摘要:

AbstractA battery of electrophysiologic tests was developed to assess the relative degree of lower and upper motor neuron (spasticity) deficit in a group of ALS patients enrolled in a therapeutic trial. Test results were correlated with strength in the tibialis anterior muscle as determined by measurement of maximum voluntary isometric contraction (MVIC), using strain gauge tensiometers, and were also correlated with a clinical spasticity rating scale. Patients were tested every 6 to 8 weeks over more than 1 year. Compound muscle action potential amplitude (CMAPa) from tibialis anterior correlated best with MVIC and also showed a strong linear correlation with time, as did MVIC. Other tests correlated poorly with MVIC on the average, although individual patients did show high correlations. In those patients where correlation between CMAPa and MVIC was low, MVIC did not show a high linear correlation with time and was also highly variable. This study suggests that the addition of CMAPa should be considered in ALS therapeutic trials if MVIC is not available. In addition, CMAPa can be useful in study samples where MVIC deterioration is not linear over time or is highly variable.

ISSN:0148-639X    

DOI:10.1002/mus.880130602

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe forward pulling tension exerted by individual mice was measured nearly isometrically in a simple apparatus designed to determine whole body tension (WBT). WBT determinations on control (C57BI10/SnJ) and experimental (C57BI10‐mdx) mice indicate muscle weakness which lasts throughoout the lifespan of mdx mice. Direct muscle stimulation experiments in vivo also showed significant decreases in peak twitch and tetanic tensions in adult mdx muscle with no obvious alterations in twitch time course or in twitch: tetanus rations. We suggest that the noninvasive WBT procedure may be used to partially assess various therapies on this murine model of Duchenne muscular dystroph

ISSN:0148-639X    

DOI:10.1002/mus.880130603

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe sensitivity of stimulated single‐fiber electromyography in the detection of early abnormalities in neuromuscular transmission in experimental autoimmune myasthenia gravis (EAMG) was tested. Increased jitter and blocking were seen up to 3 weeks before clinical illness or decrement developed. Stimulation at 10 Hz appeared more sensitive in detection of abnormalities than stimulation at 3 or 5 Hz. Jitter values did not correlate with anti‐Torpedo acetylcholine receptor (AChR), nor with anti‐rat AChR antibody titer. No correlation was found between jitter and AChR loss or AChR‐antibody complexes in muscle. It is concluded that, in addition to AChR loss and the presence of AChR‐Antibody complexes, other factors must determine the neuromuscular dysfunction in EAMG and possibly myasthen

ISSN:0148-639X    

DOI:10.1002/mus.880130604

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

年代:1990

数据来源: WILEY

摘要:

AbstractDystrophin is the protein whose deficiency results in Duchenne muscular dystrophy. The protein has homologies with a number of cytoskeletal proteins, is localized at the muscle sarcolemma and it may provide stability to the muscle plasma membrane. Using immunocytochemical techniques, we have studied dystrophin localization at the myotendinous junction, a region of membrane complexity that requires more stability because it is subjected to great mechanical stress during the transmission of contractile force to the tendon. The results showed subsarcolemmal deposits of dystrophin at the junctional folds of the myotendon as well as membrane‐associated dystrophin at extrajunctional sarcolemma. The findings suggest that dystrophin may be one of the components linking terminal actin filaments to the subplasmalemmal surface of the junctional folds of the myotendo

ISSN:0148-639X    

DOI:10.1002/mus.880130605

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn 57 of 60 nerves (29 median and 31 ulnar) sutured at the wrist, forearm and arm, we recorded motor responses in thenar or hypothenar muscles by electrical stimulation of the corresponding fingers. Recordings were made at different times during the process of regeneration, ranging from 3 months up to 11 years. The responses showed a constant shape and latency to every stimulation (simple or repetitive). The latency was shorter the more distal the level of injury and the greater the elapsed time from the reinnervation. The point of „reflexion”︁ of the responses is at or very near the line of nerve suture. The electrophysiological behavior of the responses fits well with either the criterion of axon reflex or ephaptic response. We discuss both possibilities and conclude that it is not possible, with the electrophysiological technique that we used, to distinguish between an axon reflex and an ephaptic res

ISSN:0148-639X    

DOI:10.1002/mus.880130606

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

年代:1990

数据来源: WILEY

摘要:

AbstractA survey of skeletal muscle pathology in 92 autopsied cases of AIDS revealed microscopic alterations in 64 cases. There were 40 cases of disuse atrophy, 8 of denervation atrophy, 2 of cryptococcal myositis, 1 ofMycobacterium avium intracellulare(MAI) infection and 2 of necrotizing myopathy associated with hyperkalemia. A second group of cases with changes of unknown etiology was found. These were tentatively ascribed to the direct or indirect action of HIV. This category includes 8 cases of inflammatory myopathy, 8 of necrotizing myopathy in absence of a known etiological factor, 3 of extreme atrophy and 4 of “regenerating” myopa

ISSN:0148-639X    

DOI:10.1002/mus.880130607

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn a new, typical case of Schwartz–Jampel syndrome (SJS) the origin of the disorder was found to be purely myogenic. Concentric needle EMG showed abundant and persistent spontaneous activity, maximal at insertion, and uninfluenced by local curarization. Single‐fiber EMG showed rather stable, sometimes intermittent, discharge series with occasional amplitude and/or frequency fluctuations. It could be demonstrated that this activity did not consist of complex repetitive discharges, but of independent activity of individual muscle fibers. This contrasts with findings by other investigators that have been published in this journal.8, 17Light microscopic studies of quadriceps and intercostal muscles showed no abnormalities, whereas electron‐microscopic findings were in accordance with earlier studies in SJS. Endplate analysis revealed no specific changes; the postsynaptic stectures gave the impression of an accelerated‐mat

ISSN:0148-639X    

DOI:10.1002/mus.880130608

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

年代:1990

数据来源: WILEY

摘要:

AbstractSkeletal muscle fibers from a patient with Schwartz–Jampel syndrome were studied in vitro. The fibers had normal resting membrane potentials, but their resting [Ca2+]iwas elevated. The resting potentials were unstable and spontaneous depolarizations caused twitching in all fibers. Stimulated contractions were characterized by markedly slowed relaxation which was due to electrical after‐activity. Neither curare (0.7 μM), tocainide (50 μM), nor phenytoin (80 μM) had an effect on the myotonic activity. In contrast, procainamide (200 μM) suppressed the hyperexcitability without affecting the twitch amplitude. The steady‐state current‐voltage relation was normal in 5 fibers, but altered in 3 others. These latter fibers had an increased specific membrane resistance owing to a decreased Cl‐ conductance. The Na+channels were investigated in the cell‐attached patch clamp mode. In all patches on either type of fiber, depolarizing pulses elicited delayed, synchronized openings of Na+channels. These abnormal openings occurred even after the surface membrane repolarized. We hypothesize that these altered membrane conductances are responsible for the hyperexcitability and the associated sl

ISSN:0148-639X    

DOI:10.1002/mus.880130609

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

年代:1990

数据来源: WILEY

摘要:

AbstractA clinical and electrophysiological follow‐up was carried out for 3 to 7 years on 15 patients with Friedreich's ataxia (FA). Sural nerve biopsy was performed once in all patients, and a second time 6–7 years later in three of them. Clinical worsening and progression of disturbance were evaluated according to IAP and IACR scales. Sensory orthodromic conduction along median and tibial nerves was typical of FA and did not change between first and last examinations, nor were there morphological changes between the first and the second sural nerve biopsies. Peripheral nerve involvement is thought to be a result of defective development of the largest neurons and to remain stable from a very early stage of the disease; the clinical worsening may then be due to a progressive involvement of the pyramidal tracts and the cerebellar pathw

ISSN:0148-639X    

DOI:10.1002/mus.880130610

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe report a large spectrum of histological muscle abnormalities in 50 homosexual men with AIDS and ARC. We encountered moth‐eaten fibers in 76%, angulated fibers in 76%, type groupings in 62%, type 2 fiber atrophy in 58%, mononuclear endomysial and/or perivascular in filtrates in 36%, necrosis and phagocytosis in 30%, and target fibers in 6%. Two patients showed vasculitis and two others showed perifascicular atrophy. On the whole, 96% of the biopsies showed substantial abnormalities. Muscle involvement in AIDS seems more common than previously suspecte

ISSN:0148-639X    

DOI:10.1002/mus.880130611

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

年代:1990

数据来源: WILEY