bluuebunny/crossref_metadata_2025 huggingface dataset:
The origin of muscle fasciculations and cramps
Authors: Layzer Robert B.
Published: January 2005

The anatomic site of origin of muscle fasciculations and cramps has been debated for many years. Many authors have argued for a central origin of the abnormal discharges in the anterior horn cells. However, most of the evidence favors a very distal origin in the intramuscular motor nerve terminals. The factors giving rise to these discharges are not well understood. Fasciculations may be related to chemical excitation of motor nerve terminals, whereas cramps may result from mechanical excitation of motor nerve terminals during muscle shortening. © 1994 John Wiley & Sons, Inc.
Possible role of apamin‐sensitive K+ channels in myotonic dystrophy
Authors: Behrens María Isabel , Jalil Patricio , Serani Alejandro , Vergara Fernando , Alvarez Osvaldo
Published: January 2005

Myotonic muscular dystrophy is a genetic disease characterized mainly by muscle atrophy and myotonia, a repetitive electrical activity of muscle. In the present study, the possible role of apamin‐sensitive K+ channels in the genesis of myotonia was investigated. Apamin is a peptide from bee venom that specifically blocks small conductance Ca2+‐activated K+ channels. The injection of a small amount of apamin (20–30 μl, 10 μmol/L) into the thenar muscle of myotonic dystrophy patients decreased the basal electrical activity during the electromyogram in the 6 patients studied. Myotonic discharges after muscle percussion were more difficult to trigger and of smaller intensity and duration. In 2 controls and in 2 patients with generalized myotonia, as well as in 1 patient with myotonia congenita (where the defect is in chloride channels), apamin had no effect. These results suggest that apamin‐sensitive K+ channels participate in the mechanism that generates myotonia in myotonic dystrophy. © 1994 John Wiley & Sons, Inc.
Central nervous system involvement in multifocal demyelinating neuropathy with persistent conduction block
Authors: Péréon Yann , Jardel J. , Guillon B. , Guihéneuc P.
Published: January 2005

We report the case of a 27 year‐old man treated for bilateral optic neuritis 5 and 3 years before who within a few months developed sensori‐ motor disorders of the arms and legs Characterized by asymmetric distribution and distal prominence. In addition to sensorimotor defects, which were particularly marked in the left arm and right leg, clinical examination showed nearly generalized areflexia. Electrophysiological studies revealed a rnultifocal neuropathy with persistent distal and proximal conduction blocks associated with a considerable slowing of motor nerve conduction, as well as central nervous system involvement indicated by motor‐, somatosensory‐, and visual‐evoked potentials. CSF analysis showed a mildly elevated protein level; anti‐GM, activity was negative. Sural nerve biopsy revealed onion–bulb‐like formations, and cerebral MRI showed a small, isolated, and aspecific high signal for white matter. First described by Lewis and Sumner in 1982, rnultifocal neuropathy with persistent conduction blocks may be associated with central demyelination. Our case is compared with 3 similar ones in the literature, and the favorable effects of steroid therapy are emphasized. © 1994 John Wiley & Sons, Inc.
Treatable gait disorder and polyneuropathy associated with high titer serum IgM binding to antigens that copurify with myelin‐associated glycoprotein
Authors: Pestronk Alan , Choksi Rati , Bieser Karen , Goldstein Jonathan M. , Adler Charles H. , Caselli Richard J. , George Edwin B.
Published: January 2005

We studied clinical and electrodiagnostic features of 9 patients with very high titers (>1:10, 000) of serum IgM binding to a CNS myelin antigen (CMA) preparation that copurified with myelin‐associated glycoprotein (MAG). We found that 8 of the 9 patients had a combined syndrome of gait ataxia and polyneuropathy (GAPN) with late‐age onset (mean = 70 years of age). In the 8 GAPN patients progressive difficulty with ambulation led to significant functional disability and frequent falling. Examination showed a wide‐based unsteady gait, especially when standing still or turning. There was mild‐to‐moderate distal sensory loss with involvement of joint position sense only in the toes. Motor changes, when present, were mild and mainly involved distal leg musculature. Treatment of 5 GAPN patients resulted in clear improvement of 2 after intravenous human immunoglobulin and of 3 others after other immunodulating agents. Immune‐mediated GAPN syndromes with high titers of serum IgM binding to CMA appear to be treatable causes of gait disorders in older patients. © 1994 John Wiley & Sons, Inc.
Quantitative sweat testing using acetylcholine for direct and axon reflex mediated stimulation with silicone mold recording; controls versus neuropathic diabetics
Authors: Stewart John D. , Nguyen Dang Minh , Abrahamowicz Michal
Published: January 2005

Sweat glands were stimulated by iontophoresed acetylcholine (ACh). Using a two‐chamber capsule, one group of sweat glands was stimulated directly by ACh, and another stimulated indirectly via axon reflexes. Sweat droplets were recorded with a silicone mold and counted by a dissecting microscope and a computerized scanner. Responses from 32 diabetics with generalized somatic peripheral neuropathy were compared with 32 controls. Counting sweat droplets by computerized scanning was more accurate than by microscope. The numbers of droplets, their total areas, and mean areas were all larger in the direct response. Counts of droplet numbers was more diagnostically useful than measuring the total area and the mean areas of the droplets. There was a high correlation between droplet numbers of the direct and the indirect sweat responses. Droplet number counts of the direct response had a slightly higher diagnostic yield than those of the technically more complicated indirect response: for a specificity of 95%, the direct response had a sensitivity of 55%, the indirect being 50%. © 1994 John Wiley & Sons, Inc.
Serial neurophysiological studies of intramuscular botulinum‐A toxin in humans
Authors: Hamjian John A. , Walker Francis O.
Published: January 2005

To characterize the time course of intramuscular botulinum toxin–induced paresis, we serially performed electrophysiological measurements and recorded the sonographic size of an extensor digitorum brevis (EDB) muscle in 10 human subjects before and after injecting the EDB with 10 units of botulinum‐A toxin. All EDB CMAPs decreased within 48 h, with peak decline at day 21 (8.3 ± 3.1 mV to 3.0 ± 0.9 mV). Decline of mean rectified voltage during maximal voluntary contraction of the EDB paralleled the change in CMAP amplitude. Average decrements to 2‐Hz repetitive stimulation never exceeded 6% (day 42) and exercise failed to facilitate Significantly CMAP amplitude. Atrophy peaked at day 42. The F‐wave to M‐wave ratio increased at day 2; silent periods did not change. Our findings confirm a primary peripheral action of the toxin, but a superimposed, transient central effect of the drug cannot be excluded. Intramuscular injections into EDB provide a useful model for studying chemodenervation effects. © 1994 John Wiley & Sons, Inc.
Transfer function analysis of respiratory sinus arrhythmia: A measure of autonomic function in diabetic neuropathy
Authors: Freeman Roy , Cohen Richard J. , Saul J. Philip
Published: January 2005

Standard techniques measuring heart rate (HR) variability do not account for its dependence on the rate and depth of respiration or measure the time relationship between changes in lung volume and HR. We used transfer function analysis to determine the magnitude and time relationship of the HR response to a known change in lung volume in controls and diabetics. This technique demonstrated significant differences between controls and diabetics with varying degrees of autonomic dysfunction. Specifically, reduced supine vagal and increased supine sympathetic HR modulation was found with progression of the autonomic neuropathy. In response to postural change the normal diabetics displayed impaired sympathetic HR modulation. Transfer function analysis yields new insight into the sequence of changes that occur with diabetic autonomic neuropathy and provides an accurate, easily comprehensible measurement of respiratory induced HR variability.© 1995 John Wiley &Sons, Inc.
Sympathetic skin response (SSR) is abnormal in multiple sclerosis
Authors: Elie B. , Loubo'Jtin J. P.
Published: January 2005

As the function of the autonomic nervous system is often compromised in multiple sclerosis (MS), different standardized tests are used to detect disseminated abnormalities in cardiovascular autonomic functions. Sympathetic skin response (SSR), a slow wave generated in deep layers of the skin, is induced by reflex activation of sudomotor sympathetic efferent fibers. SSR was studied in 70 patients classified into different categories according to the diagnostic criteria for MS. We also obtained pattern reversal visually evoked potentials and brainstem auditory evoked potentials as well as somatosensory evoked potentials (by median and posterior tibial nerve stimulation). SSR was abnormal in 66 patients (94.2%), including abnormal foot latency with normal hand latency in 30 (42.8%), delayed foot and hand latencies in 30 (42.8%), and no response in 6 (8.6%). The percentages of SSR abnormalities were similar in the different patient categories. Pathological SSR were more common than abnormal evoked potentials in suspected and probable MS. SSR appears to be a simple and effective means of assessing sympathetic sudomotor outflow disturbances in MS, providing a valuable addition to current electrophysiological procedures for the detection of MS lesions.© 1995 John Wiley &Sons, Inc.
Site and mechanics of failure in normal and dystrophin‐deficient skeletal muscle
Authors: Law Douglas J. , Tidball James G. , Caputo Angelo
Published: January 2005

Partial or complete tearing of skeletal muscle occurs both in acute muscle injury and in some pathological muscle conditions. Despite the impact of such tearing on normal muscle function, few studies have examined the site or mechanism of muscle injury at cellular or subcellular levels of organization. The present study determines the ultrastructural location and mechanical conditions of tensile failure in normal mouse extensor digitorum longus muscles. All of these muscles failed near a myotendinous junction (MTJ), but within the muscle fibers, in a transverse plane coincident with the edge of an A‐band. The breaking stress averaged 5.71 × 105 N/m2 for muscles stimulated tetanically during lengthening, and 5.01 × 105 N/m2 for unstimulated muscles. Breaking strain averaged 135%, and showed no dependence on the state of activation of the muscle. The energy absorbed by each muscle averaged 362.5 mJ/g in unstimulated muscle, and 613.2 mJ/g in the stimulated samples. In addition to the failure properties of normal muscle, the effect of dystrophin deficiency on the site and conditions of failure was determined using muscle from mdx mice, which lack dystrophin. The absence of dystrophin had no detectable effect on the stress, strain, or energy absorbed, regardless of the state of muscle activation. Unstimulated mdx muscle failed in the plane of an A‐band, but tetanic stimulation produced failure in the reticular lamina of the tendon, just external to the MTJ, in 75% of the fibers in the mdx muscles. Although dystrophin's cytoplasmic location makes it unlikely that this unique mode of failure is due directly to the absence of the protein, failure in the reticular lamina may result from a difference in load distribution that accompanies the response of mdx muscle to dystrophin deficiency.© 1995 John Wiley &Sons, Inc.
Early and late motor evoked potentials reflect preset agonist–antagonist organization in lower limb muscles
Authors: Tarkka Ina M. , McKay W. Barry , Sherwood Arthur M. , Dimitrijevic Milan R.
Published: January 2005

A single transcranial magnetic stimulus can evoke two involuntary muscle responses in lower limb muscles of healthy humans. The purpose of the present study was to find out if these responses, when evoked during the processing period of a simple or choice reaction time task, such as ankle dorsiflexion, have specific characteristics related to the task. During the auditory reaction time, a transcranial magnetic stimulus was delivered to observe changes in the excitability of the central nervous system. A dual‐cone coil was used, which effectively stimulated the fairly deep‐lying lower limb motor cortex. Stimuli were delivered in a random order with 20–300‐ms delays from the auditory gosignal. Motor evoked potentials (MEP) in right and left anterior tibial and soleus muscles were analyzed while early MEPs were observed invariably in both muscles; late MEPs occurred consistently only in soleus muscles. Both early and late MEP amplitudes were larger in simple reaction time trials than in choice reaction time trials. The late MEP appeared earlier in the simple reaction time task than in the choice reaction time task, reflecting faster central processing of simple reaction time tasks. The amplitude of the soleus late MEP in the simple reaction time task followed closely the amplitude of anterior tibial early MEP, suggesting a preset agonist–antagonist organization. This relationship was not present in the choice reaction time task.© 1995 John Wiley &Sons, Inc.
Evaluation of the cardiomyopathy in becker muscular dystrophy
Authors: Nigro Giovanni , Comi Lucia I. , Politano Luisa , Limongelli Francesco M. , Nigro Vincenzo , De Rimini Maria L. , Giugliano Maria A. M. , Petretta Vito R. , Passamano Luigia , Restucci Brunella , Fattore Luciano , Tebloev Konstantine , Comi Luigi , De Luca Francesco , Raia Pasquale , Esposito Maria G.
Published: January 2005

To evaluate the features and the course of cardiomyopathy in Becker muscular dystrophy, 68 patients–identified by clinical assessment and by reduced dystrophin labeling and/or DNA analysis–were followed in the years 1976–1993, for periods ranging from 3 to 18 years (mean 8). Patients periodically underwent clinical, electrocardiographic, echocardiographic, nuclear, and radiological assessments. Preclinical cardiac involvement was found in 67.4% of patients under 16 years of age, decreasing to 30% in patients older than 40. Clinically evident cardiomyopathy was found in 15% of patients under 16 years of age, increasing to 73% in patients older than 40. A real, dilated cardiomyopathy is the most frequent type of myocardial involvement after the age of 20. Results show that the severity of cardiac involvement can be unrelated to the severity of skeletal muscle damage and confirm that cardiac dysfunction is a primary feature of Becker muscular dystrophy.© 1995 John Wiley &Sons, Inc.
An EMG case report of lead neuropathy 19 years after a shotgun injury
Authors: Wu Peter B. J. , Date Elaine S. , Kingery Wade S.
Published: January 2005

The clinical picture of lead neuropathy was classically described as a painless progressive motor neuropathy with axonal loss. The literature review fails to demonstrate a consensus on the site of axonal loss. This is an EMG report of a patient who developed a late lead neuropathy after a shotgun injury. A 69‐year‐old Filipino, healthy, male nondrinker sustained a shotgun injury to his left elbow. Nineteen years later he developed abdominal pain, followed by generalized weakness, distal greater than proximal in the extremities, and impaired pin‐prick, proprioception, and two‐point discrimination. He became nonambulatory and totally dependent in daily activities. He was lost to follow‐up for 2 years until January 1993 when he presented with a blood lead level of 84 μ/dL. EMG examination revealed a sensorimotor peripheral polyneuropathy with severe axonal loss. This case demonstrates that axonal loss is the predominant feature in lead neuropathy and the location of pathology is in the peripheral nerves.© 1995 John Wiley &Sons, Inc.
Sympathetic sudomotor function and aging
Authors: Ferrer Teresa , Ramos María J. , PÉRez‐JiméNez Angeles , PÉRez‐Sales Pau , Alvarez Eduvigis
Published: January 2005

Many studies have reported the influence of aging on different portions of the autonomic nervous system components but only partially for the sympathetic cholinergic system. We evaluated postganglionic sudomotor function in 196 healthy subjects, 104 women and 92 men, by determining sweat gland density (SGD) per square centimeter of skin, on the dorsum of the hand and foot, with the impression mold technique. The age range was from 5 to 84 years. A significant decrease of SGD was observed in both hand and foot in relation to age (P < 0.001). The ANOVA analysis of foot data shows that age is the only significant factor for SGD reduction. In the hand, both sex and body surface area are significant covariates with age. The dorsum of the foot is the most appropriate place to examine sweating in studies of aging. The lower normal limits for SGD in the foot are 213/cm2 for subjects younger than 30 years, 199/cm2 for those from 30 to 59 years, and 123/cm2 for subjects over 59 years old. © 1995 John Wiley & Sons, Inc.
Calcium exchange hypothesis of skeletal muscle fatigue: A brief review
Authors: Williams Jay H. , Klug Gary A.
Published: January 2005

Skeletal muscle fatigue is often associated with diminished athletic performance and work productivity as well as increased susceptibility to injury. The exact cause of muscle fatigue probably involves a number of factors which influence force production in a manner dependent on muscle fiber type and activation pattern. However, a growing body of evidence implicates alterations in intracellular Ca2+ exchange as a major role in the fatigue process. These changes are thought to occur secondary to reductions in the rates of Ca2+ uptake and release by the sarcoplasmic reticulum (SR). This hypothesis is based on the finding that peak myoplasmic Ca2+ concentration ([Ca2+]i) is reduced as force declines during fatigue. In addition, direct measurements of Ca2+ uptake and release show that fatiguing activity causes intrinsic alterations in the functional properties of the SR. We also propose that fatigue‐induced alterations in Ca2+ exchange may be beneficial, reducing the rate of energy utilization by the muscle fiber and preventing irreversible damage to the cell. © 1995 John Wiley & Sons, Inc.
Maximal force and endurance to fatigue of respiratory and skeletal muscles in chronic hypoxemic patients: The effects of oxygen breathing
Authors: Zattara‐Hartmann Marie Caroline , Badier Monique , Guillot Chantal , Tomei Charles , Jammes Yves
Published: January 2005

The consequences of chronic hypoxemia on maximal force and endurance time to sustained 80% of maximal isometric contraction of two skeletal muscles (adductor pollicis and vastus lateralis) and the diaphragm were studied in patients with chronic obstructive pulmonary disease (COPD). Compared to normal subjects, COPD patients have lower values of Fmax for the two skeletal muscle groups and Pmax (diaphragm). Endurance time was also shorter for the diaphragm and adductor pollicis. Chronic hypoxemia was associated with an accentuation in integrated EMG changes in both low and high frequency bands for adductor pollicis and diaphragm. Inhalation of oxygen enriched gas mixture for a 15‐min period increased markedly Fmax and Pmax values, prolonged the endurance time to sustained thumb adduction, and reduced the EMG changes in the low frequency band for adductor pollicis. The present observations provide evidence for altered maximal performances of skeletal muscles in chronic hypoxemic patients and also point out the virtues of oxygen breathing in these patients. © 1995 John Wiley & Sons, Inc.
Stimulation distal to the lesion in patients with carpal tunnel syndrome
Authors: Lesser E. A. , Venkatesh S. , Preston D. C. , Logigian E. L.
Published: January 2005

In patients with carpal tunnel syndrome, low action potential amplitude after stimulation at the wrist (proximal to the lesion) is due to either demyelination or axonal degeneration. Demyelination can be distinguished from axonal degeneration by the presence of amplitude drop across the lesion. Amplitude drop is determined by comparison of action potential amplitude evoked by stimulation at the palm (distal to the lesion) with that of the wrist. Of 59 consecutive CTS patient hands, 36 (61%) showed significant reduction in CMAP and/or antidromic SNAP amplitudes at the wrist compared to the palm, indicating the presence of focal demyelination resulting in conduction block vs. pathologic dispersion with phase cancellation. Moreover, the smaller the wristevoked action potential amplitude, the greater the amplitude drop across the lesion. We conclude that in patients with CTS, as in other entrapment neuropathies, stimulation both proximal and distal to the lesion provides important pathophysiological information about the median nerve lesion. © 1995 John Wiley & Sons, Inc.
Three‐dimensional MR imaging of brain surface anomalies in fukuyama‐type congenital muscular dystrophy
Authors: Toda Tatsushi , Watanabe Toshiaki , Matsumura Kiichiro , Sunada Yoshihide , Yamada Hiroki , Nakano Imaharu , Mannen Toru , Kanazawa Ichiro , Shimizu Teruo
Published: January 2005

Fukuyama‐type congental muscular dystrophy (FCMD), the second most common childhood muscular dystrophy in Japan, is characterized by the association with severe brain anomalies such as pachygyria and focal interhemispheric fusion. Conventional imaging techniques such as X‐ray CT scan and MRI are ineffective for visualization of these brain surface anomalies. Here we investigated the efficacy of three‐dimensional (3‐D) reconstruction of brain surface MR images for the detection of brain anomalies in FCMD patients. 3‐D brain surface MR images clearly visualized anomalies of cerebral gyrus such as pachygyria, as well as focal interhemispheric fusion. In addition, reconstructed horizontal images visualized structural derangement such as abnormal protrusion of white matter into gray matter. MR image abnormalities were confirmed by autopsy in 1 patient. These abnormalities were never observed in Duchenne muscular dystrophy (DMD) patients. Our results indicate the efficacy of the present method for the differential diagnosis between FCMD and DMD with severe mental retardation, which is essential for the genetic study to identify the causative gene of FCMD. © 1995 John Wiley & Sons, Inc.
Median/ulnar premotor potential identification and localization
Authors: Dumitru Daniel , King John C.
Published: January 2005

A small negative waveform is known to precede the median and ulnar compound muscle action potentials when recorded with surface or concentric needle electrodes. This investigation documents that there are two distinct waveforms preceding the median compound muscle action potential (CMAP) depending upon the type of recording electrodes used (concentric needle versus surface) and their respective locations. The negative waveform originally described with a concentric needle electrode positioned within the substance of the distal thenar eminence and having a restricted zone of detection is referred to as the intramuscular nerve action potential (INAP). This potential is shown to be distinct from the premotor potential (the small negative waveform preceding surface recorded ulnar and median CMAPs). Detection of the median and ulnar premotor potentials at multiple locations about the hand with the same respective onset/peak latencies and amplitudes substantiates that this potential is a far‐field potential. The median and ulnar premotor potentials most likely originate from a dipolar moment imbalance generated by digital sensory nerve action potentials as they cross the first and fifth metacarpophalangeal junctions, respectively. Applying far‐field principles permits the documentation of additional far‐field potentials as they are generated at the second through fourth metacarpophalangeal junctions following median nerve stimulation. Also, because the premotor potential is a far‐field potential, caution must be exercised with respect to its diagnostic utility as joint position and other unknown factors may affect amplitude and onset/peak latency. The INAP following median nerve excitation, however, is documented to be a near‐field potential distinct from the premotor potential arising from the recurrent branch of the median nerve. Therefore, although the median intramuscular nerve action potential and premotor potentials both precede the compound muscle action potential, they are different potentials with unique generator sites. © 1995 John Wiley & Sons, Inc.
A noninvasive method of neurography in meralgia paraesthetica
Authors: Spevak Milica Klopčič , Prevec Tine S.
Published: January 2005

The lateral femoral cutaneous nerve (LFCN) becomes superficial 10 cm distal to the anterior superior iliac spine, where it can be located and stimulated by superficial electrodes. This is not the case in the inguinal region. In the present study the LFCN compound nerve action potential (NAP) was recorded with a pair of 8‐cm‐long strip electrodes placed on the anterolateral aspect of the thigh 25 cm distal to the stimulating electrodes. Normative values were obtained in 58 healthy nerves. The conduction velocity (CV) was 62.3 ± 5.5 m/s for NAP onset and 55.3 ± 4.1 m/s for the negative NAP peak. The CV variability was comparable to that obtained with needle recordings despite a relatively low NAP amplitude (2.0 ± 1.0 μV). This method provided definite neurophysiological evidence of the disorder in 12 of 13 patients with meralgia paraesthetica. According to our results, a slowing of CV is a more reliable sign of the condition than a decrease of NAP amplitude alone. © 1995 John Wiley & Sons, Inc.
Lambert—Eaton myasthenic syndrome (LEMS) in association with lymphoproliferative disorders
Authors: Argov Zohar , Shapira Yehuda , Averbuch‐Heller Lea , Wirguin Itzhak
Published: January 2005

LEMS is a presynaptic neuromuscular junction disorder typically associated with small cell lung carcinoma. The characteristic electrophysiological abnormality is a low amplitude compound muscle action potential that shows a marked increment after short maximal contraction or brief tetanic nerve stimulation. Here we describe 3 patients who had LEMS in association with lymphoproliferative disorder. The first patient had Castleman's syndrome with typical clinical and electrophysiological features of LEMS, which responded partially to treatment with 3–4‐diaminopyridine. The second patient was a 7‐year‐old boy who had an unusual acute onset of LEMS associated with relapse of his Burkitt's leukemia. The third patient was a 60‐year‐old woman with non‐Hodgkin's lymphoma. These 3 patients (together with 6 additional patients identified in the literature) lead us to suggest that lymphoproliferative diseases are another, hitherto unrecognized, type of malignancy associated with LEMS. Thus, any patient with these malignancies and unexplained muscle weakness should have electrophysiological evaluation for LEMS. © 1995 John Wiley & Sons, Inc.
Five‐year experience in the treatment of focal movement disorders with low‐dose dysportTM botulinum toxin
Authors: Van Den Bergh P. , Francart J. , Mourin S. , Kollmann P. , Laterre E. C.
Published: January 2005

We report the results of botulinum toxin type A (DysportTM, Porton Products, UK) treatment over 5 years in 107 patients with blepharospasm, Meige's syndrome, oromandibular dystonia, hemifacial spasm, cervical dystonia, and writer's cramp. Electromyography was used to localize dystonic muscles and guide DysportTM injections in Meige's syndrome, oromandibular dystonia, cervical dystonia, and writer's cramp. All but 2 Meige's syndrome and 2 writer's cramp patients responded to treatment. Improvement was dramatic in blepharospasm (79%) and hemifacial spasm (90%); pronounced in cervical dystonia (74%); and moderate in Meige's syndrome (53%), oromandibular dystonia (57%), and writer's cramp (34%). Although DysportTM doses were 50–75% lower than usually reported, response and improvement rates as well as relapse intervals were similar to those of others. To treat cervical dystonia relapses, only 50% of the initial dose was required for continued optimal relief of symptoms. Low‐dose DysportTM was associated with a very low incidence of dysphagia in cervical dystonia. © 1995 John Wiley & Sons, Inc.
Limited longitudinal sliding of the median nerve in patients with carpal tunnel syndrome
Authors: Valls‐Solé Josep , Alvarez Ramiro , He Montserrat Nuñez
Published: January 2005

During normal movements or changes in position of the limbs, nerve structures must accommodate the resulting changes in length of the nerve path. In patients with carpal tunnel syndrome, we monitored electrophysiologically the longitudinal adjustment of the median nerve to positions of extreme flexion and extreme extension of the wrist and elbow, by measuring the differences induced in the latency of the sensory nerve action potential (SNAP) recorded in the forearm and upper arm. In patients, the latency difference was significantly shorter than in normal subjects (0.196 ± 0.084 ms vs. 0.088 ± 0.059 ms in the forearm, and 0.485 ± 0.122 ms vs. 0.129 ± 0.086 ms in the upper arm). These results indicate that the displacement of the source of the median nerve SNAP with movements of flexion and extension is limited in patients with carpal tunnel syndrome. Such an abnormality may partly underlie the pathophysiology of entrapment syndromes. © 1995 John Wiley & Sons, Inc.
Cerebrospinal fluid and serum from patients with inflammatory polyradiculoneuropathy have opposite effects on sodium channels
Authors: Würz Axel , Brinkmeier Heinrich , Wollinsky Kurt H. , Mehrkens Hans‐H. , Kornhuber Hans H. , Rüdel Reinhardt
Published: January 2005

The effects of cerebrospinal fluid (CSF) and serum from patients having Guillain–Barré syndrome (GBS) or chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) on voltage‐dependent Na+ channels were compared. Bathing human myoballs in CSF substantially reduced their Na+ currents (by >40% with 8 of 10 patients) elicited at 1 Hz under whole‐cell recording conditions. This was because, at the resting potential, more Na+ channels were inactivated (left‐shift of the h∞ curve). CSF from patients with other neurological diseases (OND) produces a similar, but smaller, effect. In contrast, serum samples from the same GBS and OND patients caused an increase of the Na+ currents by reducing the number of Na+ channels inactivated at the resting potential. This right‐shift of the h∞ curve is in part explained by the effect of serum albumin. We confirm that the CSF of most GBS and CIDP patients contains factors inhibiting voltage‐dependent Na+ currents. There is no indication that such factors are effective in the serum of these patients. © 1995 John Wiley & Sons, Inc.
Involvement of the external anal sphincter in amyotrophick lateral sclerosis
Authors: Carvalho M. , Schwartz M. S. , Swash M.
Published: January 2005

In amyotrophic lateral sclerosis the striated pelvic floor sphincter muscles are functionally uninvolved, and pathological studies have confirmed the relative resistance of the Onuf nucleus motor neurons. We have evaluated the external anal sphincter (EAS) muscle in 16 patients with ALS using single fiber EMG, and compared the results with the findings in the semimembranosus‐semitendinosus (SM‐ST) muscles that have innervation from the L‐5, S‐1, and S‐2 segments. The results were compared with a group of controls matched for age and sex. None of the patients or controls had symptomatic sphincter involvement and none of the 4 women studied were parous. Eight patients with ALS showed an increased fiber density in the EAS; 6 had an abnormal neuromuscular jitter. In 1 there was fibrillation in the EAS. In the SM‐ST muscle 11 patients showed an increased fiber denstiy, and 7 had an abnormal neuromuscular jitter. In 3 patients with ALS in whom there were abnormal findings in the EAS the bulbocavernosus reflex and pudendal nerve evoked potentials were normal. Neurogenic change was more marked in the SM‐ST than in the EAS muscle. These findings show that the EAS is not normal in ALS. However, the relative resistance of the EAS to ALS is sufficient to prevent incontinence, even in the longer‐surviving older patients. © 1995 John Wiley & Sons, Inc.
Foot drop as a harbinger of aortic occlusion
Authors: Larson Wendy L. , Wald John J.
Published: January 2005

A man presented with foot drop and 2 months later an infrarenal occlusion of his abdominal aorta was discovered. Initial evaluation found no structural etiology for his nerve injury. His neurologic deficits progressed until gangrenous changes developed in his feet leading to the discovery of aortic occlusion. This case demonstrates that peripheral nerve injury in the legs may signal underlying large vessel occlusive disease. We discuss the localization and potential mechanisms of ischemic nerve injury. © 1995 John Wiley & Sons, Inc.
Single fiber electromyography of extraocular muscles: A sensitive method for the diagnosis of ocular myasthenia gravis
Authors: Rivero Alberto , Crovetto Luis , Lopez Lidia , Maselli Ricardo , Nogués Martín
Published: January 2005

We performed single fiber electromyography (SFEMG) in the superior rectus and levator palpebralis (SR‐LP) muscles of 17 patients with pure ocular myasthenia gravis (MG) and 9 controls. Thirteen patients were also assessed with SFEMG in the orbicularis oculi (OO) muscle. All the MG patients but none of the control subjects showed abnormal SFEMG jitter in the SR‐LP muscles. On the other hand, only 62% of the MG patients had abnormal SFEMG jitter in the OO muscle. The procedure was well tolerated by the patients, and complications were minor. We conclude that SFEMG of the SR–LP muscles is a safe and highly sensitive technique for the diagnosis of ocular MG. © 1995 John Wiley & Sons, Inc.
Generators of the early and late median thenar premotor potentials
Authors: Park Tracy A. , Del Toro David R.
Published: January 2005

The generator sources of the median thenar premotor potentials (PMPs) have remained elusive despite debate in the literature. By studying the median nerve in the hand with a variety of bipolar and referential recording montages, we systematically examined the possible nearfield and far‐field sources that may determine these potentials. The results suggest that the early PMP is a near‐field potential recorded by G1 and generated by the median nerve traversing the distal carpal tunnel. The late PMP represents a far‐field potential generated by the median digital nerve fibers as they pass from the palm volume into the thumb volume. Characteristics of the late PMP are explained using the leading/trailing dipole (L/TD) model of far‐field potential generation. The diagnostic utility of these PMPs is questionable, since they are recorded from “regions” along the nerve rather than from more clearly defined sites. © 1995 John Wiley & Sons, Inc.
Lysosomal enzyme activities in skeletal muscle of patients with neuromuscular diseases
Authors: Kawai Hisaomi , Yoneda Kenji , Naruo Takako , Nishida Yoshihiko , Kashiwagi Setsuko , Kunishige Makoto , Saito Shiro
Published: January 2005

Activities of nine lysosomal enzymes and pH‐dependent isozyme patterns of α‐mannosidase were examined in the skeletal muscle of patients with neuromuscular diseases, and the ratios of these enzyme activities in leukocytes to those in myocytes (L/M ratio) were determined. The activities of enzymes with a high L/M ratio were markedly increased in the muscles of patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy (MyD), or polymyositis (PM). In contrast, those which showed a low L/M ratio were increased in the muscles of amyotrophic lateral sclerosis (ALS) and disuse muscle atrophy (DUA). The isozyme pattern of α‐mannosidase in DMD muscle resembled that in leukocytes, while those in ALS and DUA muscle resembled that in normal muscle. These results may suggest that the increased activity of lysosomal enzymes in the muscles of patients with DMD, MyD, or PM is due primarily to infiltrating leukocytes, while that in patients with ALS or DUA is due to intramyofiber lysosomes. © 1995 John Wiley & Sons, Inc.
An electrophysiological investigation of deglutition in man
Authors: Ertekin Cumhur , Pehlivan Murat , Aydoǧdu Ibrahim , Ertaşl Mustafa , Uludaǧ Burhanettin , Çlelebi Gürbüz , Çlolakoǧlu Zafer , Saǧduyu Ayşle , Yüceyar Nur
Published: January 2005

This article describes a combined electrophysiological and mechanical method used to measure laryngeal movements and related submental EMG activity during swallowing. The mechanical upward and downward movements of the larynx were detected using a piezoelectric sensor while the submental integrated EMG (SM‐EMG) was recorded. Measurements were performed in 29 human subjects. The interval between the onsets of the two sensor signal deflections was used as a measure of the time the larynx remained in its superior position during swallowing. In 10 subjects, the cricopharyngeus muscle (CP) of the upper esophageal spinchter showed a continuous tonic EMG activity except during swallowing. All the parameters measured were influenced by the type and volume of the bolus material. The method presented in this study proved its usefulness in the study of the physiology of deglutition as well as in its objective clinical evaluation in patients with dysphagia.© 1995 John Wiley & Sons, Inc.
Three‐dimensional structure of cat tibialis anterior motor units
Authors: Roy Roland R. , Garfinkel Alan , Ounjian Melinda , Payne Jeremy , Hirahara Alan , Hsu Emmie , Edgerton V. Reggie
Published: January 2005

The motor unit is the basic unit for force production in a muscle. However, the position and shape of the territory of a motor unit within the muscle have not been defined precisely. The territories of five motor units in the cat tibialis anterior muscle were reconstructed three‐dimensionally (3‐D) from tracings of the glycogen‐depleted fibers belonging to each unit. The motor unit territories did not span the entire length of the muscle and their cross‐sectional areas tapered along the proximodistal axis producing a conical shape. In addition, the position of the territory of each unit shifted in an anterior–posterior plane along the longitudinal axis of the muscle, presumably as a consequence of the pinnation of the fibers. The area of the motor unit territory at any given level along the proximodistal axis was highly correlated with the number of fibers within the territory at that level. Connective tissue boundaries (outlining fascicles) appeared to have a strong influence on the shape of the territory, territories showed abrupt changes at connective tissue boundaries as groups of motor unit fibers within a fascicle often terminated together while motor unit fibers in neighboring fascicles did not terminate. It is likely that the mechanical impact of the recruitment of a motor unit is affected by the location and shape of motor units within the same muscle area. Since there is a close relationship between the area of the territory of a motor unit and the number of fibers in the motor unit, while the density of unit fibers remains the same, then the same factor(s) which regulate the number of fibers innervated by a motoneuron may also determine the territory area.© 1995 John Wiley & Sons, Inc.
Thenar motor unit number estimates using the multiple point stimulation technique: Reproducibility studies in als patients and normal subjects
Authors: Felice Kevin J.
Published: January 2005

Thenar motor unit number estimate (MUNE) reproducibility was assessed in 20 patients with amyotrophic lateral sclerosis (ALS) and 16 normal subjects using the multiple point stimulation (MPS) technique. The MUNE was calculated by dividing the thenar compound muscle action potential negative‐peak (n‐p) area by the mean n‐p area of 10 lowest threshold, all‐or‐nothing, surface‐recorded motor unit action potentials. Two trials (test–retest) were performed by the same examiner either on separate days or on the same day with new electrode placements. The mean test MUNE was 43.4 (SD: 35.9, range: 6–145) for ALS patients and 219.4 (SD: 80.8, range: 122–368) for normal subjects. Test–retest MUNE differences were not significant for ALS patients or normal subjects. The test–retest correlation coefficient (r) was 0.99 for ALS patients and 0.85 for normal subjects. The mean difference between test–retest values was 10% for ALS patients and 17% for normal subjects. Test–retest reproducibility of the thenar MUNE using the MPS technique is high in both ALS patients and normal subjects. The reliability of the MPS technique in estimating motor unit numbers may make it a useful outcome measure in following the course of patients with progressive lower motor neuron disease, especially those enrolled in experimental drug trials.© 1995 John Wiley &Sons, Inc.
Manganese‐enhanced magnetic resonance imaging (MEMRI) of mouse brain development
Authors: Wadghiri Youssef Zaim , Blind Jeffrey A. , Duan Xiaohong , Moreno Clement , Yu Xin , Joyner Alexandra L. , Turnbull Daniel H.
Published: January 2005

Given the importance of genetically modified mice in studies of mammalian brain development and human congenital brain diseases, MRI has the potential to provide an efficient in vivo approach for analyzing mutant phenotypes in the early postnatal mouse brain. The combination of reduced tissue contrast at the high magnetic fields required for mice, and the changing cellular composition of the developing mouse brain make it difficult to optimize MRI contrast in neonatal mouse imaging. We have explored an easily implemented approach for contrast‐enhanced imaging, using systemically administered manganese (Mn) to reveal fine anatomical detail in T1‐weighted MR images of neonatal mouse brains. In particular, we demonstrate the utility of this Mn‐enhanced MRI (MEMRI) method for analyzing early postnatal patterning of the mouse cerebellum. Through comparisons with matched histological sections, we further show that MEMRI enhancement correlates qualitatively with granule cell density in the developing cerebellum, suggesting that the cerebellar enhancement is due to uptake of Mn in the granule neurons. Finally, variable cerebellar defects in mice with a conditional mutation in the Gbx2 gene were analyzed with MEMRI to demonstrate the utility of this method for mutant mouse phenotyping. Taken together, our results indicate that MEMRI provides an efficient and powerful in vivo method for analyzing neonatal brain development in normal and genetically engineered mice. Copyright © 2004 John Wiley & Sons, Ltd.
Amino acid production and translocation in incubated and superfused tissues from the brain
Authors: Jones D. A. , Mc Ilwain H.
Published: January 2005

The content of 12 amino acids in guinea pig cerebral cortical tissues was measured before and after incubation in glucose salines. The incubation caused reltively little change in tissue content, but induced a considerable production and accumulation of amino acids in the incubation medium. The dietarily essential amino acids, found in uncombined form, increased 3 to 6 fold. Glycine and alanine also increased; little change occurred in the quantity of free aspartic and glutamic acids. Amino acids were retained in the tissue in vitro against concentration gradients considerably higher than those estimated to obtain in vivo; by superfusing the tissue, the ratios were further increased. Electrical stimulation of the isolated tissues increased the amino acid accumulating in the medium during incubation, and increased the efflux of radioactive leucine during superfusion. Cycloheximide also increased the efflux of radioactive leucine during superfusion, while colchicine was found to decrease the proportion of total amino acid appearing in superfusates. Reasons are given for considering incubation fluids as artificial extensions of the interstitial fluid of the brain, and for regarding amino acid output from the tissue as a process counterbalancing axoplasmic flow.
Patterns of spontaneous bioelectric activity during maturation in culture of fetal rodent medulla and spinal cord tissues
Authors: Corner Michael A. , Crain Stanley M.
Published: January 2005

Microelectrode recordings in explants of fetal rodent medulla and spinal cord demonstrate that a variety of organotypic temporal patterns of spontaneous bioelectric discharges occur during maturation of these CNS tissues in culture. The spontaneous activities include repetitive barrages of spike potentials, as well as stereotyped slow‐waves. These discharges last up to several sec, and they may occur at regular intervals of the order of 1–10 sec, although activity patterns are often much more irregular. Some explants also show clear periodicity in the recurrence of phases of relative activity and inactivity, with cycle times ranging up to about 10 min. Correlations between the network excitability properties of the CNS tissues and their patterned spontaneous discharges were obtained by electrophysiologic analyses of responses to microelectrode stimulation.

These complex, yet stereotyped, spontaneous bioelectric discharge patterns in cultures of organized CNS tissues show remarkable mimicry of rhythmic activities which occur in the embryonic CNS in situ, as determined by electrophysiologic and behavioral motility studies in the intact animal. Organotypic CNS explants provide, therefore, a valuable model system for further analyses of the cellular and molecular mechanisms underlying early development of behavior.
Glutamate uptake by brain slices and its relation to the depolarization of neurones by acidic amino acids
Authors: Balcar V. J. , Johnston G. A. R.
Published: January 2005

Uptake of L‐glutamate into rat brain slices from media containing either 10−3 or 10−8 M labelled L‐glutamate is not inhibited by (a) excitant amino acids which have an appreciably greater depolarizing action on central neurones than that of L‐glutamate, (b) antagonists of L‐glutamate induced excitation of central neurones, or (c) tetrodotoxin in concentrations which inhibit the sodium ion influx into brain slices produced by L‐glutamate and other excitant amino acids.

It is concluded that uptake of L‐glutamate is independent of both the tetrodotoxin‐insensitive depolarization and the tetrodotoxin‐sensitive sodium ion influx induced by L‐glutamate.
The visually evoked defense reflex of the crayfish: Habituation, facilitation, and the influence of picrotoxin
Authors: Glantz Raymon M.
Published: January 2005

When stimulated with rapidly approaching targets, the crayfish defense reflex exhibited habituation, spontaneous recovery, dishabituation, and stimulus generalization. The rate of habituation increased with stimulus repetition rate over a narrow range of stimulus rates. At the highest repetition rate examined, 20 min, the rate of habituation diminished. After 150 trials at 20 min, responsiveness to subsequent stimuli at lower repetition rates was enhanced. Dishabituation was elicited with mechanical prods to the dorsal thoracic carapace or a 1‐min session of 20\min stimulation. After completion of habituation a 5° shift in the axis of a 10° target resulted in substantial response recovery. Evidence for weak interocular generalization of habituation was also obtained. These results suggest both retinal‐dependent and retinal‐independent sites of habituation. Picrotoxin (2.4 mg\kg body weight) reversed a previously established response habituation and delayed the onset of rehabituation to repetitive stimuli. The effects of picrotoxin suggest the participation an inhibitory mechanism in defense reflex habituation.