bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real‐time sonography of acute and chronic muscle denervation
Authors: Gunreben Gerd , Bogdahn Ulrich 
Published: January 2005

AbstractPresented are real‐time ultrasound findings in partially and completely denervated muscles of 30 patients with focal neurpathy and various other disorders of the second motor neuron. Sonographic scans of affected muscles are analyzed in conjunction with unaffected muscles of the same individual, under identical examination conditions. Initial pathological ultrasound changes could be detected as soon as 2 weeks after an acute neurogenic lesion. In denervation, the echodensity of the muscle was high and the normal intramuscular pattern was decomposed. Findings were more intense in severe and longstanding denervation. Ultrasoudn‐indicated pathology correlated highly (chi‐square: P < 0.001) with pathological sponteneous activity detected by electromyography. Focal and systemic neuropathies showed no differences in ultrasound pathology. Six cases with central motor palsy had normal sonograms. Poor spatial resolution of real‐time ultrasonography–as compared with CT and MRI–is compensated by its bedside availability, frequent repeatability without patient risk and discomfort, and its in vivo correlation of muscle morphology with muscle function.
Relationship between electrical and vibratory output of muscle during voluntary contraction and fatigue
Authors: Zwarts Machiel J. , Keidel Matthias 
Published: January 2005

AbstractMeasurements were done on the biceps muscles of 6 healthy volunteers to record simultaneously the surface electromyogram (EMG) and vibromyogram (VMG) by means of a piezoelectric device (accelerometer). The VMG is generated by mechanical waves due to the contraction mechanism and often measured as sound. The frequency spectrum and integrated value (IEMG and IVMG) of both signals were calculated. Both IEMG and IVMG showed a clear linear correlation with force, although at high forces, the variability of the VMG became rather high. Two series of experiments were performed to study the EMG and VMG changes in relation to changes induced by fatigue: (1) during constant force at 50% of the maximal voluntary contraction (MVC) and recovery; (2) for one 1 minute during declining force at MVC. The main finding was that the IVMG was related to the absolute force, irrespective of the fatigue state of the muscle. In contrast, the IEMG showed the well‐known changes during fatigue, such as an increase during endurance. The spectral changes of the two measurements also showed a divergence. The spectra of the EMG shifted to lower frequencies in both fatigue protocols. In contrast, the spectra of the vibratory signal did not shift, except for several measurements at MVC. However, the shape did change to a somewhat flatter spectrum with less pronounced peaks. Possible explanations for this different behavior are discussed. It is concluded that the vibratory energy generated by the contraction mechanism is linearly related to force. Changes induced by fatigue do not alter this relationship: this contrasts with the behavior of the EMG. The combination of these two measurements give supplemental information regarding the state of the working muscle.
Fatigue in type I fiber predominance: A muscle force and surface EMG study on the relative role of type I and type II muscle fibers
Authors: Linssen Wim H. J. P. , Stegeman Dick F. , Joosten Ed M. G. , Binkhorst Rob A. , Merks Mieke J. H. , Laak Henk J. Ter , Notermans Servaas L. H. 
Published: January 2005

AbstractThe relative proportions of fiber types within muscle and the characteristics of these fiber types are important determinants of the surface electromyogram (SEMG) during fatigue. In this study, patients suffering from congenital myopathy characterized by a strong type I fiber predominance were studied. Six patients with 95‐100% type I fibers, 2 patients with 80% type I fibers, and 12 healthy volunteers participated in an ischemic, isometric, intermittent exercise test of m. quadriceps femoris at 80% MVC. Considering the results of the morphometric analysis of muscle biopsy specimen and of the anthropometric estimated muscle‐bone volume, it was found that type I muscle fibers had a lower force generating capacity than type II fibers. The initial conduction velocity along the muscle fiber membrane (MFCV) was low in patients with 95‐100% type I fibers. During the ischemic exercise test, the 95‐100% type I fibers showed less fatigability than type II fibers, which was reflected by a nearby absent decrease of the muscle membrane excitability as measured by the MFCV, and only a slight increase of the SEMG amplitude compared with patients having 80% type I fibers and controls. The absence of a definite MFCV decrease was related to the nearby lacking lactate formation in 95‐100% type I fibers.
Progressive motor neuron disease associated with electrical injury
Authors: Sirdofsky Michael D. , Hawley Rollin J. , Manz Herbert 
Published: January 2005

AbstractA patient in perfect health prior to electrical shock developed an ALS‐like syndrome after the shock. Onset of the disease occurred in the limb through which the shock entered, and subsequently followed a course well‐described in previous case reports. Possible mechanisms of disease are discussed.
Fibrillation and accelerated achr degradation in long‐term muscle organ culture
Authors: Wetzel Daniel M. , Salpeter Miriam M. 
Published: January 2005

AbstractEvaluation of the precise molecular dynamics of endplate maintenance and reorganization has been limited by the lack of available in vitro preparations. We describe an organ culture preparation of mouse diaphragm muscle which permits long‐term maintenance of muscle viability. Spontaneous fibrillations, increased levels of extrajunctional acetylcholine receptors, accelerated rates of junctional acetylcholine receptor turnover and maintenance of fine structure of denervated mouse diaphragm muscle in organ culture was evaluated under different culture conditions. Of several standard tissue culture media tested with and without fetal calf serum, medium 199 plus fetal calf serum was best for maintaining this muscle for greater than 2 weeks. The serum component could be partially eliminated by addition of nonglucose energy substrates such as D‐b̃‐hydroxybutyric acid and L‐glutamine. This preparation will permit a more controlled examination of the molecular components of endplate diseases.
Clinical correlations of Anti‐Gm1 antibodies in amyotrophic lateral sclerosis and neuropathies
Authors: Lamb Nancy L. , Patten Bernard M. 
Published: January 2005

AbstractClinical correlations of antiganglioside GM1 antibodies are important because high titers of these antibodies may have therapeutic significance. To further evaluate this significance, we reviewed our experience with 78 patients who had the following diagnoses: amyotrophic lateral sclerosis (ALS), ALS syndromes in patients with gammopathy or thyroid abnormalities, cervical spondylosis simulating ALS, motor neuropathies, and chronic inflammatory demyelinating polyneuropathies (CIDP). Antiganglioside antibody titers were measured “blind” by ELISA assay at the neuromuscular clinical laboratory, Johns Hopkins School of Medicine. We conclude that anti‐GM1 antibodies are found in a wide variety of neuromuscular conditions. Patients with classical ALS had a mean anti‐GM1 antibody titer significantly lower than patients with CIDP or motor neuropathy. Patients with ALS associated with gammopathy or thyroid disorders had higher anti‐GM1 titers than seen in classical ALS. The highest mean titer occurred in patients with CIDP, a treatable neuropathy.
Role of electromyography in amyotrophic lateral sclerosis
Authors: Behnia Mehrdad , Kelly John J. 
Published: January 2005

AbstractWe reviewed the role of electrodiagnostic testing in amyotrophic lateral sclerosis (ALS) in a large ALS clinic. Over 31 months, 133 patients with a clinical diagnosis of ALS were tested. In most, nerve conduction studies were normal, and needle electrode examination showed active denervation in the upper and lower limbs or the limbs and bulbar muscles (Lambert's criteria). However, 50 of 133 patients did not fulfill Lambert's criteria at presentation because of abnormal nerve conduction studies (11 patients), abnormal F‐wave latencies (6 patients), or insufficiently distributed fibrillation potentials (40 patients). This study reveals that a large proportion of patients with a clinical diagnosis of ALS fail to have classical findings on initial electrodiagnostic studies, and reveals several caveats of electrodiagnostic testing in these patients: (1) Conduction studies may be unreliable in motor nerves with markedly low compound muscle action potential (CMAP) amplitudes. (2) Sensory nerve action potential (SNAP) amplitudes may be abnormal in a small percentage of otherwise typical ALS patients. However, better controls for elderly subjects are needed. (3) Needle electrode examination may not show widespread active denervation early in the disease. (4) Some patients may have a mild polyneuropathy. (5) The classic diagnostic criteria may need to be modified to allow earlier acceptance of many ALS patients into therapeutic trials.
Enzyme and size profiles in chronically inactive cat soleus muscle fibers
Authors: Graham Scot C. , Roy Roland R. , Navarro Christine , Jiang Bian , Pierotti David , Bodine‐Fowler Sue , Reggie Edgerton V. 
Published: January 2005

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 loading.
Failure to detect HTLV‐I by in situ hybridization in the biopsied muscles of viral carriers with polymyositis
Authors: Higuchi Itsuro , Nerenberg Michael , Yoshimine Kosei , Yoshida Mitsuaki , Fukunaga Hidetoshi , Tajima Kazuo , Osame Mitsuhiro 
Published: January 2005

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. 10 No 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 direct viral interactions.
Influence of peripheral afferents on cortical and spinal motoneuron excitability
Authors: Komori Tetsuo , Watson Bradley V. , Brown William F. 
Published: January 2005

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 impossible.
Absence of malignant hyperthermia contractures in Becker‐Duchenne dystrophy at age 2
Authors: Gronert Gerald A. , Fowler William , Cardinet George H. , Grix Arthur , Ellis William G. , Schwartz Marshall Z. 
Published: January 2005

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 dominant MH.
Deficiency of acetylcholine receptors in a case of end‐plate acetylcholinesterase deficiency: A histochemical investigation
Authors: Jennekens Frans G. I. , Hesselmans Laura F. G. M. , Veldman Henk , Jansen Ernst N. H. , Spaans Frank , Molenaar Peter C. 
Published: January 2005

AbstractA young boy is described who, since early infancy, suffered from weakness of predominantly proximal limb muscles. Electromyography revealed impairment of neuromuscular transmission. There were no antibodies against acetylcholine receptors. The amplitude of miniature end‐plate potentials was reduced. Neuromuscular junctions showed somewhat coarse postsynaptic junctional folds and degeneration products in the synaptic clefts and in postsynaptic areas. Using qualitative and semiquantitative histochemical methods, at light‐ and electronmicroscopical levels, acetylcholinesterase (AChE) activity and acetylcholine receptors (AChRs) were demonstrated to be deficient. This patient demonstrates that the clinical picture of congenital myasthenia may closely resemble a congenital myopathy. The findings provide evidence that AChR deficiency offers protection from some of the effects of AChE deficiency. The clinical features of AChE deficiency depend, not only on the level of residual enzyme activity, but also on the degree of AChR reduction, if present.
Effect of low Ca2+ solution on muscle contraction of developing, preclinical dystrophic (DY2J) mice
Authors: Dangain Josette , Neering Ian R. 
Published: January 2005

AbstractEDL muscles from normal and dystrophic (dy2j) mice aged 7 to 21 days of postnatal life were examined. Muscles were divided into 2 groups according to age, 7 to 14 days and 16 to 21 days postnatal, so as to assess age‐ and/or phenotype‐related differences in the muscle response to low Ca2+ solution. Tension production was already much impaired in “predystrophic” muscles. At this stage, however, there was essentially no difference in twitch kinetics between normal and dystrophic muscles. Upon exposure to low Ca2+ solution, twitch responses of both normal and dystrophic muscles declined in a similar manner. In the youngest animals studied (7 to 14 days), the tetanic responses of both normal and dystrophic muscles to low Ca2+ solution were also similar. In animals 15 to 21 days old, however, the tetanic tension developed in low Ca2+ solution by dystrophic muscles, was significantly less than that of normal. Moreover, under these conditions (i.e., in low Ca2+ solution), and following tetanic stimulation, the membrane potential of dystrophic muscles in this age group was significantly more depolarized than that of normal muscles. Our results suggest that the ability of the cell to deal with extracellular Ca2+ is normal in predystrophic muscles up to 21 days of postnatal life. The results also clearly point to the fragility of the membrane in these muscles.
Case‐of‐the‐month: Autosomal recessive myotonia congenita: Marked muscle weakness in a 16‐year‐old boy
Authors: Miller Robert G. , Buchthal Fritz 
Published: January 2005

AbstractA 16‐year‐old boy had a 10‐year history of stiffness in leg muscles. There was marked weakness of neck flexors, shoulder abductors, and ankle dorsiflexors, with hypertrophy of most muscle groups and both action and percussion myotonia. The parents were normal. Motor unit potential mean duration was reduced in the weakest muscle (tibialis anterior), and a biopsy of the same muscle showed only minimal abnormalities. Exercise and repetitive stimulation (30 Hz) of the tibialis anterior disclosed a decline in the compound muscle action potential that appeared to correlate with the muscular weakness.
Myasthenogenicity of a human acetylcholine receptor α‐subunit peptide: Morphology and immunology
Authors: Matsuo Hidenori , Tsujihata Mitsuhiro , Satoh Akira , Takeo Gou , Yoshimura Toshiro , Nagataki Shigenobu 
Published: January 2005

AbstractEach of 10 rats inoculated with a synthetic peptide comprising residues 125–147 (without a disulfide bond) of human acetylcholine receptor (AChR) α‐subunit (Hα) had deposits of IgG and C3 (immune complexes) and showed morphological changes in the fine structure at the motor end‐plates 5 weeks after a single immunization. Antibody to the Hα peptides was elevated 1 week after immunization, but, antibody levels to solubilized human or rat AChR were very low in 8 of the 10 rats. These results suggest that the immune response to peptide Hα is the myasthenogenic site, which induces morphological change at the end‐plates.
Proximal median neuropathies: Electromyographic and clinical correlation
Authors: Gross Paul T. , Jones H. Royden 
Published: January 2005

AbstractResults of electrophysiologic and clinical findings in 17 patients with proximal median neuropathy were reviewed. The cause of neuropathy was trauma in 5 patients, overuse of the pronator teres in 3 patients, postinfectious in 2 patients, secondary to a congenital lesion in 1 patient, and undetermined in 6 patients. The neuropathy involved the main branch of the median nerve at or proximal to the pronator teres muscle (high median neuropathy) in 14 patients, and the anterior interosseous portion of the nerve in 3 patients. Electrophysiologic findings, especially needle electromyography (EMG), were more definitive than findings expected from clinical examinations. EMG and operative findings demonstrated that median nerve compression by the pronator teres produces denervation of this muscle as well as distal muscles. EMG cannot differentiate a median nerve lesion at the pronator teres from a more proximal lesion. Follow‐up data were available in 7 of 10 nonsurgically managed patients, and in 6 of 7 patients with surgical decompression. Six patients in each group were either improved or normal.
Single fiber EMG in the frontalis muscle in ocular myasthenia: Specificity and sensitivity
Authors: Rouseev R. , Ashby P. , Basinski A. , Sharpe J. A. 
Published: January 2005

AbstractPatients (n = 41) with isolated weakness of the eyelids or extraocular muscles, who had been referred for single fiber electromyography (SFEMG), were followed up after 4 to 24 months, At follow‐up the patients were classified as “definite ocular myasthenia gravis” (MG), “definite other diagnosis,” or “no definite diagnosis” on the basis of the completed investigations and subsequent course. The original SFEMG findings in the frontalis muscle were then reviewed. The specificity and sensitivity of SFEMG for “definite ocular MG” could be maximized by using as criteria for abnormality >8/20 pairs with jitter >45 μs, or a mean jitter of 20 pairs of >50 μs. Patients with abnormal SFEMG according to these criteria have MG, and are likely to require treatment in the immediate future. Patients who have normal SFEMG according to these criteria (and no other demonstrated disorder) may have MG, but it is so mild that they are unlikely to require treatment. Two patients whose final diagnosis was progressive external ophthalmoplegia had normal SFEMG according to these criteria.
Neuromuscular function and polymorphism of the acetylcholine receptor gamma gene
Authors: Degli‐Esposti Mariapia A. , Dallas Peter B. , Dawkins Roger L. 
Published: January 2005

AbstractExamination of inbred and wild mice has shown that the gene coding for the acetylcholine receptor gamma subunit is polymorphic and the polymorphism correlates with differences in neuromuscular function tested by two different methods. Polymorphism of the AChR γ gene was demonstrated after digestion of genomic DNA with Pstl and Xbal. These two restriction enzymes demonstrated RFLP patterns specific for C57Bl/6J (PsXs) and C3H/HeJ (PRXR) mice, respectively. Examination of F1 (C3H/HeJ × C57Bl/6J) and F2 hybrid populations, and other murine inbred strains, showed the inheritance and strain specificity of the RFLPs. Testing wild mice demonstrated that the PSXS form of the AChR γ gene is the most common in the wild. The AChR γ and AChR δ subunits are closely linked and carried on the same chromosome as several contractile proteins. Because these genes are essential for correct neuromuscular development and activity, we investigated the possibility that the observed AChR γ polymorphisms mark a haplotype which correlates with variations in neuromuscular function. Analysis of exercise times showed a correlation between AChR γ polymorphism and neuromuscular function. To our knowledge, this is the first description of AChR polymorphism cosegregating with variations in neuromuscular function.
Sural nerve biopsies in Guillain‐Barre syndrome: Axonal degeneration and macrophage‐associated demyelination and absence of cytomegalovirus genome
Authors: Hughes Richard , Atkinson Penny , Coates Philip , Hall Susan , Leibowitz Sidney 
Published: January 2005

AbstractT‐cell infiltration was detected by immunohistochemistry in only 2 of 10 sural nerve biopsies from patients with Guillain–Barré syndrome (GBS). The number of endoneurial macrophages, identified by the monoclonal antibody MAC 387, was increased, compared with the number in 10 cases of axonal neuropathy. Macrophage‐associated demyelination was identified in 7 and axonal degeneration in 8 cases. Cytomegalovirus (CMV) genome was not detected with the polymerase chain reaction.