bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucocorticoid excess induces preferential depletion of myosin in denervated skeletal muscle fibers
Authors: Rouleau Guy , Karpati George , Carpenter Stirling , Soza Marco , Prescott Steve , Holland Paul
Published: January 2005

The combined effects of dexamethasone treatment (1 mg/Kg/day) plus denervation (DEX‐DEN), were studied at 7, 13, and 28 days by microscopic, biochemical, and physiological techniques in plantaris and soleus muscles of adult rats. The results were compared with corresponding dexamethasone‐treated (DEX) and denervated (DEN) muscles and appropriate controls. There was a significantly more marked atrophy of all fiber types in the DEX‐DEN plantares at 7 and 13 days than in either DEX or DEN muscles. The degree of atrophy was greatest in type 2B fibers in DEX‐DEN plantares. Electron microscopy revealed a severe preferential depletion of thick myofilaments in DEX‐DEN plantares and solei but not in DEX or DEN muscles. The thick myofilament depletion in DEX‐DEN muscles occurred in addition to a severe overall reduction of myofibrillar caliber. Gel electrophoresis showed a marked preferential decrease of myosin heavy chain in DEX‐DEN plantares and solei, but not in either DEX or DEN muscles. Myosin light chains were also markedly reduced in DEX‐DEN plantares and solei. In vitro physiological studies showed a marked reduction of the denervation‐induced twitch potentiation in DEX‐DEN solei. Maximal tetanic tension (20 Hz stimulation) per gram weight of muscle as well as the twitch‐tetanus ration was significantly reduced only in DEX‐DEN solei in relation to controls. Myosin depletion in DEX‐DEN muscles may be due to a severe preferential inhibition of its synthesis coupled with an accelerated catabolism.
Effects of acidosis on tension development in mammalian skeletal muscle
Authors: Ranatunga K. W.
Published: January 2005

Effect of carbon dioxide acidosis on the tension development in a rat skeletal muscle (extensor digitorum longus) was examined at different temperatures. Experiments were done in vitro and with direct stimulation, mostly at constant temperatures between 30–35°C and 12–20°C. A decrease of saline pH (8.0 to 6.5) with carbon dioxide increased the twitch and the tetanic tensions and enhanced the tension relaxation in experiments done at high temperatures. At low temperatures the same procedure decreased the tetanic tension and enhanced the tension relaxation. An increased tetanic tension at the high temperatures and a decreased tetanic tension at the low temperatures were also obtained at constant saline pH, with procedures known to decrease intracellular pH. The observations made at higher temperatures are discussed in relation to human muscle performance in exercise.
Syringomyelia: Electrophysiologic aspects
Authors: Veilleux Martin , Stevens J. Clarke
Published: January 2005

The clinical and EMG findings in 44 patients with syringomyelia who were seen at the Mayo Clinic between 1976 and 1985 are presented. In 10 of the patients, somatosensory evoked potentials (SEPs) of the upper and lower extremities were obtained. All 44 patients had radiographic or surgical evidence of a cervical syrinx. The most common abnormality on nerve conduction studies was a reduced hypothenar compound muscle action potential amplitude (23 patients). Abnormal findings on needle electromyography were present in 33 patients and included sparse fibrillation potentials, reduced motor unit potential (MUP) recruitment, and chronic neurogenic MUP changes in muscles innervated by the C‐5, T‐1 roots, with the most pronounced changes in small hand muscles. Ulnar and median nerve SEPs were usually normal in the presence of a dissociated sensory loss and were usually abnormal when all sensory modalities were impaired. Abnormalities of tibial nerve SEPs were frequent and were related to impaired proprioceptive sensation in the lower extremities.
Trial of a cysteine proteinase inhibitor, EST, in experimental chloroquine myopathy in rats
Authors: Sugita Hideo , Higuchi Itsuro , Sano Motoki , Ishiura Shoichi
Published: January 2005

The administration of 50 mg/kg/day of chloroquine to rats for 8 weeks produced the chloroquine myopathy characterized by autophagic vacuole formation and increases in lysosomal enzymes, especially cathepsins B & L. Coadministration of 10 mg/kg/day of a potent cysteine proteinase inhibitor, EST, and chloroquine prevented the induction of the chloroquine myopathy. Rats already suffering from the chloroquine myopathy were treated with 10 mg/kg/day of EST together with chloroquine injections for 5 weeks and also recovered remarkably from the myopathy. Thus, EST may be beneficial for myopathies associated with autophagic vacuoles.
AAEE case report #13: Diabetic amyotrophy
Authors: Chokroverty Sudhansu
Published: January 2005

A case fulfilling the criteria for the diagnosis of diabetic amyotrophy is reported. Based on the clinical and electrodiagnostic features, it is concluded that diabetic amyotrophy is a recognizable clinical entity that can be differentiated from other diabetic neuropathies. The site of the lesion and the pathogenesis in diabetic amyotrophy remain controversial. The usual course of the illness is one of gradual improvement over weeks to months.
Canine masticatory muscle disorders: A study of 29 cases
Authors: Shelton G. Diane , Cardinet George H. , Bandman Everett
Published: January 2005

The histopathologic features in temporalis muscle biopsies from 29 dogs with masticatory muscle disorders were characterized and used for their subgrouping: 2 without lesions, 3 with nonspecific changes, 7 with neurogenic atrophy, and 16 with myositis. The immunocytochemical and immunochemical features of the muscle biopsies and sera from those dogs were compared among the histopathologic subgroupings and compared with biopsies and sera from healthy dogs and dogs with polymyositis. Of the 14 biopsies from dogs with masticatory muscle myositis, 12 had immune complexes limited to type 2M fibers, whereas 13 of 16 sera samples had detectable antibodies against type 2M fibers. The immune complex deposition was found only in biopsies of dogs with masticatory muscle myositis, and the antibodies were detected in the sera of only one dog that did not have masticatory muscle myositis. Immunoblot assays revealed that the antibodies were most often directed against a 185 K protein, myosin heavy chain, and a band that appeared to be LC2‐M (myosin light chain 2‐masticatory).
Temperature dependence of contraction characteristics in developing rat muscles
Authors: Wylie S. R. , Ranatunga K. W.
Published: January 2005

Contractions of rat extensor digitorum longus (EDL, a fast muscle) and soleus (SOL, a slow muscle muscles of different ages 1–4 weeks) were recorded in vitro with direct stimulation and at different temperatures (range 35–10°C). Twitch tension in 4‐week‐old EDL muscle increased in cooling from 35 to 20°C (cooling potentiation); the tension decreased in further cooling below 20°C. This pattern of temperature dependence of twitch tension was seen in fast muscles of all ages (1–4 weeks). Twitch tension in 4‐week‐old SOL muscle decreased monotonically in cooling from 35 to 10°C (cooling depression). This pattern of cooling depression was not clearly evident in younger SOL muscles. There was a marked hysteresis in the temperature dependence of twitch tension in the 1‐week‐old SOL muscles. Tetanic tension was depressed by low temperature in both EDL and SOL muscles at 1 week and at 4 weeks of age. Results show that the processes concerned with contractile activation are nearly fully developed in the fast muscle fibers at an early age (1 week), whereas they develop later in the slow muscle fibers.
Immunohistochemical localization of AMP deaminase in rimmed vacuoles in human skeletal muscle
Authors: Higuchi Itsuro , Ishiura Shoichi , Nonaka Ikuya , Sugita Hideo
Published: January 2005

High AMP deaminase reactivity was detected in the rimmed vacuoles in skeletal muscles in adult onset acid maltase deficiency and distal myopathy with rimmed vacuole formation histochemically as well as immunohistochemically. Acid phosphatase activity was positive but myosin ATPase activity was negative in the vacuoles. AMP deaminase found in rimmed vacuoles does not seem to be associated with myosin but is possibly bound to lysosomes or other related organelles in accordance with the proliferation of autophagic vacuoles.
Histoenzymatic profile of human muscle cultured in monolayer and innervated de novo by fetal rat spinal cord
Authors: Vita Giuseppe , Askanas Valerie , Martinuzzi Andrea , Engel W. King
Published: January 2005

We examined histoenzymatic characteristics of human muscle fibers grown in monolayer culture and innervated de novo in culture for 60–90 days by fetal rat spinal cord neurons. Serial cryostat cross sections were obtained using a freshly frozen sandwich of adult rat muscle and cultured human muscle. An Advanced degree of morphologic and histoenzymatic maturation of cultured human muscle was reached after innervation. In contrast to aneurally cultured human muscle fibers, the innervated muscle fibers were smaller in diameter and had myonuclei preferentially located at the periphery of the fiber. The innervated fibers contained a well‐developed intermyofibrillar network revealed by the NADH‐TR and SDH reactions. Phosphorylase activity was strong to moderate in most muscle fibers. Although most of the innervated cultured muscle fibers were still not fully differentiated into two histochemical fiber types because they had strong ATPase activity after both alkaline and acid preincubation, a few of them had an ATPase profile similar to type 2 fibers in human adult muscle and had reciprocal staining with phosphorylase and NADH‐TR reactions. This is the first evidence of differentiation into different histochemical fiber types of human muscle cultured in monolayer and innervated de novo by fetal rat spinal cord.
AAEE case report #14: Neuralgic amyotrophy (acute brachial neuropathy)
Authors: Subramony S. H.
Published: January 2005

Neuralgic amyotrophy is characterized by acute onset of arm pain, followed after a variable interval by flaccid paralysis in the distribution of the brachial plexus on one or sometimes both sides. Electromyography reveals findings suggestive of an axonal degeneration process affecting various portions of the brachial‐plexus or individual nerves emanating from it, sometimes difficult to localize to discrete cords, trunks, or nerves. Diagnosis is established by excluding other causes, including compression and vasculitides. Prognosis for recovery is excellent.
Chloroquine myopathy and myasthenia‐like syndrome
Authors: Sghirlanzoni Angelo , Mantegazza Renato , Mora Marina , Pareyson Davide , Cornelio Ferdinando
Published: January 2005

A young woman on chronic corticosteroid treatment for systemic lupus erythematosus developed a myasthenia‐like syndrome 7 weeks after starting chloroquine therapy. Discontinuation of chloroquine allowed symptomatic and immunological remission within 6 months. Ocular symptoms reappeared following a second short course of chloroquine. A motor‐point biopsy revealed a vacuolar myopathy with membranous bodies in intramuscular nerves. We discuss the possible role of chloroquine in the pathogenesis of a myasthenia‐like syndrome.
Simulation of concentric needle EMG motor unit action potentials
Authors: Nandedkar Sanjeev D. , Sanders Donald B. , Stälberg Erik V. , Andreassen Steen
Published: January 2005

Computer simulations of motor unit action potentials (MUAPs) as measured by a concentric needle (CN) electromyography (EMG) electrode in normal motor units (MUs) indicated that the MUAP amplitude is determined mainly by the proximity of the electrode to the closest muscle fiber. The area and duration of the simulated MUAPs were affected by all muscle fibers in front of the active recording surface but mainly by those that were less than 2 and 2.5 mm, respectively, from the active recording surface. The MUAP area was also affected by the proximity of the electrode to the closest muscle fiber. The number of phases of the simulated MUAPs increased when the dispersion of the arrival times of individual muscle fiber APs at the electrode was increased. Increased temporal dispersion of APs decreased the MUAP amplitude and area slightly but did not affect the MUAP duration. It is inferred that different features of the CN MUAP are determined by the distribution of muscle fibers within different portions of the MU territory and thus provide complementary information about the MU architecture.
Hexosaminidase a activity and amyotrophic lateral sclerosis
Authors: Gudesblatt Mark , Ludman Mark D. , Cohen Jeffrey A. , Desnick Robert J. , Chester Sara , Grabowski Gregory A. , Caroscio James T.
Published: January 2005

Abnormalities of GM2 ganglioside metabolism owing to hexosaminidase A (Hex A) deficiency have been associated with ALS phenotypes. The clinical features described in these ALS patients with Hex A deficiency include early onset, positive family history, and/or long disease duration. In an attempt to determine prospectively the incidence of Hex A deficiency within an ALS population, the records of The Mount Sinai Medical Center ALS Clinic were reviewed to select those patients with “atypical” ALS (total N = 52), i.e. onset before age 35, positive family history, and/or disease duration greater than 90 months. The control group (total N = 50), “typical” ALS patients, did not fulfill any of these historical criteria. Hex A activity determined in isolated peripheral blood leukocytes was normal in all typical ALS patients (mean 67.3%). Hex A deficiency was not found in any atypical ALS patients. Thus, Hex A deficiency apparently is an unusual etiology of typical or atypical ALS but is of medical and genetic importance in individual families.
Continuous motor unit activity confined to the upper extremities
Authors: Tandan Rup , Fries Timothy J.
Published: January 2005

We report a patient with clinical vermiform motor activity, muscle cramps, delayed relaxation of grip, and continuous motor unit discharges who developed mild symmetric symptoms in the upper extremities following a viral infection. Treatment with carbamazepine produced considerable symptomatic improvement. Needle electromyography (EMG) in several muscles showed irregular grouped spontaneous discharges composed of potentials resembling normal motor units. The discharges occurred asynchronously in distal muscles with identical and different peripheral nerve innervation but were not seen in more proximal muscles innervated by the same nerves. Our EMG findings indicate an origin of this spontaneous activity in the terminal branched motor nerves.
Becker muscular dystrophy recombinant DNA studies in identical twins
Authors: Ionasescu Victor , Ionasescu Rebecca , Searby Charles , Burns Trudy
Published: January 2005

Two identical twins with becker Muscular Dystrophy are reported. Both twins had the same red cell types for ABO, Rh, CDE, MNSs, Kelly, Lewis, Duffy, and Kidd. HLA typing detected the same antigens in both twins: A1, A26, B8, B17, DR3, DR7. Family history was negative. The twin patients showed identical haplotypes that were different from the haplotypes of the normal male members of the family. The sister of the twins showed a recombinant X chromosome. The informative haplotype with respect to the gene of BMD, present in the twins, was ascertained in their mother as well. Our findings strongly suggest that a mutation has occurred either in the mother or in the twins.
New concepts of the reinnervated motor unit revealed by vaccine‐associated poliomyelitis
Authors: Wiechers David O.
Published: January 2005

A late onset of slowly progressive muscle weakness 30–40 years after acute polio is well known. Previous studies by the author and others have demonstrated transmission abnormalities within the reinnervated motor unit. These transmission abnormalities shown by motor unit action potential (MUAP) instability in size and shape with repetitive discharges occurs in postpolio patients who are and who are not complaining of progressive muscle weakness. Although some reinnervated MUAPs do seem to stabilize their neuromuscular transmission with time in mildly affected muscles, the question arises as to whether or not some MUAPs ever stabilize after polio. Two cases of acute polio personally followed by the author, one over a 9 1/2 year period, are presented. In both cases, in muscles where there are more deinnervated muscle fibers than could possibly be reinnervated, the MUAPs have remained unstable. New concepts of function in the reinnervated motor unit following polio are presented.
A clinical neurophysiologic study of tropical spastic paraparesis
Authors: Ludolph Albert C. , Hugon Jacques , Román Gustavo C. , Spencer Peter S. , Schoenberg Bruce S.
Published: January 2005

During a field study in the Seychelles Islands, 19 patients with tropical spastic paraparesis (TSP) were evaluated electrophysiologically. Methods of assessment included motor and sensory nerve conduction studies, electromyography, and analysis of the somatosensory evoked potentials after stimulation of the tibial and median nerves. The results showed that the most prominent feature of the disease, a spastic paraparesis, is accompanied by subclinical involvement of spinal sensory pathways and a comparatively minor peripheral sensorimotor polyneuropathy.
False positive electrodiagnostic tests in carpal tunnel syndrome
Authors: Redmond M. David , Rivner Michael H.
Published: January 2005

Of 50 normal subjects, 23 (46%) had at least one false positive electrodiagnostic test for carpal tunnel syndrome (CTS). There were 30% of the subjects who exhibited an abnormal median to ulnar sensory amplitude ratio of less than 1.1. In 7 subjects 8 extremities (14%) revealed prolonged residual latencies, and 4 extremities in 4 subjects (8%) had a difference of 0.4 msec between the median and ulnar palmar sensory latencies. The results of this study indicate that certain reported criteria for CTS are abnormal in a high percentage of normal subjects, thereby making them of limited value in the diagnosis of CTS. Of all the criteria studied, it appears that the comparison of the median to ulnar sensory latency across the carpal tunnel is of greatest potential value. However, even here a more conservative difference of 0.5 msec between median and ulnar nerves must be used to avoid false positive tests for CTS.
Jitter correction: A computer algorithm for reduction of the velocity recovery function artifact
Authors: Davis Graham R. , Ingram David A. , Fincham William F. , Swash Michael , Schwartz Martin S.
Published: January 2005

The measurement of neuromuscular jitter in single fiber electromyography may be artifactually raised by a component of interdischarge interval (IDI)‐dependent jitter caused by the velocity recovery function (VRF) in muscle fibers. We have developed a computer algorithm for on‐line mathematical correction for this artifact, thus improving the reliability of neuromuscular jitter estimates. The method, based on a modeling technique, was validated using intramuscular stimulation in order to either exclude an IDI‐dependent component (using regular stimulation) or to include an IDI‐dependent component (using pseudorandom stimulation). In 10 normal subjects the distribution of 106 corrected jitter values obtained using voluntary activity showed no difference from the measured values. This finding implies that previously published values for normal jitter are not likely to have been influenced by the VRF effect.
Effects of glycerol injection into rat sciatic nerve
Authors: Vallat J. M. , Leboutet M. J. , Loubet A. , Hugon J. , Moreau J. J.
Published: January 2005

In recent years, injection of pure glycerol into the trigeminal cistern has been used for the treatment of trigeminal neuralgia. The mechanism of action of this therapy remains unclear. Using both light and electron microscopy, we investigated the effects of microinjections of sterile, pure glycerol into the endoneurium of the sciatic nerve of the rat. We observed total destruction of both myelinated and unmyelinated fibers. In nearly all animals, signs of automutilation were observed in the paralyzed limb. Histological evidence of nerve degeneration appeared soon after injection, with intense proliferation of perineurial cells that eventually divided the endoneurium into numerous microcompartments.
Orthodromic study of the sensory fibers innervating the fourth finger
Authors: Valls Jose , Llanas Jose M.
Published: January 2005

Fourth finger stimulation has been used to obtain the compound nerve action potential (CNAP) of the median and ulnar nerves by a single cutaneous bipolar recording electrode placed in some specific sites of the upper limb. In normal subjects, the response was a combination of both action potentials which could be seen as separated peaks only when the recording was made at midarm with the elbow flexed at 90°. This finding is mainly attributed to the longitudinal sliding of nerves according to the joint movements. In patients with a carpal tunnel syndrome, there were a striking separation between the responses of both nerves in wrist recording. This finding allows this technique to be applied in the clinical inspection of median nerve entrapment at wrist, demonstrating graphically the delay on the median nerve action potential with regard to that of the ulnar nerve.
The Ca2+ ATPase content of slow and fast twitch fibers of guinea pig
Authors: Ferguson Donald G. , Franzini‐Armstrong Clara
Published: January 2005

The Ca ATPase content in the sarcoplasmic reticulum (SR) of fast and slow twitch skeletal fibers was estimated using two well‐characterized muscles of the guinea pig: the white bundle of the vastus lateralis and the soleus. Ca ATPase surface density was determined by counting the projections of individual molecules revealed on the cytoplasmic surface of freeze‐dried, rotary‐shadowed microsomal vesicles isolated from the two muscles. The Ca ATPase densities were 32,000/μm2 and 25,000/μm2 for the vastus lateralis and soleus muscles, respectively. The percentage of membrane area occupied by Ca ATPase‐free lipid patches was estimated using freeze‐fractured, rotary‐shadowed in situ SR. In soleus muscle the free SR of terminal cisternae and the longitudinal SR have 34.5 and 19.7% of their surface free of ATPase, respectively. In the white vastus less than 1% of the surface was not occupied by Ca ATPase. These values were combined with stereological data from the literature to give a ratio of total Ca ATPase content per unit fiber volume of 1:2, slow versus fast. This is considerably less than the approximately sixfold difference in the overall relaxation time and the half times to relaxation between the two fiber types. This suggests that other factors such as differences in enzyme kinetics or cytoplasmic Ca buffering proteins must also play a role in determining rate of relaxation.
Reinnervation of sweat glands in the mouse: Axonal regeneration versus collateral sprouting
Authors: Kennedy William R. , Navarro Xavier , Kamal Hiroyuki
Published: January 2005

The capacity of sudomotor axons to reinnervate sweat glands by regeneration after freezing was compared with their capacity to reinnervate by the mechanism of collateral sprouting. Two groups of mice were prepared in the same manner, with a single exception. All nerves to the hind paw were cut and tied to prevent regrowth. The exception, the lateral plantar nerve, was left intact in one group and frozen at the ankle in the other group. Reinnervation of sweat glands in the paw was charted frequently for 10 weeks using a silastic mold method. We found that sudomotor axons regenerating from the frozen nerve functionally reinnervated sweat glands of the paw sooner, beginning at 15 days postoperation, and at a higher rate than reinnervation from the collateral branching intact nerve, that began at about 25 days. Full recovery occurred by 41 days in most animals of both groups. We also found that stimulation of sweating by pilocarpine activated more sweat glands during the reinnervation period than stimulation by heating the mice, suggesting that the newly regenerating sudomotor axons have a high threshold.
Carnitine stimulation of pyruvate dehydrogenase complex (PDHC) in isolated human skeletal muscle mitochondria
Authors: Uziel Graziella , Garavaglia Barbara , Di Donato Stefano
Published: January 2005

L‐carnitine stimulated CO2 production from 1‐14C pyruvate in mitochondria from human skeletal muscle nearly twofold. A comparable increase in the pyruvate dehydrogenase complex (PDHC) activity was seen. Moreover, in the presence of L‐carnitine and at pyruvate concentration greater than 0.25 mM, this effect was associated with a marked increase of acetylcarnitine synthesis. Deoxycarnitine, an inhibitor of carnitine acetyltransfersase (CAT), partially reversed the effect of carnitine on PDHC activity. The stimulatory effect of carnitine on PDHC activity in human mitochondria is mediated by the modulation of the intramitochondrial acetylCoA/CoASH ratio.
Conduction studies in peripheral cat nerve using implanted electrodes: I. Methods and findings in controls
Authors: Christian Krarup , Loeb Gerald E.
Published: January 2005

Silicone rubber cuff and patch electrodes with multiple contacts were implanted along the sciatic‐tibial‐plantar nerves in cat for repeated studies of conduction properties of normal peripheral nerve over periods of time. The contacts were used in various combinations for precise localization of changes in conduction velocities and excitability along the extent of normal nerves. In this paper the particular characteristics and limitations associated with cuff‐electrode recordings of neural activity are discussed. The nerve action potential was recorded using a tripolar configuration with a central lead flanked by two shunted leads at symmetrical distances. This configuration records the spatial derivative of the action potential and rejects potentials from sources outside the cuff. The voltage changes are restricted by the silicone cuff, and the dynamic range is therefore very high, allowing detection from single myelinated fibers to whole nerve responses. The electrodes are well suited for following the development of regeneration and degeneration following experimental lesions.
Changes in center of gravity in boys with duchenne muscular dystrophy
Authors: Barrett Ruth , Hyde Sylvia A. , Scott Oona M. , Dubowitz Victor
Published: January 2005

A study was undertaken, using methods of stabilometry to compare stability of stance in normal children (n = 37) and those with Duchenne muscular dystrophy (n = 61). The purpose of this study was to monitor changes in the locus of the center of gravity and the range and frequency of sway and to evaluate the effect of orthotic application in an attempt to obtain information that would assist further development of orthoses.

In group 1, boys with Duchenne muscular dystrophy who were still walking without assistance (mean age 7.2 ± 1.76 years), the analysis of sway showed that, between 5 and 6 years of age, the boys already had ranges of anteroposterior (A/P) and lateral (Lat) sway that were significantly greater than those found in normal children (A/P P < 0.05, Lat P < 0.01). In group 2, boys with Duchenne muscular dystrophy when orthoses had been introduced (n = 23, mean age 10.4 ± 1.47 years), the center of gravity was returned to a more normal position. There was a reduction of the antero‐posterior range of sway, but the lateral range of sway remained significantly greater (P < 0.01) as did the frequency of sway in both the anteroposterior and lateral directions (A/P P < 0.001, Lat P < 0.001).
Longitudinal conduction studies in hereditary motor and sensory neuropathy type 1
Authors: Roy E. Pierre , Gutmann Ludwig , Riggs Jack E.
Published: January 2005

Motor conduction studies were performed serially in 10 patients, ages 10–62 years, with clinical and electrophysiological criteria of hereditary motor and sensory neuropathy type 1 (HMSN‐1) over periods of 11–19 years. Median nerve conduction velocity (MNCV) and distal motor latency showed no significant change on serial studies. Mean median compound muscle action potential (CMAP) amplitude values, however, decreased 66% in 8 patients. Observed clinical progression in HMSN‐1, over prolonged periods of time, was not associated with MNCV slowing. However, CMAP amplitude reduction, reflecting progressive axonal loss, correlated with clinical deterioration.
Proportions and sizes of muscle fiber types in the hamster diaphragm
Authors: Reid W. Darlene , Hards Jennifer M. , Wiggs Barry R. , Wood Elizabeth N. , Wright Peggy V. , Pardy Richard L.
Published: January 2005

This study demonstrated that there was interanimal and interregional variability of proportions and sizes of the muscle fiber types in the hamster diaphragm. Muscle fiber type proportions and sizes were determined for each side (right, left), surface (abdominal, thoracic), and region (sternal, anterior costal, posterior costal, crural) in six hamsters. There was marked regional and surface‐to‐surface variability and some interanimal variability in proportions and sizes of fiber type within the hamster diaphragm. The sternal and costal regions were relatively homogeneous. However, there were differences in both proportions and sizes of fiber types between the thoracic surface of the crural region and the abdominal surface of the crural region. These two surfaces of the crural region differed from the rest of the diaphragm. For muscle fiber type proportions, type 2a fibers demonstrated the most interanimal variability. Muscle fiber size varied little between animals.
Internalized myofiber capillaries: Observations on their origin and clinical features
Authors: Gutmann Ludwig , Wolf Robert , Nix Wilfred , Goebel Hans H. , Schochet Sydney S. , Hopf Hanns C. , Kramer Günter
Published: January 2005

Internalized capillaries limited to type 1 muscle fibers were noted in seven patients. They occurred in each case in association with a similar admixture of neurogenic and myopathic features that included atrophic and hypertrophic fibers, internal nuclei, fiber splitting, and endomyseal and perimyseal fibrosis. Internalized capillaries in enlarged type 1 fibers arose from fiber splits on step section study of four patients. They occurred in the gastrocnemius, quadriceps, and soleus muscles from patients with a variety of disorders that included Becker dystrophy, diabetes mellitus and strenuous leg activities, Achilles tendon rupture, and myotonic dystrophy. Exercise‐induced myalgias were noted in the four patients with most plentiful intramuscular capillaries, and in three of these muscle hypertrophy was present. The concurrence of internalized myofiber capillaries and exercise induced myalgias may represent an associated biochemical/pathological defect.
Sural nerve biopsy in chronic inflammatory demyelinating polyradiculoneuropathy
Authors: Krendel David A. , Parks Helen P. , Anthony D. Carter , St. Clair Mary Beth , Graham Doyle G.
Published: January 2005

We compared histologic features of sural nerve biopsies in 14 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with those in other forms of neuropathy. In CIDP endoneurial pericapillary cellular infiltrates were found in 4 patients (29%), onion bulbs in 5 patients (36%), and predominant demyelination in 7 patients (50%). None of these abnormalities was specific, but cellular infiltrates and onion bulbs appear to be diagnostically useful when combined with clinical information. To detect macrophage infiltration of myelin, cell nuclei were counter‐stained in 20 teased fiber preparations. Nine patients with CIDP had a significantly higher mean number of cells per centimeter of teased fiber than 11 patients with other neuropathies. Despite overlap, significant infiltration of myelin detected by this method suggests CIDP in an appropriate clinical setting.
Diazepam improves recording of lumbar and neck somatosensory evoked potentials
Authors: Pfeiffer Frederick E. , Peterson LaVonne , Daube Jasper R.
Published: January 2005

To determine whether the decrease in muscle artifact provided by diazepam is of sufficient clinical value to justify its use, somatosensory evoked potentials recorded in examinations of 73 consecutive patients were compared with those recorded from 33 subsequent patients who were given 10 mg of diazepam orally just before the examination. With diazepam pretreatment there was clear improvement in the quality of lumbar and neck recordings—increased reproducibility and definition and ease of measurement— and also greater tolerance of the procedure and a slight shortening of time required for the test.
Effects of different sensory inputs on the median‐derived somatosensory evoked potential
Authors: Reisin Ricardo C. , Goodin Douglas S. , Aminoff Michael J. , Mantle Mary M.
Published: January 2005

We studied the effect of a variety of “interfering” stimuli on the median‐derived somatosensory evoked potentials recorded over Erb's point, cervical spine, and scalp. We found that the amplitude of N20 and P27 recorded over the scalp was attenuated by active movement, vibration, and tactile stimulation of the ipsilateral hand but not by passive movement. Cervical and peripheral responses were unaffected. The pathophysiologic basic and clinical significance of these findings are discussed.
Preferential activation of muscle fibers with peripheral magnetic stimulation of the limb
Authors: Lotz Barend P. , Dunne John W. , Daube Jasper R.
Published: January 2005

Magnetic and electric activation of limb nerve and muscle were compared in normal subjects of different age, gender, and habitus. Direct stimulation of nerve and muscle showed that activation of intramuscular nerve fibers in the arm and leg occurs at a lower threshold for magnetic stimulation than for electric stimulation. Sensory nerve fibers had a lower threshold with electric stimulation. Muscle activation and stimulus artifact with magnetic stimulation precluded reliable recording of distal sensory nerve action potential in all subjects.
Survival prediction in amyotrophic lateral sclerosis
Authors: Jablecki Charles K. , Berry Charles , Leach Judy
Published: January 2005

This longitudinal study of 194 patients with sporadic ALS demonstrated that it is possible for physicians to predict the approximate survival time for an individual ALS patient given: (1) the age of the patient, (2) the duration of his weakness and (3) an estimate of his clinical disability (ALS Score). This information is of value in the clinical management of ALS patients, and it should facilitate construction of experimental therapeutic trials in ALS.
Dystrophin distribution in heterozygote mdx mice
Authors: Watkins Simon C. , Hoffman P. , Slayter Henry S. , Kunkel Louis M.
Published: January 2005

The distribution of dystrophin in myofibers from normal, mdx hemizygous, and mdx heterozygous mice was studied at various times in development. While normal mice exhibit dystrophin immunostaining around the entire fiber periphery regardless of age, mdx hemizygous mice exhibit no staining (0–35 days). In contrast, young (10 day) heterozygous mdx mice showed neighboring dystrophin‐negative and dystrophin‐positive fibers as well as fibers with a discontinuous or patchy dystrophin labelling. Older heterozygotes displayed very few negative fibers, with most fibers exhibiting apparently complete dystrophin immunostaining. This, coupled with the absence of muscle fiber degeneration at any age point, and the apparently normal levels of dystrophin in older heterozygous mice, indicates that myonuclei containing the dystrophin gene can compensate for myonuclei which do not contain the dystrophin gene within the same myofiber.
Muscle fatigue in some neurological disorders
Authors: Lenman Andrew J. R. , Tulley Francis M. , Vrbova Gerta , Dimitrijevic Milan R. , Towle Josie A.
Published: January 2005

Fatigue of tibialis anterior (TA) was induced by repetitive electrical stimulation. Using this test, patients with upper motor neuron muscle weakness owing to multiple sclerosis (MS) and injuries to the spinal cord showed greater fatigability of their TA muscles, suggesting that the muscle fiber population changed toward that typical of fatigable motor units. During repetitive stimulation, in addition to the decrement in tension there was an increase in half‐relaxation time of tetanic contractions at 40 Hz in both subjects and patients. The increase in half relaxation during repeated activity was greater in patients with MS and spinal cord injury than in healthy subjects, suggesting that the long‐term inactivity affected the efficiency of the Ca2+ uptake mechanism of their muscle fibers. Thus long‐term inactivity of patients with upper motoneuron dysfunction leads to increased fatigability of their muscles and exaggerates the slowing of muscle relaxation after prolonged exercise.
Electrophysiologic evaluation of spinal cord motor conduction
Authors: Berger Alan R. , Shahani Bhagwan T.
Published: January 2005

Spinal cord motor conduction was determined by stimulating with a monopolar needle at the C5 cord level and recording evoked motor potentials from the ipsilateral tibialis anterior muscle. Minimal F wave and direct motor latencies from the peroneal nerve were used to calculate peripheral conduction time. Mean velocity index (defined as the distance from C5 to L4 divided by central conduction time) of 15 normal subjects was 64.9 m/sec (SD 7.5). In 5 patients with multiple sclerosis the mean velocity index was 40.6 m/sec (SD 6.5), whereas in 3 patients with cervical myelopathies, due to extradural compression, the mean velocity index was 32.8 m/sec. A repeat study in one of the latter patients, 4 days after removal of a C5 disc, documented a marked improvement in cord conduction. In a patient with a thoracic and cervical syrinx, cervical cord stimulation on the clinically affected side failed to evoke a motor potential, whereas the unaffected side was normal. This method provides a simple and effective way to evaluate spinal cord motor conduction using routine electrodiagnostic equipment.
Duchenne de boulogne: Electrodiagnosis of poliomyelitis
Authors: Reincke Hanna , Nelson Kevin R.
Published: January 2005

Duchenne de Boulogne was among the first to investigate neuromuscular diseases. He stimulated muscle and nerve with moistened surface electrodes, thereby avoiding tissue necrosis. Technique and self‐designed equipment are discussed in his first major work de I'electrisation localisee. During his 30 years of practice, he examined several hundred patients with poliomyelitis. With electrodiagnostic evaluation, he focused on “electrocontractility,” the intensity of muscle contraction elicited by electrical stimulation. Based on his electrophysiologic findings, Duchenne suggested that the responsible lesion resided within the spinal cord. He used electrical stimulation for treatment and recognized prognostic features.
Autonomic function and unmyelinated fibers in chronic inflammatory demyelinating polyradiculonuropathy
Authors: Ingall Timothy J. , McLeod James G. , Tamura Naotoshi
Published: January 2005

Because autonomic function may be abnormal in some demyelinating peripheral neuropathies, it has been studied with a number of noninvasive and invasive tests in 14 patients with chronic inflammatory demyelinating polyradiculoneuropathy. There were abnormalities of the 30:15 ratio in 3 patients and an abnormal thermoregulatory sweat test in 5 patients. These findings are indicative of mild parasympathetic and sympathetic dysfunction. Minor pathological changes in unmyelinated fibers were demonstrated on morphometric examination of sural nerves of 10 patients.
Impairment of retrograde axonal transport in wobbler mouse motor neuron disease
Authors: Mitsumoto Hiroshi , Ferut Anita L. , Kurahashi Kozo , McQuarrie Irvine G.
Published: January 2005

The earliest horseardish peroxidase (HRP) neuronal labeling (the fastest retrograde transport) was determined by histochemical techniques at various intervals after intramuscular HRP injection in wobbler mice and normal littermates. In the clinically impaired forelimb system, the retrograde transport rate was 150–170 mm/day in wobbler mice and 170–230 mm/day in controls. However, there was no statistical difference between the two groups. The neuronal HRP accumulation at the early intervals was significantly less in wobbler mice than controls, suggesting that the amount of HRP transport was dminished in each axon. For the clinically intact hindlimb nerves, the rate was normal in wobbler mice, but the amount of neuronal HRP was significantly increased. Retrograde axonal transport appeared to be affected in a differential fashion, depending on the extent of disease.
Electrophysiological monitoring during lipomyelomeningocele resection
Authors: Phillips Lawrence H. , Park T. S.
Published: January 2005

Surgical resection of a lipomyelomeningocele carries a risk of injury to nerve roots in the cauda equina. We have devised a technique for combined spinal evoked potential and peripheral nerve compound action potential recording for intraoperative monitoring of this surgical procedure. We report the results of six cases where this technique was used. In each case, the monitoring prevented resection of viable neural tissue, and all six patients were neurologically unchanged postoperatively.
Mononeuropathy multiplex associated with acute hepatitis B infection
Authors: Cohen Jeffrey A. , Wilborn Sandra L. , Rector William G. , Golitz Loren E.
Published: January 2005

Immunologic syndromes are associated with hepatitis B viral (HBV) infection. However, mononeuropathy multiplex (MM), a syndrome in which immune factors may play a role, is rare in acute HBV infection. Few cases of MM associated with HBV infection have been reported. We report a case of acute HBV infection in which MM involving the median, ulnar and lateral femoral cutaneous nerves complicated the course of the acute illness. Skin biopsy demonstrated vasculitic changes which may accompany the immunologic factors in HBV infection.
Acute sensory neuronopathy with preserved SEPs and long‐latency reflexes
Authors: Knazan Morton , Bohlega Saeed , Berry Kenneth , Eisen Andrew
Published: January 2005

A case of spontaneous acute sensory neuronopathy is described in a previously healthy 19‐year‐old male. He had marked sensory ataxia with relative sparing of cutaneous sensation. There was no recovery over 4 years. Sural nerve biopsy showed modest axonal loss. Sensory evoked potentials were mildly abnormal in the face of absent sensory nerve action potentials. The long‐latency (R2) reflex was preserved whereas the short‐latency (R1) reflex was absent. The findings indicate that loss of large‐diameter (groupla) ganglion cells are primarily responsible for this syndrome.
M wave changes with temperature in amyotrophic lateral sclerosis and disorders of neuromuscular transmission
Authors: Denys Eric H.
Published: January 2005

Local cooling of the muscle resulted in significant increases in M wave surface areas in patients with ALS, myasthenia gravis, the Lambert‐Eaton myasthenic syndrome, and also in controls. The most striking increases were seen in patients with early ALS who had minimal lower motor neuron involvement and/or little defect on neuromuscular transmission and patients with the myasthenic syndrome. Patients with myasthenia gravis had intermediate increases between these groups and the controls; there was a large increases in M wave surface area in myasthenia gravis compared with controls but this could be accounted for by improvement in neuromuscular transmission. The large increase in M wave surface area in early ALS could be the result of temporal summation of individual muscle fibers in motor units with increased fiber densities. The increase in both ALS and the myasthenic syncrome could result also from the loss of a trophic factor causing changes at the muscle membrane.
Glucose infusion abolishes the excessive ATP degradation in working muscles of a patient with McArdle's disease
Authors: Mineo Ikuo , Kono Norio , Yamada Yuya , Hara Naoko , Kiyokawa Hiroaki , Hamaguchi Tomoya , Kawachi Masanori , Yamasaki Tomoyuki , Nakajima Hiromu , Kuwajima Masamichi , Tarui Seiichiro
Published: January 2005

A 23‐year‐old woman with McArdle' disease performed mild leg exercise on a bicycle ergometer. Saline or 10% glucose solution was infused throughout exercise. After exercise with saline infusion, her plasma concentration of ammonia, hypoxathine and creatine kinase increased greatly. Conversely, after exercise with glucose infusion, there were no appreciable changes in these plasma substances. In addition, she noticed that glucose infusion relieved her from muscle symptoms during exercise. These findings seggest that glucose infusion to patiets with McArdle' desease ameliorates excessive ATP degradation in exercising muscles.
Significance of magnetic coil position in peripheral motor nerve stimulation
Authors: Ravnborg Mads , Blinkenberg Morten , Dahl Kristian
Published: January 2005

The influences of coil position and coil–nerve distance on compound muscle action potentials (CMAPs), recorded from the first dorsalinterosseus muscle during magnetic stimulation of the brachial segment of the ulnar nerve, were studied in 10 healthy volunteers. A 14‐cm coil was held tangentially to the skin with the center overlying the nerve. Mapping of the CMAP latencies and amplitudes was made as the coil was displaced laterally in steps of 1 cm and in planes 0–3 cm from the skin surface. Stimulation with the coil center positioned 3 cm laterally to the nerve with the coil current directed proximally yielded the largest amplitudes with minimal variability and the most constant relationship to electrically evoked CMAPs. In this position the interindividual and intraindividual reproducibility of the magnetically evoked latencies were at least as good as those of electric stimulation when coil–skin distance was ⩽ 2 cm.
Regenerated EDL muscle of rats requires innervation to maintain AChE molecular forms
Authors: Melone Mariarosa A. B. , De Lucia Domenico , Fratta Mario , Cotrufo Roberto
Published: January 2005

Extensores digitorum longi of rats, infarcted and denervated by different surgical procedures, were used to analyze by biochemical and cytochemical methods the acetylcholinesterase (AChE) changes during muscle degeneration, regeneration, and early or delayed reinnervation. Biochemical tests showed that the regenerating muscle produces globular AChE forms (36% of controls) and small amounts of A12 (16S) asymmetric from (5% of controls); at the end of the regeneration, innervation and electromechanical function are required for the complete recovery of globular forms, and are absolutely critical to prevent A12 (16S) disappearance. Cytochemical observations showed that, unlike nicotinic receptor, AChE deposited at the neuromuscular junction before ischemic necrosis is protected from breakdown, as is the basal lamina of muscle fibers. Taken together, these observations contribute to the understanding of the factors that play a critical role in muscle repair and are, therefore, of clinical relevance.
The anatomy and physiology of nerve injury
Authors: Sunderland Sir Sydney
Published: January 2005

Nerves have a structure of considerable complexity with features of special relevance to nerve injury and nerve regeneration. These include variations in the cross‐sectional areas devoted to fascicular and epineurial tissue, the fascicular redistribution and mixing of different branch fibers brought about by fascicular plexuses, and the numbers of nerve fibers representing individual branches. The elasticity and tensile strength of nerve trunks and their capacity to resist traction deformation reside in the fascicular tissue, while the epineurium provides a protective cushion against compression. The microstructure of nerve trunks provides the basis for a classification of nerve injuries into five degrees of severity with partial and mixed types—each with a clearly defined pathology and distinguishing clinical features. Following a transection injury, changes occur in the severed axons, endoneurial tubes, fasciculi, and nerve trunk. The type of injury and the nature of these changes determine the outcome of axon regeneration.