bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paradoxical lid elevation with sustained upgaze: A sign of lambert‐eaton syndrome
Authors: Breen Lenore A. , Gutmann Ludwig , Brick John F. , Riggs Jack R. 
Published: January 2005

AbstractMyasthenia gravis and Lambert‐Eaton myasthenic syndrome are causes of acquired extraocular muscle weakness and ptosis. Exacerbation of ptosis after sustained upgaze is a clinically useful sign in the diagnosis of myasthenia gravis. A 54‐year‐old woman with established Lambert‐Eaton myasthenic syndrome exhibited transient improvement of her ptosis after sustained upgaze. We suggest that paradoxical lid elevation after sustained upgaze may be a clinically useful sign in distinguishing Lambert‐Eaton myasthenic syndrome from myasthenia gravis.
Invited review: Motor neuropathies, motor neuron disorders, and antiglycolipid antibodies
Authors: Md Alan Pestronk, 
Published: January 2005

AbstractHigh titers of IgM anti‐GM1 antibodies are commonly found in the serum of patients with some lower motor neuron disorders and peripheral neuropathies. Enzyme‐linked immunosorbent assays (ELISA) are useful for the detection and quantitation of anti‐GM1 antibodies. Testing for serum anti‐GM1 activity is indicated in the diagnostic evaluation of lower motor neuron syndromes. The presence of high titers of anti‐GM1 antibodies mandates careful electrophysiologic testing for the motor conduction block that is found in multifocal motor neuropathy, a treatable disorder. Quantitation of anti‐GM1 antibodies may also be a useful guide in the treatment of multifocal motor neuropathy. Further study of antiglycolipid antibodies in motor neuron disorders and peripheral neuropathies may provide clues to the events that stimulate these antibodies and to the pathogenesis of such syndromes.
Estimate of motor conduction in human spinal cord: Slowed conduction in spinal cord injury
Authors: Chang Chein‐Wei , Lien I‐Nan 
Published: January 2005

AbstractBy using motor evoked potential (MEP) created by transcranial electric stimulation over the motor cortex and F‐wave measurement from the peripheral nerve stimulation, it is possible to estimate the spinal cord motor conduction velocity (SCMCV) in the diseased state. Twenty‐four patients with spinal cord injury (SCI) between T1 and T11 neurological levels participated in this study. MEP in leg muscle was absent in all neurologically complete paraplegics. In 16 patients with neurologically incomplete SCI, MEP was obtained in 13 patients. The SCMCV estimated from C7 to T12 spinal levels was 32.1 (SD = 9.4) m/s. This was significantly slower than 63.3 (SD = 8.6) m/s in 40 normal controls. This noninvasive, indirect method is measurable, and can provide valuable electrophysiological data in the assessment of motor function in patients with SCI.
Canine X‐linked muscular dystrophy studied with in vivo phosphorus magnetic resonance spectroscopy
Authors: McCully Kevin , Giger Urs , Vet Met , Argov Zohar , Valentine Beth , Cooper Barry , Chance, Britton 
Published: January 2005

AbstractDuchenne muscular dystrophy (DMD) is an X‐linked disease characterized by progressive muscle weakness and degeneration. Dystrophin is the product of the missing gene in this disorder. However, the cause of the dystrophic process is not understood. Transient muscle injury is normally seen after muscle exercise, and may be a necessary process in muscle growth and preservation. We, therefore, chose to evaluate the role of exercise in Duchenne dystrophy by studying the canine X‐linked animal model (CXMD). These dogs also lack dystrophin and have clinical signs similar to humans. Exercise was initiated by electrical stimulation, and muscle metabolism was monitored with phosphorus magnetic resonance spectroscopy (P‐MRS). Dogs with CXMD had abnormal muscle pathology and markedly elevated serum CK. The inorganic phosphate (Pi) to phosphocreatine (PCr) ratio was increased in CXMD dogs at rest compared with normal dogs (Pi/ (Pi+PCr) = 0.166 ± 0.054 for CXMD and 0.073 ± 0.017 for normals, mean ± SE). No changes in resting ATP, pH, phosphomonoesters (PME), and phosphodiesters (PDE) were seen. The mean Pi/(Pi+PCr) and pH values during stimulation were normal in the CXMD dogs. Two to three days after electrical stimulation, resting Pi/(Pi+PCr) ratios were significantly increased in the CXMD dogs (0.127 ± 0.029 compared with 0.172 ± 0.054, mean ± SD). Normal dogs showed no increase in Pi/(Pi+PCr) following stimulation. There was a 50‐fold greater increase in serum CK in CXMD compared with normal dogs following exercise. These results indicate greater muscle injury in CXMD muscle, and suggest that in the absence of dystrophin, exercise‐induced muscle injury may play a role in the dystrophic process.
Comparison of sensory nerve conduction in the palmar cutaneous branch and first digital branch of the median nerve: A new diagnostic method for carpal tunnel syndrome
Authors: Chang Chein‐Wei , Lien I‐Nan 
Published: January 2005

AbstractComparison of sensory nerve conductions in palmar cutaneous branch (PCB) and digit I nerves was applied in 50 patients suspected of having carpal tunnel syndrome (CTS) and 40 healthy persons. The abnormalities were defined as the differences in latencies and sensory nerve conduction velocities (SNCVs) of more than mean plus 2.5 SD of controls. Comparing these 2 sensory nerves, statistical differences were seen in 83.7% (36 of 43 patients) of their sensory latencies and 76.7% (33 of 43 patients) of their SNCVs. This excluded 7 patients who had unobtainable sensory nerve action potentials in digit I nerves. This method may serve as an adjunctive technique in the diagnosis of CTS. Its diagnostic sensitivity was high in comparison with other testing methods.
Myokymic discharges and enhanced facial nerve reflex responses after recovery from idiopathic facial palsy
Authors: Valls‐Sole Josep , Tolosa Eduard S. , Pujol Montserrat 
Published: January 2005

AbstractA functional disorder of facial muscle activity commonly occurs in patients after recovery from Bell's palsy with axonal degeneration. The postparalytic facial dysfunction is probably related to the aberrant growing of regenerating axons. although other theories such as ephaptic transmission, spontaneous generation of impulses, and enhancement of motoneuron excitability should also be considered. In this work, we have carried out a comparative electrophysiological study of both sides of the face in 23 patients who had recovered from a unilateral Bell's palsy with axonal degeneration. At rest, spontaneous firing of motor units was observed in muscles of the previously paralyzed side. Direct motor responses to facial nerve stimulation were smaller in the muscles of the previously paralyzed side, but reflex responses obtained in the same muscles by stimulation of either the facial or trigeminal nerve were larger when compared with those of the contralateral side. These data indicate that patients with “postparalytic facial dysfunction” may have an increased background muscle activity, as well as an enhanced recruitment of facial motoneurons to reflex activation in the side of the previous paralysis. These findings are compatible with an enhanced level of motoneuron excitability in the facial nucleus.
Possible model for generation of P9 far‐field potentials
Authors: Hashimoto Shuji , Kawamura Junichiro , Segawa Yoshiaki , Yamamoto Toru , Nakamura Michikazu 
Published: January 2005

AbstractThe distribution of P9 far‐field somatosensory evoked potentials, after ulation of the median nerve with a knee reference, was examined to mine the mechanism of the generation of P9 potentials. In addition to tive potentials (P9s), we found a negative potential (N9) recorded from the chest ipsilateral to the stimulation. The simulation of the distribution of these P9/N9 potentials by an electrical circuit diagram suggested the validity of this model for generation of the P9s.
Single fiber macro versus concentric trigger macro EMG: A comparison of methods
Authors: Nix Wilfred A. , Scherer Andreas 
Published: January 2005

AbstractThe values obtained from two different macro EMG methods were compared, and found to be different. Normally, macro electromyography (EMG) is performed with a modified single fiber (SF) needle using the SF potential as a trigger; a new method recommends a modified concentric needle and triggers on the concentric EMG signal. The concentric macro EMG has a 40% to 50% smaller amplitude and area values than data obtained with a SF macro EMG needle. The different values are the result of variant spatial relationships of the respective needles to the motor unit under stud, and may be due to a recruitment‐dependent bias resulting from different trigger properties of the two methods. The concentric macro EMG needle can be used to estimate motor unit size, to scan the unit, and to investigate its different concentric EMG signals.
Guidelines in electrodiagnostic medicine
Authors:   American Association Of Electrodiagnostic Medicine
Published: January 2005

AbstractThe American Association of Electrodiagnostic Medicine (AAEM) is committed to the development of sound and clinically relevant guidelines through review of literature, expert opinion and consensus. In 1979, with the assistance of its Professional Practice Committee and association leaders, the association published its initial guidelines, Guidelines in Electrodiagnostic Medicine, covering the practice of electrodiagnostic medicine. The committee is charged with ongoing revision of the document, as needed, and the current version includes standards of practice in clinical electromyography, risks in electrodiagnostic medicine, basic equipment requirements, and the role of paramedical support. In 1988, Educational Guidelines for Electrodiagnostic Training Programs (Appendix A) was prepared by the AAEM Training Program Committee and added to aid training program directors in establishing new training programs or in reviewing the current status of the educational aspects of existing programs. In 1986, the AAEM charged its Quality Assurance Committee with the responsibility for the development of guidelines pertinent to electrodiagnostic medical consultations. The impetus for the charge was the requests received from members of the AAEM and other interested parties for educational material on indications for and conduct of electrodiagnostic medical consultations. As a result of the committee's efforts, Suggested Guidelines for Electrodiagnostic Medical Consultations (Appendix D), was published in 1989 and additional sections added subsequently. The current document includes (1) general indications for an electrodiagnostic medical consultation for patients with suspected myopathies, neuromuscular junction disorders, polyneuropathies, mononeuropathies, plexopathies, radiculopathies, neuronopathies and central nervous system disorders, (2) specific indications for patients with suspected lumbosacral or cervical radiculopathies, (3) general principles of electrodiagnostic studies, including techniques and diagnostic categories, and (4) an overview of electrodiagnostic studies for patients with suspected carpal tunnel syndrome, idiopathic polyneuritis, amyotrophic lateral sclerosis and myasthenia gravis.
In vitro microelectrode study of neuromuscular transmission in a case of botulism
Authors: Maselli Ricardo A. , Burnett Margaret E. , Tonsgard James H. 
Published: January 2005

AbstractWe performed in vitro microelectrode studies in the anconeus muscle biopsy of a 6‐week‐old infant intoxicated with Clostridium botulinum toxin B. The most striking abnormalities were the severe reduction of the endplate potential (EPP) quantal content and the marked variability of EPP latencies. The increased variability was often limited to a “single quantum” component of the EPP. Neither the amplitudes nor the frequencies of spontaneous miniature endplate potentials (MEEPs) were decreased. However, there was a wide range of amplitudes and frequencies of MEPPs. This unique combination of electrophysiologic findings indicates a severe presynaptic failure of neuromuscular transmission, which appears to result from an impairment of the process of synaptic vesicle release taking place after the stimulus induced influx of calcium into the motor nerve terminals.
Quantitative motor unit analysis: The effect of sample size
Authors: Engstrom John W. , Olney Richard K. 
Published: January 2005

AbstractThis study of quantitative electromyography examines the influence of sample size on motor unit action potential (MUAP) tolerance limits, intertrial variability, and diagnostic sensitivity. We recorded 20 randomly selected MUAPs from the biceps muscle twice in 21 normal subjects, and once in 10 patients with myopathy. The 95% tolerance limits for mean total duration in normal subjects progressively narrowed from 6.6 to 14.2 ms for 5 MUAPs to 7.4 to 13.0 ms for 20 MUAPs. The 95% tolerance limits for intertrial variability were ±22% for mean total duration of 20 MUAPs. Larger sample size had a greater effect on reducing intertrial variability than on narrowing 95% tolerance limits for amplitude and area. Quantitative EMG results for duration supported the presence of myopathy in 2 of 10 patients with analysis of 5 MUAPs, and 9 patients with analysis of 20 MUAPs. Although analysis of 5 potentials may be adequate for diagnosis occasionally, quantitative analysis of 20 MUAPs narrows tolerance limits, reduces intertrial variability, and improves diagnostic sensitivity.
Contractility Of mdx skeletal muscle after denervation and devascularization
Authors: Mechalchuk Cheri L. , Bressler Bernard H. 
Published: January 2005

AbstractTo evaluate the regenerative capacity of mdx skeletal muscle, changes in contractile properties of the fast‐twitch extensor digitorum longus (EDL) of normal and mdx mice were studied at 7 and 16 weeks of age, following denervation and devascularization (DD) at 4 weeks of age. At 7 weeks, DD EDL of both strains showed significantly decreased isometric twitch and tetanus tensions compared with their non‐DD controls. By 16 weeks, normal operated muscle exhibited a recovery of 57% and 58% of absolute tetanus and twitch tensions while the mdx EDL recovered remarkably to 96% and 99% of 7‐week values. At 7 weeks, the DD EDL of both strains exhibited significantly slower time‐to‐peak (TTP) and one‐half relaxation time (1/2RT). By 16 weeks, TTP and 1/2RT of the mdx DD EDL no longer differed from non‐DD controls, but the normal EDL showed slowed TTP. No differences were found in the maximum velocity of shortening (Vo) or in posttetanic potentiation (PTP). Following DD, there was an increase in resistance to fatigue in both strains at 7 weeks. This resistance persisted at 16 weeks in the normal mouse, but the operated mdx EDL returned to normal. It would appear that following a denervation/devascularization insult, the mdx EDL is able to recover contractile characteristics to a remarkably larger extent than normal EDL.
Eye movement disorder: An early expression of the myotonic dystrophy gene?
Authors: ter Bruggen Jan P. , Tijssen Cees C. , Brunner Han G. , van Oost Bernard A. , Bastiaensen Louis A. K. 
Published: January 2005

AbstractEye movement recording (EMR) has been performed in 5 asymptomatic myotonic dystrophy (MyD) gene carriers, 7 mildly affected MyD patients, and 23 age‐ and sex‐matched healthy controls. The purpose of the study was to evaluate whether eye movement abnormalities are an early expression of the MyD gene, and to determine the value of this procedure for detection of otherwise asymptomatic gene carriers. EMR did not reveal any abnormalities in the asymptomatic group, but in the mildly affected group showed significantly (P < 0.01) decreased maximum velocities of the saccades, compared with controls. The results indicate that EMR may aid in the detection of mildly affected MyD patients. However, true presymptomatic diagnosis with EMR has not yet proven possible.
Repression of the embryonic myosin heavy chain phenotype in regenerating chicken slow muscle is dependent on innervation
Authors: Gao Lizhu , Kennedy John M. 
Published: January 2005

AbstractVentricular‐like and fast myosin heavy chains (VL‐MHC and FMHC) are transiently expressed during slow skeletal muscle development. The influence of innervation on repression of these MHC isoforms is investigated over an 84‐day time course in: (1) normal anterior latissimus dorsi (N‐ALD) muscles, (2) regenerating ALD (R‐ALD) muscles, (3) denervated ALD (D‐ALD) muscles, and (4) regenerating and denervated ALD (RD‐ALD) muscles. Western blotting demonstrates that the VL‐MHC is expressed in R‐, D‐, and RD‐ALD muscles, but not in N‐ALD muscles. Expression of the VL‐MHC is transient in R‐ALD musles. In contrast, VL‐MHC expression persists in RD‐ALD muscles, and appears with time in D‐ALD muscles. FMHC was not detected in N‐ALD muscles by Western blotting. Two FMHCs are seen in R‐ALD and RD‐ALD muscles, and in 13‐day emryonic ALD muscles. The slower migrating FMHC (FMHCA) comigrates with developmentally regulated FMHCs in fast pectoralis muscle, while the faster migrating FMHC (FMHCB) comigrates with the faster migrating FMHC in embryonic ALD muscle (13 days in ovo). FMHCB decreases in amount over the time course in R‐ALD muscles, while FMHCA persists. In contrast, substantial levels of both FMHCs persist in RD‐ALD muscles, and appear with time in D‐ALD muscles. The cellular distribution of MHCs is followed by immunocytochemistry. Regenerating cells expressing VL‐MHC and FMHC are replaced by a mature population in R‐ALD muscles. Some of the mature myofibers in R‐ALD muscles express FMHC, but not VL‐MHC. In RD‐ALD and D‐ALD muscles, both regenerating and mature muscle cells are seen which express VL‐MHC and FMHC. Our results indicate that innervation is required for the repression of VL‐MHC and FMHCB during regneration of slow muscle.
Evaluation of phrenic nerve and pulmonary function in hereditary motor and sensory neuropathy, type I
Authors: Carter Gregory T. , Kilmer David D. , Bonekat H. William , Lieberman James S. , Fowler William M. 
Published: January 2005

AbstractPhrenic nerve and diaphragmatic dysfunction has been assumed to be the cause of respiratory failure in hereditary motor and sensory neuropathy, type 1 (HMSN I). In order to determine the relationship between phrenic nerve and pulmonary function in this disease, 25 patients underwent a 4‐step evaluation process consisting of: (1) bilateral phrenic nerve conduction study; (2) median, peroneal, and tibial motor conduction studies; (3) measurement of forced vital capacity (FVC) and maximal inspiratory and expiratory pressures (MIP, MEP); and (4) pulmonary‐focused history and physical. Phrenic nerve motor latency was abnormally prolonged in 22 of the 23 (96%) subjects when a response was obtained. All had slowed velocity or absent peripheral motor conduction responses. Vital capacity was abnormally reduced in 6 of the 25 (24%) subjects. Eight (32%) had an abnormally reduced MIP, while 19 (76%) had an abnormally reduced MEP. Only 2 (8%) subjects had clinical evidence of pulmonary dysfunction. None of the depenent variables (FVC, MIP, MEP, peripheral nerve conduction, or clinical examination) correlated with phrenic nerve latencies. Although phrenic nerve latencies are markedly prolonged in HMSN I, these values are not useful in predicting respiratory dysfunction.
Blink reflex measurement of effects of trichloroethylene exposure on the trigeminal nerve
Authors: Feldman Robert G. , Niles Clyde , Proctor Susan P. , Jabre Joseph 
Published: January 2005

AbstractTrichloroethylene (TCE) exposure is known to have specific toxic effects on cranial nerves, the trigeminal nerve (V) in particular. The electrophysiological measurement of the blink reflex (BR) can quantify changes in the Vth and VIIth cranial nernve reflex arc. Prior study looked at the their drinking water. This study evaluated the use of the electrophysiologic blink reflex as an indicator of neurotoxic effects of TCE in occupationally exposed workers. The BR was tested in individual cases with documented histories of exposure to known chemical neurotoxins including TCE (n = 18). When compared with the nonexposed laboratory control values (n = 30), the subjects with a significant history TCE exposure demonstrated the most prolonged latencies (≥ 3.0 SD above the nonexposed group mean) in the R1 component of the blink reflex measurement. The electrophysiological study of te blink reflex has application in assesing TCE exposure and in documenting the neurotoxic effects of that exposure on trigeminal nerve functions in humans.
Guillain–Barré syndrome in children: Clinical course, electrodiagnosis, and prognosis
Authors: Bradshaw Deborah Young , Jones H. Royden 
Published: January 2005

AbstractThe electrodiagnostic features of acute childhood Guillain‐Barré syndrome (GBS) have not been distinguished from those in the adult. We report nerve conduction and electromyographic data from 23 children. Sixty‐one percent (14 of 23) fulfilled strict electrodiagnostic criteria for a demyelinating neuropathy, and the remainder demonstrated demyelination in at least one nerve. Reduced compound muscle action potential (CMAP) amplitude was the most common finding overall. Children <10 years old demonstrated significantly greater slowing of motor CV than children >10 years old. Electrodiagnostic criteria associated with poor outcome (low mean CMAP and fibrillation potentials) in previous studies, primarily of adult patients, occurred in 39% (9 of 23 children). All patients on whom follow‐up data were obtained recovered without residual disability. We conclude that electrodiagnostic prognostic indicators identified in general series of GBS may not apply to children.
Phrenic nerve conduction studies
Authors: Swenson Michale R. , Rubenstein Robert S. 
Published: January 2005

AbstractTo refine in the technique of phrenic nerve conduction, we first studied electrode positioning and sources of chest wall artifact. Diaphragmatic compound motor action potentials (DCMAPs) were mapped at close intervals over 4 hemithoraces of two subjects, finding optimum recording sites which were then used to quantitate artifacts due to EKG, chest wall EMG, and configurational thoracic changes of respiration. Based on these findings, 20 normal subjects were studied, showing ease of application and good side‐to‐side agreement for DCMAP laterncies; but, in contrast to prior reports, right‐to left correlation for amplitude and waveform was poor, making the unaffected side an unreliable standard in unilateral partial phrenic nerve lesions.