bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy
Authors: Donofrio Peter D. , Tandan Rup , Albers James W.
Published: January 2005

Eleven consecutive patients with progressive chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) underwent plasma exchange. Eight patients were previously unresponsive to prednisone, two were started on prednisone with plasma exchange, and one did not receive corticosteroids. Electrodiagnostic studies revealed evidence of an acquired demyelinating polyradiculoneuropathy with varying degrees of axonal degeneration. Neurologic impairment was monitored using conventional functional status index. Five patients demonstrated substantial clinical improvement, beginning 2 days to 3 weeks after initiating plasma exchange. Two additional patients improved following a second course of plasma exchange, and four patients demonstrated minimal or no change. Comparison of responding and onresponding patients showed no differences related to the presence or absence of antecedent illness, duration of disease, duration of maximum weakness, or severity of impairment prior to plasma exchange. Responders had significantly prolonged F‐response and motor distal latencies compared to nonresponders. Results in this unselected, consecutive patient trial suggest a temporal relationship between plasma exchange and clinical improvement in some patients with progressive CIDP.
Peripheral nerve in type III glycogenosis: Selective involvement of unmyelinated fiber schwann cells
Authors: Powell Henry C. , Haas Richard , Hall Christopher L. , Wolff Jon A. , Nyhan William , Brown Barbara I.
Published: January 2005

Electron microscopy of intramuscular nerves in biopsy material from a child with glycogenosis type III showed massive glycogen accumulation in the Schwann cells of unmyelinated nerve fibers. Other cells, including Schwann cells of myelinated fibers, perineurial cells, endoneurial fibroblasts, endothelial cells, and pericytes, were not similarly affected.
The ischemic exercise test in normal adults and in patients with weakness and cramps
Authors: Coleman Rosalind A. , Stajich Jeffrey M. , Pact Virginia W. , Pericak‐Vance Margaret A.
Published: January 2005

Data from 23 normal men and women were used to derive 95% confidence limits for maximum changes in ammonia and lactate values following ischemic forearm exercise. Most normal subjects raised serum lactate and ammonia concentrations more than 20 mg/dl and 100 μg/dl, respectively over baseline values. No significant correlations were found among age, sex, duration of exercise, or estimate of work performed and the maximum ammonia and lactate values achieved. When 70 patients with complaints of weakness, fatigue, or cramps were evaluated, the ischemic exercise test identified 5 patients who proved to have defects in glycolysis or purine metabolism. The test also distinguished those patients with type III glycogen storage disease who lacked debrancher enzyme activity in muscle.
Antimuscle and antiacetylcholine receptor antibodies in myasthenia gravis
Authors: Penn Audrey S. , Schotland Donald L. , Lamme M. S. Stella
Published: January 2005

The sera of 134 patients were examined for antimuscle antibodies by immunofluorescence (IF). These derived from 77 myasthenics, 30 myasthenics with thymoma, 6 patients with thymoma and no clinical evidence of myasthenia, and 21 patients with other autoimmune or neuromuscular diseases. Three separate patterns of antimuscle antibodies could be identified in the myasthenic sera by examination of the relaxed glycerinated myofibrils by both IF and phase‐contrast optics: A‐band (9 with thymoma, 1 without), I‐band (11 with thymoma, 17 without), and a mixed A plus I pattern (5 with thymoma, 3 without). Seventy‐seven myasthenic serum samples (24 with thymoma, 53 without) were available for evaluation of antibodies to acetylcholine receptor (antiAChR) by radioimmunoassay. Ninety‐one percent reacted with crude human receptor extract and 80% with receptor extracted from denervated rat muscle. There was no correlation between the titers of anti‐AChR and the presence or staining patterns of antimuscle antibodies, but patients without anti‐AChR did not have antimuscle antibodies. Myasthenics with thymoma had the highest prevalence of anti‐AChR (237sol;24) and of antimuscle antibodies (257sol;30), and 15 of the 20 positives stained A‐bands alone or with I‐band, as compared to 4 of 21 positive reactions in those without tumor. Immunoabsorption, which removed or significantly reduced anti‐AChR, did not alter antimuscle reactivity. The discrepancies between anti‐AChR levels and the presence and types of antimuscle antibodies suggest that these are independent autoantibodies. Current theories of immunopathogenesis implicate altered thymic antigens or a major breakdown in immune regulation, either of which could explain their production.
Comparison of distal sympathetic with vagal function in diabetic neuropathy
Authors: Low Phillip A. , Zimmerman Bruce R. , Dyck Peter J.
Published: January 2005

We measured distal sympathetic and vagal function in 73 consecutive patients with diabetic neuropathy seen at the Mayo Autonomic Reflex Laboratory. Postganglionic sympathetic failure measured proximally within the foot occurred as commonly as vagal failure (58% and 55%, respectively) and‐occurred much more frequently than did orthostatic hypotension (26%). Either vagal or distal sympathetic abnormalities occurred in isolation in about one in six patients with diabetic neuropathy. We conclude that distal sympathetic failure and vagal failure occur with equal frequency when sensitive and quantitative recording methods are used and that it is advantageous to test both systems, as only one may be involved in some patients.
Lack of cold sensitivity in hyperkalemic periodic paralysis
Authors: Subramony S. H. , Wee Abelardo S. , Mishra Shri K.
Published: January 2005

The nosologic distinction between paramyotonia congenita and hyperkalemic periodic paralysis is somewhat blurred. Muscle membrane inexcitability induced by cooling seems to be characteristics of paramyotonia congenita. The effect of cooling on the maximal compound muscle action potential (CMAP) in patients with paramyotonia congenita was compared to that in patients with hyperkalemic periodic paralysis. Diminution in CMAP amplitude and area, which was observed in paramyotonia congenita, did not occur in hyperkalemic periodic paralysis. We suggest that this effect of cooling on the CMAP can be utilized in the differentiation of these two syndromes.
Humoral factors in peripheral nerve disease
Authors: Toyka Klaus V. , Heininger Kurt
Published: January 2005

Humoral factors including soluble substances transported by the blood stream and factors released at a target tissue may play a role in diseases of the peripheral nervous system. Various criteria have to be met in order to accept humoral factors as potential pathogens. In this review these general criteria are discussed, including the evidence provided by plasma exchange therapy, demonstration of circulating or deposited autoantibodies and immune complexes, identification of antigenic molecules, animal model diseases, passive transfer experiments, and the demonstration of circulating factors not directed against specific targets. In acute, chronic, and chronic relapsing inflammatory polyneuropathies, and in the polyneuropathy associated with monoclonal gammopathy, humoral factors have been identified, but their exact pathogenic role is not fully understood. In the Lambert‐Eaton myasthenic syndrome, a disorder of the motor nerve terminal, pathogenic IgG‐antibodies have been demonstrated by passive transfer experiments. In the experimental animal model disorders, the acute and chronic variants of experimental allergic neuritis, humoral factors including antibodies to myelin basic proteins and galactocerebroside and nonspecific humoral factors may all contribute to the ultimate peripheral nerve damage, but their relative importance in relation to cell‐mediated immune reactions is not yet clear.
Sensory potentials and sural nerve biopsy: A Model evaluation
Authors: Schoonhoven Ruurd , Schellens Ronald L. L. A. , Stegeman Dick F. , Gabreëls‐Festen Anneke A. W. M.
Published: January 2005

Compound action potentials (CAPs) were recorded from the sural nerve prior to nerve biopsy in patients with various kinds of polyneuropathy. A previously developed volume conductor model for the CAP is applied to analyze the recorded CAPs in close relation with the morphological findings in the biopsy. First, the fiber diameter histograms obtained from the biopsy are used to simulate CAPs by assuming a linear relation between fiber diameter and propagation velocity. It is concluded that the simulated CAPs deviate systematically from the recorded CAPs. Next, the assumption of a linear diameter‐velocity relation is left, and the assumed fiber velocity distribution is adapted to obtain optimal model reconstructions of the recorded CAPs. It is concluded that the model is capable of reconstructing the recorded CAPs, including slow components and small polyphasic potentials in the case of severe fiber loss. It is demonstrated how the diameter histogram and the optimal velocity distribution can be combined to an empirical estimate of the diameter‐velocity relation.
The muscle fiber conduction velocity and power spectra in familial hypokalemic periodic paralysis
Authors: Zwarts Machiel J. , van Weerden Tiemen W. , Links Thera P. , Haenen Harry T. M. , Oosterhuis Hans J. G.
Published: January 2005

Surface EMG has been used to determine the average muscle fiber conduction velocity (MFCV) and power spectra of the m. biceps of 10 patients and 15 asymptomatic offspring of a large kinship with familial hypokalemic periodic paralysis (HOPP). The MFCV of the patients was 3.37 ± 0.35 m/sec (mean ± SD, n = 9), the median frequency (Fmed) of the power spectra was 55.0 ± 5.8 Hz (mean ± SD, n = 9), both values are significantly (P0.001, Student's t‐test) lower than control values: MFCV = 4.55 ± 0.33 m/sec; Fmed = 88.6 ± 15.5 Hz (mean ± SD). In 6 of the 15 asymptomatic relatives, the surface EMG results were also abnormal. It is concluded that the MFCV is reduced in familial HOPP. This results in a predominantly low‐frequency content of the power spectra, thereby providing a new model for studying the relationship between the MFCV and the frequency spectrum of surface EMG. Asymptomatic relatives that have inherited the disease probably can be detected with this method.
Differential response of the dog quadriceps muscle to external skeletal fixation of the knee
Authors: Lieber Richard L. , Fridëan Jan O. , Hargens Alan R. , Danzig Larry A. , Gershuni David H.
Published: January 2005

The change in muscle fiber size and fiber percentage was studied in three heads of the dog quadriceps following 10 weeks of immobilizationg using an external skeletal fixator. Muscle biopsy morphometric analysis revealed that muscle fiber atrophy was greatest for the vastus medialis and least for the rectus femoris. The atrophic response for type 1 fibers was, in order from most to least atrophied: VM > VL > RF, whereas for type 2 fibers the corresponding order was VM = VL > RF. An increase in connective tissue was also observed for all muscles. These results are discussed in terms of skeletal muscle architecture, initial fiber‐type distribution, and level of use. As a result, predictions are made as to the muscles that are most vulnerable to disuse atrophy, namely the postural muscles that contain a relatively large proportion of slow muscle fibers and cross a single joint. Conversely, those that are least susceptable to atrophy are those that are not used as postural muscles, that cross multiple joints, and that are predominantly composed of fast muscle fibers.
A myasthenic syndrome with congenital paucity of secondary synaptic clefts: CPSC Syndrome
Authors: Smit L. M. E. , Hageman G. , Veldman H. , Molenaar P. C. , Oen B. S. , Jennekens F. G. I.
Published: January 2005

Two cases of a newly recognized myasthenic syndrome were investigated (CPSC syndrome). The course of the disease was observed for periods of 6 and 3 years. In infancy, exacerbations of the symptoms occurred during febrile illness, but thereafter the clinical course was stable and the children appeared to be only slightly handicapped. Biopsies were taken from the intercostal muscle in both patients. Microelectrode studies revealed small Mepp amplitudes. Light microscopy demonstrated predominance of type I fibers and focal type‐grouping. There was a lowered cholinesterase activity and frequent branching of preterminal axons. Electron microscopy revealed that there were few, if any, folds of the postsynaptic membrane and that there were no signs of degeneration. Methods for localization of acetylcholine receptors (AChR) revealed a deficiency and altered distribution of AChRs at these postsynaptic membranes and the occurrence of extrajunctional AChRs in some muscle fibers. It is concluded that the syndrome is a clinicopathological entity, characterized morphologically by a congenital paucity of secondary synaptic clefts (CPSC syndrome).
Tellurium‐induced demyelination: An electrophysiological and morphological study
Authors: Uncini Antonino , England John D. , Rhee Edward K. , Duckett Serge W. , Sumner Austin J.
Published: January 2005

Tellurium (Te) is a naturally occurring element with many industrial uses. Microinjection of 0.3 μg of potassium tellurite [K(2)TeO(3)] into the endoneurial space of rat tibial nerve causes a rapidly progressing focal conduction block as measured by the disappearance of the evoked compound muscle action potential (CAMP) of the intrinsic foot muscles following stimulation proximal to the injection site. Conduction block was fully established within 6 hours and persisted for approximately 7 days, followed by the appearance of low amplitude, long latency, temporally dispersed potentials. The proximal CMAPs increased in amplitude and decreased in latency and temporal dispersion until normalization by 28 days after injection. The distal CMAP showed a minimal decline in amplitude. Morphological observations showed splitting of myelin, especially in the paranodal regions, followed by accumulation of myelin debris in Schwann cells and macrophages. Although the exact mechanism remains unknown, this in vivo model provides a unique opportunity to study the electrophysiological and morphological correlates of an acutely evolving demyelinative process.
Nonlinear force addition of newly recruited motor units in the cat hindlimb
Authors: Clamann H. Peter , Schelhorn Teresa B.
Published: January 2005

The present experiments were designed to examine the interaction of simulaltaneoously active motor units. Pairs of medial gastrocnemius (MG) or soleus (Sol) units were stimulated individually and then together with constant frequency trains of 5–40 pulses per second. Stimulating two units asynchronously produced a smoother contraction than synchronous stimulation, but rarely a force increase. This contrasts with similar experiments on whole muscle bundles. A force increase may require that adjacent muscle fibers be active. The combined force to two motor units exceeded the algebraic sum of their separate forces by 12% in MG and 5% in Sol on average. The force a unit could sustain after a second unit fell silent was greater than the force the unit produced alone (21% in MG and 8% in Sol).

We conclude that motor units produce more force when interacting than alone. During derecruitment the units remaining active produce more force than when recruited.
Demyelination induced by intraneural injection of human antimyelin‐associated glycoprotein antibodies
Authors: Willison Hugh J. , Trapp Bruce D. , Bacher John D. , Dalakas Marinos C. , Griffin John W. , Quarles Richard H.
Published: January 2005

IgM monoclonal antibodies present in the sera from some patients with peripheral neuropathy react with an antigenic carbohydrate determinant that is present on the myelin‐associated glycoprotein (MAG) and other peripheral nerve glycoproteins and glycolipids. It is generally believed that the neuropathy in these patients may be caused by antibody‐ mediated nerve damage. Intraneural injection of serum from patients with this disease produced an extensive inflammatory, macrophage‐mediated demyelination of feline peripheral nerve. This only occurred with very fresh sera which had been supplemented with additional complement. Injection of sera from normal subjects failed to produce any demyelination. These results are in accordance with a recent study by Hays et al.13 and contradict earlier negative reports of similar studies. It is important to note that the pathology observed in these experimental studies bears little resemblance to that seen in the human neuropathy, and caution must therefore be exercised when interpreting this data in relation to the pathogenic mechanisms that might operate in the human disease.
Transient Lambert‐Eaton myasthenic syndrome associated with systemic lupus erythematosus
Authors: Bromberg Mark B. , Albers James W. , McCune W. Joseph
Published: January 2005

We present a patient who developed the Lambert–Eaton myasthenic syndrome (LEMS) in association with systemic lupus erythematosus (SLE). Severe proximal weakness with electrodiagnostic evidence of LEMS developed over 2 days during an exacerbation of cutaneous manifestations (bullous pemphigoid) associated with SLE. Following an increase in the daily dose of prednisone, there was complete clinical restitution of strength within 2 weeks and a slower resolution of electrodiagnostic abnormalities over 6 months. Marked serologic abnormalities were present at the onset and showed improvement over 6–8 months. LEMS had been infrequently described in association with SLE. The immunologic features of both SLE and LEMS suggest a linkage between the two diseases in this patient. We hypothesize that increased antibodies associated with exacerbation of SLE cross reacted with the neuromuscular junction membrane to produce LEMS.
Central core disease: Ultrastructure of the sarcoplasmic reticulum and T‐tubules
Authors: Hayashi Kazuko , Miller Rodman G. , Brownell A. Keith W.
Published: January 2005

The modified Golgi staining method was used to study the sarcoplasmic reticulum (SR) and t‐ tubules of skeletal muscle in central core disease. Significant pathological changes were documented in both of these organelles in seven patients. Pathological changes were seen in both core and non‐core regions, with the abnormalities being greatest in the cores. In noncore regions, distortions in the normal anatomy were minor. In cores, there was much more significant distortion of the normal anatomy and also an increase in the amount of SR and number of t‐tubules.
AAEE case report #18: Ulnar neuropathy in the distal forearm
Authors: Campbell William W.
Published: January 2005

A 66‐year‐old professional golf instructor developed pain, numbness, and weakness in an ulnar distribution, but the lesion could not be localized to either elbow or wrist by routine nerve conduction techniques. Stimulation along serial 1‐cm increments in the distal forearm disclosed a point of focal conduction block approximately 7 cm proximal to the ulnar styloid. At surgery, the flexor carpi ulnaris was enlarged, with muscle fibers extending all along the normally tendinous distal portion. A dense fibrovascular band coursed from the ulnar artery to the abnormal muscle, compressing the adjacent ulnar nerve. Intraoperative electroneurography precisely localized the area of conduction abnormality and helped identify the band as the compressing structure. Within 2 months following surgical decompression there was complete resolution of conduction block with excellent clinical recovery.
Org.2766 stimulates collateral sprouting in the soleus muscle of the rat following partial denervation
Authors: de Koning Paul , Verhaagen Joost , Sloot Willem , Jennekens Frans G. I. , Gispen Willem H.
Published: January 2005

The influence of melanocortins on the process of collateral sprouting has been investigated in rat soleus muscle. The soleus muscle was partially denervated by transecting and ligating the L5 mixed nerve. Collateral sprouting was assessed by means of isometric twitch tension measurements of soleus motor units that remained following L5 transection. The smaller the number of remaining soleus motor units, the larger the extent of collateral sprouting. Seven days following partial denervation, the index of sprouting (ratio between twitch tension of motor units in partly denervated muscles and in normal muscles) was significantly increased by treatment with the ACTH4–9 analog Org.2766 (1 μg/48 hours). This increase appeared to be present also 28 days following partial denervation. The electrophysiological results were confirmed by histological investigations. The results provide evidence that Org.2766 increases the motor neuron collateral sprouting capacity of peripheral nerve. Org.2766 did not induce muscle fiber hypertrophy.
SSEP and F‐wave studies in acute inflammatory demyelinating polyradiculoneuropathy
Authors: Gilmore Robin L. , Nelson Kevin R.
Published: January 2005

Somatosensory evoked potentials (SSEPs) and F‐wave responses were compared after tibial (PTN) and median (MN) nerve stimulation in patients with acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Nineteen patients were evaluated within 2 weeks of AIDP onset. Each had F‐wave and PTN‐SSEP studies; 18 had MN‐SSEP studies. Ten patients had absent or prolonged MN‐SSEP latencies, whereas 16 had abnormal MN F‐wave studies. Seventeen patients had an abnormal PTN‐SSEP while 12 had abnormal PTN F waves. Every patient with an abnormal MN‐SSEP also had an abnormal PTN‐SSEP. The most common PTN‐SSEP findings were an absent or prolonged latency of N8 or N22. All patients had either an abnormal MN F wave or PTN‐SSEP.
Regeneration of skeletal muscle fibers from autologous satellite cells multiplied in vitro. An experimental model for testing cultured cell myogenicity
Authors: Alameddine Hala S. , Dehaupas Michèle , Fardeau Michel
Published: January 2005

An experimental model used to test in vivo myogenicity of autologous satellite cells multiplied in vitro is described. Free muscle autotransplantation served as the basis and was combined with x‐irradiation. Administration of 1500, 2500, and 3500 rad doses 24 hours before or after ischemia showed that inhibition of spontaneous regeneration is dose dependent and more efficient when irradiation was applied before injury. A single dose of 2500 rad before injury resulted in the formation of a cystic structure ideal for cell implantation. FITC‐latex beads and/or carbocyanine dyes were internalized by mononucleated satellite cells in vitro. Labeling did not affect survival or development of these cells. No sign of marker release or spreading from labeled to unlabeled cells was detectable unless by the fusion process. These labels were retained for several weeks. Grafting of labeled dense cellular suspensions into x‐irradiated ischemic muscles indicated that satellite cells retain their myogenic characteristic and are able to reform fully differentiated muscle fibers.
Calf enlargement in hereditary motor and sensory neuropathy
Authors: de Visser Marianne , Hoogendijk Jessica E. , de Visser Bram W. Ongerboer , Verbeeten Bernhard J.
Published: January 2005

Six members originating from two families with hereditary motor and sensory neuropathy (hypertrophic and neuronal types) were noted to have enlarged calf muscles. Muscle computed tomography revealed that muscle enlargement in the propositus of the family with the hypertrophic type of HMSN was due to an increase in muscle and/or connective tissue. Computed tomography of the legs of the propositus of the family with the neuronal type of HMSN showed infiltration of the medial head of the gastrocnemius muscle by adipose tissue.
Dystrophin is localized to the plasma membrane of human skeletal muscle fibers by electron‐microscopic cytochemical study
Authors: Carpenter Stirling , Karpati George , Zubrzycka‐Gaarn Elizabeth , Bulman Dennis E. , Ray Peter N. , Worton Ronald G.
Published: January 2005

Electron‐microscopic immunoperoxidase technique revealed plasmalemmal localization of dystrophin in microscopically normal human skeletal muscle fibers obtained from nine routine diagnostic muscle biopsies. There was no evidence of periodicity of the immunoreactive product nor was there any evidence of immunostaining in any organelle besides the plasma membrane. Dystrophin appears to be a cytoskeletal protein associated with the plasmalemma. Its function is presumed to be the maintenance of the mechanical stability of the surface membrane so that it can withstand the normal contraction‐induced stresses without disruption.
The refractory period of transmission in patients with carpal tunnel syndrome
Authors: Gilliatt Roger W. , Meer Jacob
Published: January 2005

In patients with the carpal tunnel syndrome (CTS) and in control subjects, pairs of shocks at intervals of 0.8 msec and 1.0 msec were used to stimulate the median nerve just above the wrist. Nerve action potentials were recorded at the elbow and from the index or middle finger. In patients but not in controls, recordings from the finger frequently showed loss of the second action potential of the pair, although a second action potential was present at the elbow. In these cases it seemed likely that impulse transmission through the carpal tunnel had failed because the damaged nerve at the level of the lesion had an increased refractory period of transmission (RPT) compared with its refractory period under the stimulating cathode. The possible diagnostic use of RPT measurement in CTS patients is discussed.
Diagnostic and prognostic value of electrophysiologic tests in meralgia paresthetica
Authors: Lagueny Alain , Deliac Marie M. , Deliac Philippe , Durandeau Alain
Published: January 2005

Electrophysiologic diagnosis of unilateral meralgia paresthetica is usually assessed by side‐to‐side comparison of SNAP amplitudes, SNCVs, and SEP latencies following stimulation of lateral femoral cutaneous nerves. To determine the relevance for diagnosis of these tests and side‐to‐side comparison, the results were compared in patients with unilateral meralgia paresthetica and normal subjects. The long‐term outcome was also considered, in order to determine whether electrophysiologic findings contribute to the prognosis. In our study, SNAP amplitude comparison was found to be more useful for diagnosis than SNCV and SEP latency comparisons. However the value of the SNAP amplitude on the affected side, just as the results of the other tests, was not found to be predictive of the outcome. Also the results of the tests depend on the methods used and on the nerve's route.
Effect of dantrolene in duchenne muscular dystrophy
Authors: Bertorini Tulio E. , Palmieri Genaro M. A. , Griffin Judy , Igarashi Masanori , Hinton Abbie , Karas James G.
Published: January 2005

We have demonstrated that maneuvers capable of reducing Ca influx into cells have beneficial effects in dystrophic hamsters and Duchenne muscular dystrophy. Since dantrolene inhibits Ca release from the sarcoplasmic reticulum, its effects on DMD was studied in 7 patients of 6 to 13 years of age (mean 10.8 years). Patients were studied for 4 years with tri‐monthly evaluations of manual muscle testing (MMT), functional activity, and serum CK and aldolase. During the first 2‐year period, no medicines were given and served as control. In the second 2‐year period, dantfblene 8 mg/kg/d was administered. No side effects were observed. In 1 patient, mild, weakness occurred that disappeared when the dose was reduced to 6 mg/kg/d. The 95% confidence limit for the difference in slopes of regression lines from tri‐monthly MMT was asymmetric in favor of dantrolerte in 5 of 7 patients. Serum CK did not differ between the first and second year of the control and treatment periods, respectively. However, it fell significantly from the second year of control to the first year of treatment (P = 0.003). The fall during the first year of treatment was significantly greater (P <0.01) than in age‐matched natural history controls during the same length of observation. There was a 3‐fold reduction in CK when the pooled values of the first and second year control vs. treatment periods were analyzed. No changes were observed in functional activity and serum aidolase. The data suggest that dantrolene reduces serum CK in DMD associated with a lessening trend in MMT deterioration.
Involvement of thin afferents in carpal tunnel syndrome: Evaluated quantitatively by argon laser stimulation
Authors: Arendt‐Nielsen Lars , Gregersen Hans , Toft Egon , Bjerring Peter
Published: January 2005

The thin afferent nerves were tested quantitatively by determining the thresholds of warmth and pricking pain to argon laser stimulation and by measuring the brain potentials related to pricking pain. In 27 patients with electrophysiologically verified carpal tunnel syndrome these parameters were measured from fingers 3 and 5 on both hands. All patients had had sensory symptoms ranging from 3 months to 25 years. Both the thresholds were elevated (P <0.05) at finger 3 compared to measurements from finger 5, and compared to finger 3 in a group of 39 controls. Four patients with symptoms for more than 7 years had thresholds below the control values. The power of the pain‐evoked brain potentials elicited from finger 3 was lower (P <0.05) compared to finger 5, and compared to the control group (P <0.01). No correlations were found between the measured parameters and the clinical electrophysiological investigation. The findings support previous assumptions that chronic low‐force compressions cause impairment of intraneural microcirculation, and hence can affect the function of the thin afferents.
Nerve conduction studies in experimental non‐freezing cold injury: I. Local nerve cooling
Authors: Kennett Robin P. , Gilliatt Roger W.
Published: January 2005

In rabbits, the tibial nerve was exposed in the lower thigh under general anesthesia and cooled in a metal trough at 1 to 2°C or 5°C for 2, 3, or 4 hours. Nerve conduction studies showed local failure of conduction at the site of cooling which persisted after rewarming, and which was followed by distal degeneration of affected fibers. No persistent conduction block was seen. Changes in maximal velocity indicated that the fastest‐conducting motor and afferent axons had been preferentially affected. Histological finding in nerves examined at different intervals after cooling confirmed the physiological evidence of primary axonal damage, affecting particularly large diameter fibers. Paranodal demyelination was inconspicuous and restricted to regions just proximal to sites of axonal degeneration. No segmental demyelination was seen. These results clarify previous uncertainties as to the time‐course and distribution of nerve damage after local cooling at temperatures just above freezing point.
Variations in anatomy of the ulnar nerve at the cubital tunnel: Pitfalls in the diagnosis of ulnar neuropathy at the elbow
Authors: Campbell W. W. , Pridgeon R. M. , Riaz G. , Astruc J. , Sahni K. S.
Published: January 2005

Two processes account for most instances of ulnar neuropathy at the elbow: compression in the retroepicondylar groove, and compression by the humeroulnar aponeurotic arcade joining the two heads of the flexor carpi ulnaris. While conventional electrodiagnostic criteria may localize an ulnar neuropathy to the elbow, separating retroepicondylar compression from humeroulnar arcade compression is more difficult. In 130 cadaver elbows, we examined the relationships between the medial epicondyle, flexor carpi ulnaris, and ulnar nerve. The humeroulnar arcade lay from 3 to 20 mm distal to the medial epicondyle, the intramuscular course of the nerve through the flexor carpi ulnaris ranged from 18 to 70 mm, and the nerve exited the flexor carpi ulnaris 28 to 69 mm distal to the medial epicondyle. In 6 specimens, dense fibrous bands bridged directly between the medial epicondyle and the olecranon proximal to the cubital tunnel proper; accessory epitrochleoanconeus muscles were present in 14 specimens: both may cause ulnar neuropathy at the elbow. Anatomical variations may contribute to the difficulty in separating causes of ulnar neuropathy at the elbow.
Analysis of the organophosphate‐induced electromyographic response to repetitive nerve stimulation: Paradoxical response to edrophonium and D‐Tubocurarine
Authors: Maselli Ricardo A. , Soliven Betty C.
Published: January 2005

We studied the mechanism underlying acute organophosphate intoxication (OPI) through in‐vivo and in‐vitro electrophysiologic studies in rats injected with diisopropylfluorophosphate. Intoxicated rats showed weakness, repetitive compound muscle action potentials (CMAPs) in response to a single stimulus, and decremental response to repetitive nerve stimulation that was most pronounced at the second CMAP. The decrement was worsened with the administration of edrophonium, and was completely reversed by D‐tubocurarine. In‐vitro microelectrode studies showed no reduction in the amplitude of miniature endplate potentials (MEPPs) or in the quantal content of end‐plate potentials (EPPs). However, the half‐decay times of MEPPs and EPPs were significantly prolonged. Trains of stimuli induced sustained endplate depolarization via a “staircase phenomenon” of summation of prolonged EPPs, which was enhanced by edrophonium and abolished by D‐tubocurarine. These results indicate that sustained end‐plate depolarization can directly account for the decrement and weakness in acute OPI.
Scanning electron microscopic study of denervated and reinnervated intrafusal muscle fibers in rats
Authors: Dieler Ralf , Volker Anje , Schroder J. Michael
Published: January 2005

Isolated muscle spindles from lower lumbrical muscles of rats were used to study the 3‐dimensional organization of intrafusal structures by scanning electron microscopy following (a) complete denervation, (b) reinnervation after a single crush lesion of the sciatic nerve, or (c) reinnervation after transection and immediate suture of this nerve. One week after complete denervation, previous sites of intrafusal motor endplates were transformed into sarcolemmal ovoid bulges. These bulges persisted in denervated muscle spindles up to 12 weeks. Regenerated motor nerve endings were detected on intrafusal muscle fibers 1 month, and thereafter following sciatic nerve crush injuries, and 3 months and later following transection and suture of the nerve. Furthermore, 3 different types of subsynaptic areas of motor nerve terminals were observed. The scanning electron microscopic technique also allowed visualization of splitting and fusion of intrafusal muscle fibers. The findings are discussed in view of their possible functional implications.
Reversible conduction block in human ischemic neuropathy after ergotamine abuse
Authors: Hömberg Volker , Reiners Karlheinz , Toyka Klaus V.
Published: January 2005

Conduction block [a significant reduction in compound muscle action potential (CMAP) amplitude after proximal compared to distal stimulation] is often found in demyelinating neuropathies,6 including inflammatory neuropathies and degenerative neuropathies, such as “liability to pressure neuropathy.”5 There is experimental evidence that a transient conduction block can occur in rats after ischemic lesions of peripheral nerves are induced either by ligation of arterial vessels supplying nerve trunks,3,9 or by injection of arachidonic acid into peripheral arterial vessels.11,16 Conduction block has also recently been described in cases with necrotizing vasculitis.15 To date, however, no example of a reversible conduction block has been reported in human ischemic neuropathy.
Effect of clenbuterol on protease activitiies and protein levels in rat muscle
Authors: Mantle David , Delday Margaret I. , Maltin Charlotte A.
Published: January 2005

To elucidate the biochemical mechanism by which the sympathomimetic agent clenbuterol promotes skeletal muscle growth, We have determined the activity of a range of proteolytic enzyme types (acid, neutral and alkaline proteinases and peptidases), together with the levels of souble and structural proteins (via SDS‐polyacrylamide) in 5 inner‐vated and denervated muscle types from for any enzyme type in any muscle (in‐nervated or denervated) following clenbuterol treatment; however, one enzyme, arginyl aminopeptidase, showed a small but consistent decrease in acticvity in all of the innervated muscles investigated. Smilar fractionation muscle types (innervated or denervated) in control or clenbuterol‐treated animals, with the exception of one band (subunit molecular mass 18 kD). We conclude that the anabolic action of clenbuterol in promoting skeletal muscle growth does not occur via downregulation of protease activity, or increase in levels of individual muscle proteins.
Skeletal muscle regeneration after crush injury in dystrophic mdx mice: An autoradiographic study
Authors: Grounds Miranda D. , McGeachie John K.
Published: January 2005

The X‐linked dystrophic animal model, the mdx mouse, shows an extraordinary capacity for sustained muscle regeneration compared with X‐linked dystrophic golden retriever dogs and humans with Duchenne muscular dystrophy. To test the hypothesis that muscles of mdx mice might have inherently superior muscle regeneration to that in nondystrophic animals, muscle regeneration in response to a crush injury was examined in mdx mice and in the nondystrophic, parental strain C57Bl/10Sn. Autoradiographic techniques were used specifically to investigate the timing of muscle precursor replication after crush injury. Little difference in the regenerative capacity, either histologically or with respect to the timing of muscle precursor replication, was found between mdx mice and C57Bl/10Sn or other nondystrophic strains of mice.
Case‐of‐the‐month: Perineuritis presenting as mononeuritis multiplex
Authors: Simmons Zachary , Albers James W. , Sima Anders A. F.
Published: January 2005

Perineuritis unassociated with other significant pathological changes is a rare finding. A patient is described with mild, non‐insulin dependent diabetes mellitus who presented with the clinical picture of mononeuritis multiplex, and in whom perineuritis but no occlusive vascular disease was found on sural nerve biopsy. Treatment with prednisone and plasma exchange resulted in some improvement. We conclude that the focal perineuritis, rather than the diabetes, was responsible for the clinical picture mimicking mononeuritis multiplex. In conjunction with previous reports, this suggests that perineuritis may be a treatable neuropathy.
Case of the month: Germline mosaicism in carriers of duchenne muscular dystrophy
Authors: Prior T. W. , Papp A. C. , Snyder P. J. , Mendell J. R.
Published: January 2005

Carrier testing in a Duchenne muscular dystrophy (DMD) family resulted in the identification of a case of germline mosaicism. Using dystrophin cDNA probes, this phenomenon was ascertained by the demonstration of a deletion junction fragment present in the DNA of the affected patient and one sister but absent in the mother's DNA. As a result of this finding carrier risk estimations, based on restriction fragment length polymorphism (RFLP) of cDNA deletion carrier testing and the counseling implications of germline mosaicism. © 1992 John Wiley & Sons, Inc.
Effects of age, sex, and anthropometric factors on nerve conduction measures
Authors: Stetson Diana S. , Albers James W. , Silverstein Barbara A. , Wolfe Robert A.
Published: January 2005

Associations among measures of median, ulnar, and sural nerve conduction and age, skin temperature, sex, and anthropometric factors were evaluated in a population of 105 healthy, asymptomatic adults without occupational exposure to highly repetitive or forceful hand exertions. Height was negatively associated with sensory amplitude in all nerves tested (P < 0.001), and positively associated with median and ulnar sensory distal latencies (P < 0.01) and sural latency (P < 0.001). Index finger circumference was negatively associated with median and ulnar sensory amplitudes (P < 0.05). Sex, in isolation from highly correlated anthropometric factors such as height, was not found to be a significant predictor of median or ulnar nerve conduction measures. Equations using age, height, and finger circumference for prediction of normal values are presented. Failure to adjust normal nerve conduction values for these factors decreases the diagnostic specificity and sensitivity of the described measures, and may result in misclassification of individuals. © 1992 John Wiley & Sons, Inc.
Loss and renewal of thick myofilaments in glucocorticoid‐treated rat soleus after denervation and reinnervation
Authors: Massa Roberto , Carpenter Stirling , Holland Paul , Karpati George
Published: January 2005

Denervation of rat soleus muscle and simultaneous administration of high doses of corticosteroids for 7 days caused marked muscle fiber atrophy and selective loss of thick myofilaments from many muscle fibers by light and electron microscopy. Myosin heavy chain/ actin ratios were greatly reduced on polyacrylamide gel electrophoresis. Nerve crush instead of cut permitted reinnervation after 2 weeks and demonstrated the reversibility of the muscle changes within a week after reinnervation. There was formation of new thick filaments and their reintegration into myofibrils without further breakdown, although large areas of Z‐disc streaming appeared. The mechanism of A‐band breakdown remains obscure, but it presumably starts with limited proteolysis and continues with disaggregation of myosin molecules. This is consistent with our observation that the muscle fibers retain a relatively good reactivity to antibodies against myosin heavy chain 1 week after denervation and corticosteroid administration. A syndrome recalling these experiments is seen in severely asthmatic patients receiving corticosteroids and pharmacologically paralyzed for mechanical respiration. © 1992 John Wiley & Sons, Inc.
Turns‐amplitude analysis of the electromyographic recruitment pattern disregarding force measurement. I. Method and reference values in healthy subjects
Authors: Liguori Rocco , Dahl Kristian , Fuglsang‐Frederiksen Anders
Published: January 2005

We used turns‐amplitude analysis to characterize the EMG recruitment pattern disregarding force measurement. The electrical muscle pattern of the brachial biceps (BB), abductor pollicis brevis (APB), medial vastus (MV), and anterior tibial (AT) muscles was analyzed during progressive increase in force from rest to maximum using the mean amplitude as an indicator of the force of the muscle. The following parameters were obtained on‐line: the maximal ratio of turns to mean amplitude (peak‐ratio, PR), the mean amplitude, and the number of time intervals (Tl) between turns at PR and at near maximum force (NMF). The highest PR values were obtained in BB, the lowest in MV. Analysis of the distribution of the Tl between turns at different degrees of voluntary contraction showed fewer spikes with short duration and small amplitude at high force compared with low force. © 1992 John Wiley & Sons, Inc.
Non–reflex and reflex mediated ankle joint stiffness in multiple sclerosis patients with spasticity
Authors: Sinkjér Thomas , Toft Egon , Larsen Knud , Andreassen Steen , Hansen Hans J.
Published: January 2005

In this study, we have measured the passive, the intrinsic, and the reflexmediated mechanical response to stretch of the ankle extensors and flexors in 13 spastic multiple sclerosis patients and 10 healthy control subjects. In the ankle flexors, the patients had no reflex‐mediated stiffness. The passive stiffness was increased by 138% (95% confidence interval: 26–91%) and the intrinsic stiffness by 79% (41–158%) when compared with the healthy subjects. In the ankle extensors, the reflex‐mediated stiffness and the intrinsic stiffness of the patients were equal to the reflex‐mediated and the intrinsic stiffness in healthy subjects. The passive stiffness was increased by 152% (41–352%). We conclude that spastic muscles in multiple sclerosis patients have an increased non‐reflex stiffness (passive plus intrinsic stiffness), and that the reflex‐mediated stiffness in the extensors during a sustained voluntary contraction does not differ significantly from healthy subjects. © 1993 John Wiley & Sons, Inc.
Relationship between stimulus strength and the cutaneous silent period
Authors: Shefner Jeremy M. , Logigian Eric L.
Published: January 2005

During sustained muscle contraction, an interval of reduced activity follows an electrical cutaneous stimulus, called the cutaneous silent period (CSP). To evoke a CSP, a single stimulus must be painful. We used single sural nerve stimuli to evoke a CSP in ipsilateral soleus muscle, and studied the relationships between stimulus strength, sensory action potential (SAP) morphology, and subjective experience. Near nerve electrodes were employed to record the sural SAP in order to record activity in slower conducting fibers in addition to Aα fibers. In 6 normal subjects, the stimulus strength required to evoke a CSP ranged from 8 to 10 times threshold intensity. Pain threshold was slightly below that necessary to evoke the CSP. SAP shape changed with stimulus strength; main component amplitude occasionally increased as strength increased beyond 10 times threshold, and slowly conducting late components became more prominent. At stimulus intensities or at less than CSP threshold, components were seen conducting from 15–20 m/s that were not observed at lower intensities. We suggest that activation of sensory axons with conduction velocities in the range of Aδ fibers are necessary to evoke the CSP, and that their potentials can be discerned in the SAP. © 1993 John Wiley & Sons, Inc.
Skeletal muscle extract and nerve growth factor have developmentally regulated survival promoting effects on distinct populations of mammalian sensory neurons
Authors: Valmier Jean , Mallie Sylvie , Baldy‐Moulinier Michel
Published: January 2005

Neurotrophic factors appear to be relevant to the therapy of degenerative diseases as well as neural regeneration. In this respect, we have investigated the neurotrophic effects of skeletal muscle extract on DRG neuron survival by examining the survival and neurite outgrowth promoting activity of factor(s) present in skeletal muscle extracts (SME) on dissociated cultures of embryonic or early postnatal mouse dorsal root ganglion (DRG) sensory neurons. The numbers of surviving neurons resulting from SME addition increased continuously from embryonic day 13 (15%) to birth (55%), then decreased up to 7 days after hatching (0%). Preliminary characterization of the factor(s) present in SME suggests that the active molecule is a protein different from the known neurotrophic factors NGF, BDNF, NT3, CNTF, and bFGF, and that its neurotrophic effect is not mediated by direct interaction with the substratum. © 1993 John Wiley & Sons, Inc.