摘要:

AbstractUneqivocally positive edrophonium tests, both clinically and electrophysiologically, were observed in a classic case of the Lambert–Eaton myasthenic syndrome. A review of the literature revealed that a positive edrophonium response has been reported in a majority of cases of myasthenia gravis (MG) and overlap myasthenic syndrome and in some cases of the Lambert–Eaton myasthenic syndrome, botulism, congenital myasthenic syndrome, drug‐induced myasthenic syndrome, the Guillain‐Barre syndrome, and amyotrophic lateral sclerosis. From this, we conclude that anunequivocally positive edrophonium test alone is not necessarily diagnostic of MG and that the diagnosis of MG should be based on the clinical features together with edrophonium‐responsiveness and other laboratory

ISSN:0148-639X    

DOI:10.1002/mus.880130302

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

年代:1990

数据来源: WILEY

摘要:

AbstractFive members of the same family, along three generations, presented with hypertrophic cardiomyopathy. Neurological examination, muscle strength, electromyography, and serum creatine kinase were normal. Skeletal muscle biopsy showed abnormal lipid accumulation and carnitine deficiency. In three patients the cardiac symptoms and echocardiographic findings improved after treatment withL‐carnitine, 3–4 g daily, and a long‐chain fattyacid‐fr

ISSN:0148-639X    

DOI:10.1002/mus.880130303

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

年代:1990

数据来源: WILEY

摘要:

AbstractImmunologic syndromes are associated with hepatitis B viral (HBV) infection. However, mononeuropathy multiplex (MM), a syndrome in which immune factors may play a role, is rare in acute HBV infection. Few cases of MM associated with HBV infection have been reported. We report a case of acute HBV infection in which MM involving the median, ulnar and lateral femoral cutaneous nerves complicated the course of the acute illness. Skin biopsy demonstrated vasculitic changes which may accompany the immunologic factors in HBV infection.

ISSN:0148-639X    

DOI:10.1002/mus.880130304

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe reported anabolic action of some β2agonists may have clinical applications in certain muscle wasting states. Administration of clenbuterol (2mg/kg diet for 14 days) to rats resulted in a limited degree of hypertrophy of normal muscles; the effect was more pronounced on fast‐twitch muscles than on slow‐twitch muscles. The anabolic effect was greatest in denervated muscles, where it was significantly more effective on the slow‐twitch type. Clenbuterol significantly improved the contractile properties of denervated slow‐twitch muscle, reverting them toward normal, but had little effect on contractile properties of denervated fast‐twitch muscle. Such differential effects of clenbuterol must be taken into consideration in the evaluation of any future human interven

ISSN:0148-639X    

DOI:10.1002/mus.880130305

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

年代:1990

数据来源: WILEY

摘要:

AbstractTwo patients developed acute sensorimotor polyneuropathy after intoxication with lithium carbonate. Nerve conduction studies, electromyography, and sural nerve biopsy proved it to be an axonal neuropathy. Recovery of muscle strength, reflexes, and sensory function started weeks after discontinuation of lithium therapy. One patient fully recovered within a year. In the literature we found nine other cases of lithium polyneuropathy.

ISSN:0148-639X    

DOI:10.1002/mus.880130306

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

年代:1990

数据来源: WILEY

摘要:

AbstractTwo‐dimensional gel electrophoresis (2DE) was used to compare the protein composition of human muscle biopsies that were shown by histochemical staining to be deficient in either type 1 or type 2 fibers. Distinct quantitative differences were found in the myofibrillar protein composition of muscle from a 43‐year‐old woman with proximal limb weakness that showed almost total absence of type 1 fibers and muscle from a 2.5‐year‐ girl with congenital myopathy in which there was severe lack of type 2 fibers. These data indicate that human type 1 and type 2 muscle fibers express distinct isoforms of myosin light chains and α

ISSN:0148-639X    

DOI:10.1002/mus.880130307

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

年代:1990

数据来源: WILEY

摘要:

AbstractA 40‐year‐old woman presented with progressive lower leg pain and spontaneous toe movement. The EMG showed a posterior tibial nerve mononeuropathy and continuous myokymic discharges in posterior tibial‐innervated muscles. The MRI revealed a markedly enlarged posterior tibial nerve. Toe movements and myokymia were unaffected by the proximal transection of the lesion but ceased abruptly when the distal end of the fusiform “tumor” was resected, suggesting that spontaneous electrical foci may have been located along the nerve lesion. The markedly enlarged nerve segment contained edematous, swollen fascicles with marked Schwann cell onion‐bulb lesions and angiocentric, lymphocytic, and lymphofollicular infiltration. This nerve lesion is an example of a newly recognized entity called hypertrophic m

ISSN:0148-639X    

DOI:10.1002/mus.880130308

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe usefulness of long fiber segments for the study of the pathophysiology of human skeletal muscle was evaluated. Immediately after biopsy, the fiber segments were depolarized. Within 3 hours the cut ends resealed, and if the segments were ≥ ‐ 2.5 cm long they regained normal resting membrane potentials (i.e., negative to −80 mV). Miniture endplate potentials, endplate potentials, action potentials, the current‐voltage relationship, and the resting intracellular Ca2+concentration of the resealed fiber segments were similar to those in fibers that were intact from tendon to tenon. In addition, specific properties of intact fibers obtained from patients with various neuromuscular diseases were preserved in the resealed fiber segments prepared from the same patients or patients with the same diseases. These segments are easily obtained as a routine muscle biopsy performed under local anesthesia; they provide valuable preparations for the study of the pathophysiology of human skeletal muscle as well as for in vitro pharmacologica

ISSN:0148-639X    

DOI:10.1002/mus.880130309

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

年代:1990

数据来源: WILEY

摘要:

AbstractOne hundred four normal subjects ranging in age from 17 to 77 years and in height from 115 to 203 cm underwent nerve conduction studies of sural, peroneal, tibial, and median nerves. Foot temperature was measured in each patient. A strong inverse correlation was found between height and sural (r = −0.7104), peroneal (r = −0.6842), and tibial (r = −0.5044) conduction velocities. These correlations were significant at the P<0.001 level. Median conduction velocity was not correlated with height. Height was correlated with the distal latencies of all nerves studied (sural r = 0.6518), peroneal r = 0.4583, tibial r = 0.7217, median (r = 0.5440). These correlations were significant at the P<0.001 level. Age was inversely correlated with both tibial (r = −0.4071) and median (r = −0.3464) nerve conduction velocities but not with sural and peroneal conductions. There were no correlations between distal latencies and age. If the variation in conduction velocity accounted for by the linear relationship with height was removed, then age would be inversely correlated to all conduction velocity measurements with the exception of the sural. Temperature is inversely correlated with the sural (r = −0.2233), peroneal (r = −0.2102), and tibial (r = −0.2710) distal latencies. In all instances, the effects of age and temperature were minor determinants when compared with the effects of height. Diagnostic conclusions made from nerve conduction data without correcting for height may be invalid in patients taller and shorter than normal. We believe that using normal values for nerve conductions that do not take height into account can no longer be considered an acceptable stand

ISSN:0148-639X    

DOI:10.1002/mus.880130310

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe correlation between electrical and mechanical after‐activity was studied in resealed fiber segments from patients with recessive generalized myotonia (Becker) and in intact fibers from normal muscles which were bathed in 9‐anthracene carboxylic acid. The tests were performed in vitro on small bundles of 100 fibers or less. Electromyographic activity and contractile force were measured simultaneously. The relaxation of rested‐state twitches and tetani was slowed and accompanied by after‐activity in both types of preparations. Often random activity was recorded. In all cases, the contractile force was highly correlated with the electromyographic signs of myotonia. These observations support the hypothesis that electrical afteractivity is fully responsible for the slowed relaxation in recessive generalized m

ISSN:0148-639X    

DOI:10.1002/mus.880130311

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

年代:1990

数据来源: WILEY