ISSN:0148-639X    

DOI:10.1002/mus.880150102

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe autonomic nervous system is affected, in most peripheral neuropathies. but only in a small number of conditions, such as diabetes, amyloidosis, Guillain‐Barré syndrome, porphyria, and familiar dysautonomia, is autonomic dysfunction of clinical importance. The pathological changes in the peripheral autonomic nervous system are similar to those in the peripheral somatic nerves. Autonomic disturbances are most likely to occur when there is acute demyelination or damage to small myelinated and unmyelinated fibers. Autonomic investigations should include tests of both sympathetic and parasympathetic function. Treatment consists of management of the underlying cause of peripheral neuropathy, physical and pharmacological measur

ISSN:0148-639X    

DOI:10.1002/mus.880150103

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

年代:1992

数据来源: WILEY

摘要:

AbstractDesmin is a normal constituent of skeletal muscle fibers; vimentin is contained in myoblasts and connective tissue cells. The intracellular localization of both intermediate filament proteins in regenerating rat muscles was investigated by immunohisto‐ and immunocytochemistry. Necrosis was induced by hot Ringer solution. Desmin and vimentin were diffusely distributed in myoblasts and young myotubes. Both proteins became arranged in a sarcomeric fashion between the Z‐lines when the sarcomeres got into register. Desmin reactivity persisted, but vimentin disappeared after about 2 weeks. Traces were found for up to 4 weeks. This observation is in contrast to findings in fetal and cultured muscles in which several authors did not find expression of vimentin after myoblast fusion. The presence of vimentin may well be a useful marker for regenerated muscle fibers in muscle biopsies from patients with neuromuscular disord

ISSN:0148-639X    

DOI:10.1002/mus.880150104

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

年代:1992

数据来源: WILEY

摘要:

AbstractCentral delay (CD) changes in the soleus H reflex pathway, as demonstrated by variations in the time interval between afferent (P1) and efferent (P2) neurographic volleys underlying the reflex response, were assessed in a group of normal subjects, both during the steady state and after homosynaptic spatial summation of afferent impulses. The maximal range of CD changes, regardless of whether “spontaneous” or provoked, showed significant interindividual differences whose size was positively related to the Hmax/Mmax ratio, provided that the extension of the subliminal fringe was suitably normalized. Comparatively similar variations in amplitude of the reflex motoneuronal discharge under different experimental conditions can be associated with different CD changes. Indeed, “spontaneous” CD fluctuations occurring during the steady state were consistently greater than CD reductions provoked by spatial summation, the gap size being negatively related to the Hmax/Mma

ISSN:0148-639X    

DOI:10.1002/mus.880150105

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

年代:1992

数据来源: WILEY

摘要:

AbstractSpinal isolation (SI), i.e., the isolation of the lumbar spinal cord via a rostral and a caudal cord transection and bilateral dorsal rhizotomy, was used to determine the effects of chronic (6 months) inactivity on the size and metabolic properties of fibers in the cat soleus. Fibers were classified as dark or light, based on their staining reactions to myosin ATPase, alkaline preincubation, and immunohistochemically as expressing fast and/or slow myosin heavy chains (MHC). Succinate dehydrogenase (SDH) and α‐glycerophosphate dehydrogenase (GPD) activities were assessed histochemically. Following SI, both the light and the dark ATPase fibers in the SI cats were significantly smaller than the light ATPase fibers in the controls. Normally 100% of the fibers were light ATPase and reacted exclusively with the slow antibody. After SI, ∼45% of the fibers were dark ATPase fibers, many reacting with both fast and slow MHC antibodies. The total amount and concentration of GPD were higher in the light and dark ATPase fibers in SI compared with light ATPase fibers in controls. In contrast, although the total amount of SDH per fiber was decreased, reflecting the decrease in fiber size, the mean SDH concentration per fiber was unchanged following SI. These data indicate that there is a close coordination in the regulation of GPD activity and the type of myosin. SDH activity, on the other hand, appears to be resistant to decreased levels of activity and unloading, i.e., there seems to be a minimum level of oxidative potential in the soleus that is independent of activity level. Fiber sizes, however, are very sensitive to less‐than‐normal amounts of neuromuscular activity and/or

ISSN:0148-639X    

DOI:10.1002/mus.880150106

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

年代:1992

数据来源: WILEY

摘要:

AbstractA functional disorder of facial muscle activity commonly occurs in patients after recovery from Bell's palsy with axonal degeneration. The postparalytic facial dysfunction is probably related to the aberrant growing of regenerating axons. although other theories such as ephaptic transmission, spontaneous generation of impulses, and enhancement of motoneuron excitability should also be considered. In this work, we have carried out a comparative electrophysiological study of both sides of the face in 23 patients who had recovered from a unilateral Bell's palsy with axonal degeneration. At rest, spontaneous firing of motor units was observed in muscles of the previously paralyzed side. Direct motor responses to facial nerve stimulation were smaller in the muscles of the previously paralyzed side, but reflex responses obtained in the same muscles by stimulation of either the facial or trigeminal nerve were larger when compared with those of the contralateral side. These data indicate that patients with “postparalytic facial dysfunction” may have an increased background muscle activity, as well as an enhanced recruitment of facial motoneurons to reflex activation in the side of the previous paralysis. These findings are compatible with an enhanced level of motoneuron excitability in the facial nucl

ISSN:0148-639X    

DOI:10.1002/mus.880150107

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

年代:1992

数据来源: WILEY

摘要:

AbstractDirect infection of muscle fibers by human T‐lymphotropic virus type I (HTLV‐I) has recently been reported in a patient with polymyositis infected with both HTLV‐I and human immunodeficiency virus (HIV). Coinfections of these viruses are frequently found in the United States. In Kagoshima, Japan, patients with polymyositis have a significantly increased incidence of seropositivity to HTLV‐I alone, when compared with the general population of Kagoshima. In this study, we examined muscle tissue from 6 HTLV‐I‐positive patients with polymyositis from Kagoshima. To detect HTLV‐I products, sensitive immunohistochemistry and in situ hybridization analysis were performed. These were compared with muscle fibers from a well‐characterized transgenic mouse model which expressed HTLV‐I tax.10No specific signals were detected in the biopsied muscles of patients with polymyositis infected with HTLV‐I alone. HIV co‐infection may, therefore, augment HTLV‐I expression through either immunosuppression or di

ISSN:0148-639X    

DOI:10.1002/mus.880150108

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

年代:1992

数据来源: WILEY

摘要:

AbstractThe objective of this study was to establish to what extent muscle, cutaneous, and joint afferents alter the excitability of spinal and cortical motor neurons. This question was examined by studying the impact of electrical stimulation of the second and third digits, the median nerve at the wrist, and the recurrent thenar motor branch on the F/H and magneto‐electrical cortical motor responses (MEPs) of the thenar muscles. The firing frequencies of single F/H motor unit action potentials were unaltered by the foregoing conditioning peripheral stimuli. MEPs conditioned by motor threshold stimulation of the median nerve at the wrist or the recurrent motor branch were significantly increased in size at conditioning to test intervals of 50 to 80 milliseconds. No significant change in MEP size resulted from conditioning stimulation of the digital nerves. We conclude that muscle afferents were primarily responsible for the increase in MEP size. Conditioning stimuli may allow examiners to assess central motor conduction where it would otherwise be impossibl

ISSN:0148-639X    

DOI:10.1002/mus.880150109

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

年代:1992

数据来源: WILEY

摘要:

AbstractTwo 2‐year‐old males underwent muscle biopsy that established the histopathologic diagnosis of Becker dystrophy in one, and Duchenne dystrophy in the other. Concomitant contracture testing with caffeine or halothane was normal for malignant hyperthermia (MH). The results suggest that acute hypermetabolism or acute rhabdomyolysis during anesthesia, in patients with these disorders, is related to the X‐linked myopathy and its associated muscle deterioration, rather than to the autosomal domina

ISSN:0148-639X    

DOI:10.1002/mus.880150110

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

年代:1992

数据来源: WILEY

摘要:

AbstractNerve conduction studies (NCS) and antiperipheral nerve myelin antibody (A‐PNM Ab) titers were measured serially in 29 patients with Guillain‐Barré syndrome (GBS), of whom 21 were treated with plasmapheresis. Data were obtained from 3 to 6 days until 1 to 2 years after onset of symptoms. Within 3 to 6 days, mean NCS were abnormal. They improved some by 1 week and became maximally abnormal by 4 to 8 weeks, during which time A‐PNM Ab fell to low levels. In 5 patients plasmapheresed, A‐PNM Ab fell and then increased at 4 to 8 weeks, followed by significant deterioration of NCS (P= 0.01) compared with those without antibody rebound at 18 weeks. These results suggest that, in monophasic GBS, there may be two mechanisms of conduction dysfunction such as early paranodal retraction and later demyelination. In some patients plasmapheresed, A‐PNM Ab may rebound associated with further conduction dysfunction. These patients may benefit from further plas

ISSN:0148-639X    

DOI:10.1002/mus.880150111

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

年代:1992

数据来源: WILEY