摘要:

AbstractReported here are the electrodiagnostic findings in a patient with myasthenia gravis who had dysarthria, dysphagia, and dyspnea. The use of repetitive nerve stimulation and single fiber electromyography studies for the evaluation of patients suspected of myasthenia gravis is reviewed.

ISSN:0148-639X    

DOI:10.1002/mus.880140502

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

年代:1991

数据来源: WILEY

摘要:

AbstractWe investigated the possible role of extracellular matrix in specifying the expression of superfast myosin during cat jaw muscle regeneration. Equal proportions of muscle tissue from jaw and limb were minced together after killing cellular elements from one source. We allowed the mince to regenerate in the bed of a fast limb muscle. Regenerates were analyzed immunocytochemically at 71 to 294 days after operation. Fibers in control regenerates containing live cells from both sources expressed fast, superfast or slow myosins, or a mixture of these myosins. In regenerates containing only one type of live cells, we detected only myosins appropriate to the live cells. Our results suggest that during regeneration the original extracellular matrix of jaw‐closing or limb muscle is unable to specify the expression of superfast or fast myosins, respectively; they point to the cellular elements, probably the satellite cells, as determinants of muscle specificity during regeneratio

ISSN:0148-639X    

DOI:10.1002/mus.880140503

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

年代:1991

数据来源: WILEY

摘要:

AbstractPlanter nerve conduction studies 14 months to 3.5 years after decompression surgery in 3 cases of tarsal tunnel syndrome showed an improvement in motor conduction as well as in sensory nerve conduction. This electrophysiological improvement was associated with clinical improvement. However, minor abnormalities still existed in sensory nerve conduction in all 3 cases.

ISSN:0148-639X    

DOI:10.1002/mus.880140504

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

年代:1991

数据来源: WILEY

摘要:

AbstractTo determine the natural history of minicore‐multicore myopathy (MMM) we studied 5 patients who were found to have this disorder from 6 to 16 years ago. Four of these patients had improved muscle strength since their original assessment and one patient had deteriorated. There were no clinical electrophysiological or pathological features that distinguished this last patient from the others. We conclude, therefore, that most patients with MMM may be expected to improve as time passes but, for unknown reasons, a minority may deteriorate. This information should be helpful to clinicians in their prognostic advice to new patient

ISSN:0148-639X    

DOI:10.1002/mus.880140505

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe numbers and relative sizes of motor units have been estimated in 373 muscles of 123 patients with ALS: 74 of the muscles were examined on more than one occasion. The median duration between the onset of symptoms and the initial examination was 12 months; by this time, approximately 90% of the tested muscles showed losses of motor units. The evoked motor unit potentials continued to enlarge in most, but not all, muscles as the disease progressed. Once a muscle became affected by the disease process, the average time‐course was such that the motor unit population halved in each 6‐month period of the first year and diminished more slowly thereafter. A small proportion of patients was encountered in whom the disease progressed much more slowly and there were occasional large fluctuations in the motor unit estimates suggestive of reversible motoneuron dysfunct

ISSN:0148-639X    

DOI:10.1002/mus.880140506

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

年代:1991

数据来源: WILEY

摘要:

AbstractIn chronic experiments concerning the activity‐dependent plasticity of muscle properties, a simple and noninvasive method was used for monitoring changes of twitch speed in conscious adult cats. The animals had been provided with implanted electrodes for nerve stimulation, and a hand‐held force transducer was pressed against the fully extended ankle joint while single test pulses were delivered to the common peroneal nerve. In the present report, this technique for the recording ofankle twitchesis subjected to critical analysis and evaluation. The measurements were highly reproducible with respect to contraction time (time‐to‐peak) but less so for half‐relaxation time and twitch amplitude; other methods should be used for the long‐term monitoring of contractile force. The total force (torque) of the ankle twitch was mainly produced by tibialis anterior (about 45%), peroneus longus (PerL; 27%) and extensor digitorum longus (23%). The ankle twitch produced by PerL alone had about the same contraction time as that of all the muscles together. Among muscles that had become changed as a result of long‐term electrical stimulation there was, in general, a good correspondence between the contraction times from simple external recordings of ankle twitches and those separately measured for PerL under general anesthesia (force transducer then directly connected to

ISSN:0148-639X    

DOI:10.1002/mus.880140507

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes postexhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.

ISSN:0148-639X    

DOI:10.1002/mus.880140508

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

年代:1991

数据来源: WILEY

摘要:

AbstractA diagnosis of infantile Pompe's disease (glycogenosis type II) was made by muscle biopsy on a 6‐month‐old infant boy seen with hypotonia, weakness, and developmental regression. Histochemistry and electron microscopy revealed a vacuolar myopathy with massive glycoge accumulation associated with increased neutral lipid as demonstrated on Oil Red O reactions. Pleomorphic, hypertrophic mitochondria with distortion of cristae and electron‐dense deposits within the matrix were identified. Acid α−1,4‐glucosidase activity was absent but associated with increased neutral maltase activity and a variable compensatory rise in activity of other lysosomal enzymes. Biochemical studies demonstrated low free carnitine, normal acylcarnitine, increased activity of carnitine palmityl and acyl transferases, and other enzymes of β‐oxidation with the notable exception of low normal β‐hydroxyacyl‐CoA dehydrogenase activity. The explanation for the lipid accumulation is uncertain but is likely related to the combination of low carnitine concentration in muscle, low β‐hydroxyacyl CoA dehydrogenase, representing a rate limiting enzyme of β‐oxidation, and nonspecific defectiv

ISSN:0148-639X    

DOI:10.1002/mus.880140509

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

年代:1991

数据来源: WILEY

摘要:

AbstractPain‐related somatosensory evoked potentials (pain SEPs) following co2laser stimulation as well as conventional electrically stimulated SEPs (electric SEPs) were examined in 10 patients with peripheral neuropathies in whom the histopathological examination of the sural nerve was done. Results of pain SEPs showed a positive relationship with clinical impairment of pain sensation and densities of small myelinated fibers of the sural nerve. In contrast, results of electric SEPs showed a positive relationship with clinical impairment of deep and tactile sensations and with densities of large myelinated fibers of the sural nerve. Therefore, pain SEPs are considered to be generated by ascending signals mediated through nociceptive receptors and Aδ fibers. The pain SEP is only one noninvasive and objective method currently available to investigate a physiological condition of the sensory pathway responsible for pain sense, and is especially useful when combined with the conventional electric SE

ISSN:0148-639X    

DOI:10.1002/mus.880140510

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

年代:1991

数据来源: WILEY

摘要:

AbstractThree DNA probes (APOC2, PSC11, and LDR152) detecting RFLP polymorphisms were used to test the usefulness of the RFLP approach in myotonic dystrophy (MD) families from the isolated Finnish population. The informativeness of these polymorphisms did not differ from that reported in more mixed populations: in the 13 families of the study most of the 79 meiotic events studied were informative. One known recombinant is included in the study. The highest lod score obtained in the multilocus linkage analysis wasz= 5.941 at recombination fraction θ = 0.02. The RFLP results significantly facilitated genetic counseling in problematic cases among the families studied. Although evidence could be found for linkage disequilibrium of the RFLP haplotypes formed in Finnish MD patients, our results do not exclude the possible existence of more than one ancient MD mutation in this population

ISSN:0148-639X    

DOI:10.1002/mus.880140511

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

年代:1991

数据来源: WILEY