bluuebunny/crossref_metadata_2025 huggingface dataset:
Retardation of fast axonal transport in wobbler mice
Authors: Mitsumoto Hiroshi , Kurahashi Kozo , Jacob Jane M. , McQuarrie Irvine G.
Published: January 2005

To investigate axonal function in a model of early motor neuron disease, we examined fast and slow components of anterograde axonal transport in the less‐affected hindlimb motor neurons of wobbler mice. To study the fast component (FC), we injected tritiated amino acids into the lumbar spinal cord and retrieved the sciatic nerve after 2 or 3 h. The transport distance was the extent of the plateau of labeling; regression analysis indicated that FC was 25% slower in wobbler mice than in unaffected littermates (P < 0.01). To study slow component (SC), [35S] methionine was injected. Transport distances were to the peaks of labeling for structural proteins after 2 or 3 weeks. Rates for each subcomponent (SCa and SCb) were unaffected by wobbler disease. Because the rate of retrograde FC is also unaffected (Mitsumoto et al., Muscle & Nerve 13:121–126, 1990), we conclude that wobbler disease specifically retards anterograde FC in less‐affected hindlimb motor neurons, whereas all components of axonal transport are retarded in forelimb motor neurons. © 1993 John Wiley & Soncs, Inc.
Neuromuscular response in man to repetitive nerve stimulation
Authors: Morita Hitoshi , Shindo Masaomi , Yanagawa Sohei , Yanagisawaw Nobuo
Published: January 2005

Paired stimulation has been used extensively in clinical neuropathysiology. We studies change in the sizes of compound muscle action potencial (CNAPs) in humans after a single electrical stimulus to the peripheral nerve. When the interstimulus intervals were varied, the second potentials underwent refractoriness and then were facilitated up to 20–30 ms, thereafter being depressed for 160–200 ms. When intensities were graded at fixed intervals for motor fibers the maximal effects was obtained with liminal stimulation, but was no longer observed at supramaximal stimulation. When the intrensity used to obtain M‐resposes was half the maximum, maximal facilitations were 35% (CNAP) and 17% (CMAP) of the first potential, the respective maximal depressions being 13% and 42%. When the sizes of the two CNARs were equalized by adjusting the second stimuli, the CMAP was facilitated (26%) up to 65 ms, thereafter being depressed (13%). These results must be taken into account when making clinical examinations that use paired stimulation. © 1993 John Wiley & Sons, Inc.
Comparison of directly stimulated with axon‐reflex–mediated sudomotor responses in human subjects and in patients with diabetes
Authors: Kihara Mikihiro , Opfer‐Gehrking Tonette L. , Low Phillip A.
Published: January 2005

The muscarinic receptors of human eccrine sweat gland may be directly stimulated by iontophoresis of acetylcholine (direct response; DIR) and indirectly via nicotinic receptors and an axon “reflex” (AXR). Using a specially designed multicompartmental sweat cell and dual sudorometers, we were able to simultaneously record the evoked DIR and AXR responses. On a second day, we repeated the experiment under identical ambient and stimulus conditions but instead obtained silastic imprints of DIR and AXR for morphometry. Studies were done on 24 controls (mean SD = 47.6 ± 15.1 years) and 23 diabetic subjects (mean ± SD = 49.6 ± 16.3 years). In control subjects, sudorometric DIR recordings were consistently larger than AXR. There was no difference in sweat droplet density by sex, but the size of droplets was larger in males. In diabetic patients 3 of 23 had absent AXR but preserved DIR, suggesting that failure of AXR preceded DIR in patients with neuropathy. Patients with mild neuropathy had an overrepresentation of large diameter droplets in the silastic imprints of both DIR and AXR, while patients with severe neuropathy had a markedly reduced density and small diameter droplets. © 1993 John Wiley & Sons, Inc.
Assessment of diabetic neuropathy: Definition of normal and discrimination of abnormal nerve function
Authors: Claus Detlef , Mustafa Constanze , Vogel Wilfried , Herz Matthias , Neundörfer Bernhard
Published: January 2005

One hundred one normal subjects and 46 patients were investigated. Various objective and subjective tests for polyneuropathies were compared. Motor and sensory nerve conduction velocities are the most sensitive tests. In normals, age hardly influenced nerve conduction velocities. This is believed to be a result of the strict exclusion criteria. Diagnostic sensitivity is also high with the vibration fork test and with vibratometry at the big toe. Results with the method of limits are as reliable and sensitive as more cumbersome techniques, such as the titration method and the forced choice method. Thermal thresholds and cardiovascular tests are less sensitive. The most correct overall classification is attained with a combination of tests reflecting the function of different nerve fiber classes in the peripheral and autonomic nervous systems.
Issue & Opinions: Receiver operating characterist curve anic analysis in the prediction of carpal tunnel syndrome: A model for reporting Electrophysiological data
Authors: Eisen Andrew , Schulzer Michael , Pant Bhanu , MaCneil Maureen , Stewart Heather , Trueman Sandra , Mak Edwin
Published: January 2005

Receiver operating characteristic (ROC) curves were used to predict the risk of carpal tunnel syndrome (CTS). Patients were classified clinically as (1) normal exam and no symptoms (169 hands); (2) having a motor and/or sensory deficit typical of CTS (115 hands); (3) having a history characteristic of CTS (156 hands); and (4) nondiagnostic symptomatology (122 hands). Electrophysiological studies consisted of median and ulnar motor, sensory, and palmar measurements. Group mean values for group 1 differed significantly from groups 2 and 3 (not 4) for all measurements, but values overlapped considerably. Median distal motor latency (DMML) combined with median‐ulnar palmar latency differences (MUPLD) had significantly superior discriminant power than other measurements and correlated highly for all groups (r values = 0.71–0.73). These variables were used to construct ROC curves and prediction tables. The approach used allows one to assign a percentage risk of having a CTS and can be used in outcome studies.
AAEM minimonograph #40: Clinical neurophysiology of the respiratory system
Authors: Bolton Charles F.
Published: January 2005

Disorders of nerve and muscle are frequent causes of respiratory insufficiency, but current methods often fail to adequately assess the problem. Phrenic nerve conduction and needle electromyography of the diaphragm are of great assistance in identifying the nature and site of the disorder: the various disturbances of central drive, axonal or demyelinating neuropathies of the phrenic nerves, and certain myopathies. These studies may be performed on adults, children, or infants, and in outpatient, general ward, or critical care settings. It is hoped these techniques will stimulate further developments in the field.
Issues & Opinions: Amyotrophic lateral sclerosis: Lower motor neuron disease spreading to upper motor neurons
Authors: Chou Samuel M. , Norris Forbes H.
Published: January 2005

Contrary to the recently reemphasized notion that the primary neuron involved in amyotrophic lateral sclerosis (ALS) is the cortical (upper) motor neuron (UMN), we believe that the lower motor neuron (LMN) is primarily involved by the retrograde transport of pathogens from neuromuscular junctions, and the disease process spreads monosynaptically to the UMN. Pathologically and epidemiologically, the LMN hypothesis is more logical than the UMN in light of the recent understanding of neuroaxonal transport systems, particularly in regard to anterograde cytoskeleton transport and the kinetics of the force promoting slow axonal transport. By correlating the early pathologic findings, i.e., the swelling of the initial axons and formation of intracytoplasmic inclusions in the LMN, ALS may be regarded as a disease of axonal transport, especially its slow component (SCa). Therapeutic intervention to facilitate SCa should be attempted in ALS. © 1993 John Wiley & Sons, Inc.
Chronic immune activation in the eosinophiliamyalgia syndrome
Authors: McKinley Kevin L. , Harati Yadollah , Schneider Larry W.
Published: January 2005

Eosinophilia–myalgia syndrome (EMS) is a multisystem illness of uncertain pathogenesis that occurred in an epidemic related to the ingestion of contaminated L‐tryptophan. To investigate the role of immune dysfunction in EMS we prospectively measured a serologic index of T‐cell activation, the soluble interleukin‐2 receptor (slL‐2R), in 7 patients followed into the late stages of the illness. As a group, EMS patients had significantly elevated slL‐2R levels throughout the study. Five patients suffered chronic symptoms of myalgia, arthralgia, muscle cramps, fatigue, or subjective memory impairment and all had persistently elevated slL‐2R levels. Two patients had near‐resolution of EMS and normal slL‐2R levels. We conclude that chronic symptoms are common in EMS and are associated with persistent T‐cell activation as measured by serum slL‐2R levels. These findings suggestthat immunosuppressive treatment may be beneficial in EMS. © 1993 John Wiley & Sons, Inc.
Microneurography, impulse conduction, and paresthesias
Authors: Burke David
Published: January 2005

It is possible to learn more about peripheral nerve function in human subjects than is obtainable with routine nerve conduction studies, and thereby to study the basis of “positive” symptoms, such as paresthesias. Using microneurography, ectopic impulse activity in cutaneous afferents has been recorded in patients suffering from neurologic disorders and in normal subjects in whom paresthesias were provoked by hyperventilation, prolonged tetanization of cutaneous nerves and ischemia. Using relatively simple modifications of standard nerve conduction techniques, the increases in axonal excitability responsible for this ectopic activity have been documented in human volunteers. Hyperventilation increases axonal excitability butdoes not change supernormality, probably because Na+ channels are activated by the decrease in [Ca2+] on the axonal membrane. Prolonged tetanic stimulation and ischemia probably share similar mechanisms. At least in motor axons, postischemic ectopic activity occurs when the hyperpolarization that results from activation of the Na+/K+ pump lowers the membrane potential below the equilibrium potential for K+. A high extracellular [K+] can then result in an inward current producing depolarization and possibly triggering regenerative processes. © 1993 John Wiley & Sons, Inc.
Magnetic stimulation in hemifacial spasm and post–facial palsy synkinesis
Authors: Öge A. Emre , Yazici Jale , Boyaciyan Ari , Tanyeri Sariye , Çlelik Münevver , Konyalioǧlu Rana , Baslo Aynur
Published: January 2005

The facial nerve was stimulated trascranially with a magnetic stimulator in 14 normal controls, 14 hemifacial spasm patients, and 16 post–facialpalsy synkinesis patients. Magnetic stimulation in normal controls revealed muscle responses which had latencies with a mean value of 4.99 ± 0.49 ms and amplitudes of 2.41 ± 1.08 mV. In the same group, transosseal conduction time was calculated to be 1.20 ± 0.13 ms. In the hemifacial spasm group, the amplitudes of the responses on the affected sides were lower as compared to the unaffected sides (mean values 1.78 vs. 2.41 mV, P = 0.01). Also, the threshold to magnetic stimulation was elevated on the affected sides. These findings are suggestive of the presence of a hypoexcitability to magnetic stimulation in the root entry zone. In the post–facial‐palsy synkinesis patients, magnetic stimulation of the affected sides resulted in responses with long latencies and low amplitudes (mean latency 6.34 ms, mean amplitude 0.90 mV). In the recordings made with magnetic stimulation, the difference of the latencies between the two sides was larger as compared to those obtained by electrical stimulation. The transosseal conduction time was also remarkably prolonged on the affected side. These findings may suggest that magnetic stimulation can be an effective method of showing intracranially located lesions of the facial nerve. © 1993 John Wiley & Sons, Inc.
Orthostatic tremor: Clinical and electrophysiologic characteristics
Authors: McManis Philip G. , Sharbrough Frank W.
Published: January 2005

Orthostatic tremor, sometimes known as „shaky legs syndrome,”︁ is a disorder of middle‐aged or elderly people characterized by feelings of unsteadiness in the legs and a fear of falling when standing. Patients stand on a wide base but walk normally. These symptoms are due to high‐frequency (13–18 Hz) burst firing in weight‐bearing muscles. They are attenuated by walking and are abolished immediately by sitting. Some authors believe that the disorder is a variant of essential tremor. This study reports the clinical and electrophysiologic features of orthostatic tremor in 30 patients. The findings indicate that orthostatic tremor is distinct from essential tremor, both clinically and electrophysiologically. The major differences are the frequency of electromyographic burst firing, the invariable involvement of lower limb and paraspinal muscles, and the task‐specific nature of the tremor in orthostatic tremor. The study shows that the diagnosis can be established rapidly with surface electromyographic recordings. © 1993 John Wiley & Sons, Inc.
Acute Lyme neuropathy presenting with polyradicular pain, abdominal protrusion, and cranial neuropathy
Authors: Krishnamurthy Kaarkuzhali B. , Liu Grant T. , Logician Eric L.
Published: January 2005

A 53‐year‐old man developed multifocal radicular pain. The diagnosis of Lyme neuroborreliosis was delayed until bifacial paresis and right lower abdominal wall weakness developed, prompting further evaluation. Cerebrospinal fluid (CSF) examination showed aseptic meningitis. Antibodies directed against Borrelia burgdorferi were present in the serum; higher tilers were present in the CSF, indicating local antibody production. Electrophysiologic studies showed both an axonal polyradiculopathy as well as demyelinative facial palsy. Ceftriaxone therapy led to marked improvement in pain and facial palsies. © 1993 John Wiley & Sons, Inc.
The influence of changes in the intensity of magnetic stimulation on coil output
Authors: Reutens David C. , Macdonell Richard A. L. , Berkovic Samuel F.
Published: January 2005

We measured the peak voltage induced in a sensing loop by a Magstim 200 magnetic stimulator. Coil output varied little for repeated stimulation at the same intensity over a wide range of coil output. In contrast, the first stimulus immediately after a change in intensity was of larger amplitude and showed greater variability than subsequent stimuli. The effect was seen for changes in intensity of 5% and 60% and was greater for reductions than for increases in stimulation intensity. Stimulation immediately after a reduction in intensity from 100% to 40% resulted in peak induced voltages as high as those recorded for repeated stimulation at 43% of maximum coil output. Increased coil output following changes in stimulation intensity may affect measurement of the threshold for motor cortical stimulation. The effect of a change in intensity could be minimized by delaying stimulation for at least 30 s or discarding the first stimulus after the change. © 1993 John Wiley & Sons, Inc.
Dystrophin–glycoprotein complex: Its role in the molecular pathogenesis of muscular dystrophies
Authors: Matsumura Kiichiro , Campbell Kevin P.
Published: January 2005

Dystrophin, the protein product of the Duchenne muscular dystrophy (DMD) gene, is associated with a large oligomeric complex of sarcolemmal glycoproteins, including dystroglycan which provides a linkage to the extracellular matrix component, laminin. In patients with DMD, the absence of dystrophin leads to the loss in all of the dystrophin‐associated proteins, causing the disruption of the linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. This may render the sarcolemma vulnerable to physical stress. These recent developments in the research concerning the function of the dystrophin–glycoprotein complex pave a way for the better understanding of the pathogenesis of muscular dystrophies. © 1994 John Wiley & Sons, Inc.
Myoclonic epilepsy with ragged‐red fibers (MERRF) syndrome: Report of a Chinese family with mitochondrial DNA point mutation in tRNALys gene
Authors: Fang Wan , Huang Chin‐Chang , Chu Nai‐Shun , Lee Cheng‐Chun , Chen Rou‐Shayn , Pang Cheng‐Yoong , Shih Kwang‐Dar , Wei Yau‐Huei
Published: January 2005

We report myoclonic epilepsy with ragged‐red fibers (MERRF) syndrome in a Chinese family with confirmed mitochondrial DNA point mutation. Six members of the family including the grandmother, two siblings, and three grandchildren were affected. Among them, action myoclonus was seen in five; short stature, muscle weakness, and mental retardation in four; lactic acidosis, hearing impairment, and ataxia in two; and seizures in one. Muscle biopsy from two affected siblings revealed ragged‐red fibers and abundant subsarcolemmal mitochondria with paracrystalline inclusions. Pedigree analysis suggests a maternal transmission. Analysis of mitochondrial DNA showed a point mutation from A to G at the 8344th nucleotide position located in the tRNALys gene. To our knowledge, this is the first report of MERRF syndrome with such genetic defect from a Chinese family. The present and previous reports support the notion that mitochondrial DNA point mutation at the 8344th nucleotide position is the most common cause of MERRF syndrome. © 1994 John Wiley & Sons, Inc.
Autosomal dominant distal myopathy with desmin storage: A clinicopathologic and electrophysiologic study of a large kinship
Authors: Horowitz Steven H. , Schmalbruch Henning
Published: January 2005

A large family is described with an autosomal dominant distal myopathy, the nature of which prompts the reevaluation of current classifications of these disorders. The disease begins in early to middle adulthood with gait disturbance due to distal leg weakness, and progresses over 5–10 years to involve all extremities, as well as bulbar, respiratory, and facial muscles. There is frequent cardiac involvement, manifest by arrhythmias, conduction blocks, and congestive failure, resulting in premature demise. On electromyography there is prominent spontaneous activity, short duration motor unit potentials, and polyphasia. Muscle biopsies from multiple family members at different stages of the disease are characterized by desmin storage and autophagocytosis. This distal myopathy differs from other phenotypically similar disorders in its rapidity of progression, fatal course and pathologic features. The role and specificity of excessive desmin accumulation in this and other myopathic and cardiac disorders are unknown. © 1994 John Wiley & Sons, Inc.
H reflex latency in the healthy elderly
Authors: Falco Frank J. E. , Hennessey William J. , Goldberg Gary , Braddom Randall L.
Published: January 2005

The purpose of this study was to evaluate prospectively and analyze the relationship of tibial nerve H reflex latency to age, sex, leg length, and skin temperature in a large healthy elderly population. The H reflex was recorded bilaterally in 92% of 103 carefully screened individuals aged 60–88 years. The mean H reflex latency was 30.8 (SD = 2.6) and 30.7 (SD = 2.6) ms for right and left legs, respectively. A high correlation (r = 0.55, P < 0.05) was present between H reflex latency and leg length. No significant correlation existed for H reflex latency and age. The upper normal limit for the difference between right and left H reflex latencies was 1.8 ms. This limit is greater than that reported in the literature for younger individuals due to a larger standard deviation. These findings suggest that aging increases the between‐leg variability of H reflex latency in individuals. This greater difference must be taken into account when using side‐to‐side H reflex latency comparison to detect unilateral pathology in the elderly. © 1994 John Wiley & Sons, Inc.
Dominant congenital benign spinal muscular atrophy
Authors: Frijns C. J. M. , van Deutekom J. , Frants R. R. , Jennekens F. G. I.
Published: January 2005

The affected members of the family described in this article exhibit congenital nonprogressive atrophy and weakness of lower limb muscles in association with contractures. Clinical and laboratory findings support a dominant lower motor neuron disorder. DNA analysis excluded linkage of the disease with SMA markers on the long arm of chromosome 5. The condition must be differentiated from congenital and infantile SMA, from “arthrogryposis multiplex congenita, distal type,” and from non hereditary types of congenital arthrogryposis. © 1994 John Wiley & Sons, Inc.
Expression of the low‐affinity NGF receptor during human muscle development, regeneration, and in tissue culture
Authors: Baron Pierluigi , Scarpini Elio , Meola Gianni , Santilli Ignazio , Conti Giancarlo , Pleasure David , Scarlato Guglielmo
Published: January 2005

The expression of the low‐affinity NGF receptor (LNGFR) during human muscle development, regeneration, and in tissue culture was analyzed using a murine monoclonal antibody to human LNGFR (MAb ME 20.4). Muscle cells from 12–22‐week fetuses stained strongly for LNGFR. In adult normal muscle, only intramuscular nerve endings showed immunoreactivity with MAb ME 20.4, but no staining was detected in muscle fibers. In Duchenne muscular dystrophy, immunohistologically demonstrable LNGFR was present in regenerating muscle fibers. In these fibers, LNGFR gene expression was also demonstrated at the transcriptional level using in situ hybridization with riboprobes coding with human LNGFR. Cultures from human fetal and adult muscle were studied by double label indirect immunofluorescence microscopy with MAb ME 20.4 and antisera against human fetal myosin. Most myosin‐positive cells, both at the myoblast and myotube stages, displayed surface LNGFR immunostaining. In cells from fetal muscle, LNGFR was detected during the first 2 weeks in vitro, whereas in cells from adult muscle the expression of LNGFR was observed for up to 7 weeks. These findings suggest a potential involvement of LNGFR in human muscle development and regeneration. © 1994 John Wiley & Sons, Inc.
Muscle hypertrophy secondary to the tethered cord syndrome
Authors: Bertorini Tulio , Woodhouse Charles , Horner Linda
Published: January 2005

Segmental muscle enlargement occurs in a variety of neurogenic conditions. We present a case with calf hypertrophy, likely produced by partial denervation and continuous neuromuscular irritability, which was caused by a tethered spinal cord that was demonstrated by MRI. Muscle MRI correlated with muscle biopsy findings in which atrophy and hypertrophy were accompanied by rimmed vacuoles. © 1994 John Wiley & Sons, Inc.
Topodiagnostic value of brain stem reflexes
Authors: Hopf Hanns C.
Published: January 2005

The masseter and medial pterygoid stretch reflexes, the masseter inhibitory reflexes, and the blink reflexes are useful diagnostic tools for evaluation of brain stem disorders. The structures mediating these reflexes are largely known. Characteristic changes of the normal response patterns due to various lesions have been described. Distinct reflex abnormalities indicate lesions at specific sites. Multireflex testing improves the accuracy with which localization can be made. A number of lesions suspected on clinical data may be confirmed by reflex findings only and not by imaging studies. Reflex testing can be utilized to demonstrate multiple lesions evoked by a single vascular event and evaluate dissemination of central nervous involvement in multiple sclerosis patients. © 1994 John & Sons, Inc.
What is the best diagnostic index of conduction block and temporal dispersion?
Authors: Oh Shin J. , Kim Doo E. , Kuruoglu H. Reha
Published: January 2005

In order to find the best diagnostic index of conduction block and abnormal temporal dispersion, the amplitude, duration, and area of the compound muscle action potentials (CMAP) were studied in 40 normal controls and 28 patients with acquired demyelinating neuropathies. In the normal subjects, there was a substantial difference among the various nerves in the degree of CMAP amplitude reduction and CMAP duration prolongation with proximal stimulation, and thus different criteria should be used for conduction block or abnormal temporal dispersion for a given nerve. In 28 patients with demyelinating neuropathy, 58 of 207 (28%) tested nerve segments showed nerve conduction velocity (NCV) evidence of demyelination. To identify “demyelination” in these segments, conduction block was best detected by the total area method in 71% of cases, and abnormal temporal dispersion was bast by the negative‐peak duration method. This study showed that the best diagnostic index for conduction block is the total area method and for abnormal temporal dispersion, the negative‐peak duration method. © 1994 John & Sons, Inc.
Sensory neuropathy in infantile onset spinocerebellar ataxia (IOSCA)
Authors: Koskinen Tuula , Sainio Kimmo , Rapola Juhani , Pihko Helena , Paetau Anders
Published: January 2005

Infantile onset spinocerebellar ataxia with sensory neuropathy is a new, inherited multisystem disorder discovered in 19 Finnish patients. In order to define the neuropathy of the disease, we measured sensory nerve action potentials and nerve conduction velocities in 18 patients, and recorded somatosensory evoked potentials (SEP) in 10 patients and performed a sural nerve biopsy in 13 patients. The fixed and teased nerve fascicles were examined by light and electron microscopy, and the whole transverse section of a nerve fascicle was photographed and enlarged for morphometric measurements. Our investigation revealed an early onset, rapidly progressive axonal neuropathy: the sensory action potentials were decreased after the age of 2 and a severe loss of mainly large myelinated fibers was found. © 1994 John & Sons, Inc.
Pseudofacilitation: A misleading term
Authors: McComas Alan J. , Galea Victoria , Einhorn Roman W.
Published: January 2005

The possible causes of the transient enlargement of muscle compound action potentials during repetitive stimulation (“pseudofacilitation”) are considered. The phenomenon cannot be due to mechanical artefact, while hypersynchronization of the muscle fiber action potentials, the usual explanation, can only make a minor contribution. A more convincing explanation, for which there is now experimental evidence, is that the muscle fibers undergo hyperpolarization, due to the intramuscular release of norepinephrine and consequent stimulation of the electrogenic Na+, K+‐pump. Defective phosphorylation of the Na+, K+‐pump is a possible cause of the transient weakness and myotonia in myotonic dystrophy. © 1994 John Wiley & Sons, Inc.
Deficits in the function of small and large afferent fibers in confirmed cases of carpal tunnel syndrome
Authors: Goadsby Peter J. , Burke David
Published: January 2005

Nerve conduction studies and measurements of thermal thresholds (hot and cold) were performed in 25 healthy control subjects and 24 patients with carpal tunnel syndrome: first, to compare the extent of axons; second to correlate these abnormalities with clinical severity;and third to validate a modified from of palmar stimulation as an additional neurophysiological test in suspected carpal tunnel syndrome. The routine nerve conuction studies compared the amplitudes and conduction velocities from digit II and digit V to wrist and for the digit‐II potential between wrist and elbow. With palmar stimulation, the palm‐to‐wrist segment was compared to the simultaneously evoked antidromic digital potential (palm‐to‐index). Thermal threshold testing involved determination of hot and cold thresholds for digit II and digit V using an automated forced‐choice procedure. In the patients there was selective slowing of conduction across the palm‐to‐wrist segment with normal velocities distally and proximally, and there was clear evidence of abnormal small‐fiber function, with higher thresholds for both hot and cold sensation. However, the thermal abnormalities also involved the ulnar territory, equally so for cold threshold but significantly less so for hot threshold. Thermal threshold testing confirmed the clinical impression that small‐fiber dysfunction is important in carpal tunnel syndrome, but the abnormal findings for the ulnar‐innervated digit V suggest that this test will not be routinely useful for the early detection of compression or entrapment neuropathies. © 1994 John Wiley & Sons, Inc.
Elimination of superfluous neuromuscular junctions in rat calf muscles recovering from botulinum toxin–induced paralysis
Authors: Hassan Sherif M. , Jennekens Frans G. I. , Wieneke George , Veldman Henk
Published: January 2005

In order to determine the fate of the superfluous neuromuscular junctions (NMJs) formed during the course of botulinum toxin (BoTx)‐induced paralysis, we have quantified the change in the total length of the nerve muscle contact area(s) following BoTx injection into rat calf muscles. The results indicate that: (1) at least some of the superfluous NMJs are eliminated following muscle recovery; (2) synapse elimination is a slow process, as 4 months after recovery it was not yet complete; (3) muscles with different content of type I and II fibers follow a different time course during synapse formation and elimination. We further investigated the possibility that the neural cell adhesion molecule (NCAM) would be the element whose loss from the NMJ might play a role in synapse elimination. Using immunofluorescence and immuneelectron microscopy we show that NCAM is exclusively localized between nerve terminals and Schwann cells and not between nerve terminals and muscle. This localization was maintained throughout paralysis and following recovery, suggesting that NCAM does not play a role in synapse elimination. © 1994 John Wiley & Sons, Inc.
Tuberculous infection of skeletal muscle in a case of dermatomyositis
Authors: Davidson George S. , Voorneveld Colin R. , Krishnan Nirmala
Published: January 2005

A patient with dermatomyositis associated with carcinoma was treated with steroids and antibiotics for possible tuberculosis. Autopsy showed an overwhelming diffuse nongranulomatous infection of Mycobacterium tuberculosis involving only the skeletal muscles and one inguinal lymph node. The rare localization of tuberculosis to skeletal muscle in this case is possibly due to steroid immunosuppression and the humoral immune attack on muscle blood vessels that is a part of dermatomyositis. © 1994 John Wiley & Sons, Inc.
Widespread tissue distribution of multiple mitochondrial DNA deletions in familial mitochondrial myopathy
Authors: Kawashima Shingo , Ohta Shigeo , Kagawa Yasuo , Yoshida Mitsuo , Nishizawa Masatoyo
Published: January 2005

We used Southern blot analysis and the polymerase chain reaction to analyze the tissue distribution of multiple mitochondrial DNA (mtDNA) deletions in a 45‐year‐old man with familial mitochondrial myopathy. Southern blots showed two major types of abnormal mtDNA with approximately 4‐ and 8‐kilobase deletions in the skeletal and extraocular muscles. The amount of muscle mtDNA with deletions correlated approximately with the severity of muscle involvement. The polymerase chain reaction showed multiple mtDNA deletions even in clinically asymptomatic tissues, the pattern of which differed with the type of tissue. Nucleotide sequences of several mtDNAs with deletions showed that the deletions were flanked by direct repeats consisting of 3 to 12 nucleotides. Leukocytes from the patient's affected sister and his mother exhibited the same mtDNA deletion pattern. Most of the same deletions were present in leukocytes obtained from the patient's father. © 1994 John Wiley & Sons, Inc.
Decremental motor responses to repetitive nerve stimulation in ALS
Authors: Killian James M. , Wilfong Angus A. , Burnett Leanne , Appel Stanley H. , Boland Dennis
Published: January 2005

Repetitive nerve stimulation (RNS) of the trapezius muscle at slow rates was performed on 192 patients with amyotrophic lateral sclerosis (ALS). Fifty‐six patients (29%) showed classical neuromuscular decrement of 10–43% (mean 16.8%) while 44 patients (23%) had a borderline decrement of 5–9%. The trapezius was significantly more sensitive in revealing the defect than the distal hypothenar muscles. In 30 patients followed serially, the decremental response remained constant or increased with time. However, 25% of patients continued to show no decrement in spite of progression of disease. No statistical correlation was found between decrement and clinical severity, disease staging, or disease progression. The finding that at least 50% of ALS patients show some degree of decrement on RNS of the trapezius muscle suggests that functional alterations of the neuromuscular junction accompany this disease. © 1994 John Wiley & Sons, Inc.
Pediatric median mononeuropathies: A clinical and electromyographic study
Authors: Deymeer Feza , Jones H. Royden
Published: January 2005

Seventeen children, 6 girls and 11 boys, aged 5–17 years with pediatric median mononeuropathies (PMM) were identified among 1809 who had EMGs primarily in the electromyographic laboratory at The Children's Hospital, Boston, between 1979 and 1993. Electromyography documented the PMM to be at the wrist in 7 children, including 3 children with idiopathic carpal tunnel syndrome (CTS)—1 whose symptomswere accentuated by skiing—2 with a systemic illness (mucolipidosis III and scleroderma), and in 1 child each the distal PMM was secondary to a cast or laceration. A proximal PMM was identified in 10 children, including 8 with trauma. 1 with an osteoid osteoma, cutaneous mucinosis. Five childron (3 with CTS and 1 each with mucolipidosis III and juvenile cutaneous mucinosis) had bilateral dieases. The localization (59% proximal) and cause of these PMMs differed greatly from our experience with adult median neuropathies. © 1994 John Wiley & Sons, Inc.
Limb girdle muscular dystrophy: Weakness and disease duration as predictors of functional impairment
Authors: Stübgen Joerg‐Patrick , Lahouter Annette
Published: January 2005

This cross‐sectional study compared progressive weakness to functional disability in 20 patients with limb girdle muscular dystrophy. Weakness (assessed by manual muscle testing) determined disability (assessed by functional grades, timed functional tests, and an activities of daily living scale) For any functional grade the degree of weakness varied between patients. Yet, at a certain “threshold” weakness the functional level predictably deteriorated. Change in functional grade did not reflect a parallel increase in weakness nor disease progression. Functional “milestones” were reached at varying durations of disease. Only guidelines were offered to individual patients as to the time course of progression in disability. Serial timed tests should be a sensitive, objective method to follow the rate of disease progression. Timely referral of patients to establish physical needs should delay functional deterioration and minimize handicap despite progressive weakness. © 1994 John Wiley & Sons, Inc.
Clinical, electrophysiological, and myelographic studies of 9 patients with cervical spinal root avulsions: Discrepancies between EMG and X‐ray findings
Authors: Trojaborg W.
Published: January 2005

In traumatic brachial plexus injuries a thorough neurological, electrodiagnostic, and radiological examination is essential to determine treatment and prognosis. The most important diagnostic question concerns the presence or absence of a preganglionic nerve root lesion. Electromyography and motor and sensory conduction studies were performed in 17 patients with traumatic plexus injuries who had myelographic evidence of nerve root avulsion; in 8 of these clinical and electrophysiological features confirmed the X‐ray findings. However, in 9 cases there was a discrepancy between myelographic and neurophysiological data regarding the actual number and sites of roots avulsed. Thus, in 2 cases myelography showed avulsion of one more root than did conduction studies and EMG; in 2 others, there was discordance as to the specific roots avulsed; in 4 cases fewer nerve roots seem to be avulsed radiologically than predicted clinically, and in 1, none at all, although clinical and electrophysiological data were compatible with avulsion of four roots. In 6 cases recovery showed that avulsions indicated by clinical and electrophysiological considerations could not have occurred. When both EMG and myelography are misleading, surgical exploration should be considered. © 1994 John Wiley & Sons, Inc.
Early diagnosis of n‐hexane–caused neuropathy
Authors: Pastore Carlos , Marhuenda Dolores , Marti Juan , Cardona Antonio
Published: January 2005

n‐Hexane neuropathy was studied in 20 workers exposed for prolonged periods to this solvent, and with urinary 2, 5‐hexanedione concentrations exceeding the biological exposure index recommended by the American Conference of Governmental Industrial Hygienists (5 mg/L) with a mean of 11.02 mg/L (range 5.3—24.2 mg/L). Although neurological examination did not detect significant anomalies in any of the patients, and the conduction velocity and F waves of all the nerves tested were normal, neurographic studies revealed significant differences in the amplitude of sensory nerve action potentials (SNAP) recorded from the sural (mean 14.0 μV), median (mean 17.3 μV), and ulnar (mean 7.9 μV) nerves when compared with normal values from healthy adults of the same age range, examined under identical conditions. The amplitude of the SNAP in sural and median nerves correlated significantly with the number of years worked. The notable decrease in mean amplitude of the SNAP appeared to reflect the primary neurotoxic effects of 2,5‐hexanedione. © 1994 John Wiley & Sons, Inc.
A method for the longitudinal study of human thenar motor units
Authors: Doherty Timothy J. , Brown William F.
Published: January 2005

Methods currently available to study the electrophysiological and contractile properties of single human motor units (MUs) preclude the same MU from being studied on repeated occasions. We have developed a method which allows single thenar MUs to be studied longitudinally. Sites were located along the median nerve where, using percutaneous stimulation, it was possible to selectively activate a single thenar motor axon as determined by: (a) the presence of an “all‐or‐nothing” surface‐detected motor unit action potential (S‐MUAP); (b) the occasional presence of F‐responses identical in size and shape to the direct S‐MUAP; (c) excitation thresholds widely separated from the next highest threshold motor axon so as to allow high frequency stimulation. To ensure that the same motor axon had been located and stimulated in successive studies, additional criteria included: (a) the motor axon was found at approximately the same site along the nerve; (b) the threshold for excitation remained widely separate from the next highest threshold motor axon; (c) the shape of the S‐MUAP was almost identical on repeated studies; (d) S‐MUAP and F‐response latencies were similar. This method provides, for the first time, the ability to track longitudinally the electrical and contractile properties of single MUs in health and during the course and treatment of disease. © 1994 John Wiley & Sons, Inc.
Assessment of muscular fatigue using vibromyography
Authors: Herzog Walter , Zhang Yuan‐Ting , Vaz Marco A. , Guimaraes Antonio C. S. , Janssen Christoph
Published: January 2005

The purpose of this study was to investigate the behavior of electromyographical (EMG) and vibromyographical (VMG) signals in the time and frequency domains during a fatigue protocol. EMG and VMG records were obtained from the rectus femoris (RF) and vastus lateralis (VL) muscles of 11 adult male subjects during sustained, isometric knee extensor contractions performed at 70% of maximal voluntary contraction (MVC). The average median frequencies of the power density spectra decreased during the fatigue protocol for the EMG (from 73 to 54 Hz for RF, and from 75 to 57 Hz for VL) and the VMG signals (from 40 to 19 Hz for RF, and from 25 to 12 Hz for VL). Raw EMG signals remained the same qualitatively throughout the fatigue protocol, whereas corresponding VMG records appeared to become “smoother.” The results of this study indicate that the pronounced decrease in the high‐frequency content of the VMG signal may be observed in the time domain as a “smoothing” of the signal, and thus, that the raw VMG records (which may be displayed readily online) can be used to assess qualitatively the onset and progression of muscular fatigue. © 1994 John Wiley & Sons, Inc.
Normative F wave values and the number of recorded F waves
Authors: Fisher Morris A. , Hoffen Bruce , Hultman Cheryl
Published: January 2005

F waves were recorded from the right abductor pollicis brevis of 11 normal subjects following 100 supramaximal stimuli. F wave data from sequential groups of 10 stimuli were analyzed. “True” values were considered those based on the results following all 100 stimuli. The F wave data evaluated were: minimal, mean, and median latencies; persistences (the percentage of F waves present in a series of stimuli): chronodispersion (CD) (the difference between minimal and maximal F latencies); mean F/M wave (mF/M) amplitudes; and repeater waves. F latencies appear normally distributed, and there is no statistical justification for using either median latencies or amplitudes. Following 10 stimuli, however, mean latencies are more reproducible than minimal values. In these normal data, results following 10 stimuli give latency measurements within 1 ms of “true” as well as for persistences; 20 stimuli will provide mean latencies within 0.5 ms of “true” as well as probable reasonable values (i.e., 80% of “true” or greater) for mF/M and the percentage of repeater waves; for CDs 80% of “true” or greater, 50–60 stimuli are needed; for the number of individual repeater waves, data from all 100 stimuli would be required. Analysis of repeater waves amplitudes would support a preferential activation of larger motor units in F waves. © 1994 John Wiley & Sons, Inc.
Identification, distribution, and myosin subunit composition of type IIX fibers in mouse muscles
Authors: Zardini Daniela M. , Parry David J.
Published: January 2005

The purpose of the present investigation was to study the distribution and subunit composition of type IIX fibers in mouse muscles. The existence of a population of type IIX fibers in fast‐twitch muscles of the mouse was shown by mean of immunohistochemistry and gel electrophoresis. In the hindlimb muscles, tibialis anterior (TA) and extensor digitorum longus (EDL), type IIX fibers account for approximately one third of the total fiber number, with the superficial portion of the TA (TAS) being composed exclusively of type IIB and IIX fibers. A similar proportion of IIX fibers was found in diaphragm (DIA) while in tongue muscles approximately 40% of the fibers were IIX. Single fiber gel electrophoresis revealed a significant number of fibers in TAS that contain both IIB and IIX myosin heavy chain (MyHC). This was confirmed with immunohistochemistry, which revealed the presence of fibers with various degrees of staining intensity. This suggests that there may exist a degree of plasticity which results in the conversion of IIX fibers to IIB fibers and vice versa. Analysis of myosin light chain (MyLC) composition of type IIX fibers revealed that the ratio of MyLC3f to MyLC1f was significantly lower than in type IIB fibers. © 1994 John Wiley & Sons, Inc.
Electrodiagnosis in the management of focal neuropathies: The “WOG” syndrome
Authors: Brown William F. , Dellon A. Lee , Campbell William W.
Published: January 2005

The role of electrodiagnosis in managing patients with focal neuropathies is discussed from the differing perspectives of a peripheral nerve surgeon and a practitioner of electrodiagnostic medicine. Both clinical evaluation and electrodiagnosis are useful methodologies, each having limitations. Dr. Dellon labels the overreliance on electrodiagnosis and the “WOG” (Word of God) syndrome, and describes its signs, symptoms, and treatment. Dr. Brown contends Dr. Dellon's crusade is misdirected. The exchange is an eloquent polemic on the virtues and foibles of these different approaches to evaluating peripheral nerve function and the imperative to practice them in a complementary rather than a contentious manner. © 1994 John Wiley & Sons, Inc.
Patch‐clamp analysis of the properties of acetylcholine receptor channels at the normal human endplate
Authors: Milone Margherita , Hutchinson David O. , Engel Andrew G.
Published: January 2005

Normative data were obtained on the kinetic properties of the acetylcholine receptor (AChR) channel at the human motor endplate by patch‐clamp analysis. Single channel currents were recorded from 34 endplates of 8 nonweak subjects in the presence of 1 μm acetylcholine (ACh) at 22 ± 0.5°C. The vast majority of channels opened to a conductance of about 60 pS. The dwell‐time distributions of these channels were well described as the sum of two exponential functions. The mean duration of the dominant longer component was 1.9 ms for the open intervals and 3.04 ms for the bursts. At three endplates, a small proportion of the channels had lower conductance and longer open time, resembling immature AChR channels. At 28 endplates it was also possible to obtain an estimate of the rate constant for channel closure (α) and approximate estimates for the rate constants of channel opening (β) and ACh dissociation (k−2). Estimates of k−2 varied by 15% with methods of estimation. This is attributed to errors inherent in estimating the duration of the briefest channel events. The normative data will be useful for evaluating pathologic alterations in the kinetic properties of the AChR channel found in some congenital myasthenic syndromes.
Time course of changes in plasma membrane permeability in the dystrophin‐deficient mdx mouse
Authors: McArdle Anne , Edwards Richard H. T. , Jackson Malcolm J.
Published: January 2005

Control C57BI/10 and mutant, dystrophin‐deficient mdx mice of different ages were used to study the permeability of the plasma membrane to cytosolic components, to a vital stain (procion orange) and to extra‐cellular 45calcium. Prenecrotic, 14 ± 2‐day‐old mdx mice had normal serum activities of creatine kinase (CK) and pyruvate kinase (PK). Muscles from these animals also had no increased permeability to procion orange or extracellular 45calcium. Serum activities of CK and PK had risen acutely in the 21‐day‐old mdx mouse compared with control and remained elevated up to 6 months of age. The influx of procion orange and 45calcium content were abnormally elevated in the 40 ± 4‐day‐old mdx mouse. These data provide no evidence for an increase in muscle plasma membrane permeability as a primary pathogenic effect of a lack of dystrophin, but results suggest that some factor expressed or deexpressed during mouse development may be necessary for the full expression of the dystrophic process. © 1994 John Wiley & Sons, Inc.
Cranial nerve conduction and needle electromyography in patients with acoustic neuromas: A model of compression neuropathy
Authors: Normand Marlene M. , Daube Jasper R.
Published: January 2005

Of 45 patients with acoustic neuromas (0.3–5.0 cm), 73% had facial nerve impairment on electrophysiologic testing, but only 16% had facial weakness. Cranial nerve conduction was the most sensitive measurement, especially prolongation of the ipsilateral R1 latency of the blink reflex compared with that of the contralateral reflex. The severity of nerve conduction abnormality was highly correlated with tumor size. Our results confirm and quantitate the sensitivity of nerve action potential latency in response to chronic nerve compression. © 1994 John Wiley & Sons, Inc.