Objective: The Quality Standards Subcommittee of the American Academy of Neurology and the Practi... more Objective: The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society develop practice parameters as strategies for patient management based on analysis of evidence. For this parameter the authors reviewed available evidence on the assessment of a child suspected of having cerebral palsy (CP), a nonprogressive disorder of posture or movement due to a lesion of the developing brain. Methods: Relevant literature was reviewed, abstracted, and classified. Recommendations were based on a four-tiered scheme of evidence classification. Results: CP is a common problem, occurring in about 2 to 2.5 per 1,000 live births. In order to establish that a brain abnormality exists in children with CP that may, in turn, suggest an etiology and prognosis, neuroimaging is recommended with MRI preferred to CT (Level A). Metabolic and genetic studies should not be routinely obtained in the evaluation of the child with CP (Level B). If the clinical history or findings on neuroimaging do not determine a specific structural abnormality or if there are additional and atypical features in the history or clinical examination, metabolic and genetic testing should be considered (Level C). Detection of a brain malformation in a child with CP warrants consideration of an underlying genetic or metabolic etiology. Because the incidence of cerebral infarction is high in children with hemiplegic CP, diagnostic testing for coagulation disorders should be considered (Level B). However, there is insufficient evidence at present to be precise as to what studies should be ordered. An EEG is not recommended unless there are features suggestive of epilepsy or a specific epileptic syndrome (Level A). Because children with CP may have associated deficits of mental retardation, ophthalmologic and hearing impairments, speech and language disorders, and oral-motor dysfunction, screening for these conditions should be part of the initial assessment (Level A). Conclusions: Neuroimaging results in children with CP are commonly abnormal and may help determine the etiology. Screening for associated conditions is warranted as part of the initial evaluation. NEUROLOGY 2004;62:851-863 Cerebral palsy (CP) can be defined as a disorder of aberrant control of movement and posture, appearing early in life secondary to a CNS lesion or dysfunction that is not the result of a recognized progressive or degenerative brain disease. 1 The brain abnormality may occur pre-, peri-, or postnatally. The diagnosis of CP always involves a motor deficit and the usual presenting complaint for which medical evaluation is sought is that the child is not reaching motor milestones at the appropriate chronological age. In most
McDonagh M, Helfand M, Carson S, Russman BS. Hyperbaric oxygen therapy for traumatic brain injury... more McDonagh M, Helfand M, Carson S, Russman BS. Hyperbaric oxygen therapy for traumatic brain injury: a systematic review of the evidence. Arch Phys Med Rehabil 2004;85:1198–204.
Cerebral palsy (CP) is a common problem, occurring in about 2 to 2.5 per 1000 live births. The di... more Cerebral palsy (CP) is a common problem, occurring in about 2 to 2.5 per 1000 live births. The diagnosis of CP is based upon a history of abnormal motor development that is not progressive coupled with an examination (e.g. hypertonicity, increased reflexes, clonus) "placing" the lesion in the brain. In order to establish that a brain abnormality exists in children with CP that may, in turn, suggest an etiology and prognosis, neuroimaging is recommended with magnetic resonance imaging preferred to computed tomography. Metabolic and genetic studies should be obtained if there are atypical features in the history or on the examination. Detection of a brain malformation in a child with CP might suggest an underlying genetic or metabolic etiology. As cerebral infarction is high in children with hemiplegic CP, diagnostic testing for coagulation disorders should be considered. However, there is insufficient evidence at present to be precise as to what studies should be ordered. A...
Objective: To evaluate the effects of corticosteroids on the lower extremity muscles in boys with... more Objective: To evaluate the effects of corticosteroids on the lower extremity muscles in boys with Duchenne muscular dystrophy (DMD) using MRI and magnetic resonance spectroscopy (MRS).
Physical Medicine and Rehabilitation Clinics of North America, 2012
Studies have shown promise in using various approaches of magnetic resonance imaging (MRI) and ma... more Studies have shown promise in using various approaches of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy to evaluate skeletal muscle involvement in Duchenne muscular dystrophy. However, these studies have mainly been performed using a cross-sectional design, and the correlation of these MRI changes with disease progression and disease severity has not been fully elucidated. Overall, skeletal muscle MRI is a powerful and sensitive technique in the evaluation of muscle disease, and its use as a biomarker for disease progression or therapeutic response in clinical trials deserves further study.
Journal of pediatric rehabilitation medicine, 2011
For ambulatory children with cerebral palsy, the assessment of walking energy efficiency is utili... more For ambulatory children with cerebral palsy, the assessment of walking energy efficiency is utilized to determine functional changes following surgical, pharmacologic, or orthotic interventions. While the assessment of energy efficiency is considered a useful outcome tool, minimal information exists about the changes in energy efficiency over one year in children with cerebral palsy at different gross motor function classification system (GMFCS) levels and whether the patterns of change are similar to their able-bodied peers. The purpose of this study was to determine whether energy efficiency variables change similarly over one year in children with cerebral palsy by GMFCS level and whether they differ from their age-matched peers. Forty-five able-bodied children and 34 children with cerebral palsy, GMFCS levels I-III participated in the study. Energy efficiency variables were measured at baseline and at 12 months using a Cosmed K4b2. All subjects walked at their self-selected velo...
To validate a multicenter protocol that examines lower extremity skeletal muscles of children wit... more To validate a multicenter protocol that examines lower extremity skeletal muscles of children with Duchenne muscular dystrophy (DMD) by using magnetic resonance (MR) imaging and MR spectroscopy in terms of reproducibility of these measurements within and across centers. This HIPAA-compliant study was approved by the institutional review boards of all participating centers, and informed consent was obtained from each participant or a guardian. Standardized procedures with MR operator training and quality assurance assessments were implemented, and data were acquired at three centers by using different 3-T MR imaging instruments. Measures of maximal cross-sectional area (CSAmax), transverse relaxation time constant (T2), and lipid fraction were compared among centers in two-compartment coaxial phantoms and in two unaffected adult subjects who visited each center. Also, repeat MR measures were acquired twice on separate days in 30 boys with DMD (10 per center) and 10 unaffected boys. Coefficients of variation (CVs) were computed to examine the repeated-measure variabilities within and across centers. CSAmax, T2 from MR imaging and MR spectroscopy, and lipid fraction were consistent across centers in the phantom (CV, <3%) and in the adult subjects who traveled to each site (CV, 2%-7%). High day-to-day reproducibility in MR measures was observed in boys with DMD (CSAmax, CV = 3.7% [25th percentile, 1.3%; 75th percentile, 5.1%]; contractile area, CV = 4.2% [25th percentile, 0.8%; 75th percentile, 4.9%]; MR imaging T2, CV = 3.1% [25th percentile, 1.2%; 75th percentile, 4.7%]; MR spectroscopy T2, CV = 3.9% [25th percentile, 1.5%; 75th percentile, 5.1%]; and lipid fraction, CV = 4.7% [25th percentile, 1.0%; 75th percentile, 5.3%]). The MR protocol implemented in this multicenter study achieved highly reproducible measures of lower extremity muscles across centers and from day to day in ambulatory boys with DMD.
We have developed a protocol to evaluate, prospectively, patients with spinal mus-cular atrophy (... more We have developed a protocol to evaluate, prospectively, patients with spinal mus-cular atrophy (SMA) so that the natural course may be defined and treatment effica-cy measured. A fixed myometry system with a sensitivity of 0.5 kgs. of force was used to eliminate the subjectivity ...
To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in ... more To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in the treatment of movement disorders.
To evaluate the effect of SMN2 copy number on disease severity in spinal muscular atrophy (SMA), ... more To evaluate the effect of SMN2 copy number on disease severity in spinal muscular atrophy (SMA), we stratified 45 adult SMA patients based on SMN2 copy number (3 vs. 4 copies). Patients with 3 copies had an earlier age of onset and lower spinal muscular atrophy functional rating scale (SMAFRS) scores and were more likely to be non-ambulatory. There was, however, no difference between the groups in quantitative muscle strength or pulmonary function testing. Functional scale may be a more discriminating outcome measure for SMA clinical trials.
Cerebral palsy (CP) is characterized by aberrant control of movement or posture and appears early... more Cerebral palsy (CP) is characterized by aberrant control of movement or posture and appears early in life secondary to central nervous system damage. The symptoms of CP fall into four groups: symptoms due to loss of selective motor control; symptoms due to abnormal muscle tone; symptoms due to imbalance between muscle agonists and antagonists; and symptoms due to impaired balance. The goals of treatment are to maximize function and minimize the development of joint contracture and other secondary problems. Development of a treatment plan begins with the definition of objectives and consideration of the effects of growth and development on the patient's abilities. The role of botulinum toxin in CP treatment has grown in recent years. The patient who could benefit most from botulinum toxin treatment is one who is hypertonic and whose abnormal muscle tone is interfering with function, or who is expected to develop joint contracture with growth because of this abnormal tone. By altering this muscle tone, function can be enhanced or additional therapeutic modalities can be employed. Assessing treatment outcomes for BTX injection involves the same set of questions and measurements as for other types of treatments and depends on the careful definition of treatment objectives beforehand.
To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal musc... more To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal muscular atrophy (SMA). Preclinical data in experimental models of motor neuron disease suggest a neuroprotective effect of gabapentin. Gabapentin (1200 mg), or placebo, was administered three times daily in a randomized, double-blind trial for 12 months. The primary outcome measure was the average percent change from baseline, based on the measurement of strength in four muscles (elbow flexion and hand grip bilaterally) for each patient. Drug efficacy was examined by comparing the percent change in strength for patients on drug vs. placebo. Secondary efficacy variables included: forced vital capacity (FVC), SMA functional rating scale (SMAFRS), and mini-Sickness Impact Profile (SIP). Eighty-four patients, with type II or III SMA, were enrolled at eight sites across the United States. There were no differences in baseline features. There was no difference between the placebo and drug groups in any outcome measure. This study demonstrates the feasibility of this trial design and provides data for the design of future clinical trials in SMA.
Increased gastrocnemius/soleus muscle tone in children with cerebral palsy may cause an equinus o... more Increased gastrocnemius/soleus muscle tone in children with cerebral palsy may cause an equinus of the ankle. Botulinum toxin type A (BTX), a neuromuscular blocking agent, reduces muscle tone in various neuromuscular disorders. The safety and short-term efficacy of BTX injections were evaluated in a prospective, 3-month, double-blind, randomized clinical trial involving 114 children with cerebral palsy and dynamic equinus foot deformity. Outcome was determined by observational gait analysis, ankle range-of-motion measurements, and quantification of muscle denervation by nerve conduction. Patients in the BTX group demonstrated improved gait function and partial denervation of the injected muscle. No serious adverse events were reported.
Eight infants with severe early infantile spinal muscular atrophy diagnosed by clinical presentat... more Eight infants with severe early infantile spinal muscular atrophy diagnosed by clinical presentation and muscle biopsy were studied. The extent of alterations in muscle histology, histochemistry, and ultrastructure did not reflect the relative severity of the clinical presentation or the course of the illness. In seven biopsies, ultrastructural studies demonstrated empty sleeves of basal lamina projecting from the surface of small myofibers. We conclude that severe infantile spinal muscular atrophy often results in myofiber atrophy similar to that found in other motor neuron diseases, and it is not solely a hypotrophic process. Muscle biopsy findings are important because they help to establish the diagnosis, but they do not help predict the severity of disease among infants with this condition.
A child with typical histopathologic changes of Leigh's subacute necrotizing encephalomye... more A child with typical histopathologic changes of Leigh's subacute necrotizing encephalomyelopathy presented with a chronic demyelinating neuropathy. During her 11-year course, she developed an unusual myopathy and cardiomyopathy in addition to many of the previously described manifestations of Leigh's disease. Despite an extensive evaluation, the biochemical basis of her condition was never identified. This case demonstrates another unique constellation of clinical alterations associated with subacute necrotizing encephalomyelopathy, and that chronic demyelinating neuropathy can be an important initial presentation of the disease.
We previously reported that patients with spinal muscular atrophy do not lose muscle strength ove... more We previously reported that patients with spinal muscular atrophy do not lose muscle strength over time as measured quantitatively. However, we noted that many patients with spinal muscular atrophy suffer from what they call fatigue. We wondered if we could measure fatigue during a single maximal voluntary contraction, whether fatigue might increase with time, independent of muscle strength, and whether increasing fatigue might correlate with loss of function in some patients. We measured fatigue during a single maximal voluntary contraction in a cohort of patients having spinal muscular atrophy using quantitative strength testing. We included only patients with spinal muscular atrophy aged 5 years or older, so they could follow instructions regarding muscle contraction, and who were followed for at least 2 years. Seventy-six children with spinal muscular atrophy and 24 untrained individuals, aged 5 to 57 years (mean, 16.8 years), were studied. There was no discernible abnormal fatigue in patients with spinal muscular atrophy compared to untrained controls using our methodology. Thus, spinal muscular atrophy may not be associated with fatiguability. Moreover, spinal muscular atrophy does not appear to cause progressive muscle fatigue with age or loss of function. It is possible that fatigue was undetectable by our methods. An alternative explanation is that what patients describe as fatigue may be caused by factors outside the neuromuscular system. Such factors may include chronic respiratory insufficiency with hypoventilation and carbon dioxide retention as well as chronic malnutrition and negative nitrogen balance.
Spinal muscular atrophy is a genetic disorder of the motor neurons that causes profound hypotonia... more Spinal muscular atrophy is a genetic disorder of the motor neurons that causes profound hypotonia, severe weakness, and often fatal restrictive lung disease. Patients with spinal muscular atrophy present a spectrum of disease from the most severe infantile-onset type, called Werdnig-Hoffmann disease (type 1), associated with a mortality rate of up to 90%, to a late-onset mild form (type 3), wherein patients remain independently ambulatory throughout adult life. Although many clinicians agree that patients with spinal muscular atrophy lose motor abilities with age, it is unknown whether progressive weakness occurs in all patients with spinal muscular atrophy. We present here results of the first prospective study of muscle strength in patients with spinal muscular atrophy. There was no loss in muscle strength as determined by a quantitative muscle test during the observation period. However, motor function diminished dramatically in some patients with spinal muscular atrophy. Explanations for this loss of function could not be determined from our data. Decrease in motor function could be caused by factors other than loss of strength. Therefore, it is not clear from our results whether spinal muscular atrophy is a neurodegenerative disease. We conclude that treatment trials in spinal muscular atrophy should be designed with consideration of the natural history of strength and motor function in this disorder.
Objective: The Quality Standards Subcommittee of the American Academy of Neurology and the Practi... more Objective: The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society develop practice parameters as strategies for patient management based on analysis of evidence. For this parameter the authors reviewed available evidence on the assessment of a child suspected of having cerebral palsy (CP), a nonprogressive disorder of posture or movement due to a lesion of the developing brain. Methods: Relevant literature was reviewed, abstracted, and classified. Recommendations were based on a four-tiered scheme of evidence classification. Results: CP is a common problem, occurring in about 2 to 2.5 per 1,000 live births. In order to establish that a brain abnormality exists in children with CP that may, in turn, suggest an etiology and prognosis, neuroimaging is recommended with MRI preferred to CT (Level A). Metabolic and genetic studies should not be routinely obtained in the evaluation of the child with CP (Level B). If the clinical history or findings on neuroimaging do not determine a specific structural abnormality or if there are additional and atypical features in the history or clinical examination, metabolic and genetic testing should be considered (Level C). Detection of a brain malformation in a child with CP warrants consideration of an underlying genetic or metabolic etiology. Because the incidence of cerebral infarction is high in children with hemiplegic CP, diagnostic testing for coagulation disorders should be considered (Level B). However, there is insufficient evidence at present to be precise as to what studies should be ordered. An EEG is not recommended unless there are features suggestive of epilepsy or a specific epileptic syndrome (Level A). Because children with CP may have associated deficits of mental retardation, ophthalmologic and hearing impairments, speech and language disorders, and oral-motor dysfunction, screening for these conditions should be part of the initial assessment (Level A). Conclusions: Neuroimaging results in children with CP are commonly abnormal and may help determine the etiology. Screening for associated conditions is warranted as part of the initial evaluation. NEUROLOGY 2004;62:851-863 Cerebral palsy (CP) can be defined as a disorder of aberrant control of movement and posture, appearing early in life secondary to a CNS lesion or dysfunction that is not the result of a recognized progressive or degenerative brain disease. 1 The brain abnormality may occur pre-, peri-, or postnatally. The diagnosis of CP always involves a motor deficit and the usual presenting complaint for which medical evaluation is sought is that the child is not reaching motor milestones at the appropriate chronological age. In most
McDonagh M, Helfand M, Carson S, Russman BS. Hyperbaric oxygen therapy for traumatic brain injury... more McDonagh M, Helfand M, Carson S, Russman BS. Hyperbaric oxygen therapy for traumatic brain injury: a systematic review of the evidence. Arch Phys Med Rehabil 2004;85:1198–204.
Cerebral palsy (CP) is a common problem, occurring in about 2 to 2.5 per 1000 live births. The di... more Cerebral palsy (CP) is a common problem, occurring in about 2 to 2.5 per 1000 live births. The diagnosis of CP is based upon a history of abnormal motor development that is not progressive coupled with an examination (e.g. hypertonicity, increased reflexes, clonus) "placing" the lesion in the brain. In order to establish that a brain abnormality exists in children with CP that may, in turn, suggest an etiology and prognosis, neuroimaging is recommended with magnetic resonance imaging preferred to computed tomography. Metabolic and genetic studies should be obtained if there are atypical features in the history or on the examination. Detection of a brain malformation in a child with CP might suggest an underlying genetic or metabolic etiology. As cerebral infarction is high in children with hemiplegic CP, diagnostic testing for coagulation disorders should be considered. However, there is insufficient evidence at present to be precise as to what studies should be ordered. A...
Objective: To evaluate the effects of corticosteroids on the lower extremity muscles in boys with... more Objective: To evaluate the effects of corticosteroids on the lower extremity muscles in boys with Duchenne muscular dystrophy (DMD) using MRI and magnetic resonance spectroscopy (MRS).
Physical Medicine and Rehabilitation Clinics of North America, 2012
Studies have shown promise in using various approaches of magnetic resonance imaging (MRI) and ma... more Studies have shown promise in using various approaches of magnetic resonance imaging (MRI) and magnetic resonance spectroscopy to evaluate skeletal muscle involvement in Duchenne muscular dystrophy. However, these studies have mainly been performed using a cross-sectional design, and the correlation of these MRI changes with disease progression and disease severity has not been fully elucidated. Overall, skeletal muscle MRI is a powerful and sensitive technique in the evaluation of muscle disease, and its use as a biomarker for disease progression or therapeutic response in clinical trials deserves further study.
Journal of pediatric rehabilitation medicine, 2011
For ambulatory children with cerebral palsy, the assessment of walking energy efficiency is utili... more For ambulatory children with cerebral palsy, the assessment of walking energy efficiency is utilized to determine functional changes following surgical, pharmacologic, or orthotic interventions. While the assessment of energy efficiency is considered a useful outcome tool, minimal information exists about the changes in energy efficiency over one year in children with cerebral palsy at different gross motor function classification system (GMFCS) levels and whether the patterns of change are similar to their able-bodied peers. The purpose of this study was to determine whether energy efficiency variables change similarly over one year in children with cerebral palsy by GMFCS level and whether they differ from their age-matched peers. Forty-five able-bodied children and 34 children with cerebral palsy, GMFCS levels I-III participated in the study. Energy efficiency variables were measured at baseline and at 12 months using a Cosmed K4b2. All subjects walked at their self-selected velo...
To validate a multicenter protocol that examines lower extremity skeletal muscles of children wit... more To validate a multicenter protocol that examines lower extremity skeletal muscles of children with Duchenne muscular dystrophy (DMD) by using magnetic resonance (MR) imaging and MR spectroscopy in terms of reproducibility of these measurements within and across centers. This HIPAA-compliant study was approved by the institutional review boards of all participating centers, and informed consent was obtained from each participant or a guardian. Standardized procedures with MR operator training and quality assurance assessments were implemented, and data were acquired at three centers by using different 3-T MR imaging instruments. Measures of maximal cross-sectional area (CSAmax), transverse relaxation time constant (T2), and lipid fraction were compared among centers in two-compartment coaxial phantoms and in two unaffected adult subjects who visited each center. Also, repeat MR measures were acquired twice on separate days in 30 boys with DMD (10 per center) and 10 unaffected boys. Coefficients of variation (CVs) were computed to examine the repeated-measure variabilities within and across centers. CSAmax, T2 from MR imaging and MR spectroscopy, and lipid fraction were consistent across centers in the phantom (CV, <3%) and in the adult subjects who traveled to each site (CV, 2%-7%). High day-to-day reproducibility in MR measures was observed in boys with DMD (CSAmax, CV = 3.7% [25th percentile, 1.3%; 75th percentile, 5.1%]; contractile area, CV = 4.2% [25th percentile, 0.8%; 75th percentile, 4.9%]; MR imaging T2, CV = 3.1% [25th percentile, 1.2%; 75th percentile, 4.7%]; MR spectroscopy T2, CV = 3.9% [25th percentile, 1.5%; 75th percentile, 5.1%]; and lipid fraction, CV = 4.7% [25th percentile, 1.0%; 75th percentile, 5.3%]). The MR protocol implemented in this multicenter study achieved highly reproducible measures of lower extremity muscles across centers and from day to day in ambulatory boys with DMD.
We have developed a protocol to evaluate, prospectively, patients with spinal mus-cular atrophy (... more We have developed a protocol to evaluate, prospectively, patients with spinal mus-cular atrophy (SMA) so that the natural course may be defined and treatment effica-cy measured. A fixed myometry system with a sensitivity of 0.5 kgs. of force was used to eliminate the subjectivity ...
To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in ... more To perform an evidence-based review of the safety and efficacy of botulinum neurotoxin (BoNT) in the treatment of movement disorders.
To evaluate the effect of SMN2 copy number on disease severity in spinal muscular atrophy (SMA), ... more To evaluate the effect of SMN2 copy number on disease severity in spinal muscular atrophy (SMA), we stratified 45 adult SMA patients based on SMN2 copy number (3 vs. 4 copies). Patients with 3 copies had an earlier age of onset and lower spinal muscular atrophy functional rating scale (SMAFRS) scores and were more likely to be non-ambulatory. There was, however, no difference between the groups in quantitative muscle strength or pulmonary function testing. Functional scale may be a more discriminating outcome measure for SMA clinical trials.
Cerebral palsy (CP) is characterized by aberrant control of movement or posture and appears early... more Cerebral palsy (CP) is characterized by aberrant control of movement or posture and appears early in life secondary to central nervous system damage. The symptoms of CP fall into four groups: symptoms due to loss of selective motor control; symptoms due to abnormal muscle tone; symptoms due to imbalance between muscle agonists and antagonists; and symptoms due to impaired balance. The goals of treatment are to maximize function and minimize the development of joint contracture and other secondary problems. Development of a treatment plan begins with the definition of objectives and consideration of the effects of growth and development on the patient's abilities. The role of botulinum toxin in CP treatment has grown in recent years. The patient who could benefit most from botulinum toxin treatment is one who is hypertonic and whose abnormal muscle tone is interfering with function, or who is expected to develop joint contracture with growth because of this abnormal tone. By altering this muscle tone, function can be enhanced or additional therapeutic modalities can be employed. Assessing treatment outcomes for BTX injection involves the same set of questions and measurements as for other types of treatments and depends on the careful definition of treatment objectives beforehand.
To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal musc... more To evaluate the efficacy of gabapentin in increasing muscle strength of patients with spinal muscular atrophy (SMA). Preclinical data in experimental models of motor neuron disease suggest a neuroprotective effect of gabapentin. Gabapentin (1200 mg), or placebo, was administered three times daily in a randomized, double-blind trial for 12 months. The primary outcome measure was the average percent change from baseline, based on the measurement of strength in four muscles (elbow flexion and hand grip bilaterally) for each patient. Drug efficacy was examined by comparing the percent change in strength for patients on drug vs. placebo. Secondary efficacy variables included: forced vital capacity (FVC), SMA functional rating scale (SMAFRS), and mini-Sickness Impact Profile (SIP). Eighty-four patients, with type II or III SMA, were enrolled at eight sites across the United States. There were no differences in baseline features. There was no difference between the placebo and drug groups in any outcome measure. This study demonstrates the feasibility of this trial design and provides data for the design of future clinical trials in SMA.
Increased gastrocnemius/soleus muscle tone in children with cerebral palsy may cause an equinus o... more Increased gastrocnemius/soleus muscle tone in children with cerebral palsy may cause an equinus of the ankle. Botulinum toxin type A (BTX), a neuromuscular blocking agent, reduces muscle tone in various neuromuscular disorders. The safety and short-term efficacy of BTX injections were evaluated in a prospective, 3-month, double-blind, randomized clinical trial involving 114 children with cerebral palsy and dynamic equinus foot deformity. Outcome was determined by observational gait analysis, ankle range-of-motion measurements, and quantification of muscle denervation by nerve conduction. Patients in the BTX group demonstrated improved gait function and partial denervation of the injected muscle. No serious adverse events were reported.
Eight infants with severe early infantile spinal muscular atrophy diagnosed by clinical presentat... more Eight infants with severe early infantile spinal muscular atrophy diagnosed by clinical presentation and muscle biopsy were studied. The extent of alterations in muscle histology, histochemistry, and ultrastructure did not reflect the relative severity of the clinical presentation or the course of the illness. In seven biopsies, ultrastructural studies demonstrated empty sleeves of basal lamina projecting from the surface of small myofibers. We conclude that severe infantile spinal muscular atrophy often results in myofiber atrophy similar to that found in other motor neuron diseases, and it is not solely a hypotrophic process. Muscle biopsy findings are important because they help to establish the diagnosis, but they do not help predict the severity of disease among infants with this condition.
A child with typical histopathologic changes of Leigh's subacute necrotizing encephalomye... more A child with typical histopathologic changes of Leigh's subacute necrotizing encephalomyelopathy presented with a chronic demyelinating neuropathy. During her 11-year course, she developed an unusual myopathy and cardiomyopathy in addition to many of the previously described manifestations of Leigh's disease. Despite an extensive evaluation, the biochemical basis of her condition was never identified. This case demonstrates another unique constellation of clinical alterations associated with subacute necrotizing encephalomyelopathy, and that chronic demyelinating neuropathy can be an important initial presentation of the disease.
We previously reported that patients with spinal muscular atrophy do not lose muscle strength ove... more We previously reported that patients with spinal muscular atrophy do not lose muscle strength over time as measured quantitatively. However, we noted that many patients with spinal muscular atrophy suffer from what they call fatigue. We wondered if we could measure fatigue during a single maximal voluntary contraction, whether fatigue might increase with time, independent of muscle strength, and whether increasing fatigue might correlate with loss of function in some patients. We measured fatigue during a single maximal voluntary contraction in a cohort of patients having spinal muscular atrophy using quantitative strength testing. We included only patients with spinal muscular atrophy aged 5 years or older, so they could follow instructions regarding muscle contraction, and who were followed for at least 2 years. Seventy-six children with spinal muscular atrophy and 24 untrained individuals, aged 5 to 57 years (mean, 16.8 years), were studied. There was no discernible abnormal fatigue in patients with spinal muscular atrophy compared to untrained controls using our methodology. Thus, spinal muscular atrophy may not be associated with fatiguability. Moreover, spinal muscular atrophy does not appear to cause progressive muscle fatigue with age or loss of function. It is possible that fatigue was undetectable by our methods. An alternative explanation is that what patients describe as fatigue may be caused by factors outside the neuromuscular system. Such factors may include chronic respiratory insufficiency with hypoventilation and carbon dioxide retention as well as chronic malnutrition and negative nitrogen balance.
Spinal muscular atrophy is a genetic disorder of the motor neurons that causes profound hypotonia... more Spinal muscular atrophy is a genetic disorder of the motor neurons that causes profound hypotonia, severe weakness, and often fatal restrictive lung disease. Patients with spinal muscular atrophy present a spectrum of disease from the most severe infantile-onset type, called Werdnig-Hoffmann disease (type 1), associated with a mortality rate of up to 90%, to a late-onset mild form (type 3), wherein patients remain independently ambulatory throughout adult life. Although many clinicians agree that patients with spinal muscular atrophy lose motor abilities with age, it is unknown whether progressive weakness occurs in all patients with spinal muscular atrophy. We present here results of the first prospective study of muscle strength in patients with spinal muscular atrophy. There was no loss in muscle strength as determined by a quantitative muscle test during the observation period. However, motor function diminished dramatically in some patients with spinal muscular atrophy. Explanations for this loss of function could not be determined from our data. Decrease in motor function could be caused by factors other than loss of strength. Therefore, it is not clear from our results whether spinal muscular atrophy is a neurodegenerative disease. We conclude that treatment trials in spinal muscular atrophy should be designed with consideration of the natural history of strength and motor function in this disorder.
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Papers by Barry Russman