摘要:

AbstractBy means of proton MRI, the spin‐lattice relaxation times (T1values) of pelvic and leg muscles were measured in Duchenne muscular dystrophy (DMD) patients and normal controls. The bound water fraction (BWF) was calculated from theT1value obtained. In normal children, theT1value decreased, and BWF increased with age. In DMD, theT1value rapidly decreased, from an abnormally high value in the early stages, with the progress of the disease. This reduction of theT1value in DMD was not the same for all muscles; it was most prominent in the gluteus maximus and least prominent in the sartorius and gracilis muscles. BWF was below normal in the early stages ofDMD. It is suggested that both regenerating and degenerating muscle fibers, together with the increased muscle water content, cause the highT1value and lowBWFin the early stages of DMD, whereas replacement of muscle by fat causes the decreasedT1value in the advanced stage

ISSN:0148-639X    

DOI:10.1002/mus.880110202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractWe report five patients with pure motor neuropathy characterized by multifocal weakness, muscle atrophy that was sometimes profound, cramps, and fasciculations with relatively preserved reflexes. The clinical picture led to an initial diagnosis of motor neuron disease in all cases, but nerve conduction studies revealed multifocal conduction block confined to motor axons and predominantly involving proximal nerve segments. Routine sensory nerve conduction studies, ascending compound nerve action potentials, and somatosensory evoked potentials were all normal even through nerve segments in which motor conduction was severely blocked. Onset of symptoms was insidious, and progression was indolent. In two cases, after many years of neuropathy, sensory abnormalities developed but remained clinically trivial. These unusual cases probably have the same pathogenesis as previously described patients with persistent multifocal conduction block. Distinction from motor neuron disease is critical, since chronic demyelinating neuropathy may respond to treatment.

ISSN:0148-639X    

DOI:10.1002/mus.880110203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA method is described for histological localization of carbonic anhydrase (CA) in sections of frozen human muscle using the rapid and inexpensive histochemical technique of Hansson. Results obtained in normal subjects indicate clearly that CA reactive fibers are of type 1. Similarly, abnormalities seen with CA in the muscle biopsy of a patient presenting with type 1 fiber hypotrophy and preponderance duplicated almost exactly those observed with the actinomyosine adenosine triphosphatase and the reduced nicotin‐amide adenine dinucleotide dehydrogenase reactions. Observations of grouped CA‐positive muscle fibers in a case of chronic neurogenic atrophy suggest that, like other enzymes, CA expression in muscle is under neurogenic cont

ISSN:0148-639X    

DOI:10.1002/mus.880110204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractA young woman on chronic corticosteroid treatment for systemic lupus erythematosus developed a myasthenia‐like syndrome 7 weeks after starting chloroquine therapy. Discontinuation of chloroquine allowed symptomatic and immunological remission within 6 months. Ocular symptoms reappeared following a second short course of chloroquine. A motor‐point biopsy revealed a vacuolar myopathy with membranous bodies in intramuscular nerves. We discuss the possible role of chloroquine in the pathogenesis of a myasthenia‐like syn

ISSN:0148-639X    

DOI:10.1002/mus.880110205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThere were two patients with severe dermatomyositis refractory to immunosuppressive therapy treated with 150 rad of total body irradiation given over a period of 5 weeks. Both patients responded promptly with minimal side‐effects and remain in partial remission 42 and 18 months after completion of the treatment. Total body irradiation is effective in some patients with dermatomyositis who are refractory to standard therap

ISSN:0148-639X    

DOI:10.1002/mus.880110206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractThe canine masticatory muscles contain a unique adult fiber type composition and different contractile protein isoforms than do adult limb muscles. To determine when these characteristic proteins are expressed during development, samples from canine temporalis (masticatory) and pectineus (limb) muscles were compared between 55 days gestation and 60 days postpartum by histochemical, biochemical, and immunocytochemical analysis. At 55 days gestation and 3 days postpartum, both muscles contained identical histochemical type 2C fibers, native myosin isozymes, and myosin light and heavy chains. By 14 days postpartum, fiber‐type expression in these muscles diverged, with resultant formation of type 1 and type 2M fibers in the temporalis muscle and type 1 and 2A fibers in the pectineus muscle. The distinctive myosin isoforms, light chains, and heavy chain of the temporalis muscle were also expressed 2 weeks postpartum. Based on the methods used in this study, we conclude that (1) the temporalis muscle develops from embryonic fibers that initially contain a myosin indistinguishable from embryonic limb muscle fibers, suggesting they have a common precursor, and (2) the myosin light chains and heavy chain unique to the temporalis muscle are initially expressed 2 weeks postpartu

ISSN:0148-639X    

DOI:10.1002/mus.880110207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractNumerous techniques that evaluate radial nerve conduction from the axilla or supraclavicular fossa to the elbow have been reported. A shortcoming of most protocols is determining the precise radial nerve length as it proceeds along the spiral groove. The present study dissected out and measured directly eight cadaver radial nerves from the axilla to the elbow. These values were compared with a new surface tape measurement technique from axilla to elbow across the bicep muscle, obstetrical calipers over this region, and a surface determination approximating the course of the radial nerve posteriorly in the spiral groove. The anterior surface tape‐measuring procedure compared most favorably with the actual anatomic length. Nerve conduction velocities were then calculated in 20 volunteers using all 3 techniques and compared with the median nerve in the arm. The anterior and posterior tape measurements yielded a conduction velocity of 72.5 ± 4.7 and 86.6 ± 7.0 m/s, respectively, whereas the caliper resulted in 65.7 ± 3.9 m/s. We conclude that proximal radial nerve length assessment employing an anterior tape measurement from axilla to elbow across the bicep musculature is precise and compares favorably with the actual anatomic length of the radial n

ISSN:0148-639X    

DOI:10.1002/mus.880110208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractTungsten microelectrodes of the type used for microneurography have been used to record motor units selectively from the first dorsal interosseous and abductor pollicis brevis muscles of normal subjects and patients who had had complete sections of the ulnar or median nerve. After determining the recruitment threshold and the twitch tension (spike‐triggered averaging) of a single unit, its nerve was stimulated at the wrist and the elbow using surface electrodes. By adjusting the position of the surface electrode and the stimulus intensity and by using computerized subtraction of responses just above and below threshold for a given unit, the same motor unit could often be identified in response to stimulation at both sites and its conduction velocity determined. The twitch tension and recruitment threshold of the motor units were closely correlated with the conduction velocity of the motor axons in normal subjects. Preliminary data from patients suggests that this method should be applicable to patients with a number of neuromuscular disorder

ISSN:0148-639X    

DOI:10.1002/mus.880110209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractLeft spinal accessory nerve palsy occurred in a young man when he quickly turned his head to the right while his shoulders were pulled down by heavy hand‐held objects. Electrophysiologic studies demonstrated partial axonotmesis of the spinal accessory nerve branches innervating the sternocleidomastoid and upper and middle trapezius and complete axonotmesis of spinal accessory branches to the lower trapezius. There was a separate, although functionally minor, cervical plexus innervation of the lower trapeziu

ISSN:0148-639X    

DOI:10.1002/mus.880110210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY

摘要:

AbstractComputer simulations of motor unit action potentials (MUAPs) as measured by a concentric needle (CN) electromyography (EMG) electrode in normal motor units (MUs) indicated that the MUAP amplitude is determined mainly by the proximity of the electrode to the closest muscle fiber. The area and duration of the simulated MUAPs were affected by all muscle fibers in front of the active recording surface but mainly by those that were less than 2 and 2.5 mm, respectively, from the active recording surface. The MUAP area was also affected by the proximity of the electrode to the closest muscle fiber. The number of phases of the simulated MUAPs increased when the dispersion of the arrival times of individual muscle fiber APs at the electrode was increased. Increased temporal dispersion of APs decreased the MUAP amplitude and area slightly but did not affect the MUAP duration. It is inferred that different features of the CN MUAP are determined by the distribution of muscle fibers within different portions of the MU territory and thus provide complementary information about the MU architecture.

ISSN:0148-639X    

DOI:10.1002/mus.880110211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1988

数据来源: WILEY