bluuebunny/crossref_metadata_2025 huggingface dataset:
Human peripheral nerve sheath neoplasm: Expression of Schwann cell‐related markers and their relation to malignant transformation
Authors: Yasuda Takeshi , Sobue Gen , Ito Takayuki , Doyu Manabu , Sugiura Isao , Hashizume Yoshio , Kato Kanefusa
Published: January 2005

We immunohistochemically examined the expression of Schwann cellrelated markers, nerve growth factor (NGF) receptor, S‐100 α‐ and b̃‐proteins, glial fibrillary acidic protein (GFAP), and galactocerebroside (gal C) in 5 malignant schwannomas, 21 benign peripheral nerve sheath tumors, and 4 apparently normal sural nerves. NGF receptor was expressed in the malignant schwannomas and benign peripheral nerve sheath tumors, but not in the endoneurium of apparently normal peripheral nerves. S‐100 α‐protein was observed in malignant schwannomas and in some neurofibroma cells. All cases were strongly positive for S‐100 b̃‐protein but were negative for GFAP and gal C. Our results suggest that these Schwann cell‐related markers may be useful in identifying peripheral nerve sheath neoplasms as well as their malignant transformation.
Mitochondrial abnormalities in oculopharyngeal muscular dystrophy
Authors: Pauzner Rachel , Blatt Ilan , Mouallem Meir , Ben‐David Eitan , Farfel Zvi , Sadeh Menachem
Published: January 2005

A family with oculopharyngeal muscular dystrophy (OPMD) is described. Histological and histochemical studies of muscle biopsy showed nonspecific myopathic changes; no “ragged‐red” fibers were seen. Electron microscopy demonstrated bizarre large mitochondria with abnormal cristae, but no intranuclear inclusion bodies. Our findings are compatible with the possibility that OPMD is a heterogeneous syndrome, and may be a manifestation of mitochondrial myopathy.
Comparison of electrodiagnostic criteria for primary demyelination in chronic polyneuropathy
Authors: Bromberg Mark B.
Published: January 2005

Three sets of electrodiagnostic criteria for establishing primary demyelination in chronic poly neuropathy are evaluated. Sensitivity is assessed in 70 patients with clinically established chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The criteria use different abnormal values, one adjusts for the effects of axonal loss, while another relies only on conduction velocity. However, even when consideration is given to sufficient number of nerves tested, there is no significant difference (P = 0.37) in diagnostic sensitivity among them, with 48% to 64% of CIDP patients fulfilling criteria for primary demyelination. Specificity is assessed by applying the criteria to 47 patients with motor neuron disease and 63 patients with diabetic polyneuropathy. No patients meet any of the criteria. Further analysis shows that as sensitivity increases specificity decreases, because of overlapping distributions of nerve conduction abnormalities in these neuropathic disorders. A sensitivity of approximately 66% is a practical limit for electrodiagnostic criteria in CIDP.
Central conduction and autonomic nervous function in HMSN I
Authors: Solders Göran , Andersson Thomas , Persson Anders
Published: January 2005

CNS conduction and autonomic nervous function were investigated in 15 patients with HMSN I. Central motor conduction time (CMCT) was estimated with magnetic brain stimulation and electrical nerve root stimulation. Somatosensory evoked potential (SEP) and visual evoked potential (VEP) were used for assessment of central sensory and visual conduction. Autonomic effector organ functions were assessed with the R‐R variation test for parasympathetic function, and the sympathetic skin response test (SSR) for skin sympathetic sudomotor activity. Five of the patients had prolonged CMCT. Central sensory conduction was normal in 3, and slightly prolonged in 1 of the patients, but could not be estimated in 11 due to lack of response from the cervical recording. VEP was abnormal in 2 patients. R‐R variations during normal breathing were low in 8 of 15 patients, and low also during deep breathing in 1 of 15. The SSR test was pathological in 5 of 15 patients. Thus, impaired central conduction and/or autonomic dysfunction was not an uncommon finding in patients with HMSN I.
The numbers and relative sizes of motor units estimated by Computer
Authors: Galea Victoria , De Bruin Hubert , Cavasin Richard , McComas Alan J.
Published: January 2005

A fully automated system is described for estimating the numbers and relative sizes of functioning motor units in proximal and distal muscles of the arm and leg. In this system, a computer controls the motor nerve stimulation, and analyzes the potentials evoked from the muscles; a subprogram searches for instances of “alternation.” In 33 healthy volunteers, aged 21 to 56 years, the median‐innervated thenar muscles of one hand were tested 2 to 3 times; the mean motor unit estimate was 228 ± 93 SD. For similar numbers of biceps brachii, extensor digitorum brevis, and vastus medialis muscles, the respective mean values were 113 ± 40, 131 ± 45, and 229 ± 108 units. The reproducibility of the method was such that the overall coefficient of variation, for the normalized results from the 121 muscles studied, was 22%. The reliability of the automated method was doubled if 3 estimates, rather than one, were performed on each muscle. Comparisons of the results obtained by automated and “manual” methods indicated that the computer‐derived values tended to be lower by approximately 33%.
Antidystrophin stains triadic junctions in regenerating rat muscles
Authors: Bornemann Antje , Schmalbruch Henning
Published: January 2005

Dystrophin has biochemically been found in the sarcolemma and in junctional t‐tubules, but immunocytochemistry shows reactivity at the sarcolemma only. In the present study, normal and regenerating soleus muscles of rat were perfused for 10 minutes with 2% formaldehyde; isolated fibers were stained with polyclonal antidystrophins and HRP and embedded in epoxy. Staining of triadic junctions in normal fibers was ambiguous but, in regenerated fibers, 4 weeks after injury it was distinct. Immature myotubes 3 days after injury showed reactivity at the sarcolemma and at various internal membranes. The nonselective staining of internal membranes may be due to secondary binding of the reaction product, and supports the view that dystrophin is cytoplasmic before it becomes restricted to the sarcolemma and t‐tubules.
Electrophysiologic mapping of the segmental anatomy of the muscles of the lower extremity
Authors: Phillips Lawrence H. , Park T. S.
Published: January 2005

Our knowledge of the specific root innervation of skeletal muscles is derived from accumulated clinical experience. While performing selective posterior rhizotomy for treatment of spasticity in children with cerebral palsy, we made direct electrophysiologic measurement of the root innervation of the lower extremity. We stimulated ventral roots from L2 to S2 while recording from all muscles simultaneously. The size of the evoked compound muscle action potential was used as an indication of the amount of innervation derived from stimulation of a given spinal root. We found the major root innervation for the 8 muscles studied to be: adductor longus, vastus medialis, and vastus lateralis, L3; tibialis anterior; L4; peroneus longus, L5; and medial gastrocnemius, lateral gastrocnemius, and gluteus maximus, S1. In general, each muscle received innervation from 3 or more roots. Prefixed or postfixed innervation patterns were found in 27.9% of legs examined, and there was asymmetry of innervation in 29.8%. We conclude that the segmental innervation of lower extremity muscles is broader than previously thought. Anomalous innervation occurs so frequently that caution should be used in attributing any pattern of clinical or EMG findings to a specific spinal level.
Desmin and vimentin in regenerating muscles
Authors: Bornemann Antje , Schmalbruch Henning
Published: January 2005

Desmin is a normal constituent of skeletal muscle fibers; vimentin is contained in myoblasts and connective tissue cells. The intracellular localization of both intermediate filament proteins in regenerating rat muscles was investigated by immunohisto‐ and immunocytochemistry. Necrosis was induced by hot Ringer solution. Desmin and vimentin were diffusely distributed in myoblasts and young myotubes. Both proteins became arranged in a sarcomeric fashion between the Z‐lines when the sarcomeres got into register. Desmin reactivity persisted, but vimentin disappeared after about 2 weeks. Traces were found for up to 4 weeks. This observation is in contrast to findings in fetal and cultured muscles in which several authors did not find expression of vimentin after myoblast fusion. The presence of vimentin may well be a useful marker for regenerated muscle fibers in muscle biopsies from patients with neuromuscular disorders.
Muscle excitation in elderly adults: The effects of training
Authors: Hicks Audrey L , Cupido Cynthia M. , Martin Joan , Dent Jennifer
Published: January 2005

Muscle membrane excitability is thought to decline with aging; the extent of this decline may be noninvasively assessed by measurement of the electrically evoked compound muscle action potential (M‐wave). The intent of this study was two‐fold: (1) to compare the M‐wave in the brachioradialis (BR), tibialis anterior (TA), and thenar (TH) muscles of elderly (mean age = 66.3 ± 3.7 years) and young (mean age = 31.2 ± 4.9 years) adults, and (2) to determine the effects of 12 weeks of resistance training on M‐wave characteristics in elderly adults. Prior to training, the elderly subjects had significantly smaller (P < 0.05) resting M‐waves than the young adults in the BR (4.8 mV vs. 8.7 mV), TA (8.8 mV vs. 11.0 mV), and TH (5.2 mV vs. 10.2 mV) muscles. During a 2‐minute voluntary fatigue paradigm (3 seconds MVC per 2 seconds rest for 2 minutes), there was no evidence of excitability failure in either group. Following training, there was a significant increase (P < 0.05) in the size of the M‐wave of the TH (pretraining: 5.2 mV; posttraining: 8.96 mV) and BR (pretraining: 4.8 mV; posttraining: 6.1 mV), and a nonsignificant increase in the M‐wave of the TA, but there was no change in the relative behavior of the M‐wave during the 2‐minute voluntary fatigue paradigm, It is suggested that the decline in muscle membrane excitation with aging may be due, at least in part, to the effects of a decreased membrane potential on the muscle fiber action potential. Furthermore, our results suggest that exercise training may improve muscle excitability in elderly adults, possibly reflecting a training‐induced increase in the resting membrane potential due to an increased activity and/or concentration of the skeletal muscle Na+K+‐ATPase.
Repetitive nerve stimulation vs. twitch tension in rats with EAMG
Authors: Thompson Patricia A. , Barohn Richard A. , Krolick Keith A.
Published: January 2005

Two methods were compared with regard to their ability to detect acetylcholine receptor‐dependent neuromuscular dysfunction in rats with experimental autoimmune myasthenia gravis. In both cases, detection of AChR impairment required amplification of symptoms by administration of the AChR antagonist curare and appeared to be directly related to increasing levels of circulating anti‐AChR antibodies. First, in vivo evaluations of decremental compound motor action potentials following repetitive nerve stimulation were performed by electromyography. Impaired neuromuscular function (i.e., >10% decrement) was noted only after rats had been immunized twice with AChR, requiring levels of circulating anti‐AChR antibody greater than about 200 μg/mL in serum. In contrast, the direct in vitro evaluation of stimulated isometric twitch tension appeared to be more sensitive in that impaired AChR‐dependent muscle contraction was clearly observed following a single AChR immunization, and, as shown previously, required anti‐AChR antibody levels of about 50 μg/mL in serum. Further discussion is presented concerning the advantages and disadvantages associated with each method of monitoring disease.
Voluntary discharge frequencies of human motoneurons at different muscle lengths
Authors: Bigland‐Ritchie Brenda R. , Furbush Frank H. , Gandevia Simon C. , Thomas Christine K.
Published: January 2005

The relationship between the discharge frequencies of motoneurons and the voluntary force at high contraction strengths (50% to 100%maximum) was determined for tibialis anterior with the ankle: (i) at 90° (control length) and (ii) this angle reduced by about 15° (short length), an amount sufficient to reduce the maximal voluntary force by about 35%. In the shortened position, twitch contraction and half‐relaxation times were reduced by 11% and 18%, respectively. At both muscle lengths, the ability to activate the muscle fully by voluntary effort was confirmed by twitch interpolation. Motor unit firing rates were recorded during isometric voluntary contractions lasting 10 seconds, performed at 50%, 75%, and 100% maximal force. At each length, discharge rates varied in proportion to the relative force exerted. Despite the difference in twitch contractile speed at the two lengths, no significant differences were found between motoneuron discharge rates recorded at each muscle length during maximal or submaximal contractions.
Ca2+—ATPase and Na+‐K+–ATPase content in skeletal muscle from malignant hyperthermia patients
Authors: Everts Maria E. , Ørding Helle , Hansen Otto , Nielsen Peter A.
Published: January 2005

The purpose of this study was to determine the concentration of Ca2+–ATPase and Na+‐K+–ATPase in biopsies from vastus lateralis muscle of 24 patients, who underwent a diagnostic contracture test for susceptibility to malignant hyperthermia (MH). Ca2+–ATPase was quantified as the Ca2+‐dependent 32P incorporation in whole muscle homogenates. Na+‐K+–ATPase was quantified as the [3H]ouabain‐binding capacity in intact muscle samples. These methods avoid isolation of membranes, a procedure that may influence the results due to interindividual variation in recovery. The results show that both enzymes can be determined in (frozen) muscle biopsies weighing 50 mg. Neither the concentration of Ca2+–ATPase nor that of Na+‐K+–ATPase differed in biopsies from subjects diagnosed as susceptible (MHS) or nonsusceptible (MHN) to MH. Our data support the view that changes in the concentration of Ca2+–ATPase and/or Na+‐K+–ATPase do not play a primary role in the pathogenesis of MH.
Quality control in nerve conduction studies with coupled knowledge‐based system approach
Authors: Xiang Yang , Eisen Andrew , MacNeil Maureen , Beddoes Michael P.
Published: January 2005

Contemporary equipment used for nerve conduction studies is usually capable of computerized measurement of latency, amplitude, duration, and area of nerve and muscle action potentials and resulting conduction velocities. Abnormalities can be due to technical error or disease. Identification of technical error is a major element of quality control in electromyography, and artificial intelligence could be useful for this purpose. We have developed a coupled knowledge‐based prototype system (QUALICON) to assess the correctness of recording and stimulating characteristics in routine conduction studies. QUALICON extracts numeric features from CMAPs or SNAPs, which are translated into symbolic form to drive a Bayesian network. The network uses high‐level knowledge to infer the quality of stimulating and recording electrode placement as well as polarity and stimulus strength making recommendations as to the likely technical error when abnormal potentials are detected. A preliminary assessment shows that QUALICON performs as well as manual assessment performed by professionals.
Segmental cytochrome c‐oxidase deficiency in CPEO: Teased muscle fiber analysis
Authors: Matsuoka Taro , Goto Yu‐Ichi , Hasegawa Hitomi , Nonaka Ikuya
Published: January 2005

In an attempt to elucidate the pathogenesis of focal cytochrome c‐oxidase (COX) deficiency in skeletal muscle from patients with chronic progressive external ophthalmoplegia (CPEO), we examined the longitudinal distribution of COX activity in single muscle fibers from 6 CPEO patients with muscle mitochondrial DNA (mtDNA) deletions. A new method for teasing single muscle fibers, recently developed in our laboratory, revealed fibers with COX‐positive and ‐negative segments in all 6 patients. The borders between the enzyme‐positive and ‐negative segments in these fibers were sharply delineated, so that the length of each COX‐negative segments could be accurately measured. The proportion of the sum of the lengths of the enzyme‐negative segments to the total length of the muscle fibers correlated well with the proportion of deleted mtDNA, suggesting that abnormal mitochondria harboring mutant mtDNA may be responsible for the focal loss of COX activity.
Brief communication: Becker muscular dystrophy: Detection of unusual disease courses by combined approach to dystrophin analysis
Authors: Gold Ralf , Kress Wolfram , Meurers Bernd , Meng Gerhard , Reichmann Heinz , Muüller Clemens R.
Published: January 2005

The rapid progress of research on the structure of the dystrophin gene has enormously increased our understanding of the molecular basis of Duchenne (DMD) and Becker (BMD) muscular dystrophy. Apart from “classical” clinical presentations, asymptomatic or only mildly affected individuals with deletions in the dystrophin gene have now been reported. We describe two families which were initially classified as metabolic myopathies, until the diagnosis of atypical BMD was established after dystrophin analysis at the protein and DNA level. A modern diagnostic approach to myopathies should, therefore, not only include morphological and biochemical investigations, but also be extended to the analysis of the dystrophin gene.
Amyotrophic lateral sclerosis (ALS): A phylogenetic disease of the corticomotoneuron?
Authors: Eisen Andrew , Kim Seung , Pant Bhanu
Published: January 2005

It is proposed that the primary cell involved in amyotrophic lateral sclerosis (ALS) is the corticomotoneuron. The spinal motoneuron becomes affected as a result of antegrade effects. This hypothesis does not negate most of the presently popular theories regarding the pathogenesis of ALS, but directs focus to one cell type–the corticomotoneuron. It takes cognizance of the complex, monosynaptic, corticomotoneuronal‐spinomotoneuronal connections that have evolved in primates, and especially in man. It might explain the lack of any natural or thus far induced animal model which closely mimics the human disease. Threshold measurements to transcotical magnetic stimulation might be used to test the hypothesis. Replication of ALS in an animal is only likely to succeed in a nonhuman primate.
A congenital myasthenic syndrome refractory to acetylcholinesterase inhibitors
Authors: Triggs William J. , Beric Aleksandar , Butler Ian J. , Roongta Suresh M.
Published: January 2005

We studied 4 siblings (3 men and 1 woman), ages 22 to 43 years, with congenital ptosis, external ophthalmoplegia, proximal muscle weakness and fatigability unresponsive to acetylcholinesterase (AChE) inhibitors. Repetitive nerve stimulation showed a significant compound muscle action potential (CMAP) area decrement at 2 or 3 Hz. Nerve conduction studies and concentric needle electromyography were normal, and repetitive CMAPs to single nerve stimulation were not observed. Voluntary single fiber electromyography (SFEMG) showed increased jitter and blocking. Assessment of individual end‐plates using SFEMG with intramuscular axonal microstimulation showed no uniform relationship between jitter and the rate of stimulation, consistent with a postsynaptic defect of neuromuscular transmission. Edrophonium eliminated the decremental response to repetitive nerve stimulation, but caused no significant clinical improvement, suggesting an additional mechanism for weakness in these patients.
Role of autonomic nerve functions in patients with familial amyloidotic polyneuropathy as analyzed by laser doppler flowmetry, capsule hydrograph, and cardiographic R–R interval
Authors: Ando Yukio , Araki Shukuro , Shimoda Osamu , Kano Tatsuhiko
Published: January 2005

Laser Doppler flowmetry (LDF) was conducted on familial amyloidotic polyneuropathy (FAP) patients and asymptomatic carriers of FAP. Vasoconstrictive responses in the 11 FAP patients tested, induced by deep inspiration, were markedly depressed compared with those of the healthy controls. The responses decreased with the progression of FAP, with no responses being elicited from the 7 patients in stages 2 (moderate) to 4 (terminal). Interestingly, vasoconstrictive responses following deep inspiration also were depressed in 3 of 4 asymptomatic carriers of FAP who showed no clinical sign of FAP, and who had normal sensory nerve conduction velocity. Patients who had such diseases as Shy–Drager's disease, spinocelebellar degeneration, and pandysautonomia showed no decrease in blood flow for various stimulations. In contrast, patients with primary amyloidosis, who had no autonomic dysfunction, showed a normal pattern. Detection of the autonomic functions in FAP patients and asymptomatic carriers by capsule polyhydrography and computer analysis of the cardiographic R–R interval revealed that the asymptomatic carriers of FAP, as well as the FAP patients, had disordered peripheral autonomic functions. Our results suggest that the autonomic nervous system is first affected during the very early stage of FAP.
Determining neuromuscular jitter using a monopolar electrode
Authors: Buchman Aron S. , Garratt Mark
Published: January 2005

Neuromuscular jitter was determined in the extensor digitorum communis (EDC) of 41 healthy control subjects and 8 patients with myasthenia gravis (MG). Standdard single‐fiber electromyographic (SFEMG) techniques were used, except that a monopolar electrode (MPE) was substituted for a single‐fiber electrode (SFE). In normals, means jitter for 20 pairs was 22.4 ± 2.8 μs and the mean jitter for an individual pair was 22 ± 5.6 μs. In the age range tested (18 to 49 years), jitter did not change with increasing age. When MPE jitter studies were repeated in 16 normals, mean jitter usually varied by less than 10% (mean 7.4% ± 6.2%) and remained normal. Jitter was significantly increased in MG compared to normals 73 ± 56 μs versus 22 ± 5.6 μs (F = 149.4, P < 0.0001). Using an analog pain scale, the discomfort during electromyography using MPE and SFE was compared between the left and right arms in 35 normals. MPEs caused less discomfort than SFEs (P = 0.031), and were preferred (71% versus 20%) to SFEs (χ2 = 9.21, P = 0.01). Based on these results, we conclude that MPE determined jitter studies are reproducible, can distinguish between nomals and MG, and are associated with less discomfort than SFE.
Sural nerve conduction parameters in normal subjects related to age, gender, temperature, and height: A reappraisal
Authors: Trojaborg Werner T. , Moon Agnes , Andersen Birgitte B. , Trojaborg Nanna S.
Published: January 2005

Failure to take body height into considerations in the evaluation of nerve conduction velocities (CV) has recently been deemed unacceptable. This statement prompted the present study. Besides height, the influence of age, gender, and temperature was studied in 92 normal subjects, half of whom were females. The CV decreased 0.9 m/s per 10 years increase in age, the same in women and men aged 15 to 44 years. Mean temperature between distal and proximal ends of the nerve segment examined increased 6.1 ± 0.3° C after heating followed by a CV increase of 7.0 ± 0.5 m/s. The CV decreased 0.15 m/s per 100‐mm increase in heights. When considering 37 individuals aged 25 to 34 years only, the CV increased 0.34 m/s per 1‐m increase in height. In both instances, the changes were within the experimental error (2.3%) of the method.
Early postoperative ulnar neuropathies following coronary artery bypass surgery
Authors: Watson Bradley V. , Merchant Richard N. , Brown William F.
Published: January 2005

Ulnar neuropathies following surgery are common. However, they often go undetected during the early postoperative period, because the patient may be unaware of symptoms related to the neuropathy. Nerve conduction studies are useful in localizing the lesion, but are usually employed only in cases developing signs and symptoms. We undertook this study to determine the incidence, time of onset, and outcome of clinical and subclinical ulnar neuropathies. Electrophysiological studies were carried out preoperatively, imediately following surgery, and 4 to 6 weeks postoperatively in 20 coronary artery bypass patients. Conduction velocity across the elbow was reduced in 3 limbs (8%) postoperatively, all of which were detected immediately following surgeery. One parient developed conduction block and weakness in ulnar supplied intrinsci hand muscles. Denervation was seen in 2 cases and, in 1 case (5%), a right brachial plexus injury was clinically evident 5 days following surgery. All newly developing ulnar neuropathies were asymptomatic, with most recovering to their preoperative electrophysiological status at follow‐up.
Amiodarone‐induced experimental acute neuropathy in rats
Authors: Santoro Lucio , Barbieri Fabrizio , Nucciotti Renato , Battaglia Francesco , Crispi Francesco , Ragno M. , Greco P. , Caruso G.
Published: January 2005

Amiodarone was injected endoneurially at increasing doses into the exposed tibial nerve of rats to study its electrophysiologic and pathologic effects on peripheral nerve fibers. Forty‐five male Wistar rats were used, and each of the following concentrations was injected into 15 nerves: 25 μg/mL, 50 μg/mL, and 100 μg/mL. Microinjection of a 25 μg/mL concentration of amiodarone resulted in a subacute, incomplete conduction block evident at day 3 postinjection. This conduction block remained stable until day 10 and recovery was complete at day 35. Microinjection of a 50 μg/mL concentration of amiodarone produced a faster evolving conduction block, and significant axon degeneration (approximately 40% of fibers). Injection of a 100 μg/mL concentration resulted in severe acute motor axon degeneration followed by complete but delayed regeneration. Results of morphological studies closely correlated with electrophysiological findings. Amiodarone thus seems to have a direct toxic effect on axons at high concentrations in the peripheral nerve, and we suggest that different pathological changes described in human amiodarone neuropathy could be related to different concentrations of the drug in the nerve, perhaps due to variability of blood‐nerve barrier efficacy.
Lumbosacral nerve root stimulation comparing electrical with surface magnetic coil techniques
Authors: MacDonell R. A. L. , Cros D. , Shahani B. T.
Published: January 2005

Stimulation of lumbosacral nerve roots using a monopolar needle electrode was compared with magnetic stimulation using a 7‐cm diameter surface coil. Compound muscle action potentials were recorded from the tibialis anterior (TA) and flexor hallucis brevis (FHB) muscles. Although the mean latency of CMAPs did not differ using the two techniques, amplitudes were considerably larger using a needle. Mean amplitudes were 66% (TA) and 64% (FHB) of the direct M response obtained by distal, supramaximal stimulation compared with mean values using maximal magnetic coil stimulation of 36% (TA) and 25% (FHB). Minimum F‐wave latencies from FHB were used to estimate the site of nerve root stimulation using both techniques. Although there was a large amount of variability in the data from individual subjects, the results suggested that, on the average, both forms of stimulation act proximal to the intervertebral foramen. We conclude that a needle electrode is a more suitable technique for stimulating lumbosacral nerve roots. © 1992 John Wiley & Sons, Inc.
Increasing the proliferative capacity of muscular dystrophy myoblasts
Authors: Yang Jie , Seelig Miriam , Rayner Sylvia , Bredesen Dale E.
Published: January 2005

Temperature‐sensitive immortalized neural cells may be utilized to produce genetically engineered neural transplants. We have used a similar approach with mdx myoblasts. Control and mdx myoblasts were immortalized with a recombinant retrovirus that effects the expression of a temperaturesensitive simian virus 40 large T antigen. The resultant cells divide indefinitely at 34°C, but differentiate at 38°C, both morphologically and immunocytochemically. Polymerase chain reaction analysis of RNA confirmed the presence of the dystrophin point mutation in the mdx cells and its absence in the control cells. A similar approach may be useful for the proliferation, modification, and reimplantation of autologous cells from patients with degenerative and dystrophic disorders such as Duchenne muscular dystrophy. © 1992 John Wiley & Sons, Inc.
Far‐field potentials in circular volumes: The effect of different volume sizes and intercompartmental openings
Authors: Dumitru Daniel , King John C.
Published: January 2005

Preliminary investigations of circular volume conductors suggested that farfield potential magnitude declines progressively slower with increasing radial distance from a current source and follows a cosine function with angular displacement of the recording electrode from the electrical generator's axis. Using circular volumes of 6 differing radii, the mathematical relationship between angle, radii, and far‐field potential amplitude is determined. Previous theoretical relationships of amplitude versus dipolar spacing, current, and distance from a dipole generator in a bounded volume conducting medium are verified for the near‐field. Far field potentials in circular volumes are found to become constant at radii greater than 75% of the bounded volume's radius. Additionally, an adjoining volume conductor acts simply as a passive fluid‐filled electrode (wick electrode) to the circular volume containing the generator until the intercompartmental opening to the circular volume exceeds 20% of its circumference. This finding was clinically supported by recording similar P9 somatosensory‐evoked far‐field potentials generated caudal to the foramen magnum from various portions of the cranium, whose connections to the torso, foramen magnum, and neck, average 6.2% and 17.8%, respectively. Finally, 3 circular volume conductors were connected in series by channels less than 20% of the volume conductor's circumference. Both adjoining circular volumes were equipotential to the far‐field potential present at the boundary of the first circular volume containing the dipole generator. This observation supports the clinical finding of far‐field potential transmission through multiple human bodies in conductive contact. © 1992 John Wiley & Sons, Inc.
Nerve conduction studies in amyotrophic lateral sclerosis
Authors: Cornblath David R. , Kuncl Ralph W. , Mellits E. David , Quaskey Shirley A. , Clawson Lora , Pestronk Alan , Drachman Daniel B.
Published: January 2005

Nerve conduction studies (NCS) are an integral part of the evaluation of amyotrophic lateral sclerosis (ALS) patients and are useful in distinguishing ALS from disorders that mimic it. The question often arises whether in the presence of severe atrophy and reduction of the compound muscle action potential amplitude, abnormal conduction velocity (CV), distal latency (DL), of F‐wave latency (F) exceeds what can be expected from ALS alone. To determine the limits of abnormality in classic ALS, we prospectively evaluated NCS data from 61 patients who met a strict clinical definition of ALS. We ralated CV, DL, and F to distal evoked amplitude (AMP) in peroneal (n = 63 observations), median (n = 50), and ulnar (n = 52) nerves. In nerves with reduced AMP, CV rarely fell to less than 80% of the lower limit of normal, and DL and F rarely exceeded 1.25 times the upper limit of normal. Utilizing the entire data set and regression analyses, 95% confidence limits for expected values for CV, F, and DL as a function of AMP were calculated. These limits thus derived suggest criteria for NCS abnormalities in ALS and may by useful in differentiating ALS from other illnesses. © 1992 John Wiley & Sons, Inc.
An experimental model of mitochondrial myopathy: Germanium‐induced myopathy and coenzyme Q10 administration
Authors: Wu Chien‐Ming , Matsuoka Taro , Takemitsu Masakazu , Goto Yu‐Ichi , Nonaka Ikuya
Published: January 2005

In skeletal muscles from rats treated with germanium for 23 weeks, there were numerous ragged‐red fibers and cytochrome‐c oxidase (COX)‐deficient fibers. Biochemically, germanium reduced the enzyme activities in the mitochondrial respiratory chain. Rotenone‐sensitive NADH–cytochrome‐c reductase as well as COX activities were markedly reduced, while succinate–cytochrome‐c reductase was less severely, but significantly, affected. The histopathological findings in these muslces were similar to those seen in patients with mitochondrial encephalomyopathy, suggesting that germanium‐induced myopathy may be a useful experimental model. Coenzyme Q10 administration appeared to be ineffective in preventing this experimental myopathy. © 1992 John Wiley & Sons, Inc.
Lower motor neuron dysfunction in patients with multiple sclerosis
Authors: Shefner Jermy M. , Mackin Glenn A. , Dawson David M.
Published: January 2005

A patient in whom multiple sclerosis (MS) was ultimately diagnosed presented with a lower motor neuron syndrome involving 1 hand, with EMG evidence of denervation. Twelve other patients were subsequently identified with definite MS and asymmetric hand atrophy. These patients were studied clinically and electrophysiologically. Evidence of chronic and ongoing denervation was noted in the hands of 12 of the 13 patients; in only 3 patients could the EMG abnormalities be accounted for by peripheral nerve lesions. Thus, lesions resulting in lower motor neuron damage may occur in the central nervous system in MS patients. We suggest that demyelination in the region of the ventral root exit zone may account for these findings. © 1992 John Wiley & Sons, Inc.
Acute myopathy and neuropathy in status asthmaticus: Case report and literature review
Authors: Lacomis David , Smith Thomas W. , Chad David A.
Published: January 2005

A 38‐year‐old woman developed acute, severe weakness during the treatment of status asthmaticus that included high‐dose intravenous corticosteroids. A muscle biopsy and EMG indicated a myopathy, and nerve conduction studies disclosed a neuropathic component. In association with corticosteroid tapering, the clinical, EMG, and nerve conduction abnormalities resolved. In some patients, intensive treatment of status asthmaticus may cause a reversible, toxic disorder of muscle and nerve. © 1993 John Wiley & Sons, Inc.
Ocular myastyenia gravis: The diagnostic yield of repetitive nerve stimulation and stimulated single fiber EMG of orbicularis oculi muscle and infrared reflection oculography
Authors: Oey P. Liam , Wieneke George H. , Hoogenraad Tjaard U. , Van Huffelen Alexander C.
Published: January 2005

For the diagnosis of ocular myasthenia gravis (ocular MG), testing of the muscles close to the affected ones may be important. The relative importance of several methods: stimulated single fiber EMG (stimulated SFEMG), repetitive nerve stimulation test (RNS) of orbicularis oculi muscle, and infrared reflection oculography (IROG) was investigated. Thirty‐two patients in whom a diagnosis of ocular MG was considered on clinical grounds were admitted to the study. Based on the results of the three neurophysiological tests, the patients could be divided in three groups: a first group with an abnormal stimulated SFEMG, and an abnormal RNS and/or abnormal IROG; a second group with only a slightly abnormal stimulated SFEMG; and a third group with normal tests in all three tests. The clinical diagnosis of ocular MG was made in all 11 patients of the first group; in 86% (6 of 7) of the patients of the second group; and in 7% (1 of 14) of the patients of the third groups. This study demonstrates that the orbicularis oculi muscle is a suitable muscle for stimulated SFEMG in patients with ocular MG, and that the results obtained with this technique showed a better relation with the clinical diagnosis than those of the two other techniques. We also demonstrate that there is no additional value in studying the jitter with different stimulation rates in patients with suspected ocular MG. © 1993 John Wiley & Sons, Inc.
The value of magnetic stimulation in the diagnosis of radiculopathies
Authors: Bischoff Christian , Meyer Bernd‐Ulrich , Machetanz Jochen , Conrad Bastian
Published: January 2005

We studied 42 patients with cervical and lumbar radiculopathies using magnetic stimulation. Prolonged latencies following magnetic stimulation of the brain, the paravertebral spinal nerve, or both, showed a highly significant correlation with muscle weakness in clinical testing (24 of 26 patients with weakness had pathological motor evoked potentials) as well as with spontaneous activity of the target muscles in needle electromyography (24 of 25 subjects). The determination of both the central and the peripheral motor conduction time was found to be essential in patients with radiculopathies, because different patterns of latency changes correlated with different morphological results in computed tomography: in patients diagnosed as having a lateral compression of the nerve root the peripheral nerve latency was delayed; whereas, in patients with more medially localized herniations, a prolonged central motor latency was the most frequent finding. This study posits that combined magnetic stimulation of the brain and nerve root is an effective and painless technique for the noninvasive evaluation of nerve root function. © 1993 John Wiley & Sons, Inc.
Search for HIV proviral DNA and amplified sequences in the muscle biopsies of patients with HIV polymyositis
Authors: Leon‐Monzon Marta , Lamperth Lajos , Dalakas Marinos C.
Published: January 2005

We searched for the presence of human immunodeficiency virus (HIV) in fresh‐frozen muscle biopsy specimens from 10 patients with HIV‐associated polymyositis (HIV‐PM) using (a) 35S‐labeled HIV‐RNA transcript of the virus and in situ hybridization, and (b) polymerase chain reaction and slot‐blot hybridization utilizing primers amplifying sequences from the gag and pol genes of the HIV genome. With in situ hybridization, positive signals were detected in sparse lymphoid cells surrounding the muscle fibers, but not within the muscle fibers, in up to two consecutive sections in 6 of the 10 specimens. By the polymerase chain reaction, amplified HIV‐specific sequences were noted in 2 specimens, but in only 2 of 8 consecutive sections, implying infection of lymphoid cells rather than muscle fibers. Muscle cultures from six specimens failed to show integrated HIV sequences within the myotubes. We conclude that HIV sequences or transcriptional products are not present within the muscle fibers or the cultured myotubes of patients with HIV‐PM. This indicates that: (a) viral replication does not take place within the muscle; (b) integration of HIV proviral genome does not occur within the myonuclei or satellite cells; and (c) HIV‐PM does not seem to be due to a persistent infection of the muscle fiber by the virus. © 1993 John Wiley & Sons, Inc.
Adult acid maltase deficiency
Authors: Barohn Richard J. , McVey April L. , Dimauro Salvatore , Griggs Robert C. , Mendell Jerry R. , Miller Robert G.
Published: January 2005

A 30‐year‐old man was referred for neurologic evaluation because of elevated creatine kinase. He had noted symptoms of proximal arm and distal leg weakness for several years, and, on examination, he had weakness in a scapuloperoneal distribution. An electromyogram showed myotonic discharges in the paraspinous muscles, and a muscle biopsy revealed severe vacuolar myopathy. Biochemical analysis of muscle showed acid maltase deficiency. The patient's only brother had childhood‐onset acid maltase deficiency and died of respiratory failure at age 27. Acid maltase deficiency may have heterogeneous presentations within a family, and adult AMD can present as a scapuloperoneal neuromuscular syndrome. © 1993 John Wiley & Sons, Inc.
Variability and interrelationships of surface EMG parameters during local muscle fatigue
Authors: Linssen Wim H. J. P. , Stegeman Dick F. , Joosten Ed M. G. , Notermans Servaas L. H. , van't Hof Martin A. , Binkhorst Rob A.
Published: January 2005

The inter‐and intraindividual variability of the frequency power density spectral and surface EMG amplitude parameters and of the muscle fiber conduction velocity (MFCV) is studied in 26 healthy volunteers during fatiguing isometric ischemic intermittent exercise of the m, biceps brachii at 80% of the maximal voluntary contraction level, with a contraction rate of 30/min. No significant age effects were found. Males were significantly stronger compared with females. The higher initial SEMG amplitude and the strongershift of the frequency power density spectrum (PDS) to lower frequencies appear to be significantly correlated with males. Fatigue induces an almost proportional compression of the SEMG frequency content. The muscle fiber conduction velocity has the highest intraindividual reproducibility (r = 0.81). Despite the definite and strong influence of the MFCV on the PDS, the shift of the PDS can not be explained by a change of MFCV alone.© 1993 John Wiley & Sons, Inc.
Persistent and transient “conduction block” in motor neuron diseases
Authors: Lange Dale J. , Trojaborg Werner , McDonald T. Drake , Blake David M.
Published: January 2005

Although conduction block indicates dysfunction of peripheral nerve, itmay occur in patients with clinically typical motor neuron disease. There are no universally accepted criteria to identify conduction block, so diagnosis may be difficult. In some peripheral neuropathies, conduction block persists over long periods of time. If conduction block persists in motor neuron disease, then a more reproducible means for identification would be available. We repeatedly studied 9 patients with different forms of motor neuron diseases; conduction block was suspected because of excessive loss of the amplitude of motor evoked responses between distal and proximal stimulation sites. Five showed persistent amplitude loss at intervals between 12 and 36 months. All had focal loss of amplitude and area across a specific segment; all were men; none had definite upper motor neuron signs, 2 had probable and 3 had no upper motor neuron signs; 1 had IgM paraproteinemia, one elevated anti‐GM1 titers; the duration of symptoms spanned 4–13 years. Four patients had transient loss of amplitude that was not reproduced in intervals between 3 and 13 months. None had focal loss of both amplitude and area; 2 were men; all had definite upper motor neuron signs and none had symptoms for more than 3–13 months; and none had immunological abnormalities. Thus, patients with persistent amplitude loss fulfill other criteria for conduction block, have prolonged survival but otherwise have clinical syndromes indistinguishable from ALS, except that definite upper motor neuron signs seem to be exceptional. © 1993 John Wiley & Sons, Inc.
Mechanisms of fatigue in normal intercostal muscle and muscle from patients with myasthenia gravis
Authors: Pagala Murali , Nandakumar N. V. , Venkatachari S. A. T. , Ravindran Kadirimangalam , Amaladevi Bellamakonda , Namba Tatsuji , Grob David
Published: January 2005

Fatigue mechanisms in normal intercostal muscle and muscle from patients with myasthenia gravis (MG) were evaluated by monitoring the compound muscle action potential (CMAP) and tetanic tension responses to repetitive nerve or muscle stimulation in vitro. When fatigue was induced by nerve stimulation at 30 Hz for 0.5 s every 2.5 s, about half of the original tension decreased after 30 min in normal muscle and 5 min in MG muscle. Analysis of the changes in area of CMAPs and tension indicated that impairment of neuromuscular transmission, muscle membrane excitation, and excitation‐contraction (E‐C) coupling and contractility accounted for 40%, 29%, and 31% of fatigue in normal muscle, and 83%, 0%, and 17% of fatigue in MG muscle. When fatigue was induced by muscle stimulation at 30 Hz, tension declined by a quarter after 30 min in normal muscle, but by a half after 17 min in MG muscle. Impairment of muscle membrane excitation and E‐C coupling and contractility accounted for 58% and 42% of fatigue in normal muscle, and 22% and 78% of fatigue in MG muscle. Thus, fatigue of normal muscle is caused by impairment of at least four processes, and enhanced fatigue of MG muscle is caused by greater impairment of neuromuscular transmission, E‐C coupling, and contractility. © 1993 John Wiley & Sons, Inc.
Antigalactocerebroside antibody increases demyelination in adoptive transfer experimental allergic neuritis
Authors: Hahn Angelika F. , Feasby Thomas E. , Wilkie Lora , Lovgren David
Published: January 2005

There is suggestive but inconclusive evidence for a contribution of T cells and antimyelin antibodies to the pathogenesis of the Guillain–Barré polyneuropathy. We have studied the potential synergism of cellular and humoral immunity in the adoptive transfer model of EAN. EAN was induced in Lewis rats by injecting varying doses of P2 peptide (SP26)‐sensitized T lymphocytes. Disease severity was dose‐dependent. The addition of intravenous GC‐AB to a subclinical dose of SP26‐sensitized T cells resulted in overt clinical disease and markedly enhanced demyelination. Intravenous injection of antibody alone had no effect. We conclude that activated neuritogenic T cells, while entering into peripheral nerves, alter the blood‐nerve barrier, which gives circulating demyelinating antibodies access to the endoneurium. The observations support the concept of a synergistic role of T‐cell autoimmunity and humoral responses in the inflammatory demyelination of Lewis rat EAN. © 1993 John Wiley & Sons, Inc.
Peripheral neuromuscular manifestations in systemic sclerosis (scleroderma)
Authors: Hietaharju Aki , Jääskeläinen Satu , Kalimo Hannu , Hietarinta Marja
Published: January 2005

Systemic sclerosis (scleroderma) is thought to be the least likely of the collagen vascular disorders to cause nervous system damage. We evaluated the peripheral neuromuscular manifestations in 32 patients with scleroderma. A clinically defined peripheral nervous system (PNS) lesion was manifest in 5 of 32 patients (16%), including 2 patients with trigeminal neuropathy and single cases of polyneuropathy, brachial plexopathy, and lumbosacral radiculopathy. Neurophysiological studies suggested subclinical PNS involvement in 6 additional patients (3 with distal axonal polyneuropathy, 1 with probable myopathy and superimposed polyneuropathy, 1 with trigeminal neuropathy, and 1 with focal ulnar neuropathy). Even though subjective muscular complaints were numerous (16 patients, 50%), a defined primary muscular disease could be demonstrated only in 5 patients (16%). Our results indicate that peripheral neuropathy in scleroderma is not as uncommon as previously estimated. © 1993 John Wiley & Sons, Inc.
Histochemical and contractile property changes during human muscle development
Authors: Elder Geoffrey C. B. , Kakulas Byron A.
Published: January 2005

When the histochemical and contractile properties of infant muscles change postnatally, and what influence muscle function has on these changes, were the focus of this study. Contractile properties were measured in the plantaflexor (PF) and dorsiflexors (DF) of 19 newborns and 36 infants aged 5–16 months. Infants were tested between one and four times at monthly intervals. Measurements included maximal twitch tension (Pt), time to peak tension (TPT), and half‐relaxation times (1/2RT). TPT was similar in PF (77 ms) and DF (73 ms) at birth, remained unchanged in DF, and slowed in PF to 110–120 ms between 9 and 12 months. Type I distributions were determined at autopsy in fetal through to adult muscles. Completion of differentiation occurred in soleus at about the age that contractile properties slowed and infants started to use these muscles more. A trend of higher percentages of type I distributions was also noted in children than either newborns or adults in other muscles. The implications of these findings and the clinical use of these methods for evaluating peripheral neuromuscular function is discussed. © 1993 John Wiley & Sons, Inc.