bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of dose of microspheres on nerve blood flow, electrophysiology, and fiber degeneration of rat peripheral nerve
Authors: Kihara Mikihiro , Zollman Paula J. , Schmelzer James D. , Low Phillip A. 
Published: January 2005

AbstractMicrosphere embolization of peripheral nerve results in a variable degree of ischemic fiber degeneration. To enhance the utility of the model, we evaluated the relationship between dose of microspheres to the supplying arteries of the sciatic‐tibial nerve to nerve blood flow (NBF), electrophysiology, morphology, and behavioral changes. There was considerable variability in the effect of embolization on nerve pathology in individual nerves. However, the dose of microspheres regressed with the degree of hindlimb paresis, reduction in NBF, degree of fiber pathology, and ischemic conduction failure of the tibial nerve, evaluated at day 7. All nerves with severe (grade 4) fiber degeneration had flows of < 3mL · 100g‐1 · min‐1. We conclude that it is possible to predict with a high degree of accuracy the severity of fiber degeneration by the degree of NBF reduction and by the electrophysiologic abnormalities. © 1993 John Wiley & Sons, Inc.
Antiganglioside antibodies do not necessarily play a role in multifocal motor neuropathy
Authors: Parry Gareth John Glyn 
Published: January 2005

AbstractMultifocal motor neuropathy (MMN) is a disorder with a highly characteristic clinical picture and one which is defined by a specific electrodiagnostic abnormality, namely, multifocal conduction block which is confined to motor axons. Sensory axons which traverse segments of severe or even complete motor conduction block conduct normally. A proportion of patients with MMN also have elevated levels of antibodies to GM1 ganglioside. However, about one half of MMN patients lack elevated levels of these antibodies and many others have only modest elevations, to a degree often seen in other neurological and even non‐neurological disorders. Furthermore, clinical and electrophysiological improvement of MMN in response to treatment with high dose intravenous immunoglobulin is achieved in the absence of any change in antiglycolipid levels. Injection of serum from patients with MMN and elevated GM1 antibody levels produces demyelination in recipient rat nerves, suggesting a pathogenetic role for these antibodies in demyelination. However, sera of patients with identical antibody liters in other motor system diseases produced no demyelination, suggesting that the demyelinating factor resides in some other serum fraction. At present, there is insufficient evidence to support the contention that these antibodies play a critical pathogenetic role in MMN. Until more evidence is available it is important to define MMN on the basis of a characteristic clinical picture and a unique electrodiagnostic abnormality rather than on a pattern of serum antibodies. © 1994 John Wiley & Sons, Inc.
The clinical and diagnostic role of anti‐GM1 antibody testing
Authors: Kornberg Andrew J. , Pestronk Alan 
Published: January 2005

AbstractThere is increasing evidence that multifocal motor neuropathy (MMN) and some lower motor neuron (LMN) syndromes are immune‐mediated and treatable. The frequent occurrence of high titers of anti‐GM1 antibodies in these motor neuropathies raised hopes that serum testing would provide useful diagnostic information. Unfortunately, in routine practice, simple quantification of IgM binding to GM1 ganglioside has proved to be a test with poor sensitivity and specificity. We have found that much greater sensitivity and specificity for MMN and LMN syndromes can be obtained by determining serum antibody binding to panels of antigens, such as GM1, histone H3, and NP‐9. These results suggest that combined measurement of serum antibody binding to GM1 and other antigens can provide tests that are useful in the diagnosis and management of motor neuropathy syndromes. © 1994 John Wiley & Sons, Inc.
Single fiber EMG and repetitive stimulation of the same muscle in myasthenia gravis
Authors: Gilchrist James M. , Massey Janice M. , Sanders Donald B. 
Published: January 2005

AbstractWe performed RNS and SFEMG studies of the same muscle in 46 patients with myasthenia gravis. Maximum decrement to 3–5‐Hz stimulation before and after maximum voluntary exercise, percentage of action potential pairs with increased jitter and blocking, and mean MCD in each study were compared. A significant decrement (> 10% decrease in CMAP area or amplitude between the first and fourth response) was never found without increased jitter and impulse blocking on SFEMG. Increased jitter, blocking, and mean MCD were each correlated with maximum decrement (r > 0.61, P < 0.0001). We conclude that decrement to RNS and impulse blocking on SFEMG result from the same physiologic phenomenon, and that SFEMG is more sensitive at detecting disordered neuromuscular transmission given its ability to detect impulse blocking at levels below the resolution of RNS and increased neuromuscular jitter when there is not blocking. © 1994 John Wiley & Sons, Inc.
Multifocal motor neuropathy: Electrodiagnostic features
Authors: Chaudhry Vinay , Corse Andrea M. , Cornblath David R. , Kuncl Ralph W. , Freimer Miriam L. , Griffin John W. 
Published: January 2005

AbstractDiagnosis of multifocal motor neuropathy (MMN), a syndrome characterized by progressive asymmetric weakness with intact sensation, is important because the disorder often responds to treatment. Multifocal partial motor conduction block (PMCB) has been emphasized as a cardinal feature in the diagnosis of this syndrome, but detailed nerve conduction studies are not available. Nine patients, ages 28–58, had chronic, progressive, asymmetric, predominantly distal limb weakness for 5–18 years. Sensation was normal and reflexes were reduced asymmetrically. Although all 9 demonstrated PMCB localized to short nerve segments, additional features of multifocal motor demyelination were present, including temporal dispersion (5 patients), segmentally reduced motor nerve conduction velocity (7 patients), prolonged distal motor latency (4 patients), and prolonged F‐wave latency (9 patients). The strength of all patients improved after treatment with human immune globulin. A reduction in the degree of PMCB or an increase in the distal motor amplitude or both accompanied the clinical improvement. These studies suggest that patients with MMN demonstrate widespread evidence of motor demyelination in addition to the well‐described PMCB, and that reduction of PMCB accounts for the increase in strength following therapy. © 1994 John Wiley & Sons, Inc.
X‐linked bulbospinomuscular atrophy (Kennedy's disease) masquerading as lead neuropathy
Authors: Albers James W. , Bromberg Mark B. 
Published: January 2005

AbstractA 43‐year‐old male was referred by a veterinarian who evaluated his dog for a seizure and suspected a toxic lead exposure for both. He refurbished houses, removing old paint, and complained of decreased cognition, fatigue, and muscle cramps. He had a depressed affect, postural tremor, right arm weakness with partial denervation on EMG, and borderline‐low sensory nerve action potential (SNAP) amplitudes. A mild anemia and elevated serum and urine lead levels supported a diagnosis of lead neuropathy. Chelation therapy increased urine lead excretion without symptomatic improvement. His brother worked part‐time with him and developed similar findings, but also had difficulty chewing, dysphagia, perioral twitching, gynecomastia, and multifocal denervation of extremity and facial muscles. His lead levels were not elevated, but an androgen receptor mutation identified on the X chromosome for both brothers confirmed the diagnosis of X‐linked bulbospinomuscular atrophy (Kennedy's disease). © 1994 John Wiley & Sons, Inc.
Electromyography and biopsy correlation with suggested protocol for evaluation of the floppy infant
Authors: David William S. , Jones H. Royden 
Published: January 2005

AbstractEighty infants with nonarthrogrypotic floppy infant syndrome (FIS) were evaluated between 1979 and 1990. Electromyographic data were correlated with results of muscle and nerve biopsies in 41 of 80 who had concomitant biopsies (38) or other diagnostic analyses (3). A diagnosis was made of Werdnig–Hoffmann disease (WHD) in 15, a congenital infantile polyneuropathy (IPN) in 3, neuromuscular transmission defect (NMTD) in 2, myopathy in 12, and presumed “central” hypotonia in 9. A very positive correlation rate between nerve conduction studies with electromyography and biopsy results was found in 93% (14 of 15) with WHD and 100% in IPN (3 of 3). However, only 4 of 10 infants (40%) with biopsy‐proven myopathy had an abnormal EMG. Only once did the results of electromyography and biopsy conflict. © 1994 John Wiley & Sons, Inc.
Motor unit territory in relation to tendons in the human masseter muscle
Authors: Tonndorf Mônica L. , Hannam Alan G. 
Published: January 2005

AbstractIn the human masseter, motor‐unit (MU) territories are reportedly focal and it is possible that they are confined to the muscle's internal aponeuroses. However, previous electromyographic (EMG) investigations of MU sizes have not correlated them with the muscle's internal architecture. In this study, 162 single‐MU territories were assessed by scanning EMG recordings throughout the masseter muscles of 4 subjects. The needle‐electrode scans were stereotactically located with magnetic resonance imaging and an optical system capable of tracking the needle movement in three dimensions. Mediolateral territorial dimensions were then displayed graphically within muscle reconstructions. The mean territorial width was 3.7 ± 2.3 mm and varied between 0.4 and 13.1 mm. The widths were comparable in size to those of previous reports, and were related to the subject's muscle size. Most MU territories were confined, and lay between tendons, although 10% of the units clearly extended across at least one tendon. The dispersion of most territories within discrete tendon‐bounded compartments in the masseter provides an anatomical basis for selective activation of the muscle. However, it is also possible that this arrangement provides a flexible means for ensuring tendon stiffness and mechanical adaptation of the multipennate masseter during growth and development, whether or not the muscle is activated selectively. © 1994 John Wiley & Sons, Inc.
Temperature dependence of nerve conduction and EMG in neuropathy associated with gammopathy
Authors: Notermans Nicolette C. , Franssen Hessel , Wieneke George H. , Wokke John H. J. 
Published: January 2005

AbstractThe effects of warming on nerve conduction variables and electromyography were studied in 15 patients with a polyneuropathy associated with monoclonal gammopathy of undetermined significance. In each patient median nerve (motor, sensory) and tibial nerve (motor) conduction parameters were measured before and after warming in water at 36°C. Warming: (1) increased the conduction velocity (CV); (2) decreased the distal motor latency, amplitude, and duration of the corn f pound muscle or nerve action potential; and (3) caused fibrillations to appear in 1 patient. The increase in CV with temperature depended upon the CV after warming: the lower this CV, the smaller the increase in CV with temperature (ΔCV/Δ). Correction of median nerve motor CV before warming with 2.2 m/s per °C yielded CV values which were higher than the CV values after warming, because in most patients ΔCV/Δ was less than 2.2 m/s per °C. Because of differences in ΔCV/Δ values, it is more accurate to warm the extremity than to correct for temperature. © 1994 John & Sons, Inc.
Immunocytochemistry of muscle cytoskeletal proteins in acid maltase deficiency
Authors: Vita Giuseppe , Migliorato Alba , Toscano Antonio , Bordoni Andreina , Bresolin Nereo , Fiumara Agata , Messina Corrado 
Published: January 2005

AbstractImmunocytochemistry of dystrophin, spectrin, vinculin (sarcolemmaspecific proteins), and desmin (an intermediate filament protein) were investigated in 5 patients with acid maltase deficiency (AMD). One patient had infant onset, 2 had childhood onset, and 2 had adult onset. All had a vacuolar myopathy with autophagic vacuoles containing glycogen and cytoplasmic degradation products. Dystrophin, spectrin, and vinculin were localized at the sarcolemma as in normal muscle fibers. Within the cytoplasm of many fibers, immunoreactivity for the three proteins was seen as single or multiple spots or as circular structures, which most likely corresponded to the limiting membrane of vacuoles. Desmin was overexpressed at the periphery of some vacuoles. It is plausible that, before exocytosis occurs, sarcolemma‐specific proteins appear within the vacuole membrane. Vacuole immunolabeling frequently occurred in the patients with childhood and adult onset AMD, but very rarely occurred in the case with infant onset. We hypothesize that a reduced exocytosis rate might explain the infrequent vacuole immunolabeling and the early onset of the infant form of the disease. © 1994 John Wiley & Sons, Inc.
Axonal Guillain–Barré syndrome
Authors: Feasby Thomas E. 
Published: January 2005

AbstractThe issue of “axonal” Guillain–Barré syndrome (GBS) remains controversial. Supportive evidence comes from pathological examination of peripheral nerves in 4 extreme cases of GBS 17–29 days after onset which showed severe axonal degeneration without inflammatory‐demyelination. It has been suggested that inflammatory‐demyelination may have been missed. This is difficult to disprove but it seems unlikely, given the known correlation between the severity of axonal degeneration and inflammation/demyelination in the experimental model of GBS, experimental allergic neuritis (EAN). Electrically inexcitable nerves in GBS may reflect axonal degeneration, terminal demyelination or both. This finding proved to be a sign of poor prognosis in 19 of 27 (70%) patients, although a good outcome occurred in some cases. © 1994 John Wiley & Sons, Inc.
Central fatigue as revealed by postexercise decrement of motor evoked potentials
Authors: Brasil‐Neto Joaquim P. , Cohen Leonardo G. , Hallett Mark 
Published: January 2005

AbstractWe have previously shown that the amplitudes of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) were transiently decreased after exercise, indicating fatigue of motor pathways in the central nervous system. The responsible mechanism is apparently decreased efficiency in the generation of the descending volleys in the motor cortex. We also noted a progressive decrement inamplitude from the first to the fourth MEP. To further clarify the mechanism of this phenomenon, 5 subjects were studied with TMS deliveredat the rates of 0.1, 0.15, 0.3, 1, 3, and 6 Hz. The effect was best demonstrated at 0.3 Hz, and occurred after both isometric and isotonic exercise. Three of the subjects also had 0.3‐Hz percutaneous electrical stimulation of the brainstem, and a decrement in MEP amplitude did not occur. Further, the delivery of TMS during muscle contraction after muscle fatigue failed to produce a decrement. The results are similar to those found at the neuromuscular junction in myasthenia gravis and are consistent with a reduced safety factor of cortical synaptic transmission in central nervous system fatigue. © 1994 John Wiley & Sons, Inc.
Acute postasthmatic amyotrophy (Hopkins' syndrome)
Authors: Liedholm Laps Johan A. , Eeg‐Olofsson Orvar , Ekenberg B. Ewa K. , Nicolaysen Randi Beck , Torbergsen Torberg 
Published: January 2005

AbstractAcute postasthmatic amyotrophy is a rare condition, previously reported in only 26 cases. It is characterized by a sudden onset of a flaccid paralysis of an arm or a leg with completely preserved sensibility, about 1 week after an asthmatic attack. The cause is probably due to a lesion of the anterior horn of the spinal cord, but evidence indicates a more widespread pathological process. The etiology is unknown. but infectious or immunological mechanisms are likely. © 1994 John Wiley & Sons, Inc.
Sensory and mixed nerve conduction studies in the evaluation of ulnar neuropathy at the elbow
Authors: Raynor Elizabeth M. , Shefner Jeremy M. , Preston David C. , Logician Eric L. 
Published: January 2005

AbstractThe relative sensitivities of sensory, mixed nerve, and motor conduction studies in assessing ulnar neuropathy at the elbow have not yet been established. Using surface electrodes, we performed conduction studies across the elbow segment in 43 patients with symptoms referable to the ulnar nerve and 40 control subjects. Segmental slowing of motor conduction localized the lesion to the elbow in 14 of 21 patients (67%) with clear evidence of ulnar neuropathy on physical examination but only in 2 of 22 (9%) with subtle or no physical examination abnormalities. The diagnostic yield was increased by the finding of segmental slowing of sensory or mixed nerve conduction across the elbow to 86% and 68%, respectively, for each of the groups. We conclude that surface‐recorded sensory and mixed nerve conduction studies appear to be more sensitive than motor studies in the electrodiagnosis of ulnar neuropathy at the elbow and are especially valuable in patients with subtle clinical involvement. © 1994 John Wiley & Sons, Inc.
Acute peripheral neuropathy due to hereditary coproporphyria
Authors: Barohn Richard J. , Sanchez Jose A. , Anderson Karl E. 
Published: January 2005

AbstractA 23‐year‐old man with epilepsy and a past history of abdominal pain and ileus, developed hypertension and arm and bulbar weakness when valproic acid and carbarnazepine were reinitiated. Electrophysiologic studies demonstrated a peripheral neuropathy with features of axonal degeneration and demyelination. Axonal degeneration was documented by sural nerve biopsy. Markedly elevated urinary 8‐aminolevulinic acid and porphobilinogen indicated a diagnosis of acute porphyria. Other laboratory studies were most consistent with hereditary coproporphyria. Motor function improved considerably but incompletely over 1 year. An acute, primarily motor neuropathy can occur in several forms of porphyria, including acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria, sometimes even in the absence of concomitant gastrointestinal symptoms. © 1994 John Wiley & Sons, Inc.
Computational methods for improving estimates of motor unit twitch contraction properties
Authors: Lim K. Y. , Rymer W. Z. , Thomas C. K. 
Published: January 2005

AbstractEstimates of mechanical properties of human motor units have usually been made indirectly, using the technique of “spike‐triggered averaging” (STA). In this method, a single motor unit action potential is used to synchronize the accumulation of an ensemble average of correlated force transients. However, under most realizable conditions, these transients are recorded during periods of sustained motor unit discharge, in which each motor unit is producing a partially fused tetanus. Therefore, the STA technique extracts the characteristics of the unfused force transient, instead of the desired single motor unit twitch. Although the STA method has been widely used, there is as yet no wellestablished relation between the force transient in the unfused tetanus, and the twitch contraction properties of the motor unit. To evaluate the accuracy of the STA as a measure of the motor unit mechanical properties, we applied two types of muscle models to the force transients recorded in an unfused tetanus, using data derived from experiments in which the response to a single twitch was also recorded. Our objective was to see whether accurate predictions of single motor unit mechanical characteristics are possible, working backward from the STA. The models chosen for this task were a linear second order model, and the distribution‐moment (DM) model. These model predictions were then compared with the STA response, and with the twitch properties of the individual motor units. We also evaluated the utility of extrapolating the initial slope of the STA backward to improve the accuracy of the mechanical estimates. The results of our simulation suggest that there is no straightforward relation bwtween the characteristics of the unfused tetanus and the mechanical properties of the single twitch. Although our attempts to predict the properties of the single twitch from the STA were only partly successful, the results of the simulations were far more accurate than those derived from the STA alone. Because the errors in the use of the STA method were so substantial, we would urge that the STA technique be used with great caution as a measure of twitch contraction properties, unless accompanied by appropriate simulations of muscle mechanical behavior.© 1995 John Wiley &Sons, Inc.
Multiple innervation of muscle fibers in myasthenia gravis
Authors: Trontelj Jožze V. , Stålberg Erik V. 
Published: January 2005

AbstractSingle fiber EMG recordings from patients with myasthenia gravis obtained during axonal microstimulation revealed an occasional bimodal distribution of response latencies. This phenomenon could be dependent on stimulus strength, however, in a way different from that in the axon reflex. It is suggested to be due to dual neuromuscular junctions (NMJs) supplied by two different motor neurons. Some cases of bimodal jitter were not dependent on stimulus strength and are assumed to be due to dual innervation by the same neuron. The phenomenon could only be demonstrated at abnormal NMJs with partial impulse blocking. It is suggested to reflect multiple reinnervation of muscle fibers that had undergone functional or structural denervation in the course of the immune attack against the original NMJ. This study suggests that the coexisting NMJs from the same or different motor neurons may be functional at the same time.© 1995 John Wiley &Sons, Inc.
Comparison of the flexed and extended elbow positions in localiziing ulnar neuropathy at the elbow
Authors: Kothari M. J. , Preston D. C. 
Published: January 2005

AbstractElectrophysiologic localization of ulnar neuropathy at the elbow often depends on demonstration of segmental slowing. Based on normative data obtained from 50 control subject, we compared the utility of flexed and extended elbow positions in demonstrating focal slowing at the elbow as compared to the forearm segment in patients with ulnar neuropathy. We studied 35 patients with ulnar neuropathy with definite electrophysiologic localization to the elbow segment defined by conduction block across the elbow segment or by focal slowing demonstrated either in the flexed or extended position. Applying cutoff values from the control group, all 35 patients demonstrated focal slowing at the elbow in the flexed position, whereas only 5 of 35 (14%) patients did so in the extended position. We Conclude that the flexed elbow position is more sensitive than the extended position in localizing ulnar neuropathy at the elbow and should be the preferred method when performing ulnar motor conduction studies.© 1995 John Wiley &Sons, Inc.
Transcranial magnetic stimulation of the trigeminal nerve: Intraoperative study on stimulation characteristics in man
Authors: Schmid Urs D. , Møller Aage R. , Schmid Judith 
Published: January 2005

AbstractWe studied responses from the masseter and nasalis muscles following magnetic stimulation (magStim) and compared these responses with those obtained by direct electrical stimulation of the trigeminal (NV) and facial (NVII) nerve near the root exit zone during microvascular decompression operations of NVII. We found that (1) magStim threshold to excite the nerve is high for NV and low for NVII; (2) excitation of all motor fibers is impossible for NV, and easy for NVII; (3) optimal coil placement is critical for NV, but not critical for NVII; and (4) between and within subjects, the excitation site is variable on NV, but stable on NVII. We estimated that the anatomical location of magStim to be either within or outside the cerebrospinal fluid for NV, and to be in the labyrinthine segment of the facial canal for NVII. Physical models explain and clinical lesion models support these differences found between NV and NVII. © 1995 John Wiley & Sons, Inc.