bluuebunny/crossref_metadata_2025_split huggingface dataset:
EMG power spectrum of respiratory and skeletal muscles during static contraction in healthy man
Authors: Badier Monique , Guillot Chantal , Lagier‐Tessonnier Françoise , Burnet Henry , Jammes Yves 
Published: January 2005

AbstractChanges in EMG power spectrum during isometric voluntary contraction maintained until exhaustion in the range of 20–80% MVC were studied in three skeletal muscles (adductor pollicis or AP, vastus lateralis, and medialis) and two respiratory muscles (diaphragm and rectus abdominis). Quantitative EMG analysis consisted of computation of the median frequency (MF) of power spectra and also the continuous measurement of EMG power in two bands of high (EH) and low (EL) frequencies using bandpass filters. This allowed the calculation of the H/L ratio and its time constant of decay rate (TCHδ /L) throughout the sustained static contraction. The main results were: (1) highly significant, positive correlations between TCδH/L and the maximal MF changes and also the endurance time to fatigue; (2) EMG changes were determined early, within the first 10–20 s of contraction; and (3) EL always increased throughout the fatiguing isometric contraction, but EH changes markedly varied within the five muscle groups studied. These observations are discussed in terms of the differences in muscle fiber composition and also the variations in motor unit recruitment. © 1993 John Wiley & Sons, Inc.
Multifrequency characteristics of disposable and nondisposable EMG needle electrodes
Authors: Ackmann James J. , Lomas John N. , Hoffmann Raymond G. , Wertsch Jacqueline J. 
Published: January 2005

AbstractThe physical properties of recording electrodes coupled with the input characteristics of recording amplifiers can affect motor unit parameters. In recent years, there has been increased use of disposable needle electrodes; thus, a comparison of impedance characteristics with disposable types is of interest. Impedances at 10, 100, 1000, and 10,000 Hz of eight different electrode models including concentric and monopolar, both disposable and reusable, were measured. For all models of monopolar electrodes, no significant difference in impedance was found between disposable and nondisposable types. Intramodel variability was seen, however, with a twofold difference between minimum and maximum impedances for each model. For concentric electrodes, a moderate difference in impedance was found between disposable and nondisposable types, but less intramodel variability was seen; there was also more intermodel variability. To determine whether the measured impedances could affect recorded motor unit potentials, a theoretical analysis was conducted using typical waveforms along with circuit analysis techniques. Electrode impedances as high as 50 times nominal values caused no significant waveform distortion. © 1993 John Wiley & Sons, Inc.
Effects of chronic electrostimulation on rat soleus skinned fibers during hindlimb suspension
Authors: Furby Alain , Mounier Yvonne , Stevens Laurence , Leterme Damien , Falempin Maurice 
Published: January 2005

AbstractIn order to counteract the changes of the contractile properties of the rat soleus occurring during 10 days of hypokinesia‐hypodynamia, due to hindlimb suspension (HS), two different patterns of electrostimulation were applied to the tibial nerve. The contractile properties of single chemically skinned muscle fibers were investigated using the tension–pCa relationship characteristics, the similar or different calcium and strontium affinities, and by measuring the P/tmax kinetic parameters. Our results showed that a pattern similar to firing rates of motoneurons innervating slow twitch muscles inhibited the slow to fast fiber changes observed during HS, whereas a pattern similar to firing rates of motoneurons from fast twitch muscles seemed to favor these changes. Since neither pattern maintained the isometric contractile force developed by the soleus fibers, we concluded that the decrease in mechanical strains imposed on the muscle during unloading was the main factor for the development of atrophy, while the kinetic changes might be predominantly modulated by the nervous command.
Axonal form of Guillain–Barré syndrome: Evidence for macrophage‐associated demyelination
Authors: Berciano José , Coria Francisco , Montón Fernando , Calleja Jesús , Figols Javier , Lafarga Miguel 
Published: January 2005

AbstractWe report on the clinical, electrophysiological, and pathological findings in a patient with pure motor and axonal Guillain–Barré syndrome, who died 29 days after onset. There was marked reduction of compound motor action potential amplitudes and denervation potentials in the tibialis anterior muscle. Motor and sensory conduction velocities of median nerve were normal. Peroneal nerve was inexcitable at the ankle but its latency from knee to tibialis anterior was normal. F waves were absent or delayed. The major burden of pathological changes fell on ventral spinal roots. Fundamental lesions included segmental demyelination, axonal degeneration, widespread endoneurial lipid‐laden macrophage infiltrates, remyelination, and clusters of small regenerating fibers. These findings suggest that axonal damage in the axonal form of Guillain–Barré syndrome is secondary to demyelination.
Hereditary motor–sensory neuropathy and movement disorders
Authors: Cardoso Francisco E. C. , Jankovic Joseph 
Published: January 2005

AbstractTo explore the relationship between hereditary motor and sensory neuropathy (HMSN) and movement disorders, we examined 7 patients with HMSN referred to our Movement Disorders Clinic and surveyed members of the Charcot‐Marie‐Tooth association. The following movement disorders were observed in the index patients: postural tremor in 6, rest tremor in 3, and Parkinsonism and dystonia in 2. Tremor, present in 40% of the 201 patients who responded to the survey, was first noted at a mean age of 36 years, and mostly involved the hands. Family history of tremor was more frequent in the tremor group (P > 0.005), which also had a significantly worse writing score than the nontremor group (P > 0.001). The overlap in clinical features between HMSN‐associated tremor and essential tremor (ET), the high frequency of family history of tremor, and the lack of a relationship between the severity of tremor and of peripheral neuropathy suggest that the tremor in HMSN is pathogenically related to ET. © 1993 John Wiley & Sons, Inc.
Sympathetic skin response abnormalities in amyotrophic lateral sclerosis
Authors: Dettmers Christian , Fatepour David , Faust Harald , Jerusalem Felix 
Published: January 2005

AbstractThe sympathetic skin response (SSR) was evaluated in 25 patients with amyotrophic lateral sclerosis (ALS) to assess for involvement of the autonomic nervous system. Twenty‐two age‐matched normals and 6 patients with muscular dystrophy served as controls. The SSR was intact in all normal volunteers and all patients with muscular dystrophy. The mean SSR latency in the ALS patients was prolonged compared to that of normals (2.29 ± 0.28 versus 2.13 ± 0.16 s, P > 0.05). The SSR was absent in one or both legs of 10 ALS patients (40%). Absence or abnormal latency of SSR in patients with ALS without clinical findings of autonomic failure suggests involvement of the autonomic nervous system in addition to the motor system. © 1993 John Wiley & Sons, Inc.
Quantifying how location and dose of botulinum toxin injections affect muscle paralysis
Authors: Shaari Christopher M. , Sanders Ira 
Published: January 2005

AbstractDespite the widespread use of botulinum toxin to treat muscle dystonias, no method exists to quantify muscle paralysis in either human or nonhuman models. In this study we examined how the location, dose, and volume of botulinum injection affects paralysis in the rat tibialis anterior muscle. Paralysis was quantified by electrically stimulating the nerve to the tibialis anterior and then staining sections of the muscle for glycogen. The areas of glycogen‐containing fibers represented regions of botulinum action. The results showed that the most important injection technique is to inject botulinum directly into the motor endplate region of a muscle. Injections only 0.5 cm from the motor endplate resulted in a 50% decrease in paralysis. Increases in dose increased paralysis, however, some of that increase was simply due to the increased volume of injection. Thus, delivering toxin in small volumes near the MEP band of a muscle should produce the most effectiveparalysis. © 1993 John Wiley & Sons, Inc.
An animal model of neuropathic pain: A review
Authors: Bennett Gary J. 
Published: January 2005

AbstractRecent work has succeeded in producing models of painful peripheral neuropathies in laboratory animals. There is evidence that the animals experience both abnormal spontaneous pain and abnormal evoked pains (allodynia and hyperalgesia). Experimental analyses of these models have demonstrated potential pathophysiologic mechanisms in both the peripheral and central nervous systems; it is likely that the model neuropathic pain syndromes are due to several different mechanisms. One line of evidence suggests that these pain states gradually become centralized due to an excitotoxic effect on spinal cord dorsal horn inhibitory interneurons. The role of the sympathetic nervous system appears to vary, depending on the type of nerve injury and the temporal evolution of the syndrome. There is evidence indicating that theabnormality of cutaneous temperature regulation that often accompanies painful peripheral neuropathy is not necessarily due to the activity of sympathetic vasomotor efferents. © 1993 John Wiley & Sons, Inc.
Congenital myasthenic syndromes: II. Syndrome attributed to abnormal interaction of acetylcholine with its receptor
Authors: Uchitel Osvaldo , Engel Andrew G. , Walls Timothy J. , Nagel Alexandre , Atassi M. Zouhair , Bril Vera 
Published: January 2005

AbstractA 21‐year‐old woman had myasthenic symptoms since birth that responded poorly to anticholinesterase therapy. Tests for acetylcholine receptor (AChR) antibodies were negative. An intercostal muscle specimen was obtained to investigate the character of the neuromuscular transmission defect. There were no immune deposits at the endplates. The quantal content of the endplate potential was normal. Miniature endplate potentials and currents were very small, but the number of AChR per endplate was normal. On electron microscopy, the synaptic vesicles were of normal size, the junctional folds were intact, and the density and distribution of AChR on the folds was normal. The kinetic properties of AChR were studied by analysis of acetylcholine (ACh)‐induced current noise. The mean single channel conductance was normal. The noise power spectrum was abnormal, containing two components of different time course. This could result from an abnormal interaction of ACh with AChR, or from two populations of AChR at the endplate. The second possibility is unlikely because if two populations of AChR were present at the endplate, then both would have to have low conductance to explain the small miniature endplate current, but the average conductance of the channels that did open was normal. © 1993 John Wiley & Sons, Inc.
F tacheodispersion: Quantitative analysis of motor fiber conduction velocities in patients with polyneuropathy
Authors: Chroni Elisabeth , Panayiotopoulos Chrysostomos P. 
Published: January 2005

AbstractThe distribution of motor fiber conduction velocities (FCVs) of the ulnar and peroneal nerves in patients with polyneuropathy was estimated using F tacheodispersion, a technique based on F wave latencies. Twenty‐three ulnar and 23 peroneal nerves were studied. Three groups of nerves were identified according to conventional, M response, and F wave measurements: those with all parameters normal (group 1), those with abnormal F wave parameters only (group 2), and those with all parameters abnormal (group 3). Application of F tacheodispersion to nerves in group 1 revealed a shift of the distribution of FCVs toward the lower normal values in 6 of 7 nerves. In group 2, a significant proportion of FCVs were below the lower normal limits despite normal maximum conduction velocity estimated by the M response. In group 3, all nerve fibers were abnormally slow. The results indicate that application of F tacheodispersion in clinical practice will increase sensitivity of nerve conduction studies and enable quantitative estimation of conduction in a motor nerve fiber population. © 1993 John Wiley & Sons, Inc.
Effect of the inhibitory phenomenon following magnetic stimulation of cortex on brainstem motor neuron excitability and on the cortical control of brainstem reflexes
Authors: Leis A. Arturo , Kofler Markus , Stokic Dobrivoje S. , Grubwieser Gert J. , Delapassebme J. Scott 
Published: January 2005

AbstractWe studied the effect of the inhibitory phenomenon following transcranial magnetic stimulation (TMS) on brainstem motor neuron excitability and on the cortical control of brainstem reflexes in 5 normal subjects. The R1 component of the blink reflex assessed excitability of the facial nucleus during the period of post‐TMS inhibition (experiment 1). TMS effect on the cortical control of brainstem reflexes was assessed by delivery of a stimulus that was less than or equal to the threshold for the R1 with the subject relaxed, yet elicited a potentiated reflex during maneuvers requiring cortical input (i.e., voluntary eye‐closure and anticipation, experiment 2). In experiment 1, a suprathreshold electric stimulus applied during post‐TMS inhibition elicited an R1 response that was preserved in amplitude (mean 476 ± 44 μV; 123%) compared to control responses not preceded by TMS (mean 386 ± 31 μV). Conversely, in experiment 2, when the R1 was dependent on cortical drive, the mean R1 amplitude during post‐TMS inhibition was only 15% (P < 0.01) and 8% (P < 0.01) of control values obtained during eye‐closure and anticipation, respectively. These findings imply that the inhibition following TMS originates rostral to the facial nucleus, at a cortical level. © 1993 John Wiley & Sons, Inc.
The effects of hyperthyroidism on muscular dystrophy in the mdx mouse: Greater dystrophy in cardiac and soleus muscle
Authors: Anderson J. E. , Liu L. , Kardami E. 
Published: January 2005

AbstractMuscle damage and repair were studied in mdx mice treated with triiodothyronine (T3) for 14 days. Hindlimb and cardiac muscles were examined for the severity of dystrophy, the degree of muscle centronucleation, and fiber size. In control and mdx mice, cardiac hypertrophy and skeletal muscle atrophy were present after T3 treatment. Both cardiac and soleus (but not fast‐twitch) muscles had larger, more frequent dystrophic lesions in T3‐treated mdx mice, and mdx soleus had an increased area of new myotubes after T3. Skeletal myogenesis in mdx mice may have been delayed by excess T3, possibly related to the general reduction in staining for basic fibroblast growth factor in hyperthyroid mice. These are the first observations of a metabolic perturbation which worsens mdx dystrophy and possibly repair in a musclespecific manner, and are likely related to T3‐induced changes in myosin heavy chain expression, and to increased mechanical strain on dystrophin‐deficient muscles. © 1994 John Wiley & Sons, Inc.
Long lasting excitability changes in human peripheral nerve
Authors: Potts Frisso , Young Robert R. , Shefner Jeremy M. 
Published: January 2005

AbstractWhen pairs of equal but submaximal electrical stimuli are delivered to a peripheral nerve, the second stimulus does not always excite the same number of fibers as the first. The number of fibers responding to the second stimulus depends on the interstimulus interval; the refractory period, a well‐defined period of hypoexcitability, is followed by longer lasting and less well‐characterized periods of hyper‐ and hypoexcitability. These cycles last at least 200 ms after the initial stimulus. We have carefully studied these cycles of excitability in human peripheral nerve in 12 normal subjects. The magnitude of excitability changes were found to be much greater in motor fibers than in mixed nerve; under some conditions, the motor response was reduced by more than 80% at interstimulus intervals of 40 ms, while the mixed nerve response never varied by more than 20%. In addition, the amplitude of the excitability changes varied as a function of the stimulus strength, so that stimuli that were near threshold or evoked near maximal responses were associated with smaller excitability changes than stimuli evoking midrange responses. Given that the excitability fluctuations are of large magnitude and occur at interresponse intervals easily achieved during physiological firing, it is suggested that they may be important modifiers of firing rate under experimental or physiological conditions. © 1994 John Wiley & Sons, Inc.
Inability of insulin to maintain normal nerve function during high‐frequency stimulation in diabetic rat tail nerves
Authors: Andersen H. , Nielsen J. F. , Nielsen V. Kamp 
Published: January 2005

AbstractThe effect of insulin on the response to long‐term high‐frequency stimulation (HFS = 143 Hz for 20 min) was studied in mixed tail nerves of acute streptozotocin‐induced diabetic rats. In consecutive tests, untreated diabetic rats showed a significant decrease in nerve conduction velocity (NCV) and peak‐to‐peak amplitude (P‐Pamp) and the depression of the P‐Pamp during HFS was augmented. In contrast, NCV and P‐Pamp in the insulin‐treated rats were unchanged from the prediabetic state, but the depression of the P‐Pamp during HFS reached the same degree as in untreated rats. This implies that although insulin treatment of acute experimental diabetes is able to preserve a normal NCV and P‐Pamp in the resting state, it is unable to preserve normal nerve function under stress produced by HFS. Monitoring of the axon membrane functional capacity may have clinical implications in the control of peripheral neuropathies. © 1994 John Wiley & Sons, Inc.
Do GM1 antibodies induce demyelination?
Authors: Lange Dale J. , Trojaborg Werner 
Published: January 2005

AbstractWe review clinical, neurophysiological, immunological, and experimental data concerning multifocal motor neuropathy (MMN), a newly recognized disorder that mimics MND. It is separated from MND by the presence of multifocal conduction block (CB) demonstrated electrophysiologically, and in some instances by the association of high liters of GM1 antibodies. The possible immunopathogenetic effect of GM1 antibodies is discussed. However, 70% of patients with MMNCB do not have elevated titers of GM1 antibodies, but may respond nevertheless to immunosuppressive treatment. Thus, so far unrecognized antibodies may react against some other epitopes in the paranodal region than those attacked by GM1 antibodies to cause CB. © 1994 John Wiley & Sons, Inc.
Transcranial magnetic stimulation in patients with cervical spondylotic myelopathy: Clinical and radiological correlations
Authors: Tavy Dénes L. J. , Wagner G. Louis , Keunen Ruud W. M. , Wattendorff A. Rolf , Hekster Ruben E. M. , Franssen Hessel 
Published: January 2005

AbstractMotor evoked potentials (MEPs) were studied in 28 patients with cervical spondylotic myelopathy. MEPs after cortical stimulation were abnormal in 27 patients, the responses in the leg muscles being affected the most often. Clinically asymptomatic motor lesions were detected in 7 patients (25%). The central motor conduction time (CMCT) for the abductor digiti minimi muscles correlated significantly with the clinical disability, whereas the radiological findings did not correlate with the clinical and neurophysiological parameters. In 9 patients MEPs were also recorded in the biceps muscles. The 7 patients with an abnormal CMCT for the biceps muscles had the most severe stenosis at the C‐4–C‐5 level or higher. The 2 patients with normal MEPs of the biceps muscles both had a stenosis at the C‐5–C‐6 level. The results of this study suggest that MEPs are useful for detecting spinal cord dysfunction and for localizing the level of the lesion. Some recommendations regarding the possible use of MEPs in the clinical evaluation of patients with cervical spondylotic myelopathy are given. © 1994 John Wiley & Sons, Inc.
Pseudoneurogenic thoracic outlet syndrome
Authors: Simpson David M. 
Published: January 2005

AbstractA 61‐year‐old man developed progressive weakness, numbness, and exercise‐induced vascular symptoms in the left hand. There was left thenar wasting. The presence of a supraclavicular bruit and vascular studies indicated left subclavian artery stenosis, but electrophysiological studies demonstrated no evidence for brachial plexopathy. Subsequent neuroimaging studies revealed multifocal right cerebral infarction. Focal atrophy and weakness from a cerebral lesion can simulate a brachial plexus lesion. © 1994 John Wiley & Sons, Inc.
Median nerve sensory responses evoked by tactile stimulation of the finger proximal and distal phalanx in normal subjects
Authors: Caruso Giuseppe , Nolano Maria , Lullo Francesco , Crisci Claudio , Nilsson Jan Bsee , Massini Riccardo 
Published: January 2005

AbstractWe compared the characteristics of near‐nerve recorded sensory potentials elicited in response to electrical stimulation of digital nerves versus tactile stimulation of the digital skin in 17 healthy subjects with a mean age of 26 years. We also calculated the density of Meissner's corpuscles in the distal and proximal phalanx of digit III of 6 males who had suffered a violent death, but were free from diseases of the peripheral nerve system. Responses to tactile stimulation had a longer latency and lower amplitude than responses to electrical stimulation. Unlike electrically elicited responses, responses to tactile stimulation, which consisted of six or seven main spike components plus several minor components, were similar in recordings from the wrist and elbow. However, with proximal stimulation the electrically evoked responses were more compact and had a higher amplitude and area, whereas the tactile evoked potential became significantly reduced in maximum amplitude and cumulative area. The differences in sensory conduction between distal and proximal could reflect activation of a larger number of nerve fibers when electrical stimuli are used and a smaller amount of mechanoreceptors when tactile stimuli are used. © 1994 John Wiley & Sons, Inc.
Retrograde effects of digital nerve severance on somatosensory evoked potentials in man
Authors: Chu Nai‐Shin 
Published: January 2005

AbstractTo determine if retrograde conduction changes might occur long after injury of the most distal peripheral nerves, short‐latency somatosensory evoked potentials (SEPs) to median or ulnar nerve stimulation at the wrist were studied in 10 subjects who had sustained traumatic digit amputation 4 months to 15 years previously. SEPs were recorded from Erb's point (N9), the cervical region (N13), and the contralateral scalp hand area (N20). While N9 latency was slightly delayed or not affected, the amplitude was either markedly reduced or undetectable. For N13 and N20 components, latency prolongation and amplitude reduction were mild to moderate, but the central conduction time (N13–N20) remained normal. The present data indicate that even the most distal nerve injury may have profound long‐term retrograde effects on parental nerve function which are presumed mainly due to an axonopathy. © 1994 John Wiley & Sons, Inc.
Focal lipoatrophy
Authors: Jablecki Charles K. 
Published: January 2005

AbstractFocal atrophy of a limb is usually caused by loss of muscle due to nerve or muscle disease. However, focal atrophy of subcutaneous tissues, an uncommon but well described entity, can mimic neuromuscular disease by producing a similar appearance of the limb. The clinical sign of thinness of the subcutaneous tissues (the “pinch‐an‐inch” test) suggests lipoatrophy as the cause of limb asymmetry. © 1994 John Wiley & Sons, Inc.