摘要:

AbstractMonoclonal gammopathy of undetermined significance (MGUS) is the most common paraproteinemia associated with polyneuropathy. Although the clinical and electrodiagnostic manifestations most resemble those of chronic inflarnmatory demyelinating polyneuropathy, some patients manifest a pure sensory neuropathy or neuronopathy. The M protein is usually IgM, and its concentration in serum is low. Nerve pathology from patients with demyelinating disease shows a reduction of large myelinated fibers and segmental demyelination with remyelination. In some cases, the M protein possesses antibody activity against components of the myelin sheath or axon. These neuropathies may respond to treatment with steroids, immunosuppressant agents, and plasma exchange.

ISSN:0148-639X    

DOI:10.1002/mus.880120102

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

年代:1989

数据来源: WILEY

摘要:

AbstractEvaluation of morphological alterations at the neuromuscular junction associated with sprouting or other pathological changes has been limited by the inability to visualize simultaneously the multiple cell types that make up a junction. A new combined stain for the concurrent demonstration of motor nerve terminals, cholinesterase, and Schwann cell myelin and other antigens at neuromuscular junctions using bromoindoxyl acetate dye staining for cholinesterase, silver‐gold impregnation for nerve terminals, and immunocytochemistry of selected antigens is described. The clarity of the stain permits graphic demonstration of the alteration of neuromuscular junction components during sprouting as well as other pathological change

ISSN:0148-639X    

DOI:10.1002/mus.880120103

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

年代:1989

数据来源: WILEY

摘要:

AbstractWe present a patient who developed the Lambert–Eaton myasthenic syndrome (LEMS) in association with systemic lupus erythematosus (SLE). Severe proximal weakness with electrodiagnostic evidence of LEMS developed over 2 days during an exacerbation of cutaneous manifestations (bullous pemphigoid) associated with SLE. Following an increase in the daily dose of prednisone, there was complete clinical restitution of strength within 2 weeks and a slower resolution of electrodiagnostic abnormalities over 6 months. Marked serologic abnormalities were present at the onset and showed improvement over 6–8 months. LEMS had been infrequently described in association with SLE. The immunologic features of both SLE and LEMS suggest a linkage between the two diseases in this patient. We hypothesize that increased antibodies associated with exacerbation of SLE cross reacted with the neuromuscular junction membrane to produce L

ISSN:0148-639X    

DOI:10.1002/mus.880120104

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

年代:1989

数据来源: WILEY

摘要:

AbstractRat leg muscles, rendered ischaemic 1 hour previously by ligation of the femoral artery, were submitted to 20 minutes exercise by electrical stimulation of the sciatic nerve.31P‐NMR spectroscopy was used to monitor the changes in high‐energy phosphate content of the muscles before, during, and after exercise. Fifteen of the 35 studied muscles evolved toward total necrosis, whereas the others showed signs of recovery over a 2–5‐hour postexercise period. Those muscles which did not subsequently recover contained significantly more inorganic phosphate (Pi) at rest (before exercise) than those which recovered. It is suggested that under acute ischaemic conditions the Pilevel at rest is correlated with the extent of blood flow restriction and can be used to predict the severity of the i

ISSN:0148-639X    

DOI:10.1002/mus.880120105

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

年代:1989

数据来源: WILEY

摘要:

AbstractWe describe a patient with a chronic, symmetric, monophasic, acquired, pure motor, demyelinating polyneuropathy. Electrodiagnostic studies showed the presence of multifocal conduction blocks in motor nerves at sites not prone to compression. A sural nerve biopsy was normal. The patient responded to immunosuppressive therapy and plasma exchange. We postulate that this disorder is an unusual variant of chronic inflammatory polyradiculoneuropathy.

ISSN:0148-639X    

DOI:10.1002/mus.880120106

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

年代:1989

数据来源: WILEY

摘要:

AbstractMuscle fibers from the lateral gastrocnemius muscles of five normal adult males were chemically skinned (sarcolemma disrupted) and each fiber was divided into two parts for histochemical determination of fiber type and calcium‐induced tension measurements. The calcium concentration associated with half‐maximal tension was 2.5 μMfor fast‐twitch and 1.3–1.4 μMfor slow‐twitch fibers. Fast‐oxidative‐glycolytic (type 2A) and fast‐glycolytic (type 2B) fibers had similar calcium sensitivities. Maximum tensions (kg/ cm2) were 2.24 for fast‐twitch and 2.19 for

ISSN:0148-639X    

DOI:10.1002/mus.880120107

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe diagnostic usefulness of single‐fiber electromyography (SFEMG) in the diagnosis of neuromuscular transmission disorders is well established. Increased jitter is one of the earliest indications of abnormality. In patients with severe weakness, tremor, or altered consciousness, performance of the study is difficult because of the degree of cooperation needed.We studied five patients and eight normal subjects with voluntary and stimulation SFEMG techniques. Our results, in search of normal values and changes with pathology, revealed differences in the values of jitter and the percentage of abnormal fibers between both techniques. The mean consecutive difference (MCD) is smaller (on average 30% less), and the percentage of abnormal fibers is lower (on average 10% less) with the stimulation technique. These differences are largely explained by the jitter measurement of one endplate with the stimulation technique versus two endplates with the voluntary. They may also be related, however, to the difference in motor unit populations sampled with each techniqu

ISSN:0148-639X    

DOI:10.1002/mus.880120108

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

年代:1989

数据来源: WILEY

摘要:

AbstractMuscle biopsies from 20 cases of spinal muscular atrophy (SMA), mostly diagnosed as Werdnig–Hoffmann (W–H) disease, were examined for myosin heavy chain (HC) composition. The fetal, fast, and slow heavy chains were characterized in the isolated muscle myosin, and in myosin of single, chemically skinned fibers, by electrophoresis in SDS‐6% polyacrylamide gels and by immunoblot techniques, using specific antibodies directed to each main type of myosin HC. The fiber distribution of myosin HC isozymes was further investigated on muscle cryostat sections by an indirect immunofluorescent technique. Fetal myosin HC was found to be expressed in a subpopulation of severely atrophic fibers, alone or together with the slow form of myosin HC. Triangulated fibers of intermediate size contained fetal and fast myosin or fast myosin alone. The hypertrophic fibers were characterized by the predominant expression of slow myosin HC; but in some of these fibers, also low amounts of HC fetal were found to be expressed. These findings are discussed in relation to developmental transitions of myosin heavy chains in human m

ISSN:0148-639X    

DOI:10.1002/mus.880120109

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

年代:1989

数据来源: WILEY

摘要:

AbstractMotor conduction studies were performed serially in 10 patients, ages 10–62 years, with clinical and electrophysiological criteria of hereditary motor and sensory neuropathy type 1 (HMSN‐1) over periods of 11–19 years. Median nerve conduction velocity (MNCV) and distal motor latency showed no significant change on serial studies. Mean median compound muscle action potential (CMAP) amplitude values, however, decreased 66% in 8 patients. Observed clinical progression in HMSN‐1, over prolonged periods of time, was not associated with MNCV slowing. However, CMAP amplitude reduction, reflecting progressive axonal loss, correlated with clinical deteri

ISSN:0148-639X    

DOI:10.1002/mus.880120110

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

年代:1989

数据来源: WILEY

摘要:

AbstractHalothane‐induced malignant hyperthermia (MH) is thought to result from a defect in the regulation of cytosolic calcium concentration in MH‐susceptible (MHS) skeletal muscle. Such a defect might be expected to alter the time course of contractile responses. To test this hypothesis, isolated intact cell bundles from external intercostal and common digital extensor muscles of normal and MHS pigs were stimulated electrically to elicit twitch and tetanic tension in the presence and absence of halothane (2.5%). Time intervals measured for both twitches and tetani were (1) the latent period between the stimulus and tension increase, (2) the time to peak tension, and (3) the half‐relaxation time. In contrast to previous reports, halothane had no effect on any measured time course parameter of twitches of either type of normal or MHS muscle, nor did the twitches of MHS and normal muscles differ in any parameter in the absence of halothane. However, the tetanic tension relaxation in both types of MHS muscle was markedly slowed by halothane, whereas in normal muscles there was little change. The slower rate of relaxation induced by halothane in MHS muscles suggests that halothane, either directly or indirectly, enhances the release or slows the removal of calcium in intact MHS muscles following maximal activation. This slowed tetanus relaxation could be of use in identification of MHS indivi

ISSN:0148-639X    

DOI:10.1002/mus.880120111

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

年代:1989

数据来源: WILEY