bluuebunny/crossref_metadata_2025 huggingface dataset:
Peripheral and central conduction in n‐hexane polyneuropathya
Authors: Öge A. Emre , Yazici Jale , Boyaciyan Arl , Eryildiz Derya , Örnek Ibrahim , Konyaliǧlu Rana , Cengiz Salih , Okşak O. Zeki , Asar Saim , Baslo Aynur
Published: January 2005

Electrophysiological findings of 27 males with industrial n‐hexane polyneuropathy (HPNP) are presented. The results of needle electromyography and nerve conduction studies were compatible with primarily axonal polyneuropathy with secondary segmental demyelination. Motor conduction velocities were the slowest in distal regions of the nerves. In the proximal nerve segments, which were partly tested by magnetic stimulation of the nerve roots, this slowing was much less pronounced. The reduction in mean motor conduction velocities in the forearm segments of ulnar nerves was more than 30% in comparison to the control group means. This reduction was only 10% in the neckaxilla segments. We think that this finding is a reflection of the distal axonopathy process. Central motor conduction times calculated by transcranial magnetic stimulation and spinal nerve root stimulation were found to be prolonged in HPNP patients, indicating that descending motor pathways are affected in human HPNP. © 1994 John Wiley & Sons, Inc.
Is heat hypoalgesia a useful parameter in quantitative thermal testing of alcoholic polyneuropathy?
Authors: Hilz Max J. , Claus Detlef , Neundörfer Bernhard , Zimmermann Peter , Berić Aleksandar
Published: January 2005

Detection of thermal hypoaesthesia, hyperalgesia, and paradoxical sensation significantly contribute to the diagnosis of polyneuropathy (PNP). There is controversy about the clinical usefulness of detected heat hypoalgesia. In 50 chronic alcoholic patients we compared the prevalence and diagnostic value of heat hypoalgesia (HPT) to that of cold (CT) and warm (WT) hypoaesthesia using a “Marstock” thermotest. Clinical examination revealed PNP in 56%, cold hypoaesthesia was present in 62%, warm hypoaesthesia in 24%, paradoxical thermal sensation in 10%, cold and heat hyperalgesia in 12%, and heat hpypoalgesia in 22%. Only 1 patient (2%) presented with heat hypoalgesia but normal warm and cold thresholds; he reported paradoxical thermal sensation and had PNP. One patient suffered first degree burn injury from heat pain examination. Heat hypoalgesia contributed least to the diagnosis of polyneuropathy (HPT versus CT: P < 0.001). In patients with sensory loss, testing heat hypoalgesia bears some risk of burn injury. In contrast to thermal hypoaesthesia and hyperalgesia, it does not significantly enrich the diagnostic workup of alcoholic polyneuropathies. © 1994 John Wiley & Sons, Inc.
Efficacy of obidoxime in human organophosphorus poisoning: Determination by neuromuscular transmission studies
Authors: Besser Roland , Weilemann Ludwig S. , Gutmann Ludwig
Published: January 2005

Six patients with organophosphorus compound intoxications developed an intermediate syndrome (weakness and fasciculations) and obidoxime was given on eight occasions. The efficacy of the acetylcholinesterase (AChE) reactivator was monitored electrophysiologically by neuromuscular transmission studies using single and repetitive nerve stimulation (20 and 50 Hz) and the activity of the serum (butyryl) cholinesterase (ChE). Dramatic electrophysiologic improvement was seen when obidoxime was given early within 12 h in 3 patients, although evidence of AChE inhibition did not subside completely. When administration of obidoxime was delayed 26 h or more after intoxication on five occasions, electrophysiologic improvement was mild or absent. In one case, 66 h after intoxication with oxydemeton‐S‐methyl, the neuromuscular block worsened, indicating that aging of the AChE had been completed. The electrophysiologic improvement was always accompanied with better motor function but not necessarily with improvement of the overall clinical status. Serum ChE did not predict the oxime effect at the motor endplate. In humans, the efficacy of oximes in AChE reactivation can be determined rapidly using electrophysiologic studies.© 1995 John Wiley &Sons, Inc.
Expression of heat‐shock/stress proteins in duchenne muscular dystrophy
Authors: Bornman Liza , Gericke George S. , Polla Barbara S. , Lotz Barend P.
Published: January 2005

Heat‐shock/stress proteins (HSPs) are induced in response to stressful conditions and are essential for survival during and after cellular stress. We investigated whether dystrophin deficiency in muscle from Duchenne muscular dystrophy (DMD) patients induces HSPs. Immunohistochemical studies were performed on cryosections from normal muscle, heat‐shocked muscle, and muscle from patients with DMD, dermatomyositis, and mitochondrial myopathy using antibodies against HSP 72/73, HSP 72, HSP 90, groEL (HSP 65 homologue), and ubiquitin. Computer‐assisted image processing revealed a significant (P<0.05) induction of HSP 72/73, 72, 65, and ubiquitin in hypercontracted fibers; HSP 90 and ubiquitin in regenerating fibers; and ubiquitin in macrophage invaded necrotic fibers of DMD muscle. No significant induction of HSPs was observed in dermatomyositis or mitochondrial myopathies. The stress response induced in DMD may relate to the metabolic stress characteristic of the disease and could represent and autoprotective mechanism. Manipulation of this protective response may reduce injury and have potential therapeutic application.© 1995 John Wiley & Sons, Inc.
Factors which influence alterations of phosphates and pH in exercising human skeletal muscle: Measurement error, reproducibility, and effects of fasting, carbohydrate loading, and metabolic acidosis
Authors: Miller Robert G. , Carson Paul J. , Moussavi Robabe S. , Green April , Baker Anthony , Boska Michael D. , Weiner Michael W.
Published: January 2005

Previous studies have shown considerable variability in the metabolic response of human skeletal muscle during a standardized exercise protocol. The goal of these studies was to investigate the factors responsible for the broad range of metabolic changes produced by fatiguing exercise. Experiments were performed to quantitate the measurement error of 31P nuclear magnetic resonance spectroscopy of human muscle, the reproducibility of changes within a single subject, and the effects of fasting, carbohydrate loading, and metabolic acidosis. The results show that none of these factors appear to be responsible for the wide variation between subjects. However, the effects of training and genetic factors were not investigated and are likely to be responsible for the substantial variability between subjects.© 1995 John Wiley &Sons, Inc.
Radiation inhibition of mdx mouse muscle regeneration: Dose and age factors
Authors: Quinlan John G. , Michaels Scott E. , Denman David L. , Lyden Sean P. , Cambier Denise M. , Johnson Scott R.
Published: January 2005

A single hind limb was irradiated with 12, 18, 24, or 30 Gy in mdx and C57 mice aged 12, 21, or 42 days to determine regeneration inhibition dose‐response curves in different aged dystrophic mice and to characterize radiation side‐effects in normal mice. The anterior tibial muscle mass (8 weeks postirradiation) and percent central nucleated (i.e., regenerated) muscle fibers were measures of regeneration inhibition. Twenty‐one‐day‐old mdx mice irradiated with 18 Gy had complete inhibition of muscle regeneration, but 30 Gy only partially blocked regeneration in mdx mice irradiated at 12 and 42 days in age. In working to produce a clinically relevant model for Duchenne dystrophy, it is crucial to regard mouse age as a major factor in determining radiation effects on mdx muscle regeneration.© 1995 John Wiley &Sons, Inc.
Function of thick and thin nerve fibers in carpal tunnel syndrome before and after surgical treatment
Authors: Lang Eberhard , Spitzer Alfred , Claus Detlef , Neundörfer Bernhard , Pfannmüller Dagmar , Handwerker Hermann O.
Published: January 2005

Present studies evaluated the functions of thick and thin nerve fibers in carpal tunnel syndrome (CTS) to determine whether data of thin nerve fibers can add further information to the diagnosis of CTS. Measurements were performed in 22 patients and 16 age‐matched control subjects. Motor and sensory nerve conduction, vibratory testing, thresholds of warmth and cold sensations, suprathreshold magnitude of pain and flare response, as well as sympathetic reflexes induced by noxious mechanostimulation were examined before and 1, 3, 6, 12, and 18 months after decompression of the median nerve. Nerve dysfunction in CTS was mainly indicated by the electrophysiological parameters of thick myelinated nerve fibers. Impairment of thin nerve functions in CTS and postoperative recovery was demonstrated by quantitative somatosensory thermotesting. In contrast, assessment of flare response and sympathetic reflexes using infrared thermography and photoplethysmography did not add further information for the diagnosis of CTS.© 1995 John Wiley &Sons, Inc.
Isolated femoral mononeuropathy to the vastus lateralis: EMG and MRI findings
Authors: Carter Gregory T. , McDonald Carig M. , Chan Terence T. , Margherita Anthony J.
Published: January 2005

A 16‐year‐old female track athlete experienced sudden onset of right anterolateral thigh pain, initially thought to be cramping. After 2 months of continued postexercise pain she sought medical evalution. A 3‐cm thigh circumference discrepancy was noted on physical exam. She was referred for electromyography (EMG) and magnetic resonance imaging (MRI) studies. Femoral and screening nerve conduction studies were normal. Needle EMG revealed acute neuropathic changes confined to the right vastus lateralis only. These findings were confirmed by MRI, including short T1 inversion recovery (STIR) sequences. All other medical work‐up was normal, including lumber and pelvic MRI, and complete serologic studies. This case represents a unique presentation of an idiopathic femoral mononeuropathy isolated to the vastus lateralis only, which has not been previously reported. The highly unusual anatomical presentation of this case illustrates the emerging complementary usefulness of EMG and MRI in delineating neuromuscular pathology.© 1995 John Wiley &Sons, Inc.
Motor unit estimation: Anxieties and achievements
Authors: McComas Alan J.
Published: January 2005

The history of motor unit number estimation (MUNE) is given, together with brief descriptions of the various methods presently available. A small muscle of the hand contains about 100 motor units and greater numbers are found in larger muscles; beyond 60 years the numbers begin to decline. In ALS approximately half the motor units cease to function within 6 months of the involvement of the motoneuron pool, while in adult spinal muscular atrophy further loss may not occur over several years. The reduction in MUNE values in myotonic dystrophy remains an enigma, but even more curious are the losses and subsequent recoveries occasionally observed in hyperthyroidism and chronic renal failure; possibly, nontransmitting (“silent”) synapses are involved. MUNE may also be used to study CNS problems such as hemiplegia and congenital brachial palsy. The availability of more powerful computers for EMG should lead to advances in MUNE. © 1995 John Wiley & Sons, Inc.
Differentiation between axonal and demyelinating neuropathies: Identical segments recorded from proximal and distal muscles
Authors: Raynor E. M. , Ross M. H. , Shefner J. M. , Preston D. C.
Published: January 2005

The presence of significant slowing of motor nerve conduction velocity is considered one of the electrodiagnostic hallmarks of demyelinating neuropathies; however, slowing of conduction velocity may also accompany severe axonal loss. When compound muscle action potential (CMAP) amplitudes are markedly reduced, it is frequently difficult to determine if conduction velocity slowing is due to axonal loss with dropout of the fastest conducting fibers or demyelination. To evaluate the relationship between conduction velocity and axonal dropout, we compared conduction velocities through the same segment of nerve recording from distal and proximal peroneal muscles in patients with chronic neuropathies, in patients with motor neuron disease, and in control subjects. In controls and patients with motor neuron disease, conduction velocities were normal with no significant difference between proximal and distal sites. In patients with axonal neuropathies, conduction velocities were preferentially slowed when recording from distal muscles and relatively normal when recording from proximal sites. Patients with demyelinating neuropathies showed marked slowing of conduction at both sites. We conclude that comparing conduction velocity obtained from proximal versus distal muscle recordings provides a simple, reliable aid for differentiating between chronic axonal and demyelinating polyneuropathies, especially in cases with conduction velocity slowing and low CMAP amplitudes. © 1995 John Wiley & Sons, Inc.
Anti‐gal‐C antibody in autoimmune neuropathies subsequent to mycoplasma infection
Authors: Kusunoki Susumu , Chiba Atsuro , Hitoshi Seiji , Takizawa Hajime , Kanazawa Ichiro
Published: January 2005

Four of 82 patients with Guillain‐Barré syndrome (GBS) and 1 of 12 with multifocal motor neuropathy (MMN), who previously had had Mycoplasma pneumoniae infections, had serum antibody to galactocerebroside (Gal‐C). Two patients with GBS without mycoplasma infection also had anti‐Gal‐C antibody, whereas none of the normal or the disease controls had it. As Gal‐C is a major glycolipid antigen in myelin, anti‐Gal‐C antibody may function in the pathogenesis of autoimmune demyelinative neuropathies. Mycoplasma pneumoniae appears to be an important preceding infectious agent in autoimmune neuropathies with anti‐Gal‐C antibody. © 1995 John Wiley & Sons, Inc.
The electrophysiologic features of sciatic neuropathy in 100 patients
Authors: Yuen Eric C. , So Yuen T. , Olney Richard K.
Published: January 2005

We reviewed the electrophysiologic data of 100 consecutive patients with sciatic neuropathy in order to better understand this disorder. Most patients (93%) had electrodiagnostic signs of significant axonal loss. Seven patients had predominantly signs of demyelination; 6 were due to compression and 1 was idiopathic. The peroneal division was more severely affected than the tibial division in 64% of patients. Tibialis anterior EMGs were abnormal in 92%, and the EDB CMAP was low in amplitude or absent in 80%. CMAP and SNAP amplitudes and EMGs were all normal in the tibial division in 12%. In contrast, the tibial division was more severely affected in only 8 patients. Of those, 5 were due to thigh trauma (gunshot wounds or femur fracture), 2 from gunshot wounds to the hip, and the other was chronic and idiopathic. Sciatic neuropathies are commonly, but not always, axonal loss lesions that affect the peroneal greater than tibial division. © 1995 John Wiley & Sons, Inc.
AAEM case report #2: The carpal tunnel syndrome
Authors: Ross Mark A. , Kimura Jun
Published: January 2005

The symptoms and sings which constitute the carpal tunnel syndrome (CTS) result from entrapment or compression of the median nerve within the carpal tunnel. Electrodiagnostic studies may objectively document the presence of median neuropathy within the carpal tunnel and help distinguish CTS from other disorders such as cervical radiculopathy, neurogenic thoracic outlet syndrome, proximal median nerve compression syndromes, and polyneuropathy which may either mimic or occasionally coexist with CTS. Recording median nerve responses with wrist and palm stimulation allows determination of the wrist segment conduction velocity which is a more sensitive nerve conduction parameter than wrist latency measurements. Electrodiagnostic testing permits estimation of severity and relative contribution of axonal versus demyelinative nerve injury. This information can provide prognostic information and help guide therapeutic decisions. © 1995 Mark A. Ross, MD and Jun Kimura, MD. Published John Wiley & Sons, Inc.
Does ulnar neuropathy predispose to focal dystonia?
Authors: Ross Majorie H. , Charness Michael E. , Lee D. , Logigian Eric L.
Published: January 2005

We have observed a high incidence of ulnar neuropathy in musicians with dystonic flexion of the ipsilateral little and ring fingers. To investigate the relationship between ulnar neuropathy and focal dystonia, we compared the patterns of surface EMG activity in extensor digitorum communis (EDC4) and flexor digitorum superficialis (FDS4) during tapping of the ring finger in normal controls and patients with ulnar neuropathy or local dystonia. Ten of 10 normal subjects exhibited wellformed alternating EMG bursts in EDC4 and FDS4 separated by clear silent periods. Seven of 7 patients with dystonic flexion of the little and ring fingers showed loss of silent periods between poorly formed bursts in FDS or EDC. Surprisingly, 9 of 10 patients with ulnar neuropathy showed burst pattern abnormalities qualitatively similar to those observed in the dystonic patients. These data suggest that ulnar neuropathy alters the execution of a motor task involving multiple peripheral nerves. © 1995 John Wiley & Sons, Inc.
Altered muscle calcium channel binding kinetics in autoimmune motoneuron disease
Authors: Smith R. Glenn , Kimura Fumiharu , Harati Yadollah , McKinley Kevin , Stefani Enrico , Appel Stanley H.
Published: January 2005

While skeletal muscle is not apparently affected directly in amyotrophic lateral sclerosis (ALS), immunoglobulin G fractions purified from patients with ALS (ALS IgG) bind dihydropyridine (DHP)‐sensitive L‐type voltage‐gated calcium channel (VGCC) antigen isolated from skeletal muscle in ELISA and Western immunoblot, and alter VGCC function in vitro. To determine whether muscle VGCC properties are altered in ALS, VGCC‐enriched subsarcolemmal membrane fractions were prepared from biopsied quadriceps muscle of patients with ALS, with other neurologic diseases, or without apparent muscle disease, and tested for DHP binding with [3H]PN200‐110. ALS muscle VGCCs from muscle fractions of most other patients, independent of denervation‐induced increases in DHP binding site number. Similarly elevated DHP binding affinities were observed in specimens from patients with autoimmune motor neuropathies, suggesting that ALS and immunemediated motoneuron disease share skeletal muscle L‐type VGCC alterations. © 1995 John Wiley & Sons, Inc.
Site‐dependent pathological differences in smooth muscles and skeletal muscles of the adult MDX mouse
Authors: Boland B. , Himpens B. , Denef J. F. , Gillis J. M.
Published: January 2005

This study presents a survey of the morphometric characteristics, the regeneration rate, and the extent of muscle dystrophy in several smooth and skeletal muscles from adult mdx mice, an animal model of the Duchenne muscular dystrophy (DMD). Smooth muscles from adult mdx mice showed neither cell necrosis nor fibrosis. As compared to control C57 mice, the thickness of the mdx smooth muscle was normal in the vascular and urogenital layers but significantly reduced in the digestive layers, a finding relevant to clinical reports of gastrointestinal dilatation in DMD patients, and suggesting that gastrointestinal dysfunctions should be systemically searched for in DMD patients. Adult mdx skeletal muscles, however, presented different patterns of muscle suffering: either absent (esophagus); very mild (trunk and limb muscles); or severe (diaphragm). In these three conditions we studied the fiber diameters, the nuclei locations, and the regeneration rate. From this comparative study, it seems that severe dystrophy occurs in muscle tissues showing large fiber diameter and peripheral location of the nuclei. We showed that this combination occurs in the mouse diaphragm which is thus a realistic model for human DMD muscles. © 1995 John Wiley & Sons, Inc.
Dynamic electromyography and muscle biopsy changes in a 4‐year follow‐up: Study of patients with a history of polio
Authors: Stålberg Erik , Grimby Gunnar
Published: January 2005

Eighteen patients who had had polio 29–56 years prior to the first investigation were studied on two occasions, 4 years apart. Isokinetic and isometric strength measurements and Macro EMG were performed in 28 legs. Muscle biopsy specimens were obtained on both occasions from 11 legs. On average the muscle strength was 56% of control values at the first examination, and decreased by another 8% during the observation period. The muscle fiber area was increased compared to that of controls and did not change significantly. Macro EMG, comprising muscle fiber area and number of muscle fibers, and/or single fiber EMG showed clear signs of reinnervation in all legs. The motor units at the first examination were increased 11‐fold, on average, compared with age‐matched control values. During the observation period, reinnervation continued and the size of motor units increased by another 56% as a result of ongoing denervation, that is, loss of neurons. This compensation was particularly pronounced in patients with stable conditions. The parameters studied did not reveal any definite pattern predicting future development of new muscle weakness in individual subjects. © 1995 John Wiley & Sons, Inc.
Motor conduction parameters in neuropathies associated with anti‐mag antibodies and other types of demyelinating and axonal neuropathies
Authors: Trojaborg W. , Hays A. P. , Van Den Berg L. , Younger D. S. , Latov N.
Published: January 2005

We measured residual latency (RL), motor conduction velocity (MCV), and terminal latency index (TLI) in 15 patients with neuropathy and anti‐MAG or SGPG antibodies and compared these to values obtained in 103 patients with other types of polyneuropathy (PN) and to 57 normal subjects. Ten patients had anti‐MAG antibody titers of 25,600 or higher, and 5 had titers between 800 and 12,600. Patients with the highest titers had longer RL, slower MCV and shorter TLI than those with lower titers, acute or chronic inflammatory demyelinating PN, hereditary neuropathy, and metabolic or axonal neuropathy. In contrast F‐wave latencies did not contribute to the differentiation between the groups of demyelinating neuropathies. RL and TLI correlated best with anti‐MAG antibody titers, whereas there was a poor correlation with anti‐SGPG titers suggesting that MAG more than SGPG may be the antigen in PN, and that the distal nerves are affected more than their proximal segments. The RL rather than TLI turned out to be the best variable to classify the demyelinating type of anti‐MAG neuropathy. Sural nerve biopsy in 5 of the patients with the highest titer of anti‐MAG antibodies showed deposits of lgM and C3 on the myelin sheaths, pronounced demyelination and widening of the myelin lamellae. In 4 of the patients with lower titers demyelination was absent or less pronounced. © 1995 John Wiley & Sons, Inc.
Pretreatment of myoblast cultures with basic fibroblast growth factor increases the efficacy of their transplantation in mdx mice
Authors: Kinoshita Ikuo , Vilquin Jean‐Thomas , Tremblay Jacques P.
Published: January 2005

The effect of pretreatment of cultures with basic fibroblast growth factor (bFGF) on myoblast allotransplantation to C57BL/10ScSn mdx/mdx mouse (mdx mouse) muscles not previously damaged and not irradiated was studied. Transgenic CD1 mice which have a β‐galactosidase gene under the control of the promoter of the quail fast skeletal muscle troponin I gene, were used as donors. The myoblasts were grown with 100 ng/mL bFGF during the last 2 days before injecting them in the left tibialis anterior (TA) muscles of mdx mice. Myoblasts from the same primary cultures were also grown without bFGF and injected in the right TA muscles as control. The recipient mice were immunosuppressed with FK 506. Twenty‐eight days after myoblast transplantation, the percentage of β‐galactosidase‐positive fibers was significantly higher (more than fourfold) following culture with bFGF than without bFGF. Almost all β‐galactosidase‐positive fibers were also dystrophin positive. Direct intramuscular injections of bFGF or of Hank's balanced salt solution (HBSS) at the time of myoblast transplantation and at several intervals afterwards were also investigated. The percentage of β‐galactosidase‐positive fibers did not differ significantly following intramuscular injection of bFGF from controls injected with HBSS. In vitro, this high concentration of bFGF significantly reduced the formation of myotubes, and the percentage of mononuclear cells which were myoblasts was significantly increased by 34%. These observations alone do not account for the fourfold increase in transplantation success. The presence of bFGF in the culture did not significantly increase the cell survival 3 days after their transplantation. Our results indicate that culture of myoblasts with bFGF permits to obtain a high percentage of hybrid muscle fibers following myoblast transplantation without using damaging treatments such as notexin injection and irradiation. This suggests that such pretreatment may be helpful for myoblast transplantation in humans. The mechanism of this effect is still unclear. © 1995 John Wiley & Sons, Inc.
Peroneal nerve repetitive nerve stimulation test: Its value in diagnosis of myasthenia gravis and Lambert–Eaton myasthenic syndrome
Authors: Oh Shin J. , Head Thomas , Fesenmeier James , Claussen Gwendolyn
Published: January 2005

We have developed a repetitive nerve stimulation (RNS) technique for the peroneal nerve. Normal limits for the decremental responses for the anterior tibialis and extensor digitorum brevis muscles are 6–21% at the low rate of stimulation and 44–70% at the high rate of stimulation. These values exceed the normal limits for other commonly tested muscles. This may be due to the lower safety factor for neuromuscular transmission for the anterior tibialis and extensor digitorum brevis muscles. We present 4 cases in which the peroneal nerve RNS test was crucial for the diagnosis of the limb‐girdle form of MG or LEMS. Thus, we conclude that, in a small number of patients with neuromuscular transmission disorders, the peroneal nerve RNS test is needed for confirmation of disease. © 1995 John Wiley & Sons, Inc.
The utility of various sensory nerve conduction responses in assessing brachial plexopathies
Authors: Ferrante Mark A. , Wilbourn Asa J.
Published: January 2005

To determine which sensory nerve conduction studies (S‐NCS) are helpful in detecting supraclavicular axon loss brachial plexopathies, we selected 53 cases (of 417 reviewed) in whom complicating factors were absent and which, by needle electrode examination findings, involved only a single “truncal” element (upper, middle, or lower) of the brachial plexus. Extensive S‐NCS included: median, recording thumb (Med‐D1), index (Med‐D2), and middle fingers (Med‐D3); ulnar, recording fifth finger (Uln‐D5); dorsal ulnar cutaneous, recording dorsum of the hand (DUC); radial, recording base of thumb; and both medial and lateral antebrachial cutaneous (MABC, LABC), recording forearm. Except for the median sensory fibers, the “cord” elements traversed by the sensory fibers assessed during the S‐NOS listed above are anatomically defined (i.e., the sensory fibers enter the brachial plexus at only one cord). In regard to the median sensory fibers, however, there are two possible pathways through the infraclavicular plexus: (1) the lateral cord and/or (2) the medial cord. Because the lower trunk is only accessible via the medial cord, any sensory fibers found to be traversing the lower trunk had to first traverse the medial cord. Similarly, those traversing the upper and middle trunks must first be a component of the lateral cord. The frequency that the various S‐NCS responses were abnormal (unelicitable, below laboratory normal value, or ≤ 50% of the contralateral response) for a given brachial plexus element lesion was as follows: (1) upper trunk (UT): 25 of 26 Med‐D1, 25 of 26 LABC, 15 of 26 radial, 5 of 26 Med‐D2, 2 of 26 Med‐D3; (2) middle trunk (MT): 1 of 1 Med‐D3; (3) lower trunk (LT): 25 of 26 Uln‐D5, 22 of 23 DUC, 11 of 17 MABC, 3 of 23 Med‐D3. With lower trunk brachial plexopathies, both “routine” (Uln‐D5) and “uncommon” (DUC; MABC) S‐NCS are abnormal. With upper trunk brachial plexopathies, in contrast, only the “uncommon” S‐NCS (Med‐D1; LABC) are consistently affected. The “routine” median S‐NCS recording digit 2 (Med‐D2) is far less reliable than the median S‐NCS recording digit 2 (Med‐D1) in detecting upper trunk axon loss brachial plexopathies. Additionally, the various pathways traversed by the fibers contributing to the individual S‐NCS responses can be predicted, an important point when the full extent of a brachial plexus lesion is sought. © 1995 John Wiley & Sons, Inc.
AAEM case report #29: Prolonged paralysis after neuromuscular blockade
Authors: Gooch Judith L.
Published: January 2005

Nondepolarizing neuromuscular blocking agents (NMBA) are being used with increasing frequency in critically ill patients. Recently, many centers have described patients with prolonged muscle weakness after long‐term use of these agents, either alone or in combination with other agents or disorders. Brief weakness lasting several hours to several days is probably the result of prolonged neuromuscular blockade, while more prolonged weakness lasting several weeks to months is, in all likelihood, caused by a myopathy. Patients with this myopathic disorder have flaccid paralysis with intact cognition and sensation. Electrodiagnostic findings include decreased M‐wave amplitudes, positive waves and fibrillations, and rapid recruitment of small amplitude short duration, polyphasic motor unit potentials. Muscle biopsy findings include atrophy of type I and type II fibers, myofiber necrosis, and selective loss of thick myofilaments. The myopathy is believed to be related to the prolonged use of NMBA either alone or in combination with other disorders or medications, particularly corticosteroids. The weakness experienced by these patients leads to additional respiratory compromise, difficulty weaning from the ventilator, and prolonged hospitalization. © 1995 John Wiley & Sons, Inc.
Lateral rectus emg and contractile responses elicited by cat abducens motoneurons
Authors: Shall Mary S. , Goldberg Stephen J.
Published: January 2005

Stimulation of 41 single, abducens nucleus motoneurons in the cat evoked electromyographic (EMG) and contractile responses in the ipsilateral lateral rectus muscle. Separate, bipolar, fine wire EMG recording electrodes in the global and orbital muscle layers showed that 22 muscle units were confined to the global layer, 8 to the orbital layer, and 11 units were contained in both (“bilayer”) muscle layers. “Bilayer” units demonstrated significantly greater twitch (P ≤ 0.002) and maximum tetanic (P ≤ 0.001) tensions as well as faster fusion frequencies (P ≤ 0.022) than either global or orbital units. “Bilayer” units also showed the lowest average kt values (the slope of the linear relationship between motoneuron stimulation frequency and isometric tetanic tension). “Bilayer” units were predominantly fast fatigable (FF). Global units displayed all muscle unit types including all the nonwitch (NT) units. Orbital units were identified as slow fatigable (SF) and fast fatigue resistant (FR). © 1995 John Wiley & Sons, Inc.
Thoracic spinal nerve and root conduction: A magnetic stimulation study
Authors: Chokroverty Sudhansu , Deutsch Alan , Guha Chandralekha , Gonzalez Andres , Kwan Peter , Burger Robert , Goldberg Jerucham
Published: January 2005

We describe a technique of magnetic coil (MC) stimulation of the thoracic spinal nerves and roots in 12 normal subjects and a patient with diabetes mellitus. We kept the MC flat against the vertebral column in the midline over T‐7, T‐8, and T‐9 spinous processes and obtained compound muscle action potentials from the upper rectus abdominis, external oblique, and intercostal muscles. We obtained mean latencies to these muscles after stimulation in the posterior axillary line. We noted that the onset latencies remained fixed despite increasing the intensity of stimulation from 30% to 100% and on moving the coil up to 3 cm lateral to the spinous processes suggesting that the stimulation of the fastest conducting fibers was occurring at a fixed site, most likely at the intervertebral foramina. Prolonged latencies in the diabetic patient confirmed the diagnosis of radiculoneuropathy. © 1995 John Wiley & Sons, Inc.
Conduction study of digital nerve function recovery following toe‐to‐digit transplantation and a comparison with digit‐to‐digit replantation
Authors: Chu Nai‐Shin , Chu Eric C. , Yu Jia‐Ming
Published: January 2005

Recovery of digital nerve function following toe‐to‐digit transplantation was studied by nerve conduction in 16 patients, and a comparison was made with digit‐to‐digit replantation in 7 patients. For toe transplantation and digit replantation, the mean interval between injury and surgery was 7 months and 8 h, respectively, while the mean interval between surgery and study was 39 months and 25 months, respectively. Sensory nerve action potentials (NAPs) from digital nerve stimulation were recorded at the wrist and the elbow, whereas mixed NAPs from median nerve stimulation at the wrist were recorded at the elbow. Sensory NAPs from stimulation of the transplanted toe were detectable in 14 patients and showed reduced amplitude, prolonged latency, and slowed conduction velocity. There was retrograde amplitude reductiond in the median nerve and in the proximal segment of the digital nerve. Sensory NAPs from the replanted digit were not different from those of to normal digit, nor was a retrograde effect observed. The present data indicate that digital nerve function recovery was incomplete in toe transplantation and nearly complete in digit replantation. The reasons for the differences in recovery following two types of nerve repair are discussed. © John Wiley & Sons, Inc.
Comparison of digital sensory studies in patients with carpal tunnel syndrome
Authors: Kothari M. J. , Rutkove S. B. , Caress J. B. , Hinchey J. , Logigian E. L. , Preston D. C.
Published: January 2005

Electrodiagnosis of carpal tunnel syndrome (CTS) often depends on the demonstration of focal slowing of median sensory fibers across the wrist. We compared the relative sensitivity of the four median innervated digits in demonstrating focal slowing in patients with CTS. Antidromic sensory studies of digits 1, 2, 3, and 4 were performed on 30 control subjects to develop normative data. Fifty‐nine consecutive patients with CTS were then studied to determine the sensitivity of focal slowing of each median innervated digit. In the 26 CTS patients with a normal distal motor latency (DML) to abductor pollicis brevis, digit 1 was abnormal in 81%, digit 2 in 42%, digit 3 in 54%, and digit 4 in 38%. In the 33 CTS patients with a prolonged DML, digit 1 was abnormal in 94%, digit 2 in 88%, digit 3 in 91%, and digit 4 in 88%. We conclude that in milder cases of CTS with a normal DML, digit 1 is the most sensitive in identifying focal slowing of sensory conduction across the wrist. However, in patients with a prolonged DML, the sensitivity of sensory conduction is not significantly different among the four digits. © John Wiley & Sons, Inc.
Influence of recording site withing the muscle on motor unit potentials
Authors: Falck Björn , Stålberg Erik , Bischoff Christian
Published: January 2005

The influence of the recording site on the motor unit potentials (MUPs) was investigated in the brachial biceps muscle of 8 healthy subjects. The MUPs were recorded with a concentric needle electrode and analyzed with a new decomposition EMG program we call multi‐MUP analysis. MUPs had shorter durations and smaller amplitudes at superficial recording sites than at deeper sites in the muscle. This is mainly due to the cannula of the concentric electrode, which records a higher potential at superficial recording sites and partially cancels the recorded potentials from the tip in a differential recording. The MUPs had longer durations and higher amplitudes distally than in the middle of the muscle. The longer durations and spike durations are probably due to increased temporal dispersion at a greater distance from the endplate zone. We do not have an adequate explanation for the larger amplitudes distally in the biceps, they may be due to anatomical factors. To increase the diagnostic sensitivity of quantitative MUP analysis the recordings should be obtained from standardized recording sites. © 1995 John Wiley & Sons, Inc.
Beneficial versus adverse effects of long‐term use of clenbuterol in mdx mice
Authors: Dupont‐Versteegden Esther E. , Katz Michael S. , McCarter Roger J.
Published: January 2005

Long‐term administration of the β2‐adrenergic agonist clenbuterol in mdx mice was used to test the hypothesis that increasing contractile protein content in skeletal muscle will decrease the progression of muscular dystrophy. C57BL/10SNJ (control) and dystrophic (mdx) mice were given clenbuterol (1.0–1.5 mg/kg body weight/day) in the drinking water. Ventilatory function and morphological and functional characteristics of soleus (SOL) and diaphragm (DIA) muscles were evaluated. Clenbuterol administration was associated with increased SOL muscle weight, and SOL muscle weight to body weight ratio in control and mdx mice at both ages. There was a 22% increase in myosin concentration of mdx DIA at 1 year of age, correlating well with increased normalized active tension in mdx DIA at this age. Also, absolute tetanic tension increased in control and mdx SOL with clenbuterol at both ages. Ventilatory function was significantly impaired in mdx mice at both ages and clenbuterol administration did not alleviate this. Clenbuterol treatment was associated with a 30–40% increase in fatigability in DIA and SOL muscles of control and mdx mice at both ages. Furthermore, 1‐year‐old mdx mice receiving clenbuterol exhibited deformities in hindlimbs and spine. These results suggest that long‐term clenbuterol treatment has a positive effect on muscle growth and force generation, but has adverse side effects such as increased muscle fatigability and development of deformities. © 1995 John Wiley & Sons, Inc.
Simultaneous assessment of left‐ventricular infarction size, function and tissue viability in a murine model of myocardial infarction by cardiac manganese‐enhanced magnetic resonance imaging (MEMRI)
Authors: Hu Tom C.‐C. , Bao Weike , Lenhard Stephen C. , Schaeffer Thomas R. , Yue Tian‐li , Willette Robert N. , Jucker Beat M.
Published: January 2005

Owing to its signal‐enhancing characteristics in viable well‐perfused tissue, divalent manganese (Mn2+) has been used as a myocardial imaging contrast agent. Because Mn2+ can enter excitable cells through the voltage‐gated L‐type calcium channels, manganese‐enhanced MRI (MEMRI) has been used to determine the viability and the inotropic state of the heart. In this study, we examined the correlation between left ventricular infarction zone as assessed by cardiac MEMRI and function in mice with permanent coronary artery occlusion. At an Mn2+ infusion dose of 1.72±0.47 nmol/min/g body weight, the steady‐state signal intensity (SI) enhancement 20–26 min post‐Mn2+ infusion of the normal septum and left‐ventricular wall during diastole was 128.2±14.4 and 127.9±26.5%, respectively, whereas the infarction zone was 56.0±7.1%. During systole, the SI enhancement was 144.6±33.0, 116.0±18.7 and 48.3±20.0% for the normal septum, left‐ventricular wall and infarction zone, respectively. A good correlation was obtained between the MEMRI determined infarction volume and conventional histological TTC staining (r = 0.9582, p<0.01). There was also a strong negative correlation between MEMRI determined infarction percentage (compared with whole left ventricle) and ejection fraction (r = −0.94, p<0.05). These data suggest that the Mn2+ concentration at steady state in the heart may reflect altered tissue viability in the infarcted tissue as well as surrounding region following myocardial infarction. In conclusion, in vivo cardiac MEMRI offers a manner in which functional, pathologic and viability data may be obtained simultaneously in myocardial tissue. Copyright © 2004 John Wiley & Sons, Ltd.
Manganese‐enhanced magnetic resonance imaging (MEMRI) of brain activity and applications to early detection of brain ischemia
Authors: Aoki Ichio , Naruse Shoji , Tanaka Chuzo
Published: January 2005

Divalent manganese ion (Mn2+) has been reported to be a useful contrast agent for functional MRI, through a technique named activity‐induced manganese‐dependent MRI (AIM). In AIM, signal enhancement is related to functional increases in calcium influx, and therefore AIM is, thus far, the only MRI method able to map brain activation in vivo independently of the surrogate hemodynamic changes used in functional MRI. Because of its high signal‐to‐noise ratio (SNR) and high sensitivity, AIM allows the use of multi‐slice or three‐dimensional MRI techniques to map functional activity at high spatial resolution. In the present review, we define AIM as a functional MRI tool based on the administration of divalent ionized manganese through an open or disrupted blood–brain barrier (BBB). The adequacy and efficacy of AIM in detecting neural activation is described in light of supporting experiments on inhibition of calcium channels, FOS expression, and on direct comparison to BOLD‐ and perfusion‐based functional MRI. Two main applications of AIM, mapping brain activation in rat somatosensory cortex, as well stroke research based on the well‐established middle cerebral artery occlusion model, are described in detail. Methodological problems associated with a strong dependence on anesthetic conditions, potential corruption due to disruption of the BBB, and unspecific increase of the baseline signal due to acoustical noise are discussed. Finally, recommended preparation methods and experimental protocols for AIM are introduced. Copyright © 2004 John Wiley & Sons, Ltd.
Manganese‐enhanced magnetic resonance imaging (MEMRI): methodological and practical considerations
Authors: Silva Afonso C. , Lee Jung Hee , Aoki Ichio , Koretsky Alan P.
Published: January 2005

Manganese‐enhanced MRI (MEMRI) is being increasingly used for MRI in animals due to the unique T1 contrast that is sensitive to a number of biological processes. Three specific uses of MEMRI have been demonstrated: to visualize activity in the brain and the heart; to trace neuronal specific connections in the brain; and to enhance the brain cytoarchitecture after a systemic dose. Based on an ever‐growing number of applications, MEMRI is proving useful as a new molecular imaging method to visualize functional neural circuits and anatomy as well as function in the brain in vivo. Paramount to the successful application of MEMRI is the ability to deliver Mn2+ to the site of interest at an appropriate dose and in a time‐efficient manner. A major drawback to the use of Mn2+ as a contrast agent is its cellular toxicity. Therefore, it is critical to use as low a dose as possible. In the present work the different approaches to MEMRI are reviewed from a practical standpoint. Emphasis is given to the experimental methodology of how to achieve significant, yet safe, amounts of Mn2+ to the target areas of interest. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of motor activity on the reactivity of single visual units in the crayfish
Authors: Aréchiga Hugo , Wiersma C. A. G.
Published: January 2005

Metal microelectrodes were chronically implanted in the optic nerve and circumesophageal commissure of the crayfish. The activity from single units was recorded in freely moving animals, and responsiveness to visual stimuli was found correlated with motor activity of the animal. The lowest firing rate corresponded to states of quietness and the highest to fighting reactions. The two types of visual units studied showed a different degree of modulation. The sustaining fibers, which signal the intensity of illumination, were facilitated at all levels of motor excitation. The movement fibers, which are phasic units, reacted to great enhancements of motor activity by an increased number of spikes in each response to movement, and by a lowering in the rate of “habituation.” This facilitatory influence is neural in origin, presumably conveyed by the “activity” fibers, which run efferently in the optic nerve, carrying information about movement of the various body parts.
Retrograde amnesia: Time dependent effects of rhinencephalic lesions
Authors: Hudspeth William J. , Wilsoncroft William E.
Published: January 2005

Retrograde amnesia (RA) produced by post‐trial lesions of mouse anterior limbic field was found to be inversely related to trial‐lesion intervals. Control experiments demonstrated that the RA was not due to response bias, seizures, spreading depression, or generalized electrical stimulation. Damage of the motor cortex failed to produce RA. The results support the contention that small lesions of the anterior limbic field selectively interfere with memory storage processes without disrupting retieval of memory.
Studies on the mechanism of axoplasmic transport in the crayfish cord
Authors: Fernandez H. L. , Huneeus F. C. , Davison P. F.
Published: January 2005

Following the injection of 3H‐leucine into a crayfish ganglion, tritiumlabeled proteins were detected remaining in the ganglion and moving at a slow linear rate caudad along the nerve cord. The rate of movement increased linearly with temperature between 5 and 20°C, but ceased at 3° C. The movement was also blocked for a distance around a colchicine‐injected ganglion. Both of these observations would be compatible with the involvement of microtubules in slow axoplasmic transport. However, in both instances normal‐appearing microtubules were observed by electron microscopy. Gel electropherograms of the denatured labeled proteins showed that the transported proteins are complex and may correspond to most of the axoplasmic proteins including the microtubules.
Influence of ionic environment on the relationship between pre‐ and postsynaptic potentials
Authors: Kusano Kiyoshi
Published: January 2005

The effects of various ions on the relationship between pre‐ and postsynaptic potentials were studied using untreated squid giant synapses, or those injected presynaptically with tetraethylammonium ions (TEA) in the presence of 10−6 g/ml tetrodotoxin (TTX). The synaptic transfer function was, in general, augmented by increasing [Ca2+]0 or by reducing [Mg2+]0. Opposite results were found by lowering either [Na+]0 or [Ca2+]0, or by increasing [K+]0 or [Mg2+]0. When [Ca2+]0 was removed, presynaptically applied depolarizations failed to produce both “On‐” and “Off‐PSP's.” Electrophoretically injected Ca2+ into the presynaptic terminal reduced synaptic transmission.

The minimal level of presynaptic membrane potential produced by an applied outward current pulse, which suppressed On‐PSP completely, averaged 106 mV inside positive (ranging between 52–205 mV from 12 preparations). The potential level was shifted more negatively on lowering [Ca2+]0 and more positively in high [Ca2+]0‐media. However, altering the [Na+]0 did not change the suppression level appreciably. Under these ionic circumstances the maximum amplitude of On‐PSP, as well as Off‐PSP, was markedly changed, but the level of the presynaptic depolarization required to evoke a maximum On‐PSP appeared to be unchanged, and the average value was 50 mV from the resting membrane potential level. Although the data are only qualitative, they appear to support the “Ca hypothesis” for the transmitter release and its shut‐off mechanism. Replacement of 423 mM Cl− by Br− or with isethionate did not affect synaptic transmission.