bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial dispersion of magnetic stimulation in peripheral nerves
Authors: Cros Didier , Day Timothy J. , Shahani Bhagwan T. 
Published: January 2005

AbstractTo assess the longitudinal dispersion of the stimulus induced by the magnetic coil, collision experiments were performed in seven normal ulnar nerves. A supramaximal electrical stimulus S1 was delivered at the wrist, and followed by a supramaximal stimulus S2 in the upper arm, which was either electrical (electrical collision studies), or magnetic (magnetic collision studies). The interstimulus interval was varied by 0.2 msec increments from the time of complete cancellation of the S2 evoked motor response onwards, to include the entire span of recovery of that compound motor action potential. Collision curves were obtained for both magnetic and electrical stimuli by plotting the amplitude of the motor response elicited by S2 as a function of the interstimulus interval. In all seven normal ulnar nerves, comparison of the collision curves showed that the S2 evoked motor response is restored significantly more slowly when magnetic stimulation is used. This finding is best explained by longitudinal dispersion of the stimulus induced by the magnetic coil relative to conventional electrical stimulation, the large fibers being stimulated further away from the coil than the small ones. This interpretation is confirmed by the findings obtained with the same method in two cases of ulnar neuropathy, and by comparison of different intensities of magnetic stimulation.
Latencies of peripheral nerve and cerebral evoked responses to air‐puff and electrical stimuli
Authors: Hashimoto Isao , Yoshikawa Kazuyoshi , Sasaki Makoto 
Published: January 2005

AbstractThis study examined the latency relationship between mechanically and electrically elicited sensory nerve action potentials (SNAPs) and the somatosensory‐evoked potentials (SEPs) they produce. Brief air‐puff and electrical stimuli were applied to the tip of the index finger in separate trials and SNAPs from the median nerve at the wrist and SEPs from the scalp were recorded for each stimulus presentation. Air‐puff evoked SNAPs were polyphasic, usually consisting of 2 to 4 separate waves, unlike triphasic activity elicited by electrical stimulation. The SEPs produced by these 2 distinct forms of inputs, however, were similar in morphology. The latencies of the initial components of SNAPs and SEPs were longer for air‐puff stimulation. The conduction time, however, of the fastest afferent volleys from the wrist to cortex was not significantly different for air‐puff (20.52 ± 1.06 ms, mean ± SD) and electrical stimulation (20.17 ± 0.66 ms). It is therefore concluded that the latency delays for air‐puff evoked SNAPs and SEPs are due solely to a transduction time at the skin receptors and not due to differences in conduction velocities as suggested in the previous literature.
Reversible myeloneuropathy of nitrous oxide abuse: Serial electrophysiological studies
Authors: Vishnubhakat S. Murthy , Beresford H. Richard 
Published: January 2005

AbstractDetailed electrophysiological studies were performed in 4 patients with myeloneuropathy induced by abuse of nitrous oxide for 1 to 4 years. All presented with paresthesias, weakness, and Lhermitte's phenomena, and exhibited signs of sensorimotor polyneuropathy, ataxia, and arreflexia. Two had subnormal serum vitamin B12 levels. Baseline electrophysilogic testing revealed reduced motor unit potentials, prolonged F wave latencies, absent H refelxes, denervation potentials, and delays in motor and sensory conduction. Three had peripheral and nuchal delay after median nerve stimulation. All were reevaluated after 3 to 12 months abstinence and treatment with vitamin B12, and all showed substantial clinical improvement. Parallel improvement in electrophysiologic findings occurred, but residual minor conduction delays, loss of H reflexes, electromyographic evidence of denervation, or abnormalities of posterior tibial SEP were noted. These findings confirm the reversibility of myeloneuropathy of nitrous oxide abuse and describe the profile of electrophysiologic recovery in subjects who abstain from further neurotoxic exposure.
Abnormal single motor unit behavior in the upper motor neuron syndrome
Authors: Shahani Bhagwan T. , Wierzbicka Margaret M. , Parker Stephen W. 
Published: January 2005

AbstractWe studied the discharge pattern of single motor units (SMUs) in the left and right biceps muscles from a patient with nonspastic weakness of the left arm. Detailed statistical analysis of the behavior of discharge patterns of 4 of 4 single motor units on the affected side showed abnormalities with characteristic features of an upper motor neuron lesion. Five out of 5 single motor units recorded from the right biceps were normal. An upper motor neuron lesion affecting the left arm, predicted by our results, was confirmed by magnetic resonance imaging (MRI), which showed a lesion in the right precentral gyrus. It appears that changes in single motor unit firing characteristics, caused by an upper motor neuron lesion, can be detected at a time when there is no evidence of increased “tone” and/or hyperreflexia (spasticity) in the affected extremity.
Paraneoplastic vasculitic neuropathy: A treatable neuropathy
Authors: Oh Shin J. , Slaughter Robert , Harrell Lindy 
Published: January 2005

AbstractParaneoplastic vasculitic neuropathy has been recently described. We report the first case of this disorder which responded both clinically and electrophysiologically to cyclophosphamide treatment. A 54hyphen;year‐old women with a history of metastatic endometrial carcinoma in remission had asymmetrical polyneuropathy, electrophysiological findings consistent with a diffuse axonal neuropathy, high sedimentation rate and spinal fluid protein, and microvasculitis with axonal degeneration on nerve biopsy. The patient was treated with 150 mg of cyclophosphamide daily with gradual clinical and electrophysiological improvement.
Human acid maltase‐deficient myogenic cell transformation with origin‐defective SV40: Characterization of a cloned line
Authors: Usuki Fusako , Higuchi Itsuro , Soejima Yasuko , Hattori Masakazu , Maruyama Ikuro , Osame Mitsuhiro 
Published: January 2005

AbstractA clonal human skeletal muscle cell line showing acid maltase deficiency (AMD) was established through the transfection of origin‐defective SV40 DNA. The low acid α‐glucosidase activity and glycogenosomes in this clone corresponded to AMD. This clone, in spite of loading glycogenosomes, was competent not only as to proliferation without contact inhibition but also as to myogenic differentiation to some extent. Dexamethasone promoted the formation by the transformant of multinucleated myotubes, which expressed acetylcholine receptors. The existence of glycogenosomes did not seem to affect the proliferation or differentiation of myoblasts. The aberrant acid α‐glucosidase expressed in the transformed myogenic clone was shown to be biochemically identical to that in AMD fibroblasts. This transformant should be of great value for investigating the pathogenesis of AMD because of the possibility of supplying semi‐permanently a uniform myogenic cell line expressing AMD.
Dystrophic changes in mdx muscle regenerating from denervation and devascularization
Authors: Anderson Judy E. 
Published: January 2005

AbstractThe regenerative capacity of young mdx muscle after a denervating and devascularizing injury (DD) was examined in extensor digitorum longus (EDL) and compared with that of age‐matched control mouse EDL. DD of the right EDL was produced at the age approximating the onset of dystrophy in the mdx model, and mice recovered for 2 weeks. Contralateral unoperated EDLs from mdx and control mice served as internal controls for histopathology, myofiber cross‐sectional area (CSA), and ultrastructure of fiber regeneration in DD‐EDL. Mdx DD‐EDL were composed of small, uniformly mature myofibers with mostly peripheral nuclei. This contrasted with control DD‐EDL in which fibers were centrally nucleated. In addition, the unoperated mdx EDL exhibited the central nucleation of spontaneous recovery from dystrophy. The CSA distribution of mdx DD‐EDL myofibers was significantly shifted toward smaller CSA compared with unoperated mdx EDL, although mean CSA did not differ between the two mdx muscle groups. The CSA distribution of control DD‐EDL was significantly different and shifted toward smaller CSA from both unoperated control EDL and from mdx DD‐EDL distributions. Ultrastructural features of dystrophy were present in both mdx DD‐EDL and in the unoperated mdx EDL, although they appeared more prevalent in the latter. These results suggest that short‐term plasticity of mdx muscle recovery from imposed injury may be greater than that of normal muscle in establishing a regenerating fiber population.
Arrangement of fiber types within fascicles of human vastus lateralis muscle
Authors: Pernuš Franjo , Eržen Ida 
Published: January 2005

AbstractA total of 106 fascicles at 6 predetermined areas of the vastus lateralis muscle from 9 healthy men, aged 18 to 40 years, were analyzed. Fibers in a fascicle were divided into layers according to their relation to the perimysium. In each layer the proportions of type 1 and 2, subdivided into 2a, 2b, and 2c fibers were determined and normalized by the fiber type proportion in the whole fascicle. A consistent arrangement of fiber types within the fascicles was obtained, regardless of subject, sampling site, fiber type proportion, and fascicle size. A high proportion of 2b fibers on the border, a prevalence of type 1 fibers in the layer beneath, and a rather uniform distribution of 2a fibers in all layers are the main characteristics of the distribution of fibers in a fascicle. Developmental processes in fiber type differentiation most probably constitute the basis for fiber type arrangement, which can further be influenced by local factors.
The extent and time course of motoneuron involvement in amyotrophic lateral sclerosis
Authors: Dantes Marita , McComas Alan 
Published: January 2005

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 dysfunction.
Age‐Related changes and tissue distribution of parvalbumin in normal and dystrophic mice of strain 129 ReJ
Authors: Greaves Douglas S. , Dufresne Michael J. , Fackrell Hugh B. , Warner Alden H. 
Published: January 2005

AbstractIn murine muscular dystrophy, hindlimb muscle contains a functionally defective thiol protease inhibitor (TPI) which has been implicated in the onset and progression of the disease in mice. More recently, this protease inhibitor has been identified as parvalbumin, a calcium binding protein. In this study, a polyclonal antibody against mouse muscle parvalbumin was used to study the concentration and distribution of this protein in normal and dystrophic male mice at various ages. Immunodetection assays were used to screen extracts of hindlimb, forelimb, brain, heart, lung, liver, and kidney in 60‐day‐old normal and dystrophic male mice for parvalbumin content. Parvalbumin was detected in relatively high amounts in both hindlimb and forelimb muscle extracts, while much lower concentrations were detected in brains of normal and dystrophic animals. No parvalbumin was detected in the lung, liver, heart, or kidney extracts using the immunoassay. With aging, the parvalbumin concentration in hindlimb muscle of normal mice remained fairly constant for 90 days, whereupon the level increased at 120 days. In contrast, the parvalbumin concentration in hindlimb muscle of dystrophic mice decreased steadily with age to about 22%% of normal animals at 120 days. The parvalbumin content was also reduced in dystrophic brain.
Invited review: Motor unit estimation: Methods, results, and present status
Authors: McComas Alan J. 
Published: January 2005

AbstractThe renewed interest in motor unit estimation (counting) has coincided with the introduction of computer‐based methodology and with the application of the technique to proximal as well as distal muscles. The advantages and disadvantages of the different methods are considered, together with the assumptions inherent in this type of examination. In normal subjects, the extensor digitorum brevis (EDB) muscle has approximately 200 motor units while each of the intrinsic muscles of the hand has about 100 units; larger muscles in the limbs contain greater numbers of units. Beyond the age of 60 years, there is a decline in the number of functioning motor units in both proximal and distal muscles. In denervating disorders, motor unit estimation is useful for diagnosis and assessment; abnormal values may often be observed in muscles judged clinically to be unaffected. Serial studies have enabled the rate of motor unit loss to be determined in ALS and in spinal muscular atrophy. Depletion of motor units has also been found following upper motoneuron lesions caused by injury to the spinal cord or by cerebral hemorrhage; trans‐synaptic dysfunction has been presumed responsible. Rather surprisingly, reduced numbers of motor units have been observed in a variety of myopathic disorders; of these, the most consistent abnormalities have been reported in myotonic muscular dystrophy.
An endogenous inhibitor of calcium‐activated neutral protease in UMX 7.1 hamster dystrophy
Authors: Nakamura Megumi , Imajoh‐Ohmi Shinobu , Suzuki Koichi , Kawashima Seiichi 
Published: January 2005

AbstractAn endogenous inhibitor for calcium‐activated neutral protease (CANP) from skeletal and cardiac muscles of muscular dystrophic hamsters (UMX 7.1) was compared with that from normal control animals at 4 and 10 weeks of age by Western blotting using antibody raised against CANP inhibitor. Fragmented CANP inhibitor was found in dystrophic skeletal muscles in all cases at both ages, while only intact inhibitor was detected in the skeletal muscle of the normal hamsters. A total absence of intact inhibitor was shown in one 10‐week‐old dystrophic hamster. In contrast, there was little difference in CANP inhibitor from heart between dystrophic and control hamsters at 4 weeks. However, fragmentation similar to that in skeletal muscle was seen in the heart inhibitor in a few of the 10‐week‐old dystrophic hamsters.
Muscle fiber recovery functions studied with double pulse stimulation
Authors: Mihelin Marjan , Trontelj Jože V. , Stålberg Erik 
Published: January 2005

AbstractDirect electrical stimulation with paired pulses at varied intervals was used to study the propagation velocity and action potential amplitude recovery functions (VRF and ARF) of single muscle fibers. Following a subnormal period with slowed conduction, most of the muscle fibers tested in healthy subjects showed a period of supernormal propagation velocity starting at 3 to 12 ms, with a peak between about 5 and 15 ms, a mean increase of 7%, and an approximately logarithmic decay toward 1 second. The onset of supernormality was earlier in muscle fibers from patients with muscular dystrophy and significantly delayed in those from denervated muscles. Denervated muscle fibers also had a significantly longer refractory period.
Human peripheral nerve sheath neoplasm: Expression of Schwann cell‐related markers and their relation to malignant transformation
Authors: Yasuda Takeshi , Sobue Gen , Ito Takayuki , Doyu Manabu , Sugiura Isao , Hashizume Yoshio , Kato Kanefusa 
Published: January 2005

AbstractWe immunohistochemically examined the expression of Schwann cellrelated markers, nerve growth factor (NGF) receptor, S‐100 α‐ and b̃‐proteins, glial fibrillary acidic protein (GFAP), and galactocerebroside (gal C) in 5 malignant schwannomas, 21 benign peripheral nerve sheath tumors, and 4 apparently normal sural nerves. NGF receptor was expressed in the malignant schwannomas and benign peripheral nerve sheath tumors, but not in the endoneurium of apparently normal peripheral nerves. S‐100 α‐protein was observed in malignant schwannomas and in some neurofibroma cells. All cases were strongly positive for S‐100 b̃‐protein but were negative for GFAP and gal C. Our results suggest that these Schwann cell‐related markers may be useful in identifying peripheral nerve sheath neoplasms as well as their malignant transformation.
Mitochondrial abnormalities in oculopharyngeal muscular dystrophy
Authors: Pauzner Rachel , Blatt Ilan , Mouallem Meir , Ben‐David Eitan , Farfel Zvi , Sadeh Menachem 
Published: January 2005

AbstractA family with oculopharyngeal muscular dystrophy (OPMD) is described. Histological and histochemical studies of muscle biopsy showed nonspecific myopathic changes; no “ragged‐red” fibers were seen. Electron microscopy demonstrated bizarre large mitochondria with abnormal cristae, but no intranuclear inclusion bodies. Our findings are compatible with the possibility that OPMD is a heterogeneous syndrome, and may be a manifestation of mitochondrial myopathy.
Comparison of electrodiagnostic criteria for primary demyelination in chronic polyneuropathy
Authors: Bromberg Mark B. 
Published: January 2005

AbstractThree sets of electrodiagnostic criteria for establishing primary demyelination in chronic poly neuropathy are evaluated. Sensitivity is assessed in 70 patients with clinically established chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The criteria use different abnormal values, one adjusts for the effects of axonal loss, while another relies only on conduction velocity. However, even when consideration is given to sufficient number of nerves tested, there is no significant difference (P = 0.37) in diagnostic sensitivity among them, with 48% to 64% of CIDP patients fulfilling criteria for primary demyelination. Specificity is assessed by applying the criteria to 47 patients with motor neuron disease and 63 patients with diabetic polyneuropathy. No patients meet any of the criteria. Further analysis shows that as sensitivity increases specificity decreases, because of overlapping distributions of nerve conduction abnormalities in these neuropathic disorders. A sensitivity of approximately 66% is a practical limit for electrodiagnostic criteria in CIDP.
Central conduction and autonomic nervous function in HMSN I
Authors: Solders Göran , Andersson Thomas , Persson Anders 
Published: January 2005

AbstractCNS conduction and autonomic nervous function were investigated in 15 patients with HMSN I. Central motor conduction time (CMCT) was estimated with magnetic brain stimulation and electrical nerve root stimulation. Somatosensory evoked potential (SEP) and visual evoked potential (VEP) were used for assessment of central sensory and visual conduction. Autonomic effector organ functions were assessed with the R‐R variation test for parasympathetic function, and the sympathetic skin response test (SSR) for skin sympathetic sudomotor activity. Five of the patients had prolonged CMCT. Central sensory conduction was normal in 3, and slightly prolonged in 1 of the patients, but could not be estimated in 11 due to lack of response from the cervical recording. VEP was abnormal in 2 patients. R‐R variations during normal breathing were low in 8 of 15 patients, and low also during deep breathing in 1 of 15. The SSR test was pathological in 5 of 15 patients. Thus, impaired central conduction and/or autonomic dysfunction was not an uncommon finding in patients with HMSN I.
The numbers and relative sizes of motor units estimated by Computer
Authors: Galea Victoria , De Bruin Hubert , Cavasin Richard , McComas Alan J. 
Published: January 2005

AbstractA fully automated system is described for estimating the numbers and relative sizes of functioning motor units in proximal and distal muscles of the arm and leg. In this system, a computer controls the motor nerve stimulation, and analyzes the potentials evoked from the muscles; a subprogram searches for instances of “alternation.” In 33 healthy volunteers, aged 21 to 56 years, the median‐innervated thenar muscles of one hand were tested 2 to 3 times; the mean motor unit estimate was 228 ± 93 SD. For similar numbers of biceps brachii, extensor digitorum brevis, and vastus medialis muscles, the respective mean values were 113 ± 40, 131 ± 45, and 229 ± 108 units. The reproducibility of the method was such that the overall coefficient of variation, for the normalized results from the 121 muscles studied, was 22%. The reliability of the automated method was doubled if 3 estimates, rather than one, were performed on each muscle. Comparisons of the results obtained by automated and “manual” methods indicated that the computer‐derived values tended to be lower by approximately 33%.
Antidystrophin stains triadic junctions in regenerating rat muscles
Authors: Bornemann Antje , Schmalbruch Henning 
Published: January 2005

AbstractDystrophin has biochemically been found in the sarcolemma and in junctional t‐tubules, but immunocytochemistry shows reactivity at the sarcolemma only. In the present study, normal and regenerating soleus muscles of rat were perfused for 10 minutes with 2% formaldehyde; isolated fibers were stained with polyclonal antidystrophins and HRP and embedded in epoxy. Staining of triadic junctions in normal fibers was ambiguous but, in regenerated fibers, 4 weeks after injury it was distinct. Immature myotubes 3 days after injury showed reactivity at the sarcolemma and at various internal membranes. The nonselective staining of internal membranes may be due to secondary binding of the reaction product, and supports the view that dystrophin is cytoplasmic before it becomes restricted to the sarcolemma and t‐tubules.
Electrophysiologic mapping of the segmental anatomy of the muscles of the lower extremity
Authors: Phillips Lawrence H. , Park T. S. 
Published: January 2005

AbstractOur knowledge of the specific root innervation of skeletal muscles is derived from accumulated clinical experience. While performing selective posterior rhizotomy for treatment of spasticity in children with cerebral palsy, we made direct electrophysiologic measurement of the root innervation of the lower extremity. We stimulated ventral roots from L2 to S2 while recording from all muscles simultaneously. The size of the evoked compound muscle action potential was used as an indication of the amount of innervation derived from stimulation of a given spinal root. We found the major root innervation for the 8 muscles studied to be: adductor longus, vastus medialis, and vastus lateralis, L3; tibialis anterior; L4; peroneus longus, L5; and medial gastrocnemius, lateral gastrocnemius, and gluteus maximus, S1. In general, each muscle received innervation from 3 or more roots. Prefixed or postfixed innervation patterns were found in 27.9% of legs examined, and there was asymmetry of innervation in 29.8%. We conclude that the segmental innervation of lower extremity muscles is broader than previously thought. Anomalous innervation occurs so frequently that caution should be used in attributing any pattern of clinical or EMG findings to a specific spinal level.