The role of physiatry in the management of neuromuscular disease

Patients with neuromuscular disease (NMD) are complex and pose a myriad of clinical problems. Management is best carried out by a team consisting of physicians, physical, occupational, and speech therapists, social workers, vocational counselors, and psychologists, among others. Physiatrists are well-suited to this type of multi-disciplinary care and can play a significant role in the care of these patients.

Comprehensive management of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive motor neuron disease that poses a myriad of clinical problems. Patients with ALS are best treated in a multidisciplinary setting involving physicians, clinical nursing specialists, and physical, occupational, speech, and respiratory therapists, as well as psychologists and social workers. Palliative and rehabilitative strategies may ease suffering, while new treatments provide hope for effective treatment of this disease.

Effects of aging and voluntary exercise on the function of dystrophic muscle from mdx mice

To understand how exercise affects the contractile function of dystrophic muscle, we examined the effect of long-term voluntary exercise on mdx mice and related these effects to our findings in sedentary aging mice. Although the mdx mouse is the genetic homolog for Duchenne muscular dystrophy, it does not demonstrate the same progression in limb muscle dysfunction as Duchenne muscular dystrophy as it ages. We postulated that the sedentary lifestyle of this animal plays an important role in its minimal phenotypic expression. To examine the effect of exercise, eight C57BL/10 (C57) and eight mdx mice were allowed to run ad libitum for one year. Forty sedentary mdx mice and 40 sedentary C57 from one month to 18 months of age were used as controls. Contractile characteristics of the extensor digitorum longus and soleus muscles and morphometric characteristics of the mice were examined. The mdx mice ran approximately 45% fewer kilometers per day than C57 mice. Long-term voluntary running had beneficial training effects on both the old mdx mice and their C57 controls. The exercise ameliorated the age-associated loss in tension production that was observed in the soleus of sedentary mdx and sedentary C57 mice. There was a 9% reduction in the fatigability of the extensor digitorum longus muscle of the old mdx mice after the exercise. Despite these improvements, the old mdx mice exhibited significant functional deficits compared with their C57 controls. Our hypothesis, that long-term voluntary exercise would have a beneficial training effect on control mice and a deleterious effect on mdx mice as they aged, was not supported by this study. This study shows that dystrophin-less muscles from sedentary mice display significant signs of muscle damage, yet can respond beneficially to low-level voluntary running in a manner similar to that of the C57 control.

Electromyographic and lower extremity short time to inversion recovery magnetic resonance imaging findings in lumbar radiculopathy

To determine if short TI (time to inversion) recovery (STIR) magnetic resonance imaging (MRI) is useful in assessing lower extremity (LE) denervation in subacute lumbar radiculopathy (LR), 25 subjects underwent lumbar spine MRI, LE STIR MRI and needle electromyography (EMG). In 23 (92%) subjects there was a positive correlation between LE STIR MRI and EMG (P < 0.009). Increased signal intensity on LE STIR MRI corresponds closely with spontaneous activity on EMG in subacute LR and may be a useful adjunct diagnostic tool.

Focal posterior interosseous neuropathy in the presence of hereditary motor and sensory neuropathy, type I

A 30-year-old male with hereditary motor and sensory neuropathy, type I (HMSN I), presented with asymmetric weakness of finger extension and radial deviation with left wrist extension, previously felt to be a manifestation of the peripheral neuropathy. Nerve conduction studies confirmed HMSN I; however, needle EMG revealed marked, ongoing axonal loss in muscles innervated by the left posterior interosseous nerve (PIN) only. At surgery there was focal fusiform swelling in the PIN at exit from the supinator muscle, compatible with localized hypertrophic neuropathy, which has not been reported before in HMSN I. A concomitant focal mononeuropathy should be considered in cases of hereditary neuropathy with marked asymmetry of weakness.

Base-catalyzed isomerism in elfamycin antibiotics. Structures of ganefromycins epsilon and epsilon 1

The structures of ganefromycins epsilon (2a) and epsilon 1 (2b) have been determined by spectroscopic techniques. The compounds are isomeric deoxygenated precursors of the parent antibiotics ganefromycins alpha and beta. The nature of the isomerism was determined by chemical interconversion experiments and spectroscope analysis to be a change in configuration at C-21. Evidence is provided for other cases of this type of isomerism in the elfamycin class of antibiotics.

Profiles of neuromuscular diseases. Myotonic dystrophy

Ninety-two individuals with myotonic dystrophy (MD) were evaluated prospectively over a 10-yr period and separated into two types, 75 noncongenital (NC-MD) and 17 congenital (C-MD) MD. Muscle weakness was relatively mild and similar in both types, 4.0 +/- 0.7 manual muscle test (MMT) scores for NC-MD and 3.8 +/- 0.7 in C-MD. However, weakness was progressive in the former, -0.36 MMT units per decade, and nonprogressive in C-MD. Weakness was usually generalized in both types, with no significant differences between upper and lower extremities or the proximal and distal muscles. Flexor and extensor differences were variable. Quantitative strength measurements showed a similar pattern but were more sensitive showing marked strength losses of 40-50% in muscle groups with MMT scores of four or more. There was a high frequency (47%) of relatively mild, nonprogressive scoliosis in C-MD, whereas spine deformity was unusual in NC-MD. Contractures, usually at the ankles, were also more common in C-MD. In NC-MD and C-MD, respectively, there was a low frequency of severe restrictive lung disease (14 and 20%) but a high percentage of significant electrocardiographic (ECG) abnormalities (75 and 81%), including conduction defects. There was a marked difference between the two types of MD in intellectual and cognitive function. Seventy-five percent of C-MD subjects showed impairment, frequently severe, compared with 35% impairment, usually mild, for NC-MD individuals. Functional evaluation was not markedly affected, but timed motor performance showed significant disability especially for individuals with C-MD.

Profiles of neuromuscular diseases. Limb-girdle syndromes

Sixty-six individuals with Limb-Girdle Syndrome (LGS) were evaluated over a 10-yr period and classified into three types: 19 severe autosomal recessive muscular dystrophy of childhood (ARMDC), alternatively referred to by some as SCARMD, 18 autosomal dominant late onset (ADLO), and 29 pelvifemoral (PF) individuals. ARMDC subjects showed the greatest weakness, 2.5 +/- 1.0, mean Manual Muscle Test (MMT) grade for all muscles combined, and the only significant progression of loss of strength, -0.59 MMT unit decline per decade. Strength loss in ADLO and PF types was about the same, 3.7 +/- 0.7 and 4.0 +/- 0.7 grades, respectively. Quantitative strength measurements in ADLO and PF types were more sensitive than MMTs, showing losses of 30-40% strength in muscle groups with MMT grades of 4 or higher. All three types showed greater proximal and lower extremity weakness but usually no difference between flexor and extensor strength. There was a high percentage (44%) of mild very slowly progressive scoliosis in ARMDC, but spine deformity was unusual in ADLO and PF (11%) LGS. Contractures were few, slowly progressive, and usually mild in severity in all types, although more frequent in ARMDC. There also was a low frequency of severe restrictive lung disease in all types (10%) but a high percentage of electrocardiogram abnormalities (62-73%). The most common electrocardiogram abnormalities were increased R/S ratio in V1 and infranodal conduction defects. Intellectual and cognitive functions were within normal limits. Mobility and extremity function reflected the strength differences between the ARMDC and other types of LGS. Eight-five percent of ARMDC individuals relied on a wheelchair for all or part of their mobility, and all were unable to complete timed motor performance tests within the 99th percentile range for controls.

Profiles of neuromuscular diseases. Becker's muscular dystrophy

Fifteen subjects with Becker's muscular dystrophy (BMD) were studied prospectively over a 10-yr period to provide a profile of impairment and disability. Proximal lower extremity musculature (particularly the hip and knee extensors), ankle dorsiflexors, and neck flexors showed significantly early weakness. Extensor muscle groups were weaker than flexor muscles at the elbow and knee. The mean manual muscle test (MMT) strength grade for all muscle groups combined was 3.7 +/- 0.8 MMT units. There was a slowly progressive decline in strength, only -0.31 MMT units per decade, and the decline was relatively equal in all muscle groups. There was not side dominance. Severe contractures did not appear to be a problem until after transition to a wheelchair, and scoliosis was rare. Restrictive lung disease occurred as a late complication in a small percentage of cases; however, maximal expiratory pressure was significantly reduced early in the disease. Only two individuals (19%) had severe restrictive lung disease and a history of significant respiratory complications. There was a slight but significant decline in forced vital capacity and maximal expiratory pressure with age and disease duration. The cardiomyopathy in BMD appeared to be disproportionately severe in some cases. Eleven individuals (73%) had abnormal electrocardiograms, and five (25%) had a history of significant cardiovascular complication, with no age or disease duration effect. Functional evaluations and timed motor performance tests showed only mild disability in most individuals. Mean intellectual and neuropsychologic function was within normal limits, but with a large variability in intelligence quotient scores. This report and others suggest a tremendous heterogeneity of severity among males with BMD.

Profiles of neuromuscular diseases. Hereditary motor and sensory neuropathy, types I and II

Data were collected prospectively for an impairment and disability profile for 86 hereditary motor and sensory neuropathy, types I and II (HMSN) subjects over a 10-yr period. Our data confirm that HMSN is a slowly progressive disorder that has a very heterogeneous phenotypical expression. The disorder was characterized primarily by diffuse muscle weakness with prominent distal atrophy. The mean manual muscle test (MMT) strength grade for all muscle groups combined was 3.9 +/- 0.7 MMT units. There was a slowly progressive decline in strength, only -0.15 MMT units per decade. Distal muscle groups were weaker than proximal muscles, and the decline in strength of the ankle muscles was greater than for the proximal muscles. There was no side dominance. Anthropometric data revealed that distal atrophy may be masked by subcutaneous fat in female subjects. On average, HMSN subjects produced 20-40% less force than normal controls, using quantitative isometric and isokinetic strength measures, even when MMT scores were normal. Pulmonary and cardiac abnormalities were uncommon, as were spine deformity and joint contractures. Only 1 individual had severe restrictive lung disease, and 12 (14%) had a history of significant respiratory complications with no age or disease duration effect. As with the other neuromuscular diseases, maximum expiratory pressure was more affected than forced vital capacity. Fourteen individuals (30%) had abnormal electrocardiograms, and six (7%) had a history of significant cardiovascular complications with no age or disease duration effect. Kyphosis was the major spine deformity. Cardiopulmonary responses to exercise testing were markedly abnormal, showing reduced aerobic capacity. Functional evaluations and timed motor performance tests showed only mild disability in most individuals. With timed motor performance testing muscle weakness translated to impaired motor performance skills. Overall, mean scores on intellectual function and neuropsychologic profiles were normal.

Profiles of neuromuscular diseases. Duchenne muscular dystrophy

One hundred and sixty-two patients with Duchenne muscular dystrophy (DMD) were followed over a 10-yr period to provide a profile of impairment and disability. The median height and weight of DMD boys were normally distributed before ages 9-10, but during the second decade height was markedly reduced, and weight was no longer normally distributed. Younger boys gained more weight than normals, whereas older individuals actually showed weight loss. Manual muscle test (MMT) measurements showed loss of strength in a fairly linear fashion from ages 5-13 yr, -0.25 MMT units per year. Upper extremity muscles were stronger than lower extremity muscles, proximal muscle groups were weaker than distal muscle groups, and extensor muscles were weaker than flexor muscles. There was no side dominance. There was a change in the rate of strength loss at 14-15 yr, and the decline slowed to only -0.06 MMT units per year. Although MMT and quantitative strength measurement profiles were similar, the latter were far more sensitive. In general, by the time strength declined to MMT grade 4, isometrically measured strength was 40-50% of normal control values. Joint contractures were rare before age 9, increased in frequency and severity with age, and were present in most individuals older than 13. Lower extremity contractures were strongly related to onset of wheelchair reliance, but there was no association between muscle imbalance around a joint. The prevalence of scoliosis increased between ages 11 and 16, with about 50% of the boys acquiring scoliosis between ages 12 and 15, corresponding to the onset of the adolescent growth spurt. Wheelchair reliance and scoliosis were both age-related. Percent predicted forced vital capacity declined at different yearly rates: ages 7-10, -0.3%; ages 10-20, -8.5%; after age 20, -6.2%. There was a direct relationship between percent predicted FVC and MMT scores. Decreased airway pressures, especially maximal expiratory pressure, appeared earlier than reductions in FVC but followed the same pattern. Thirty percent of the DMD boys had a history of respiratory complications, and the frequency increased with age. Spine deformity did not have a significant additive effect on the age-related decrement in pulmonary function. There was a high occurrence (79%) of abnormal electrocardiograms with age-related progression of some abnormalities, but only 30% of the patients had a history of cardiovascular complications. Functional level grades and timed motor performance measurements had a nonlinear relationship with strength and age.(ABSTRACT TRUNCATED AT 400 WORDS)

Profiles of neuromuscular diseases. Facioscapulohumeral muscular dystrophy

Data were collected prospectively over a 10-yr period from 53 subjects with facioscapulohumeral muscular dystrophy (FSHD) to provide a profile of impairment and disability. Manual muscle testing (MMT) indicated greater involvement of proximal musculature, although a subgroup demonstrated early weakness of the ankle dorsiflexors. Asymmetry of upper extremity musculature was noted, with greater weakness of selected dominant limb muscle groups. Weakness, in general, was relatively mild, with an overall mean MMT score of 3.7 units. The rate of strength loss was quite slowly progressive, a decline of only -0.22 MMT units per decade of age. An early age of onset was associated with greater likelihood of more severe and progressive weakness. Isometric and isokinetic quantitative strength testing revealed that all muscle groups were 36-68% weaker than a control population. Although nearly 50% of the subjects had vital capacity evidence of restrictive lung disease, only 13% had severe involvement, and only 22% had a history of pulmonary complications. There was no age or disease duration effect on pulmonary function measurements or complications. As with the other neuromuscular diseases, maximal expiratory pressure measurements were more sensitive than other pulmonary function tests. Abnormal electrocardiogram findings were rare and minor and not related to overt cardiac disease. Contractures were rare and mild. Thirty-five percent of the patients had spine deformity; however, most had hyperlordosis. Intellectual function was normal, and there were few abnormalities on personality tests. Functional testing demonstrated wide variation in disability with FSHD, but motor weakness uniformly translated into impaired motor performance skills. This profile demonstrates the clinical heterogeneity of FSHD.

Profiles of neuromuscular diseases. Spinal muscular atrophy

Forty-five individuals with spinal muscular atrophy (SMA) types II and III were evaluated prospectively over a 10-yr period to develop an impairment and disability profile. SMA II subjects showed marked weakness and progressive decline of strength. Mean manual muscle test (MMT) score for all muscles combined was 2.3 +/- 0.6, with a decline in strength of -0.24 MMT units per decade. SMA III individuals had a relatively static or very slowly progressive course and were far stronger. Mean MMT score for all muscles combined was 3.8 +/- 0.7, and the decline in strength per decade was not significant. In both types proximal weakness was greater than distal, but there was greater involvement of the lower extremities and the extensor muscle groups only in SMA II. Contractures, progressive scoliosis, and restrictive lung disease (RLD) were present in most of the SMA II individuals, but these complications were rare in SMA III. Maximal expiratory pressures were affected earlier and to a greater degree than vital capacity. Seventy-eight percent of those with SMA II had scoliosis with a mean Cobb angle of the primary curve of 62 +/- 37 degrees. Forty-one percent had severe RLD, and 17% had moderate RLD. In both types, 63% had abnormal electrocardiograms although most had minor findings. Timed motor performance and functional evaluations indicated that muscle weakness translated to substantial disability in both SMA II and III, with more severe impairment noted in SMA II. Neither type was associated with abnormal means scores on intellectual and neuropsychologic test batteries.

Profiles of neuromuscular diseases. Design of the protocol

The purpose of this 10-yr investigation was to develop comprehensive impairment and disability profiles of the clinical characteristics of seven neuromuscular diseases: spinal muscular atrophy, hereditary motor sensory neuropathy, Duchenne muscular dystrophy, Becker's muscular dystrophy, facioscapulohumeral muscular dystrophy, limb-girdle syndrome, and myotonic dystrophy. Based on the World Health Organization's classification of disablement, as applied to neuromuscular diseases, impairment was evaluated by measurements of strength, range of motion, spine deformity, cardiac and pulmonary function, and intellectual capacity. Disability was evaluated by measures of mobility and upper extremity function, cardiopulmonary adaptations, cardiac and pulmonary complications, and psychosocial adjustment.

Effect of voluntary wheel-running exercise on muscles of the mdx mouse

The purpose of this study is to determine whether dystrophin-deficient mdx mice are more susceptible to muscle injury and functional impairment than normal C57 mice when allowed to exercise voluntarily on mouse wheels. The mdx mice were significantly impaired when compared to controls as shown by functional, contractile and morphometric responses. The distance young mdx mice ran was 67-78% of young C57 mice, while adult mdx mice ran 31-48% of adult controls. After exercise the slow, oxidative soleus of young and adult mdx mice exhibited hypertrophy with no changes in strength or fatiguability, while the young C57 mice increased strength and the adults became less fatiguable. In the adult mdx mice the fast EDL, which is primarily glycolytic, exhibits slight hypertrophy with a loss of strength, while the young exhibit no changes. These results indicate that the mdx mouse adapts differently than the C57 mouse to even moderate exercise.

Isolation, characterization and structure of a new allenic polyine antibiotic produced by fungus LL-07F275

Antibiotic 07F275 (1), produced by submerged fermentations of fungal culture LL-07F275, was isolated and characterized despite its inherent instability. Its UV spectrum was identical with that of nemotin, a member of the allenic polyacetylene family, but a molecular weight of 218 daltons indicated a new compound. Structure 1 was determined on the basis of spectroscopic evidence, particularly NMR. Since 1 is a thirteen carbon-containing allenic diyne, it is closely related to mycomycin.

Isolated femoral mononeuropathy to the vastus lateralis: EMG and MRI findings

A 16-year-old female track athlete experienced sudden onset of right anterolateral thigh pain, initially thought to be cramping. After 2 months of continued postexercise pain she sought medical evaluation. A 3-cm thigh circumference discrepancy was noted on physical exam. She was referred for electromyography (EMG) and magnetic resonance imaging (MRI) studies. Femoral and screening nerve conduction studies were normal. Needle EMG revealed acute neuropathic changes confined to the right vastus lateralis only. These findings were confirmed by MRI, including short T1 inversion recovery (STIR) sequences. All other medical work-up was normal, including lumbar and pelvic MRI, and complete serologic studies. This case represents a unique presentation of an idiopathic femoral mononeuropathy isolated to the vastus lateralis only, which has not been previously reported. The highly unusual anatomical presentation of this case illustrates the emerging complementary usefulness of EMG and MRI in delineating neuromuscular pathology.

Martinomycin, a new polyether antibiotic produced by Streptomyces salvialis. I. Taxonomy, fermentation and biological activity

Actinomycete culture LL-D37187 has been found to produce the new polyether antibiotic martinomycin. Taxonomic studies, including morphological, physiological, and cell wall chemistry analyses, revealed that culture LL-D37187 is a novel streptomycete species, and the proposed name is Streptomyces salvialis. Martinomycin exhibits activity against the Southern Army Worm (Spodoptera eridania) and Gram-positive bacteria.

The use of fluorescent dextrans as a marker of sarcolemmal injury

We investigated the use of intravenously injected fluorescent dextran molecules (FDx) as a histological marker of sarcolemmal injury. Using fluorescent microscopy, uptake of FDx (average MW 10 kD) was assessed in sections of quadriceps muscles from three models: 1) normal (C57BL/10SnJ) mice, 2) normal mice run downhill (0, 3, and 7 days post exercise), and 3) non-exercised mdx (dystrophin-deficient) mice. These were compared to serial sections stained with hematoxylin and eosin (H&E). In control muscles, strong fluorescence was seen between fibers (intercellular). Intracellular FDx was observed within cells of the quadriceps from normal mice run downhill at days 0 and 3 post exercise, but not at day 7. On H&E staining, muscle pathology was not observed until day 3, with regeneration by day 7. Intracellular FDx was also observed within mdx muscles, particularly in fibers that appeared pre-necrotic on H&E stained sections. FDx appears to be useful as a histological marker of changes in sarcolemmal integrity associated with muscle injury from eccentric exercise or muscle disease.