bluuebunny/crossref_metadata_2025_split huggingface dataset:
Early and late motor evoked potentials reflect preset agonist–antagonist organization in lower limb muscles
Authors: Tarkka Ina M. , McKay W. Barry , Sherwood Arthur M. , Dimitrijevic Milan R. 
Published: January 2005

AbstractA single transcranial magnetic stimulus can evoke two involuntary muscle responses in lower limb muscles of healthy humans. The purpose of the present study was to find out if these responses, when evoked during the processing period of a simple or choice reaction time task, such as ankle dorsiflexion, have specific characteristics related to the task. During the auditory reaction time, a transcranial magnetic stimulus was delivered to observe changes in the excitability of the central nervous system. A dual‐cone coil was used, which effectively stimulated the fairly deep‐lying lower limb motor cortex. Stimuli were delivered in a random order with 20–300‐ms delays from the auditory gosignal. Motor evoked potentials (MEP) in right and left anterior tibial and soleus muscles were analyzed while early MEPs were observed invariably in both muscles; late MEPs occurred consistently only in soleus muscles. Both early and late MEP amplitudes were larger in simple reaction time trials than in choice reaction time trials. The late MEP appeared earlier in the simple reaction time task than in the choice reaction time task, reflecting faster central processing of simple reaction time tasks. The amplitude of the soleus late MEP in the simple reaction time task followed closely the amplitude of anterior tibial early MEP, suggesting a preset agonist–antagonist organization. This relationship was not present in the choice reaction time task.© 1995 John Wiley &Sons, Inc.
Evaluation of the cardiomyopathy in becker muscular dystrophy
Authors: Nigro Giovanni , Comi Lucia I. , Politano Luisa , Limongelli Francesco M. , Nigro Vincenzo , De Rimini Maria L. , Giugliano Maria A. M. , Petretta Vito R. , Passamano Luigia , Restucci Brunella , Fattore Luciano , Tebloev Konstantine , Comi Luigi , De Luca Francesco , Raia Pasquale , Esposito Maria G. 
Published: January 2005

AbstractTo evaluate the features and the course of cardiomyopathy in Becker muscular dystrophy, 68 patients–identified by clinical assessment and by reduced dystrophin labeling and/or DNA analysis–were followed in the years 1976–1993, for periods ranging from 3 to 18 years (mean 8). Patients periodically underwent clinical, electrocardiographic, echocardiographic, nuclear, and radiological assessments. Preclinical cardiac involvement was found in 67.4% of patients under 16 years of age, decreasing to 30% in patients older than 40. Clinically evident cardiomyopathy was found in 15% of patients under 16 years of age, increasing to 73% in patients older than 40. A real, dilated cardiomyopathy is the most frequent type of myocardial involvement after the age of 20. Results show that the severity of cardiac involvement can be unrelated to the severity of skeletal muscle damage and confirm that cardiac dysfunction is a primary feature of Becker muscular dystrophy.© 1995 John Wiley &Sons, Inc.
An EMG case report of lead neuropathy 19 years after a shotgun injury
Authors: Wu Peter B. J. , Date Elaine S. , Kingery Wade S. 
Published: January 2005

AbstractThe clinical picture of lead neuropathy was classically described as a painless progressive motor neuropathy with axonal loss. The literature review fails to demonstrate a consensus on the site of axonal loss. This is an EMG report of a patient who developed a late lead neuropathy after a shotgun injury. A 69‐year‐old Filipino, healthy, male nondrinker sustained a shotgun injury to his left elbow. Nineteen years later he developed abdominal pain, followed by generalized weakness, distal greater than proximal in the extremities, and impaired pin‐prick, proprioception, and two‐point discrimination. He became nonambulatory and totally dependent in daily activities. He was lost to follow‐up for 2 years until January 1993 when he presented with a blood lead level of 84 μ/dL. EMG examination revealed a sensorimotor peripheral polyneuropathy with severe axonal loss. This case demonstrates that axonal loss is the predominant feature in lead neuropathy and the location of pathology is in the peripheral nerves.© 1995 John Wiley &Sons, Inc.
Sympathetic sudomotor function and aging
Authors: Ferrer Teresa , Ramos María J. , PÉRez‐JiméNez Angeles , PÉRez‐Sales Pau , Alvarez Eduvigis 
Published: January 2005

AbstractMany studies have reported the influence of aging on different portions of the autonomic nervous system components but only partially for the sympathetic cholinergic system. We evaluated postganglionic sudomotor function in 196 healthy subjects, 104 women and 92 men, by determining sweat gland density (SGD) per square centimeter of skin, on the dorsum of the hand and foot, with the impression mold technique. The age range was from 5 to 84 years. A significant decrease of SGD was observed in both hand and foot in relation to age (P < 0.001). The ANOVA analysis of foot data shows that age is the only significant factor for SGD reduction. In the hand, both sex and body surface area are significant covariates with age. The dorsum of the foot is the most appropriate place to examine sweating in studies of aging. The lower normal limits for SGD in the foot are 213/cm2 for subjects younger than 30 years, 199/cm2 for those from 30 to 59 years, and 123/cm2 for subjects over 59 years old. © 1995 John Wiley & Sons, Inc.
Calcium exchange hypothesis of skeletal muscle fatigue: A brief review
Authors: Williams Jay H. , Klug Gary A. 
Published: January 2005

AbstractSkeletal muscle fatigue is often associated with diminished athletic performance and work productivity as well as increased susceptibility to injury. The exact cause of muscle fatigue probably involves a number of factors which influence force production in a manner dependent on muscle fiber type and activation pattern. However, a growing body of evidence implicates alterations in intracellular Ca2+ exchange as a major role in the fatigue process. These changes are thought to occur secondary to reductions in the rates of Ca2+ uptake and release by the sarcoplasmic reticulum (SR). This hypothesis is based on the finding that peak myoplasmic Ca2+ concentration ([Ca2+]i) is reduced as force declines during fatigue. In addition, direct measurements of Ca2+ uptake and release show that fatiguing activity causes intrinsic alterations in the functional properties of the SR. We also propose that fatigue‐induced alterations in Ca2+ exchange may be beneficial, reducing the rate of energy utilization by the muscle fiber and preventing irreversible damage to the cell. © 1995 John Wiley & Sons, Inc.
Maximal force and endurance to fatigue of respiratory and skeletal muscles in chronic hypoxemic patients: The effects of oxygen breathing
Authors: Zattara‐Hartmann Marie Caroline , Badier Monique , Guillot Chantal , Tomei Charles , Jammes Yves 
Published: January 2005

AbstractThe consequences of chronic hypoxemia on maximal force and endurance time to sustained 80% of maximal isometric contraction of two skeletal muscles (adductor pollicis and vastus lateralis) and the diaphragm were studied in patients with chronic obstructive pulmonary disease (COPD). Compared to normal subjects, COPD patients have lower values of Fmax for the two skeletal muscle groups and Pmax (diaphragm). Endurance time was also shorter for the diaphragm and adductor pollicis. Chronic hypoxemia was associated with an accentuation in integrated EMG changes in both low and high frequency bands for adductor pollicis and diaphragm. Inhalation of oxygen enriched gas mixture for a 15‐min period increased markedly Fmax and Pmax values, prolonged the endurance time to sustained thumb adduction, and reduced the EMG changes in the low frequency band for adductor pollicis. The present observations provide evidence for altered maximal performances of skeletal muscles in chronic hypoxemic patients and also point out the virtues of oxygen breathing in these patients. © 1995 John Wiley & Sons, Inc.
Stimulation distal to the lesion in patients with carpal tunnel syndrome
Authors: Lesser E. A. , Venkatesh S. , Preston D. C. , Logigian E. L. 
Published: January 2005

AbstractIn patients with carpal tunnel syndrome, low action potential amplitude after stimulation at the wrist (proximal to the lesion) is due to either demyelination or axonal degeneration. Demyelination can be distinguished from axonal degeneration by the presence of amplitude drop across the lesion. Amplitude drop is determined by comparison of action potential amplitude evoked by stimulation at the palm (distal to the lesion) with that of the wrist. Of 59 consecutive CTS patient hands, 36 (61%) showed significant reduction in CMAP and/or antidromic SNAP amplitudes at the wrist compared to the palm, indicating the presence of focal demyelination resulting in conduction block vs. pathologic dispersion with phase cancellation. Moreover, the smaller the wristevoked action potential amplitude, the greater the amplitude drop across the lesion. We conclude that in patients with CTS, as in other entrapment neuropathies, stimulation both proximal and distal to the lesion provides important pathophysiological information about the median nerve lesion. © 1995 John Wiley & Sons, Inc.
Three‐dimensional MR imaging of brain surface anomalies in fukuyama‐type congenital muscular dystrophy
Authors: Toda Tatsushi , Watanabe Toshiaki , Matsumura Kiichiro , Sunada Yoshihide , Yamada Hiroki , Nakano Imaharu , Mannen Toru , Kanazawa Ichiro , Shimizu Teruo 
Published: January 2005

AbstractFukuyama‐type congental muscular dystrophy (FCMD), the second most common childhood muscular dystrophy in Japan, is characterized by the association with severe brain anomalies such as pachygyria and focal interhemispheric fusion. Conventional imaging techniques such as X‐ray CT scan and MRI are ineffective for visualization of these brain surface anomalies. Here we investigated the efficacy of three‐dimensional (3‐D) reconstruction of brain surface MR images for the detection of brain anomalies in FCMD patients. 3‐D brain surface MR images clearly visualized anomalies of cerebral gyrus such as pachygyria, as well as focal interhemispheric fusion. In addition, reconstructed horizontal images visualized structural derangement such as abnormal protrusion of white matter into gray matter. MR image abnormalities were confirmed by autopsy in 1 patient. These abnormalities were never observed in Duchenne muscular dystrophy (DMD) patients. Our results indicate the efficacy of the present method for the differential diagnosis between FCMD and DMD with severe mental retardation, which is essential for the genetic study to identify the causative gene of FCMD. © 1995 John Wiley & Sons, Inc.
Median/ulnar premotor potential identification and localization
Authors: Dumitru Daniel , King John C. 
Published: January 2005

AbstractA small negative waveform is known to precede the median and ulnar compound muscle action potentials when recorded with surface or concentric needle electrodes. This investigation documents that there are two distinct waveforms preceding the median compound muscle action potential (CMAP) depending upon the type of recording electrodes used (concentric needle versus surface) and their respective locations. The negative waveform originally described with a concentric needle electrode positioned within the substance of the distal thenar eminence and having a restricted zone of detection is referred to as the intramuscular nerve action potential (INAP). This potential is shown to be distinct from the premotor potential (the small negative waveform preceding surface recorded ulnar and median CMAPs). Detection of the median and ulnar premotor potentials at multiple locations about the hand with the same respective onset/peak latencies and amplitudes substantiates that this potential is a far‐field potential. The median and ulnar premotor potentials most likely originate from a dipolar moment imbalance generated by digital sensory nerve action potentials as they cross the first and fifth metacarpophalangeal junctions, respectively. Applying far‐field principles permits the documentation of additional far‐field potentials as they are generated at the second through fourth metacarpophalangeal junctions following median nerve stimulation. Also, because the premotor potential is a far‐field potential, caution must be exercised with respect to its diagnostic utility as joint position and other unknown factors may affect amplitude and onset/peak latency. The INAP following median nerve excitation, however, is documented to be a near‐field potential distinct from the premotor potential arising from the recurrent branch of the median nerve. Therefore, although the median intramuscular nerve action potential and premotor potentials both precede the compound muscle action potential, they are different potentials with unique generator sites. © 1995 John Wiley & Sons, Inc.
A noninvasive method of neurography in meralgia paraesthetica
Authors: Spevak Milica Klopčič , Prevec Tine S. 
Published: January 2005

AbstractThe lateral femoral cutaneous nerve (LFCN) becomes superficial 10 cm distal to the anterior superior iliac spine, where it can be located and stimulated by superficial electrodes. This is not the case in the inguinal region. In the present study the LFCN compound nerve action potential (NAP) was recorded with a pair of 8‐cm‐long strip electrodes placed on the anterolateral aspect of the thigh 25 cm distal to the stimulating electrodes. Normative values were obtained in 58 healthy nerves. The conduction velocity (CV) was 62.3 ± 5.5 m/s for NAP onset and 55.3 ± 4.1 m/s for the negative NAP peak. The CV variability was comparable to that obtained with needle recordings despite a relatively low NAP amplitude (2.0 ± 1.0 μV). This method provided definite neurophysiological evidence of the disorder in 12 of 13 patients with meralgia paraesthetica. According to our results, a slowing of CV is a more reliable sign of the condition than a decrease of NAP amplitude alone. © 1995 John Wiley & Sons, Inc.
Lambert—Eaton myasthenic syndrome (LEMS) in association with lymphoproliferative disorders
Authors: Argov Zohar , Shapira Yehuda , Averbuch‐Heller Lea , Wirguin Itzhak 
Published: January 2005

AbstractLEMS is a presynaptic neuromuscular junction disorder typically associated with small cell lung carcinoma. The characteristic electrophysiological abnormality is a low amplitude compound muscle action potential that shows a marked increment after short maximal contraction or brief tetanic nerve stimulation. Here we describe 3 patients who had LEMS in association with lymphoproliferative disorder. The first patient had Castleman's syndrome with typical clinical and electrophysiological features of LEMS, which responded partially to treatment with 3–4‐diaminopyridine. The second patient was a 7‐year‐old boy who had an unusual acute onset of LEMS associated with relapse of his Burkitt's leukemia. The third patient was a 60‐year‐old woman with non‐Hodgkin's lymphoma. These 3 patients (together with 6 additional patients identified in the literature) lead us to suggest that lymphoproliferative diseases are another, hitherto unrecognized, type of malignancy associated with LEMS. Thus, any patient with these malignancies and unexplained muscle weakness should have electrophysiological evaluation for LEMS. © 1995 John Wiley & Sons, Inc.
Five‐year experience in the treatment of focal movement disorders with low‐dose dysportTM botulinum toxin
Authors: Van Den Bergh P. , Francart J. , Mourin S. , Kollmann P. , Laterre E. C. 
Published: January 2005

AbstractWe report the results of botulinum toxin type A (DysportTM, Porton Products, UK) treatment over 5 years in 107 patients with blepharospasm, Meige's syndrome, oromandibular dystonia, hemifacial spasm, cervical dystonia, and writer's cramp. Electromyography was used to localize dystonic muscles and guide DysportTM injections in Meige's syndrome, oromandibular dystonia, cervical dystonia, and writer's cramp. All but 2 Meige's syndrome and 2 writer's cramp patients responded to treatment. Improvement was dramatic in blepharospasm (79%) and hemifacial spasm (90%); pronounced in cervical dystonia (74%); and moderate in Meige's syndrome (53%), oromandibular dystonia (57%), and writer's cramp (34%). Although DysportTM doses were 50–75% lower than usually reported, response and improvement rates as well as relapse intervals were similar to those of others. To treat cervical dystonia relapses, only 50% of the initial dose was required for continued optimal relief of symptoms. Low‐dose DysportTM was associated with a very low incidence of dysphagia in cervical dystonia. © 1995 John Wiley & Sons, Inc.
Limited longitudinal sliding of the median nerve in patients with carpal tunnel syndrome
Authors: Valls‐Solé Josep , Alvarez Ramiro , He Montserrat Nuñez 
Published: January 2005

AbstractDuring normal movements or changes in position of the limbs, nerve structures must accommodate the resulting changes in length of the nerve path. In patients with carpal tunnel syndrome, we monitored electrophysiologically the longitudinal adjustment of the median nerve to positions of extreme flexion and extreme extension of the wrist and elbow, by measuring the differences induced in the latency of the sensory nerve action potential (SNAP) recorded in the forearm and upper arm. In patients, the latency difference was significantly shorter than in normal subjects (0.196 ± 0.084 ms vs. 0.088 ± 0.059 ms in the forearm, and 0.485 ± 0.122 ms vs. 0.129 ± 0.086 ms in the upper arm). These results indicate that the displacement of the source of the median nerve SNAP with movements of flexion and extension is limited in patients with carpal tunnel syndrome. Such an abnormality may partly underlie the pathophysiology of entrapment syndromes. © 1995 John Wiley & Sons, Inc.
Cerebrospinal fluid and serum from patients with inflammatory polyradiculoneuropathy have opposite effects on sodium channels
Authors: Würz Axel , Brinkmeier Heinrich , Wollinsky Kurt H. , Mehrkens Hans‐H. , Kornhuber Hans H. , Rüdel Reinhardt 
Published: January 2005

AbstractThe effects of cerebrospinal fluid (CSF) and serum from patients having Guillain–Barré syndrome (GBS) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) on voltage‐dependent Na+ channels were compared. Bathing human myoballs in CSF substantially reduced their Na+ currents (by >40% with 8 of 10 patients) elicited at 1 Hz under whole‐cell recording conditions. This was because, at the resting potential, more Na+ channels were inactivated (left‐shift of the h∞ curve). CSF from patients with other neurological diseases (OND) produces a similar, but smaller, effect. In contrast, serum samples from the same GBS and OND patients caused an increase of the Na+ currents by reducing the number of Na+ channels inactivated at the resting potential. This right‐shift of the h∞ curve is in part explained by the effect of serum albumin. We confirm that the CSF of most GBS and CIDP patients contains factors inhibiting voltage‐dependent Na+ currents. There is no indication that such factors are effective in the serum of these patients. © 1995 John Wiley & Sons, Inc.
Involvement of the external anal sphincter in amyotrophick lateral sclerosis
Authors: Carvalho M. , Schwartz M. S. , Swash M. 
Published: January 2005

AbstractIn amyotrophic lateral sclerosis the striated pelvic floor sphincter muscles are functionally uninvolved, and pathological studies have confirmed the relative resistance of the Onuf nucleus motor neurons. We have evaluated the external anal sphincter (EAS) muscle in 16 patients with ALS using single fiber EMG, and compared the results with the findings in the semimembranosus‐semitendinosus (SM‐ST) muscles that have innervation from the L‐5, S‐1, and S‐2 segments. The results were compared with a group of controls matched for age and sex. None of the patients or controls had symptomatic sphincter involvement and none of the 4 women studied were parous. Eight patients with ALS showed an increased fiber density in the EAS; 6 had an abnormal neuromuscular jitter. In 1 there was fibrillation in the EAS. In the SM‐ST muscle 11 patients showed an increased fiber denstiy, and 7 had an abnormal neuromuscular jitter. In 3 patients with ALS in whom there were abnormal findings in the EAS the bulbocavernosus reflex and pudendal nerve evoked potentials were normal. Neurogenic change was more marked in the SM‐ST than in the EAS muscle. These findings show that the EAS is not normal in ALS. However, the relative resistance of the EAS to ALS is sufficient to prevent incontinence, even in the longer‐surviving older patients. © 1995 John Wiley & Sons, Inc.
Foot drop as a harbinger of aortic occlusion
Authors: Larson Wendy L. , Wald John J. 
Published: January 2005

AbstractA man presented with foot drop and 2 months later an infrarenal occlusion of his abdominal aorta was discovered. Initial evaluation found no structural etiology for his nerve injury. His neurologic deficits progressed until gangrenous changes developed in his feet leading to the discovery of aortic occlusion. This case demonstrates that peripheral nerve injury in the legs may signal underlying large vessel occlusive disease. We discuss the localization and potential mechanisms of ischemic nerve injury. © 1995 John Wiley & Sons, Inc.
Single fiber electromyography of extraocular muscles: A sensitive method for the diagnosis of ocular myasthenia gravis
Authors: Rivero Alberto , Crovetto Luis , Lopez Lidia , Maselli Ricardo , Nogués Martín 
Published: January 2005

AbstractWe performed single fiber electromyography (SFEMG) in the superior rectus and levator palpebralis (SR‐LP) muscles of 17 patients with pure ocular myasthenia gravis (MG) and 9 controls. Thirteen patients were also assessed with SFEMG in the orbicularis oculi (OO) muscle. All the MG patients but none of the control subjects showed abnormal SFEMG jitter in the SR‐LP muscles. On the other hand, only 62% of the MG patients had abnormal SFEMG jitter in the OO muscle. The procedure was well tolerated by the patients, and complications were minor. We conclude that SFEMG of the SR–LP muscles is a safe and highly sensitive technique for the diagnosis of ocular MG. © 1995 John Wiley & Sons, Inc.
Generators of the early and late median thenar premotor potentials
Authors: Park Tracy A. , Del Toro David R. 
Published: January 2005

AbstractThe generator sources of the median thenar premotor potentials (PMPs) have remained elusive despite debate in the literature. By studying the median nerve in the hand with a variety of bipolar and referential recording montages, we systematically examined the possible nearfield and far‐field sources that may determine these potentials. The results suggest that the early PMP is a near‐field potential recorded by G1 and generated by the median nerve traversing the distal carpal tunnel. The late PMP represents a far‐field potential generated by the median digital nerve fibers as they pass from the palm volume into the thumb volume. Characteristics of the late PMP are explained using the leading/trailing dipole (L/TD) model of far‐field potential generation. The diagnostic utility of these PMPs is questionable, since they are recorded from “regions” along the nerve rather than from more clearly defined sites. © 1995 John Wiley & Sons, Inc.