摘要:

AbstractAlcoholic polyneuropathy is a common disorder, characterized by nonspecific clinical, electromyographic, and pathologic features. Nerve conduction studies and needle electromyography disclose findings consistent with a generalized, sensorimotor, axonal degenerative, polyneuropathy. Alcoholic polyneuropathy may be suspected when such findings occur in the setting of long‐standing alcoholism and malnutrition. The lack of specific diagnostic criteria for alcoholic polyneuropathy requires that other potential etiologies be excluded before that diagnosis is made. The institution of a nutritionally‐balanced diet constitutes the principal therapy for alcoholic polyneuropathy, however, significant improvement following such therapy is not frequently s

ISSN:0148-639X    

DOI:10.1002/mus.880080302

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

年代:1985

数据来源: WILEY

摘要:

AbstractAcoustic myography is the recording of sounds produced by contracting muscle. These sounds become louder with increasing force of contraction. We have compared muscle sounds with surface EMG to monitor the dissociation of electrical from mechanical events (presumably, the loss of excitation–contraction coupling) which occur with motor unit fatigue. Acoustic signals were amplified using a standard phonocardiograph, recorded on FM magnetic tape, and digitally analyzed. Muscles were examined at rest, with intermittent contractions, and with sustained contractions. We found that with fatigue, the acoustic amplitude decayed, but the surface EMG amplitude did not. With decreased effort, however, the acoustic and the surface EMG amplitudes declined simultaneously. By simultaneously recording acoustic signals and needle EMG, individual motor units were resolved acoustically in two muscles with decreased numbers of motor units and increased motor unit size. Fasciculations also produced acoustic signals, although no acoustic signal has yet been found that correlates with fibrillations. Analysis of acoustic signals from muscle provides a noninvasive method for monitoring motor unit fatigue in vivo. It may also be useful in distinguishing muscle fatigue from decreased volitio

ISSN:0148-639X    

DOI:10.1002/mus.880080303

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe histochemical features of muscle injury and repair were examined in an experimental form of acute alcoholic myopathy in the rat. Typical features of rhabclomyolysis were found, which were indicated by scattered muscle fiber necrosis followed by sequential phases of fiber degeneration, phagocytosis, and regeneration. Nests of small, regenerated, or split fibers remained 2 months after the episode of acute myopathy. Vulnerability of type 1 fibers to alcohol‐induced muscle injury was evident by selective involvement of muscles with type 1 fiber predominance and by the fact that regenerating fibers were virtually exclusively type 1. The histologic features of myopathy in this model closely parallel those in human acute alcoholic myopath

ISSN:0148-639X    

DOI:10.1002/mus.880080304

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe electrophysiologic differences between chronic acquired demyelinative neuropathy and the demyelinative form of Charcot‐Marie‐Tooth disease have recently been reported. The present report extends these observations to include the genetically determined demyelinating neuropathies seen in metachromatic leukodystrophy, Krabbe's leukodystrophy, and Cockayne's syndrome. The electrophysiologic features of metachromatic leukodystrophy (five patients), Krabbe's (four patients), and Cockayne's syndrome (three patients) were all similar. There was uniform slowing of conduction (both in different nerves and in different nerve segments), and conduction block was not seen. These findings are consistent with a uniform degree of demyelination in multiple nerves and throughout the entire length of individual axons. Thus, uniform slowing of nerve conduction constitutes strong evidence for a familial demyelinative neuropathy, as opposed to the multifocal slowing seen in acute and chronic acquired demyelinative neuropa

ISSN:0148-639X    

DOI:10.1002/mus.880080305

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

年代:1985

数据来源: WILEY

摘要:

AbstractThis study demonstrates age‐related changes in fiber type, distribution, and diameter that suggest that the diaphragm does not attain a static pattern of fiber type in adults. Furthermore, the progressive increase in the FG fiber diameters may be of importance in the interpretation of physiologic and biochemical parameters measured in the diaphragm muscle of animals of different age group

ISSN:0148-639X    

DOI:10.1002/mus.880080306

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

年代:1985

数据来源: WILEY

摘要:

AbstractThe time course and pattern of the initiation of satellite cell mitoses was studied following a crush injury of the distal third of the 30‐day‐old rat extensor digitorum longus, a muscle in which myofibers run the entire length of the belly. Satellite cell mitotic activity was monitored using autoradiography after injection of3H‐thymidine. Satellite cell labeling rose above control values by 15 hours post injury at the injured site and by 20 hours in the middle third or adjacent undamaged portion of the muscle. Labeling decreased in the proximal third of the muscle, so that by 25 hours post injury, a gradient of labeling was established along the muscle length. Electron microscopy (EM) quantitation showed that the reduced labeling in the proximal third resulted from a reduction in satellite cell numbers. The results suggest that mitotic activity of satelite cells after localized injury occurs mainly at or near the site of injury, but that many of the dividing cells have migrated from undamaged areas distant from the lesion

ISSN:0148-639X    

DOI:10.1002/mus.880080307

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

年代:1985

数据来源: WILEY

摘要:

AbstractFour patients with refractory or poorly responsive chronic progressive demyelinating polyneuropathy (CPDP) were treated with total lymphoid irradiation (total dose, 2000 rad) in an uncontrolled feasibility study. All patients had previously failed conventional therapy for CPDP, as well as other unconventional treatments. During a follow‐up period of 7 to 12 months after total lymphoid irradiation, there was a profound and sustained suppression of the absolute lymphocyte count and in vitro lymphocyte function, as well as an increase in the ratio of Leu‐2 (suppressor/cytotoxic subset) to Leu‐3 (helper/inducer subset) T cells in the blood. Three of the four patients demonstrated improvement in distal muscle strength, and this was associated with increased functional capabilities in two patients. In contrast, no clinical improvement in sensation was noted in any patient. Nerve conduction studies showed patchy improvement in three patients. The results of this preliminary uncontrolled study indicate that radiotherapy deserves further study in the treatment of

ISSN:0148-639X    

DOI:10.1002/mus.880080308

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

年代:1985

数据来源: WILEY

摘要:

AbstractIn polymyositis (PM), neither the precise target nor the mechanism of the attack against skeletal muscle have yet been defined. In this study, we report evidence of a pathologic process involving a membrane component of muscle, acetylcholine receptors (AChRs). Our results show that PM patients have significantly reduced AChRs at neuromuscular junctions, averaging 55% below control values (P<0.001). Incubation of cultured mammalian muscle cells with sera from PM patients significantly reduced (P<0.005) the number of surface AChRs and increased their rate of degradation in 7/8 cases (P<0.005). Similar effects were produced by purified lgG from PM patients. These results demonstrate the presence in PM patients of circulating lgG with functional effects on a component of the surface membrane of skeletal muscle. They suggest that PM and myasthenia gravis may have important features in common.

ISSN:0148-639X    

DOI:10.1002/mus.880080309

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

年代:1985

数据来源: WILEY

摘要:

AbstractIntramuscular nerves were obtained at autopsy from five adult controls and were morphometrically analyzed. The number of myelinated fibers was directly proportional to the diameter of the fascicles. The fascicles were grouped into six sizes according to diameter. For each group, the normal range of distribution of the number of myelinated fibers could be estimated. Fiber size distribution and myelinated fiber density were also calculated. A unimodal fiber size distribution was observed for the small fascicles (<50m̈m in diameter), and bimodal pattern was observed for the large fascicles. Total myelinated fiber density was high in the small fascicles, and it decreased as the fascicles became larger in size, approaching the values observed In the large peripheral nerves. This study will be helpful in objectively evaluating morphological changes of intramuscular nerves in adult neuromuscular disorders

ISSN:0148-639X    

DOI:10.1002/mus.880080310

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

年代:1985

数据来源: WILEY

摘要:

AbstractWe measured the number of acetylcholine receptors (AChRs) at neuromuscular junctions (NMJs) in motor point biopsies from 76 patients with myasthenia gravis (MG) and 49 control subjects, using an α‐bungarotoxin binding technique. The mean number of AChRs/NMJ was significantly lower (P<0.001) in muscles of MG patients (deltoid 0.7 ± 0.1 × 107) than in controls (2.1 × 0.2 × 107). None of the control muscles had fewer than 0.9 × 107AChRs/NMJ, and 75% of MG muscles were below that level. Conversely, 88% of controls had 1.5% × 107or more AChRs/NMJ, whereas only one of the MG muscles (2.5%) was at or above that level. The reduction of AChRs correlated approximately with the clinical severity of weakness (P<0.02). Patients with focal weakness had reduced numbers of AChRs/NMJ in clinically strong muscles. The only other condition in which junctional AChRs were reduced was polyositis. These findings in a large sample of patients confirm the reduction of junctional AChRs in MG, the relationship of available junctional AChRs to clinical manifestations, and the systemic nature of the disorder even in cases with focal weakness. Measurement of AChRs can be useful diagnostically in situations where other tests are inco

ISSN:0148-639X    

DOI:10.1002/mus.880080311

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

年代:1985

数据来源: WILEY