targeted therapies increase SMN protein; mRNA therapies, nusinersen and risdiplam, increase the amount of fSMN transcripts alternatively spliced from the SMN2 gene, while gene transfer therapy, onasemnogene abeparvovec xioi, increases SMN protein by introducing the hSMN gene into various tissues, including spinal cord via an AAV9 vector. These SMN-targeted therapies have been found effective in improving outcomes and are approved for use in SMA in the US and elsewhere. This article discusses the clinical trial results for SMN-directed therapies with a focus on efficacy, side effects and treatment response predictors. It also discusses preliminary data from muscle-targeted trials, as single agents and in combination with SMN-targeted therapies, as well as other classes of SMA treatments.

Newborn Screening for Spinal Muscular Atrophy in New York State: Clinical Outcomes From the First 3 Years

BACKGROUND AND OBJECTIVES

Spinal muscular atrophy (SMA) was added to the Recommended Uniform Screening Panel in July 2018 largely on the basis of the availability and efficacy of newly approved disease-modifying therapies. New York State (NYS) started universal newborn screening for SMA in October 2018. The authors report the findings from the first 3 years of screening.

METHODS

Statewide neonatal screening was conducted using DNA extracted from dried blood spots using a real-time quantitative PCR assay. Retrospective follow-up data were collected from 9 referral centers across the state on 34 infants.

RESULTS

In the first 3 years since statewide implementation, nearly 650,000 infants have been screened for SMA. Thirty-four babies screened positive and were referred to a neuromuscular specialty care center. The incidence remains lower than previously predicted. The majority (94%), including all infants with 2-3 copies of survival motor neuron (SMN) 2, have received treatment. Among treated infants, the overwhelming majority (94%; 30/32) have received gene replacement. All infants in this cohort with 3 copies of SMN2 are clinically asymptomatic posttreatment based on early clinical follow-up data. Infants with 2 copies of SMN2 are more variable in their outcomes. Electrodiagnostic outcomes data obtained from a subgroup of patients (n = 11) demonstrated either improvement or no change in compound muscle action potential (CMAP) amplitude at last clinical follow-up compared with pretreatment baseline. Most infants were treated before 6 weeks of age (median = 34.5 days of life; range 11-180 days). Delays and barriers to treatment identified by treating clinicians followed 2 broad themes: medical and nonmedical. Medical delays most commonly reported were the presence of AAV9 antibodies and elevated troponin I levels. Nonmedical barriers included delays in obtaining insurance and insurance policies regarding specific treatment modalities.

DISCUSSION

The findings from the NYS cohort of newborn screen-identified infants are consistent with other reports of improved outcomes from early diagnosis and treatment. Additional biomarkers of motor neuron health including EMG can potentially be helpful in detecting preclinical decline.

Onasemnogene abeparvovec for presymptomatic infants with three copies of SMN2 at risk for spinal muscular atrophy: the Phase III SPR1NT trial

Most children with biallelic SMN1 deletions and three SMN2 copies develop spinal muscular atrophy (SMA) type 2. SPR1NT ( NCT03505099 ), a Phase III, multicenter, single-arm trial, investigated the efficacy and safety of onasemnogene abeparvovec for presymptomatic children with biallelic SMN1 mutations treated within six postnatal weeks. Of 15 children with three SMN2 copies treated before symptom onset, all stood independently before 24 months (P < 0.0001; 14 within normal developmental window), and 14 walked independently (P < 0.0001; 11 within normal developmental window). All survived without permanent ventilation at 14 months; ten (67%) maintained body weight (≥3rd WHO percentile) without feeding support through 24 months; and none required nutritional or respiratory support. No serious adverse events were considered treatment-related by the investigator. Onasemnogene abeparvovec was effective and well-tolerated for presymptomatic infants at risk of SMA type 2, underscoring the urgency of early identification and intervention.

Treatment of infantile-onset spinal muscular atrophy with nusinersen: final report of a phase 2, open-label, multicentre, dose-escalation study

BACKGROUND

Nusinersen showed a favourable benefit-risk profile in participants with infantile-onset spinal muscular atrophy at the interim analysis of a phase 2 clinical study. We present the study's final analysis, assessing the efficacy and safety of nusinersen over 3 years.

METHODS

This phase 2, open-label, multicentre, dose-escalation study was done in three university hospital sites in the USA and one in Canada. Infants aged between 3 weeks and 6 months with two or three SMN2 gene copies and infantile-onset spinal muscular atrophy were eligible for inclusion. Eligible participants received multiple intrathecal loading doses of 6 mg equivalent nusinersen (cohort 1) or 12 mg dose equivalent (cohort 2), followed by maintenance doses of 12 mg equivalent nusinersen. The protocol amendment on Jan 25, 2016, changed the primary efficacy endpoint from safety and tolerability to reaching motor milestones, assessed using the Hammersmith Infant Neurological Examination section 2 (HINE-2) at the last study visit, in all participants who successfully completed the loading dose period and day 92 assessment. The statistical analysis plan was amended on Feb 10, 2016, to include additional analyses of the subgroup of participants with two SMN2 copies. Adverse events were assessed in all participants who received at least one dose of study treatment. The study is registered at ClinicalTrials.gov (NCT01839656).

FINDINGS

Between May 3, 2013, and July 9, 2014, 20 symptomatic participants with infantile-onset spinal muscular atrophy (12 boys and 8 girls; median age at diagnosis 78 days [range 0-154]) were enrolled. Median time on study was 36·2 months (IQR 20·6-41·3). The primary endpoint of an incremental improvement in HINE-2 developmental motor milestones was reached by 12 (63%) of 19 evaluable participants. In the 13 participants with two SMN2 copies treated with 12 mg nusinersen, the HINE-2 motor milestone total score increased steadily from a baseline mean of 1·46 (SD 0·52) to 11·86 (6·18) at day 1135, representing a clinically significant change of 10·43 (6·05). At study closure (Aug 21, 2017), 15 (75%) of 20 participants were alive. 101 serious adverse events were reported in 16 (80%) of 20 participants; all five deaths (one in cohort 1 and four in cohort 2) were likely to be related to spinal muscular atrophy disease progression.

INTERPRETATION

Our findings are consistent with other trials of nusinersen and show improved survival and attainment of motor milestones over 3 years in patients with infantile-onset spinal muscular atrophy, with a favourable safety profile.

FUNDING

Biogen and Ionis Pharmaceuticals.

Onasemnogene abeparvovec gene therapy for symptomatic infantile-onset spinal muscular atrophy in patients with two copies of SMN2 (STR1VE): an open-label, single-arm, multicentre, phase 3 trial

BACKGROUND

Spinal muscular atrophy type 1 is a motor neuron disorder resulting in death or the need for permanent ventilation by age 2 years. We aimed to evaluate the safety and efficacy of onasemnogene abeparvovec (previously known as AVXS-101), a gene therapy delivering the survival motor neuron gene (SMN), in symptomatic patients (identified through clinical examination) with infantile-onset spinal muscular atrophy.

METHODS

STR1VE was an open-label, single-arm, single-dose, phase 3 trial done at 12 hospitals and universities in the USA. Eligible patients had to be younger than 6 months and have spinal muscular atrophy with biallelic SMN1 mutations (deletion or point mutations) and one or two copies of SMN2. Patients received a one-time intravenous infusion of onasemnogene abeparvovec (1·1 × 10¹⁴ vector genomes per kg) for 30-60 min. During the outpatient follow-up, patients were assessed once per week, beginning at day 7 post-infusion for 4 weeks and then once per month until the end of the study (age 18 months or early termination). Coprimary efficacy outcomes were independent sitting for 30 s or longer (Bayley-III item 26) at the 18 month of age study visit and survival (absence of death or permanent ventilation) at age 14 months. Safety was assessed through evaluation of adverse events, concomitant medication usage, physical examinations, vital sign assessments, cardiac assessments, and laboratory evaluation. Primary efficacy endpoints for the intention-to-treat population were compared with untreated infants aged 6 months or younger (n=23) with spinal muscular atrophy type 1 (biallelic deletion of SMN1 and two copies of SMN2) from the Pediatric Neuromuscular Clinical Research (PNCR) dataset. This trial is registered with ClinicalTrials.gov, NCT03306277 (completed).

FINDINGS

From Oct 24, 2017, to Nov 12, 2019, 22 patients with spinal muscular atrophy type 1 were eligible and received onasemnogene abeparvovec. 13 (59%, 97·5% CI 36-100) of 22 patients achieved functional independent sitting for 30 s or longer at the 18 month of age study visit (vs 0 of 23 patients in the untreated PNCR cohort; p<0·0001). 20 patients (91%, 79-100]) survived free from permanent ventilation at age 14 months (vs 6 [26%], 8-44; p<0·0001 in the untreated PNCR cohort). All patients who received onasemnogene abeparvovec had at least one adverse event (most common was pyrexia). The most frequently reported serious adverse events were bronchiolitis, pneumonia, respiratory distress, and respiratory syncytial virus bronchiolitis. Three serious adverse events were related or possibly related to the treatment (two patients had elevated hepatic aminotransferases, and one had hydrocephalus).

INTERPRETATION

Results from this multicentre trial build on findings from the phase 1 START study by showing safety and efficacy of commercial grade onasemnogene abeparvovec. Onasemnogene abeparvovec showed statistical superiority and clinically meaningful responses when compared with observations from the PNCR natural history cohort. The favourable benefit-risk profile shown in this study supports the use of onasemnogene abeparvovec for treatment of symptomatic patients with genetic or clinical characteristics predictive of infantile-onset spinal muscular atrophy type 1.

FUNDING

Novartis Gene Therapies.

Seven-Year Experience From the National Institute of Neurological Disorders and Stroke-Supported Network for Excellence in Neuroscience Clinical Trials

Importance

One major advantage of developing large, federally funded networks for clinical research in neurology is the ability to have a trial-ready network that can efficiently conduct scientifically rigorous projects to improve the health of people with neurologic disorders.

Observations

National Institute of Neurological Disorders and Stroke Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) was established in 2011 and renewed in 2018 with the goal of being an efficient network to test between 5 and 7 promising new agents in phase II clinical trials. A clinical coordinating center, data coordinating center, and 25 sites were competitively chosen. Common infrastructure was developed to accelerate timelines for clinical trials, including central institutional review board (a first for the National Institute of Neurological Disorders and Stroke), master clinical trial agreements, the use of common data elements, and experienced research sites and coordination centers. During the first 7 years, the network exceeded the goal of conducting 5 to 7 studies, with 9 funded. High interest was evident by receipt of 148 initial applications for potential studies in various neurologic disorders. Across the first 8 studies (the ninth study was funded at end of initial funding period), the central institutional review board approved the initial protocol in a mean (SD) of 59 (21) days, and additional sites were added a mean (SD) of 22 (18) days after submission. The median time from central institutional review board approval to first site activation was 47.5 days (mean, 102.1; range, 1-282) and from first site activation to first participant consent was 27 days (mean, 37.5; range, 0-96). The median time for database readiness was 3.5 months (mean, 4.0; range, 0-8) from funding receipt. In the 4 completed studies, enrollment met or exceeded expectations with 96% overall data accuracy across all sites. Nine peer-reviewed manuscripts were published, and 22 oral presentations or posters and 9 invited presentations were given at regional, national, and international meetings.

Conclusions and Relevance

NeuroNEXT initiated 8 studies, successfully enrolled participants at or ahead of schedule, collected high-quality data, published primary results in high-impact journals, and provided mentorship, expert statistical, and trial management support to several new investigators. Partnerships were successfully created between government, academia, industry, foundations, and patient advocacy groups. Clinical trial consortia can efficiently and successfully address a range of important neurologic research and therapeutic questions.

Psychometric properties of the PEDI-CAT for children and youth with spinal muscular atrophy

PURPOSE

The purpose of this study was to examine the psychometric properties of the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT) in children and youth with Spinal Muscular Atrophy (SMA).

METHODS

In this prospective cross-sectional study, caregivers of children and youth with SMA completed the PEDI-CAT Daily Activities and Mobility domains. A subset of caregivers completed a questionnaire about the measure.

RESULTS

Mean ranks of scaled scores for Daily Activities (n = 96) and Mobility (n = 95) domains were significantly different across the three SMA types and across the three motor classifications. Normative scores indicated that 85 participants (89.5%) had limitations in Mobility and 51 in Daily Activities (53.1%). Floor effects were observed in≤10.4% of the sample for Daily Activities and Mobility. On average, caregivers completed the Mobility domain in 5.4 minutes and the Daily Activities domain in 3.3 minutes. Most caregivers reported that they provided meaningful information (92.1%), were willing to use the PEDI-CAT format again (79%), and suggested adding content including power wheelchair mobility items.

CONCLUSION

Convergent validity was demonstrated for the Daily Activities and Mobility domains. Normative scores detected limitations in Mobility and Daily Activity performance for most participants with SMA. The PEDI-CATwas feasible to administer and caregivers expressed willingness to complete the PEDI-CAT in the future.

Muscle-specific SMN reduction reveals motor neuron-independent disease in spinal muscular atrophy models

Paucity of the survival motor neuron (SMN) protein triggers the oft-fatal infantile-onset motor neuron disorder, spinal muscular atrophy (SMA). Augmenting the protein is one means of treating SMA and recently led to FDA approval of an intrathecally delivered SMN-enhancing oligonucleotide currently in use. Notwithstanding the advent of this and other therapies for SMA, it is unclear whether the paralysis associated with the disease derives solely from dysfunctional motor neurons that may be efficiently targeted by restricted delivery of SMN-enhancing agents to the nervous system, or stems from broader defects of the motor unit, arguing for systemic SMN repletion. We investigated the disease-contributing effects of low SMN in one relevant peripheral organ - skeletal muscle - by selectively depleting the protein in only this tissue. We found that muscle deprived of SMN was profoundly damaged. Although a disease phenotype was not immediately obvious, persistent low levels of the protein eventually resulted in muscle fiber defects, neuromuscular junction abnormalities, compromised motor performance, and premature death. Importantly, restoring SMN after the onset of muscle pathology reversed disease. Our results provide the most compelling evidence yet for a direct contributing role of muscle in SMA and argue that an optimal therapy for the disease must be designed to treat this aspect of the dysfunctional motor unit.

Lack of effect on ambulation of dalfampridine-ER (4-AP) treatment in adult SMA patients

SMA is a genetically determined motor system disorder that results in muscle weakness, selective motor neuron death, muscle atrophy, and impaired functional mobility. In SMA model systems, long-term treatment with 4-aminopyridine (4-AP) has been shown to improve motor function. To assess tolerability and preliminary efficacy of 4-AP on walking ability, endurance and EMG in adult ambulatory SMA patients, we conducted a double blind, placebo control, crossover pilot study with dalfampridine (4-AP, 10 mg BID). The study is comprised of a short-term (2 weeks) treatment arm with 1-week washout and a long-term (6 weeks) treatment arm with a 2-week washout. The primary outcome measure, for which the study was powered, was the 6 min walk test (6MWT, distance and percent fatigue); secondary outcome measures were the Hammersmith Functional Motor Scale Expanded (HFMSE), Manual Muscle Testing (MMT), Myometry with Hand held Dynamometry, HHD) and Quantitative Gait Analyses. We performed electrophysiology, including CMAP and H-reflex, during the short-term treatment trial. The mean age of the 11 participants enrolled was 37.7 ± 11.9 years; 54.5% were male. Dalfampridine was safe and well tolerated and no patient suffered a serious adverse event related to treatment. We observed no statistically significant positive effects of dalfampridine treatment on our primary functional motor outcome (6MWT distance, fatigue). Dalfampridine had a positive effects on H-reflex and H/M ratio but not on CMAP amplitude. The effect on the H-reflex is of interest, as it suggests dalfampridine may enhance neuronal activity, an effect observed in SMA Drosophila and mouse models at doses (mg/kg) not recommended for clinical use. Larger studies with dalfampridine in SMA patients are needed to confirm our findings, especially in light of studies in other populations showing drug effects in only a subset of patients.

066 Avxs-101 gene-replacement therapy (GRT) for spinal muscular atrophy type 1 (SMA1): pivotal phase 3 study (STR1VE) update

Introduction

SMA1 is a neurodegenerative disease caused by bi-allelic survival motor neuron 1 gene (SMN1) deletion/mutation. In the phase 1 study, SMN GRT onasemnogene abeparvovec (AVXS-101) improved outcomes of symptomatic SMA1 patients. We report preliminary data of STR1VE, a pivotal study (NCT03306277) evaluating efficacy and safety of a one-time intravenous AVXS-101 infusion.

Methods

STR1VE is a phase 3, multicenter, open-label, single-arm study in SMA1 patients aged <6 months (bi-allelic SMN1 loss, 2xSMN2). Primary outcomes: independent sitting for ≥30 seconds (18 months) and survival (14 months). Secondary outcomes: ability to thrive and ventilatory support (18 months). Exploratory outcomes: Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and Bayley Scales of Infant and Toddler Development scores.

Results

Enrollment is complete with 22 patients dosed. Mean age at symptom onset, genetic diagnosis, and enrollment was 1.9 (0–4.0), 2.1 (0.5–4.0), and 3.7 (0.5–5.9) months. At baseline, no patient required ventilatory/nutritional support, and all exclusively fed by mouth. Mean baseline CHOP-INTEND score was 32.6 (17.0–52.0), which increased 6.9 (-4.0–16.0, n=20), 10.4 (2.0–18.0, n=12), and 11.6 (-3.0–23.0, n=9) points at 1, 2, and 3 months. Updates will be provided at the congress.

Conclusions

Preliminary data from STR1VE show rapid motor function improvements in SMA1 patients, paralleling phase 1 findings.

Nusinersen in later-onset spinal muscular atrophy: Long-term results from the phase 1/2 studies

Objective

To report results of intrathecal nusinersen in children with later-onset spinal muscular atrophy (SMA).

Methods

Analyses included children from a phase 1b/2a study (ISIS-396443-CS2; NCT01703988) who first received nusinersen during that study and were eligible to continue treatment in the extension study (ISIS-396443-CS12; NCT02052791). The phase 1b/2a study was a 253-day, ascending dose (3, 6, 9, 12 mg), multiple-dose, open-label, multicenter study that enrolled children with SMA aged 2–15 years. The extension study was a 715-day, single-dose level (12 mg) study. Time between studies varied by participant (196–413 days). Assessments included the Hammersmith Functional Motor Scale–Expanded (HFMSE), Upper Limb Module (ULM), 6-Minute Walk Test (6MWT), compound muscle action potential (CMAP), and quantitative multipoint incremental motor unit number estimation. Safety also was assessed.

Results

Twenty-eight children were included (SMA type II, n = 11; SMA type III, n = 17). Mean HFMSE scores, ULM scores, and 6MWT distances improved by the day 1,150 visit (HFMSE: SMA type II, +10.8 points; SMA type III, +1.8 points; ULM: SMA type II, +4.0 points; 6MWT: SMA type III, +92.0 meters). Mean CMAP values remained relatively stable. No children discontinued treatment due to adverse events.

Conclusions

Nusinersen treatment over ∼3 years resulted in motor function improvements and disease activity stabilization not observed in natural history cohorts. These results document the long-term benefit of nusinersen in later-onset SMA, including SMA type III.

Clinicaltrials.gov identifier

NCT01703988 (ISIS-396443-CS2); NCT02052791 (ISIS-396443-CS12).

Classification of evidence

This study provides Class IV evidence that nusinersen improves motor function in children with later-onset SMA.

Recruitment & retention program for the NeuroNEXT SMA Biomarker Study: Super Babies for SMA!

Background/Aims

Recruitment and retention of research participants are challenging and critical components of successful clinical trials and natural history studies. Infants with spinal muscular atrophy (SMA) have been a particularly challenging population to study due to their fragile and complex medical issues, poor prognosis and, until 2016, a lack of effective therapies. Recruitment of healthy infants into clinical trials and natural history studies is also challenging and sometimes assumed to not be feasible.

Methods

In 2011, our group initiated a two-year, longitudinal natural history study of infants with SMA and healthy infant controls to provide data to assist in the analysis and interpretation of planned clinical trials in infants with SMA. The recruitment goal was to enroll 27 infants less than 6 months of age with SMA and 27 age-matched healthy infants within the two-year enrollment period. A detailed recruitment and retention plan was developed for this purpose. In addition, a survey was administered to participant families to understand the determinants of participation in the study.

Results

All healthy infants were recruited within the study's first year and 26 SMA infants were recruited within the two-year recruitment period. Thirty-eight participant families responded to the recruitment determinants survey. Nearly half of respondents (18/38, 48%) reported that they first heard of the study from their physician or neurologist. The most common reason to decide to enroll their infant (22/38, 58%) and to remain in the study (28/38, 74%) was their understanding of the importance of the study. Thematic recruitment tools such as a study brochure, video on social media, and presentations at advocacy meetings were reported to positively influence the decision to enroll.

Conclusions

A proactive, thematic and inclusive recruitment and retention plan that effectively communicates the rationale of a clinical study and partners with patients, advocacy groups and the local communities can effectively recruit participants in vulnerable populations. Recommendations for the proactive integration of recruitment and retention plans into clinical trial protocol development are provided.

Zika Virus-Associated Cognitive Impairment in Adolescent, 2016

Incidence of neurologic manifestations associated with Zika virus infection has been increasing. In 2016, neuropsychological and cognitive changes developed in an adolescent after travel to a Zika virus–endemic area. Single-photon emission computed tomography and neuropsychological testing raised the possibility that Zika virus infection may lead to neuropsychiatric and cognitive symptoms.

Nusinersen versus Sham Control in Later-Onset Spinal Muscular Atrophy

BACKGROUND

Nusinersen is an antisense oligonucleotide drug that modulates pre-messenger RNA splicing of the survival motor neuron 2 ( SMN2) gene. It has been developed for the treatment of spinal muscular atrophy (SMA).

METHODS

We conducted a multicenter, double-blind, sham-controlled, phase 3 trial of nusinersen in 126 children with SMA who had symptom onset after 6 months of age. The children were randomly assigned, in a 2:1 ratio, to undergo intrathecal administration of nusinersen at a dose of 12 mg (nusinersen group) or a sham procedure (control group) on days 1, 29, 85, and 274. The primary end point was the least-squares mean change from baseline in the Hammersmith Functional Motor Scale-Expanded (HFMSE) score at 15 months of treatment; HFMSE scores range from 0 to 66, with higher scores indicating better motor function. Secondary end points included the percentage of children with a clinically meaningful increase from baseline in the HFMSE score (≥3 points), an outcome that indicates improvement in at least two motor skills.

RESULTS

In the prespecified interim analysis, there was a least-squares mean increase from baseline to month 15 in the HFMSE score in the nusinersen group (by 4.0 points) and a least-squares mean decrease in the control group (by -1.9 points), with a significant between-group difference favoring nusinersen (least-squares mean difference in change, 5.9 points; 95% confidence interval, 3.7 to 8.1; P<0.001). This result prompted early termination of the trial. Results of the final analysis were consistent with results of the interim analysis. In the final analysis, 57% of the children in the nusinersen group as compared with 26% in the control group had an increase from baseline to month 15 in the HFMSE score of at least 3 points (P<0.001), and the overall incidence of adverse events was similar in the nusinersen group and the control group (93% and 100%, respectively).

CONCLUSIONS

Among children with later-onset SMA, those who received nusinersen had significant and clinically meaningful improvement in motor function as compared with those in the control group. (Funded by Biogen and Ionis Pharmaceuticals; CHERISH ClinicalTrials.gov number, NCT02292537 .).

Natural history of infantile-onset spinal muscular atrophy

OBJECTIVE

Infantile-onset spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, typically resulting in death preceding age 2. Clinical trials in this population require an understanding of disease progression and identification of meaningful biomarkers to hasten therapeutic development and predict outcomes.

METHODS

A longitudinal, multicenter, prospective natural history study enrolled 26 SMA infants and 27 control infants aged <6 months. Recruitment occurred at 14 centers over 21 months within the NINDS-sponsored NeuroNEXT (National Network for Excellence in Neuroscience Clinical Trials) Network. Infant motor function scales (Test of Infant Motor Performance Screening Items [TIMPSI], The Children's Hospital of Philadelphia Infant Test for Neuromuscular Disorders, and Alberta Infant Motor Score) and putative physiological and molecular biomarkers were assessed preceding age 6 months and at 6, 9, 12, 18, and 24 months with progression, correlations between motor function and biomarkers, and hazard ratios analyzed.

RESULTS

Motor function scores (MFS) and compound muscle action potential (CMAP) decreased rapidly in SMA infants, whereas MFS in all healthy infants rapidly increased. Correlations were identified between TIMPSI and CMAP in SMA infants. TIMPSI at first study visit was associated with risk of combined endpoint of death or permanent invasive ventilation in SMA infants. Post-hoc analysis of survival to combined endpoint in SMA infants with 2 copies of SMN2 indicated a median age of 8 months at death (95% confidence interval, 6, 17).

INTERPRETATION

These data of SMA and control outcome measures delineates meaningful change in clinical trials in infantile-onset SMA. The power and utility of NeuroNEXT to provide "real-world," prospective natural history data sets to accelerate public and private drug development programs for rare disease is demonstrated. Ann Neurol 2017;82:883-891.

Nusinersen versus Sham Control in Infantile-Onset Spinal Muscular Atrophy

BACKGROUND

Spinal muscular atrophy is an autosomal recessive neuromuscular disorder that is caused by an insufficient level of survival motor neuron (SMN) protein. Nusinersen is an antisense oligonucleotide drug that modifies pre-messenger RNA splicing of the SMN2 gene and thus promotes increased production of full-length SMN protein.

METHODS

We conducted a randomized, double-blind, sham-controlled, phase 3 efficacy and safety trial of nusinersen in infants with spinal muscular atrophy. The primary end points were a motor-milestone response (defined according to results on the Hammersmith Infant Neurological Examination) and event-free survival (time to death or the use of permanent assisted ventilation). Secondary end points included overall survival and subgroup analyses of event-free survival according to disease duration at screening. Only the first primary end point was tested in a prespecified interim analysis. To control the overall type I error rate at 0.05, a hierarchical testing strategy was used for the second primary end point and the secondary end points in the final analysis.

RESULTS

In the interim analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (21 of 51 infants [41%] vs. 0 of 27 [0%], P<0.001), and this result prompted early termination of the trial. In the final analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (37 of 73 infants [51%] vs. 0 of 37 [0%]), and the likelihood of event-free survival was higher in the nusinersen group than in the control group (hazard ratio for death or the use of permanent assisted ventilation, 0.53; P=0.005). The likelihood of overall survival was higher in the nusinersen group than in the control group (hazard ratio for death, 0.37; P=0.004), and infants with a shorter disease duration at screening were more likely than those with a longer disease duration to benefit from nusinersen. The incidence and severity of adverse events were similar in the two groups.

CONCLUSIONS

Among infants with spinal muscular atrophy, those who received nusinersen were more likely to be alive and have improvements in motor function than those in the control group. Early treatment may be necessary to maximize the benefit of the drug. (Funded by Biogen and Ionis Pharmaceuticals; ENDEAR ClinicalTrials.gov number, NCT02193074 .).

Nusinersen for the treatment of spinal muscular atrophy

INTRODUCTION

Spinal muscular atrophy (SMA) is an autosomal recessive degenerative neuromuscular disorder characterized by loss of spinal motor neurons leading to muscle weakness. This review article focuses on a novel antisense oligonucleotide treatment, first ever approved for SMA (nusinersen, Spinraza^TM) and describes the exciting journey from early ASO clinical trials to regulatory approval of the first ever known effective treatment for SMA. Areas covered: This article reviews the results of the published open label nusinersen studies in infants and children, and briefly covers the preliminary findings of the recently completed but as yet unpublished nusinersen-sham controlled trials, as well as the presymptomatic nusinersen trial known as Nurture. Clinical use of nusinersen is also reviewed. Expert commentary: Collectively, the studies show improvement in motor function across SMA of all types, including SMA type 3. Best motor response was observed with early treatment; presymptomatic treatment prevented disease manifestations. Nusinersen was found to be safe and well tolerated across all age groups studied. Nusinersen has irrevocably altered the natural history of SMA and allowed for the first time children to transition between SMA types. Nusinersen should be considered as standard of care for the treatment of SMA of all types.

Phenotype of GABA-transaminase deficiency

OBJECTIVE

We report a case series of 10 patients with γ-aminobutyric acid (GABA)-transaminase deficiency including a novel therapeutic trial and an expanded phenotype.

METHODS

Case ascertainment, literature review, comprehensive evaluations, and long-term treatment with flumazenil.

RESULTS

All patients presented with neonatal or early infantile-onset encephalopathy; other features were hypotonia, hypersomnolence, epilepsy, choreoathetosis, and accelerated linear growth. EEGs showed burst-suppression, modified hypsarrhythmia, multifocal spikes, and generalized spike-wave. Five of the 10 patients are currently alive with age at last follow-up between 18 months and 9.5 years. Treatment with continuous flumazenil was implemented in 2 patients. One patient, with a milder phenotype, began treatment at age 21 months and has continued for 20 months with improved alertness and less excessive adventitious movements. The second patient had a more severe phenotype and was 7 years of age at initiation of flumazenil, which was not continued.

CONCLUSIONS

GABA-transaminase deficiency presents with neonatal or infantile-onset encephalopathy including hypersomnolence and choreoathetosis. A widened phenotypic spectrum is reported as opposed to lethality by 2 years of age. The GABA-A benzodiazepine receptor antagonist flumazenil may represent a therapeutic strategy.

Treatment of infantile-onset spinal muscular atrophy with nusinersen: a phase 2, open-label, dose-escalation study

BACKGROUND

Nusinersen is a 2'-O-methoxyethyl phosphorothioate-modified antisense drug being developed to treat spinal muscular atrophy. Nusinersen is specifically designed to alter splicing of SMN2 pre-mRNA and thus increase the amount of functional survival motor neuron (SMN) protein that is deficient in patients with spinal muscular atrophy.

METHODS

This open-label, phase 2, escalating dose clinical study assessed the safety and tolerability, pharmacokinetics, and clinical efficacy of multiple intrathecal doses of nusinersen (6 mg and 12 mg dose equivalents) in patients with infantile-onset spinal muscular atrophy. Eligible participants were of either gender aged between 3 weeks and 7 months old with onset of spinal muscular atrophy symptoms between 3 weeks and 6 months, who had SMN1 homozygous gene deletion or mutation. Safety assessments included adverse events, physical and neurological examinations, vital signs, clinical laboratory tests, cerebrospinal fluid laboratory tests, and electrocardiographs. Clinical efficacy assessments included event free survival, and change from baseline of two assessments of motor function: the motor milestones portion of the Hammersmith Infant Neurological Exam-Part 2 (HINE-2) and the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) motor function test, and compound motor action potentials. Autopsy tissue was analysed for target engagement, drug concentrations, and pharmacological activity. HINE-2, CHOP-INTEND, and compound motor action potential were compared between baseline and last visit using the Wilcoxon signed-rank test. Age at death or permanent ventilation was compared with natural history using the log-rank test. The study is registered at ClinicalTrials.gov, number NCT01839656.

FINDINGS

20 participants were enrolled between May 3, 2013, and July 9, 2014, and assessed through to an interim analysis done on Jan 26, 2016. All participants experienced adverse events, with 77 serious adverse events reported in 16 participants, all considered by study investigators not related or unlikely related to the study drug. In the 12 mg dose group, incremental achievements of motor milestones (p<0·0001), improvements in CHOP-INTEND motor function scores (p=0·0013), and increased compound muscle action potential amplitude of the ulnar nerve (p=0·0103) and peroneal nerve (p<0·0001), compared with baseline, were observed. Median age at death or permanent ventilation was not reached and the Kaplan-Meier survival curve diverged from a published natural history case series (p=0·0014). Analysis of autopsy tissue from patients exposed to nusinersen showed drug uptake into motor neurons throughout the spinal cord and neurons and other cell types in the brainstem and other brain regions, exposure at therapeutic concentrations, and increased SMN2 mRNA exon 7 inclusion and SMN protein concentrations in the spinal cord.

INTERPRETATION

Administration of multiple intrathecal doses of nusinersen showed acceptable safety and tolerability, pharmacology consistent with its intended mechanism of action, and encouraging clinical efficacy. Results informed the design of an ongoing, sham-controlled, phase 3 clinical study of nusinersen in infantile-onset spinal muscular atrophy.

FUNDING

Ionis Pharmaceuticals, Inc and Biogen.

Six-minute walk test is reliable and valid in spinal muscular atrophy

INTRODUCTION

The Six-Minute Walk Test (6MWT) was adopted as a clinical outcome measure for ambulatory spinal muscular atrophy (SMA). However, a systematic review of measurement properties reported significant variation among chronic pediatric conditions. Our purpose was to assess the reliability/validity of the 6MWT in SMA.

METHODS

Thirty participants performed assessments, including the 6MWT, strength, and function. Reproducibility was evaluated by intraclass correlation coefficients. Criterion/convergent validity were determined using Pearson correlation coefficients.

RESULTS

Test-retest reliability was excellent. The 6MWT was associated positively with peak oxygen uptake, Hammersmith Functional Motor Scale Expanded (HFMSE), lower extremity manual muscle testing, knee flexion hand-held dynamometry, and inversely with 10-m walk/run. The 6MWT discriminates between disease severity, unlike the HFMSE.

CONCLUSIONS

This study documents measurement properties of reproducibility, positive criterion validity, and convergent validity with established clinical assessments and reaffirms the value of the 6MWT as a pivotal outcome measure in SMA clinical trials. Muscle Nerve 54: 836-842, 2016.

Results from a phase 1 study of nusinersen (ISIS-SMN(Rx)) in children with spinal muscular atrophy

Objective:

To examine safety, tolerability, pharmacokinetics, and preliminary clinical efficacy of intrathecal nusinersen (previously ISIS-SMN_Rx), an antisense oligonucleotide designed to alter splicing of SMN2 mRNA, in patients with childhood spinal muscular atrophy (SMA).

Methods:

Nusinersen was delivered by intrathecal injection to medically stable patients with type 2 and type 3 SMA aged 2–14 years in an open-label phase 1 study and its long-term extension. Four ascending single-dose levels (1, 3, 6, and 9 mg) were examined in cohorts of 6–10 participants. Participants were monitored for safety and tolerability, and CSF and plasma pharmacokinetics were measured. Exploratory efficacy endpoints included the Hammersmith Functional Motor Scale Expanded (HFMSE) and Pediatric Quality of Life Inventory.

Results:

A total of 28 participants enrolled in the study (n = 6 in first 3 dose cohorts; n = 10 in the 9-mg cohort). Intrathecal nusinersen was well-tolerated with no safety/tolerability concerns identified. Plasma and CSF drug levels were dose-dependent, consistent with preclinical data. Extended pharmacokinetics indicated a prolonged CSF drug half-life of 4–6 months after initial clearance. A significant increase in HFMSE scores was observed at the 9-mg dose at 3 months postdose (3.1 points; p = 0.016), which was further increased 9–14 months postdose (5.8 points; p = 0.008) during the extension study.

Conclusions:

Results from this study support continued development of nusinersen for treatment of SMA.

Classification of evidence:

This study provides Class IV evidence that in children with SMA, intrathecal nusinersen is not associated with safety or tolerability concerns.

Baseline results of the NeuroNEXT spinal muscular atrophy infant biomarker study

OBJECTIVE

This study prospectively assessed putative promising biomarkers for use in assessing infants with spinal muscular atrophy (SMA).

METHODS

This prospective, multi-center natural history study targeted the enrollment of SMA infants and healthy control infants less than 6 months of age. Recruitment occurred at 14 centers within the NINDS National Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) Network. Infant motor function scales and putative electrophysiological, protein and molecular biomarkers were assessed at baseline and subsequent visits.

RESULTS

Enrollment began November, 2012 and ended September, 2014 with 26 SMA infants and 27 healthy infants enrolled. Baseline demographic characteristics of the SMA and control infant cohorts aligned well. Motor function as assessed by the Test for Infant Motor Performance Items (TIMPSI) and the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) revealed significant differences between the SMA and control infants at baseline. Ulnar compound muscle action potential amplitude (CMAP) in SMA infants (1.4 ± 2.2 mV) was significantly reduced compared to controls (5.5 ± 2.0 mV). Electrical impedance myography (EIM) high-frequency reactance slope (Ohms/MHz) was significantly higher in SMA infants than controls SMA infants had lower survival motor neuron (SMN) mRNA levels in blood than controls, and several serum protein analytes were altered between cohorts.

INTERPRETATION

By the time infants were recruited and presented for the baseline visit, SMA infants had reduced motor function compared to controls. Ulnar CMAP, EIM, blood SMN mRNA levels, and serum protein analytes were able to distinguish between cohorts at the enrollment visit.

Spinal muscular atrophy functional composite score: A functional measure in spinal muscular atrophy

INTRODUCTION

With clinical trials underway, our objective was to construct a composite score of global function that could discriminate among people with spinal muscular atrophy (SMA).

METHODS

Data were collected from 126 participants with SMA types 2 and 3. Scores from the Hammersmith Functional Motor Scale-Expanded and Upper Limb Module were expressed as a percentage of the maximum score and 6-minute walk test as percent of predicted normal distance. A principal component analysis was performed on the correlation matrix for the 3 percentage scores.

RESULTS

The first principal component yielded a composite score with approximately equal weighting of the 3 components and accounted for 82% of the total variability. The SMA functional composite score, an unweighted average of the 3 individual percentage scores, correlated almost perfectly with the first principal component.

CONCLUSIONS

This combination of measures broadens the spectrum of ability that can be quantified in type 2 and 3 SMA patients.

Leg muscle function and fatigue during walking in spinal muscular atrophy type 3

INTRODUCTION

Spinal muscular atrophy (SMA) causes muscle weakness and fatigue. Better understanding of the relationship between weakness and fatigue may help identify potential targets for rehabilitation.

METHODS

Gait and surface electromyography (EMG) from 4 muscle groups were measured during the Six-Minute Walk Test (6MWT) in 10 ambulatory participants, aged 9-49 years. Average root mean square amplitude (RMS) of muscle activity was calculated. Strength was assessed using manual and quantitative methods.

RESULTS

RMS, stride length, and velocity decreased during the 6MWT. Knee flexor and hip abductor strength was associated with fatigue-related changes; overall strength correlated with disease duration; and leg strength was associated with 6MWT distance.

CONCLUSIONS

Clinical measures are valid in assessing fatigue and function in SMA, and these assessments can be enhanced by use of gait analysis and EMG. Disease duration and strength measures may represent further stratification refinements when enrolling patients in clinical trials.

Neurobehavioral and Developmental Traiectories Associated with Level of Prenatal Cocaine Exposure

INTRODUCTION

In experimental models, prenatal cocaine exposure has been found to perturb GABA and dopamine development. Clinically, abnormalities in tone, posture and state regulation are noted in early infancy but the evolution of these findings over time is not well described. The current study assesses the longitudinal effects of prenatal cocaine exposure in dose-dependent fashion on developmental & behavioral and neurological trajectories over the first 2 years of life.

METHODS

Three hundred and eighty infants, 113 cocaine-exposed, were enrolled at birth from an urban hospital from 2000 to 2004. Exposure was determined by maternal interview, segmental hair analyses (RIAH^™) in all, and meconium and urine in a subset. Developmental, behavioral and neurological assessments were carried out blind to drug exposure at 6, 12 and 24 months of age in the 306 children who returned in follow-up. Mixed-effects linear modeling (developmental growth curve) assessed change in outcome over time.

RESULTS

The mental developmental growth curve showed a negative slope (2.2 points) in adjusted analyses among cocaine-exposed children over the first 2 years of life. (p=.04), while the slope of the motor development growth curve did not. Adjusting for microcephaly at 6 months diminished the strength of the association between cocaine exposure and mental developmental growth curve (effect modification). Cocaine exposure was marginally associated with behavioral outcomes in adjusted analyses. Total Behavior scores and Orientation/Engagement scores improved with age. At 1 year of age, prenatal cocaine exposure was significantly associated with lower motor development scores. High rates of hypertonia (global and diparesis) identified at the 6-month visit dropped dramatically in the first 2 years of life: cocaine-exposed children showed a more rapid rate of resolution of hypertonia than unexposed children, with hypertonia improving 2.2 times faster among those with heavy cocaine exposure.

CONCLUSION

We found differences in mental performance over the first 2 years of life associated with prenatal cocaine exposure that was mediated by microcephaly implying that cocaine exerts a sustained teratogenic effect on brain development. Early neurological (hypertonia) and behavioral findings associated with prenatal cocaine exposure improved over time. Hypertonia did not predict long-term development impairments. Conceivably, the transient nature of neurobehavioral manifestations reflects postnatally a tendency towards homeostasis of cocaine-related embryopathic perturbations of GABA and dopaminergic systems.

Reduction in upper-extremity tone after lumbar selective dorsal rhizotomy in children with spastic cerebral palsy

OBJECT

Randomized clinical trials have established that lumbar selective dorsal rhizotomy (SDR) reduces lower-extremity tone and improves functional outcome in children with spastic cerebral palsy. Significant data exist to support a secondary effect on upper-extremity function in patients with upper-extremity spasticity. The effects of SDR on upper-extremity tone, however, are not well characterized. In this report, the authors sought to assess changes in upper-extremity tone in individual muscle groups after SDR and tried to determine if these changes could be predicted preoperatively.

METHODS

The authors retrospectively reviewed 42 children who underwent SDR at Columbia University Medical Center/Morgan Stanley Children's Hospital of NewYork-Presbyterian between 2005 and 2011. Twenty-five had upper-extremity spasticity. All underwent pre- and postoperative examination for measuring tone (Modified Ashworth Scale) and assessing functional outcome. Follow-up examinations with therapists were performed at least once at a minimum of 2 months postoperatively (mean 15 months).

RESULTS

In the upper extremities, 23 (92%) of 25 patients had improvements of at least 1 Ashworth point in 2 or more independent motor groups on the Modified Ashworth Scale, and 12 (71%) of 17 families surveyed reported increases in motor control or spontaneous movement. The mean Modified Ashworth Scale scores for all upper-extremity muscle groups demonstrated an improvement from 1.34 to 1.22 (p < 0.001). Patients with a mean preoperative upper-extremity tone of 1.25-1.75 were most likely to benefit from reduction in tone (p = 0.0019). Proximal and pronator muscle groups were most likely to demonstrate reduced tone.

CONCLUSIONS

In addition to improvements in lower-extremity tone and function, SDR has demonstrable effects on upper extremities. Greater than 90% of our patients with elevated upper-extremity tone demonstrated reduction in tone in at least 2 muscle groups postoperatively. Patients with a mean Modified Ashworth Scale upper-extremity score of 1.25-1.75 may encounter the greatest reduction in upper-extremity tone.

Weakness and fatigue in diverse neuromuscular diseases

Weakness and fatigue are captured by the 6-minute walk test, but the relationship between these symptoms is uncertain. Comparison across neuromuscular diseases has not been examined. A cohort study of 114 patients with spinal muscular atrophy, Duchenne/Becker muscular dystrophy, myasthenia gravis, and energy failure syndromes were included. Percent-predicted distance on the 6-minute walk test was computed from normative values to determine weakness. Fatigue was determined by the decrement in distance from the first to sixth minute. Weakness was seen across all groups (61.9%) but significant fatigue was seen only in spinal muscular atrophy (21.0%). Other groups showed little fatigue. Correlation between weakness and fatigue was significant only in spinal muscular atrophy (R = -0.71; P < .001). Longitudinally, distance walked declined only in Duchenne/Becker muscular dystrophy. In spinal muscular atrophy, weakness did not change, but fatigue increased significantly. These findings suggest independent mechanisms underlying weakness and fatigue in diverse neuromuscular conditions.

Facial palsy and idiopathic intracranial hypertension in twins with cystic fibrosis and hypovitaminosis A

Facial nerve palsies are uncommon in infants. We report on 10-week-old monozygotic twins, diagnosed with cystic fibrosis by newborn screening, who developed facial palsy and increased intracranial pressure. Cranial imaging and cerebrospinal fluid analysis produced normal results. Levels of serum vitamin A were below normal range. Low levels of vitamin A are associated with facial nerve paralysis, and are at least partly implicated in the development of increased intracranial pressure in infants with cystic fibrosis.

Subclinical seizures in children diagnosed with localization-related epilepsy: clinical and EEG characteristics

OBJECTIVE

Subclinical seizures (SCSs) are characterized by paroxysmal rhythmic epileptiform discharges that evolve in time and space in the absence of objective clinical manifestation or report of a seizure. The aim of this study was to evaluate the frequency and characteristics of SCSs in children with localization-related epilepsy (LRE).

METHODS

The results of video/EEG monitoring were reviewed to identify patients with SCS. We identified 187 children diagnosed with LRE, in 32 of whom SCSs were reported in the EEG recording.

RESULTS

SCSs were reported only in the children who had received a diagnosis of either symptomatic or cryptogenic LRE. All children had a history of clinical seizure(s). The ictal onset of SCSs was most frequent from the temporal and frontal lobes. SCSs were lateralized to the left hemispheres in 19, right hemisphere in 8, and both hemispheres independently in 5 children. SCSs were more often reported in young children, and associated with a history of developmental delay, infantile spasms, and frequent seizures. EEG abnormalities included background slowing and lack of normal sleep architecture in addition to the epileptiform activity. Seizure freedom was reported less often in children with SCSs. Six patients seizure free at the time of the admission were found to have SCSs.

CONCLUSION

Subclinical seizures are not uncommon in children with LRE, in particular, with younger age, developmental disability, and medically refractory clinical course. Video/EEG monitoring will be informative in selected children with LRE to assess the seizure frequency more accurately.

The frequency of non-epileptic spells in children: results of video-EEG monitoring in a tertiary care center

RATIONALE

the diagnosis of non-epileptic spells (NES) in children can be challenging, even for experienced clinicians. Our objective was to describe the characteristics of such events.

METHODS

this was a retrospective study conducted from January 2004 to December 2006. Inclusion criteria were age >1 month and <18 years and the diagnosis of NES established by video-EEG monitoring.

RESULTS

among 746 monitored children (1203 recorded video-EEG sessions), 109 (14.6%) had NES. The mean age of patients with NES was 6.6 years (range 0.1-18). Seventy patients were diagnosed with NES alone; the remaining 39 with both NES and epilepsy. Developmental delay was more frequent among patients with a co-morbid diagnosis of epilepsy (p<0.001). Similar clinical events were reported in both of these groups, save for crying spells/irritability which was more common in children with epilepsy. Frequent manifestations of NES included staring spells in preschool children, crying/irritability, tremor and eye deviation in young children and preschoolers, and limb shaking in adolescents. All of the patients with epilepsy and 19 (27%) of those without epilepsy were receiving antiepileptic drugs.

CONCLUSION

our data highlights the importance of accurate diagnosis of NES toward the appropriate treatment of affected children.

Prenatal cocaine exposures and dose-related cocaine effects on infant tone and behavior

BACKGROUND

In experimental models, prenatal cocaine exposure has been found to perturb monoaminergic development. In humans, numerous studies have sought clinical correlates, but few have focused on dose-related effects, especially as regards neurologic function beyond the neonatal period.

OBJECTIVE

To assess whether prenatal cocaine exposure has adverse effects on infant neurologic, developmental and behavioral outcomes and whether any effects are dose-dependent.

DESIGN/METHODS

Infants (398) were enrolled at birth from an urban hospital. Drug exposure was ascertained with biomarkers in hair (n=395), urine (n=170) and meconium (n=109). Children were followed prospectively and 286 (72%) were evaluated blind to drug exposure at 6 months of age with the Bayley scales, Fagan Scale of Infant Intelligence and a standardized neurological examination.

RESULTS

Certain neurological findings increased significantly by the amount of cocaine detected in maternal hair, e.g. abnormality of tone, as indicated by extensor posture was detected among 28% of cocaine-unexposed infants, 43% of infants exposed to lower and 48% exposed to higher cocaine levels in maternal hair (p<0.009). Persistent fisting increased in a similar dose-dependent manner. These associations persisted in adjusted analyses. Prenatal cocaine exposure was not associated with developmental scores (mental, motor or novelty preference) but was associated with lower orientation scores in adjusted analyses.

CONCLUSIONS

At 6 months of age, prenatal cocaine exposure was associated with abnormalities of tone and posture and with lower orientation scores. Perturbations in monoaminergic systems by cocaine exposure during fetal development may explain the observed neurological and behavioral symptoms. Whether such findings in infancy increase the risk of later neurobehavioral problems requires further study.

Incidence and prevalence of HIV encephalopathy in children with HIV infection receiving highly active anti-retroviral therapy (HAART)

OBJECTIVE

To describe neurologic outcomes in children infected with HIV in the era of highly active anti-retroviral therapy (HAART), including rates of progressive HIV encephalopathy (PHE) and clinical sequelae among PHE survivors.

STUDY DESIGN

Neurobehavior and school placement was assessed prospectively in the year 2000 in 126 children infected with HIV. PHE, developmental delay, and attention deficit disorder (ADHD) were the main outcome variables analyzed. Predictors of PHE were assessed in controlled analysis among age-matched controls.

RESULTS

The rate of active PHE in 2000 was 1.6% (n = 2), and the prevalence of arrested PHE was 10% (n = 13). Residual motor and cognitive sequelae and need for special education was found in the majority of survivors. PHE relapse occurred in 3 (23%) children with previously arrested PHE. Viral load (VL) was the only significant factor associated with PHE. HIV or PHE was not associated with ADHD. Isolated developmental delay was not associated with HIV.

CONCLUSIONS

PHE is an infrequent and reversible complication of HIV infection that responds to HAART and that may relapse if control of the virus is lost. Children with arrested PHE show higher rates of residual neurologic, cognitive, and scholastic impairments compared with children who never had PHE. Children with arrested PHE are the group of children with HIV infection most at risk for PHE, in the form of a relapse.

Aromatic L-amino acid decarboxylase deficiency: clinical features, treatment, and prognosis

BACKGROUND

Deficiency of aromatic L-amino acid decarboxylase (AADC) is associated with severe developmental delay, oculogyric crises (OGC), and autonomic dysfunction. Treatment with dopamine agonists and MAO inhibitors is beneficial, yet long-term prognosis is unclear.

OBJECTIVE

To delineate the clinical and molecular spectrum of AADC deficiency, its management, and long-term follow-up.

RESULTS

The authors present six patients with AADC deficiency and review seven cases from the literature. All patients showed reduced catecholamine metabolites and elevation of 3-O-methyldopa in CSF. Residual plasma AADC activity ranged from undetectable to 8% of normal. Mutational spectrum was heterogeneous. All patients presented with hypotonia, hypokinesia, OGC, and signs of autonomic dysfunction since early life. Diurnal fluctuation or improvement of symptoms after sleep were noted in half of the patients. Treatment response was variable. Two groups of patients were detected: Group I (five males) responded to treatment and made developmental progress. Group II (one male, five females) responded poorly to treatment, and often developed drug-induced dyskinesias.

CONCLUSIONS

The molecular and clinical spectrum of AADC deficiency is heterogeneous. Two groups, one with predominant male sex and favorable response to treatment, and the other with predominant female sex and poor response to treatment, can be discerned.

Progressive multifocal leukoencephalopathy successfully treated with highly active antiretroviral therapy and cidofovir in an adolescent infected with perinatal human immunodeficiency virus (HIV)

Progressive multifocal leukoencephalopathy is an infectious demyelinating brain disease caused by the JC virus that is associated with significant morbidity and mortality in the immunocompromised host. We report a case of progressive multifocal leukoencephalopathy successfully treated with highly active antiretroviral therapy and cidofovir in an adolescent patient perinatally infected with human immunodeficiency virus (HIV).

Factors associated with microcephaly at school age in a very-low-birthweight population

The neonatal predictors of microcephaly, defined as a head circumference <5th centile in children born preterm, has not been systematically assessed. Children were drawn from the Developmental Epidemiology Network (DEN) cohort of very low-birthweight children (VLBW: 500-1500g) born from 1991 to 1993 at three sites in the USA. Neurological assessments were carried out among 198 singleton children (mean age 6 years 8 months, SD 0.5 years). Ninety-six children (48.5%) were male. Microcephaly was observed in 30 children (15%) and, using multivariate analysis, it was found to be associated with gestational age <26 weeks and bronchopulmonary dysplasia (BPD). Sonography-defined white-matter damage (WMD, i.e. echolucency or echodensities) was not associated with increased odds of microcephaly, while occurrence of intraventricular hemorrhage (IVH) was in univariate but not multivariate analysis. In analyses that excluded children with IVH/WMD, odds of microcephaly increased in dose-related fashion according to number of days on ventilator: >5 days, OR=4.5; 95%CI=1.4 to 15; >10 days, OR=5.7; 95%CI=1.7 to 19; >15 days OR=8.3; 95% CI=2.3 to 29.2. Among children without BPD, microcephaly was not associated with differences in IQ, while IQ scores among children with BPD or any ventilation were disproportionately lower among those with microcephaly. In multivariate analyses predicting IQ at age 7 years, microcephaly was found to modify the association between neonatal lung disease and IQ.

Fetal Alcohol and Drug Effects

BACKGROUND

Alcohol and drug use by pregnant women are harmful to the developing embryo and fetus. Teasing apart the specific contributions of each substance to adverse child outcome, however, proves difficult in practice. The risks to the neonate include intra-uterine growth retardation, birth defects, altered neurobehavior, and withdrawal symptoms. Subsequent behavior, development, and neurologic function may also be impaired.

REVIEW SUMMARY

Maternal cigarette smoking carries the greatest risk of impaired fetal growth of any of the substances discussed herein and has been linked to subsequent externalizing behaviors. Alcohol is a well-established teratogen. Heavy exposure to alcohol in a subset of infants is associated with fetal alcohol syndrome (FAS). Mental retardation is one of the main sequelae of alcohol exposure in utero. Fetal marijuana exposure has no consistent effect on outcome. Prenatal cocaine exposure has not been shown to have any detrimental effect on cognition, except as mediated through cocaine effects on head size. Although fetal cocaine exposure has been linked to numerous abnormalities in arousal, attention, and neurologic and neurophysiological function, most such effects appear to be self-limited and restricted to early infancy and childhood. Opiate exposure elicits a well-described withdrawal syndrome affecting central nervous, autonomic, and gastrointestinal systems, which is most severe among methadone-exposed infants.

CONCLUSION

Most adverse effects of prenatal drug exposure are self-limited, with catch-up growth and resolution of withdrawal and of prior neurobehavioral abnormalities noted over time. The exception is alcohol, which is linked to life-long impairments (i.e., mental retardation and microcephaly) and possibly cigarette-related behavioral effects. The absence of tangible evidence of detrimental long-term cocaine effects may reflect limitations in the methodology used to identify children at greatest risk for adverse outcome.

Sickle cell anemia with moyamoya disease: outcomes after EDAS procedure

Moyamoya disease is a relatively uncommon neurovascular complication of sickle cell anemia. We report a case series of six patients with sickle cell anemia who developed moyamoya disease and underwent encephaloduroarteriosynangiosis procedures. These six patients presented with either cerebrovascular accidents, transient ischemic attacks, or seizures, and subsequent magnetic resonance imaging scans were suggestive of moyamoya-like changes in the cerebral vasculature. Conventional cerebral angiography was used to confirm the diagnosis in all six patients. Four of six patients manifested a cerebrovascular accident before surgery, and two of these patients were compliant on a transfusion protocol at the time of their cerebrovascular accident. Bilateral (n = 4) or unilateral (n = 2) encephaloduroarteriosynangiosis procedures were performed without any complications. The patient who was stroke-free preoperatively had a cerebrovascular accident 2 weeks after the procedure; otherwise, all patients have remained free of neurovascular complications with an average follow-up of 33 months. Collateral anastomoses between external and internal carotid arteries were established by magnetic resonance angiography in three patients. The encephaloduroarteriosynangiosis procedure is a safe and effective treatment option in patients with sickle cell anemia who develop moyamoya disease.

Neonatal blood carnitine concentrations: normative data by electrospray tandem mass spectometry

Despite a number of published reports, there is limited information about carnitine metabolism in the newborn. To establish normative data, we analyzed whole-blood carnitine concentrations in 24,644 newborns at age 1.85 +/- 0.95 d and umbilical cord whole blood and plasma carnitine concentrations in 50 full-term newborns. Total carnitine (TC), free carnitine (FC), and acylcarnitine (AC) were measured by electrospray tandem mass spectrometry. AC/FC ratios were derived from these measurements. The entire cohort was stratified according to TC values into a middle TC group representing 90% of the population and lower and upper TC groups representing 5% of the population, respectively. Normative data were derived from the middle TC group of full-term infants (N = 19,595). TC was 72.42 +/- 20.75 microM, FC was 44.94 +/- 14.99 microM, AC was 27.48 +/- 8.05 microM, and AC/FC ratio was 0.64 +/- 0.19 (+/-SD). These values differed significantly from umbilical cord whole blood TC values of 31.27 +/- 10.54 microM determined in 50 samples. No meaningful correlation was found between TC and gestational age or birth weight in any group. In controlled analyses, prematurity was not associated with TC levels, whereas low birth weight (<2500 g) and male sex were significantly associated with higher TC levels. The association of low birth weight with higher TC values may be related to decreased tissue carnitine uptake. The sex effect may be related to hormonal influences on carnitine metabolism. Our study provides normative data of carnitine values measured by the highly precise method of electrospray tandem mass spectrometry in a large cohort of newborns and provides the basis for future studies of carnitine metabolism in health and disease states during the neonatal period.

Human Immunodeficiency Virus (HIV) in Children

Recent advances in antiretroviral treatment have changed the landscape of pediatric HIV--not only has perinatal treatment markedly diminished HIV transmission rates, but highly active antiretroviral treatments (HAART) have, with few exceptions, transformed HIV into a chronic nonfatal disorder. Antiretroviral therapies are complex and fraught with potential for side effects. The neurologist involved with HIV-infected children should have a firm grasp on the different therapeutic agents used among infected children, especially as regards drug metabolism and indications for treatment.

Dose-response effect of cocaine on newborn head circumference

OBJECTIVE

To evaluate the relationship between head circumference, birth weight, and cocaine dose in healthy term and near-term newborns exposed to cocaine in utero.

METHODS

We used radioimmune assay (RIAH) of cocaine metabolite in maternal hair to quantify third trimester cocaine exposure in 240 healthy newborn infants (gestational age: >36 weeks). Cocaine exposure was categorized into 3 levels: no exposure (n = 136), low cocaine exposure (n = 52; RIAH: 2-66 ng/10 mg hair), and high cocaine exposure (n = 52; RIAH: 81-4457 ng/10 mg hair). We collected information on maternal demographic characteristics, the pregnancy, and the use of substances through a structured interview and from the medical record.

RESULTS

Means of birth weight, length, and head circumference of infants with high cocaine exposure differed significantly from those with low exposure and no exposure, but were similar between low exposure and no exposure. We used a multiple linear regression model to assess the association between newborn head circumference and cocaine level, adjusting for the effects of birth weight; gestational age; infant sex; and several maternal factors, including height, weight gain during pregnancy, syphilis during pregnancy, and the use of alcohol, cigarettes, marijuana, and opiates during pregnancy. Only birth weight, sex, and high cocaine exposure were significantly associated with newborn head circumference. The predicted head circumference deficit associated with high cocaine exposure (.44 cm) represents 34% of the unadjusted difference (1.28 cm) between mean head circumferences of infants in the high cocaine exposure and no exposure groups.

CONCLUSION

Newborns exposed to a high level of cocaine in utero (RIAH: >81 ng/10 mg hair) exhibit asymmetric intrauterine growth retardation in which the head circumference is disproportionately smaller than would be predicted from the birth weight (head wasting). The deficit in head size associated with cocaine exposure may reflect the effects of a specific central nervous system insult that interferes with prenatal brain growth.

Intracerebral aneurysms in human immunodeficiency virus infection: case report and literature review

We describe a child with human immunodeficiency virus infection who presented with a large subarachnoid hemorrhage. She had multiple saccular and fusiform aneurysms in the proximal cerebral arterial circulation and no evidence of bacterial or fungal infection. The arteriopathy coincided with a high human immunodeficiency virus RNA load. Human immunodeficiency virus may cause cerebral arteriopathy with potentially life-threatening complications.

Dose-response effect of fetal cocaine exposure on newborn neurologic function

BACKGROUND

Studies of fetal cocaine exposure and newborn neurologic function have obtained conflicting results. Although some studies identify abnormalities, others find no differences between cocaine-exposed and cocaine-unexposed infants. To determine the effects of prenatal cocaine exposure on intrauterine growth and neurologic function in infants, we prospectively evaluated 253 infants shortly after birth.

METHODS

Women who delivered a live singleton >36 weeks by dates were eligible for enrollment. Maternal exclusionary criteria were known parenteral drug use, alcoholism, and acquired immunodeficiency syndrome; infant exclusionary criteria were Apgar scores </=4 at 5 minutes, obvious congenital malformations, seizures, or strokes. A total of 98% of infants were evaluated between 1 to 7 days of age. Newborns were assessed with the Neurological Examination for Children (NEC) by a pediatric neurologist (C.A.C.) who was blinded to exposure status. Gestational age was determined by Ballard's examination. Cocaine exposure was determined for the last trimester by radioimmunoassay of maternal hair (RIAH). Exposure values ranged from 2 to 4457 ng/10 mg hair. Infants were excluded if a maternal hair sample was missing (N = 13). The sample comprises 240 woman and infant pairs-104 cocaine-exposed and 136 cocaine-unexposed.

RESULTS

Compared with unexposed controls, cocaine-exposed infants exhibited higher rates of intrauterine growth retardation (24% vs 8%), small head circumference ([HC] <10th% percentile) (20% vs 5%) and neurologic abnormalities: global hypertonia (32% vs 11%), coarse tremor (40% vs 15%), and extensor leg posture (20% vs 4%). We found increasing odds (odds ratio) of growth and neurologic impairment with increasing level of cocaine exposure in stratified analyses. The odds ratio associated with three levels of cocaine exposure (no exposure, low exposure = RIAH 2-66 ng/mg; and high exposure = RIAH 81-4457 ng/mg) respectively are: 1.0, 3.3, and 6.1 for small head size (chi2 for trend); 1.0, 3. 3, and 4.3 for global hypertonia (chi2 for trend); 1.0, 3.4, and 7.4 for extensor leg posturing (chi2 for trend); and 1.0, 3.8, and 3.8 for coarse tremor (chi2 for trend). Significant associations between cocaine exposure and neurologic signs were found in logistic regression equations that controlled for 20 or more variables.

CONCLUSION

We conclude that adverse neonatal effects associated with fetal cocaine exposure follow a dose-response relationship: newborns with higher levels of prenatal cocaine exposure show higher rates of impairments in fetal head growth and abnormalities of muscle tone, movements, and posture. Significant relationships between cocaine exposure and these outcomes remain in controlled analyses.