bluuebunny/crossref_metadata_2025_split huggingface dataset:
The neurophysiological profile of vitamin B12 deficiency
Authors: Fine Edward J. , Soria Emlllo , Paroski Margaret W. , Petryk Diane , Thomasula Linda 
Published: January 2005

AbstractReports of the incidence and severity of physiological abnormalities of vitamin B12 deficiency sharply differ. To resolve these controversies we performed evoked response and nerve conduction studies in 10 males with vitamin B12 deficiency. The minimum criteria for this diagnosis were diminished position and vibration sensation and vitamin B12 levels <220 pg/ml. We found normal BAERs in 9/10 patients. The central interpeak latencies of the median and peroneal SERs were abnormal in 4/10 and 818 patients, respectively. The VERs were abnormal in 7/10 patients. Wefound absent or diminished amplitudes of sural sensory and peroneal motor action potentials in 8/10 patients. Abnormal peroneal F response chronodispersion was present in 7/10 patients. Nerve conduction velocities (NCV) were normal in 9/10 patients. EMG demonstrated abnormalities consistent with denervation in lower extremity muscles in 8/10 patients. These studies present a profile of vitamin B12 deficiency: essentially normal BAERs, mildly abnormal VERs and median SERs, and markedly abnormal peroneal SERs. NCV studies are consistent with sensory‐motor axonopathy.
Edrophonium responsiveness not necessarily diagnostic of myasthenia gravis
Authors: Oh Shin J. , Cho Hyo K. 
Published: January 2005

AbstractUneqivocally positive edrophonium tests, both clinically and electrophysiologically, were observed in a classic case of the Lambert–Eaton myasthenic syndrome. A review of the literature revealed that a positive edrophonium response has been reported in a majority of cases of myasthenia gravis (MG) and overlap myasthenic syndrome and in some cases of the Lambert–Eaton myasthenic syndrome, botulism, congenital myasthenic syndrome, drug‐induced myasthenic syndrome, the Guillain‐Barre syndrome, and amyotrophic lateral sclerosis. From this, we conclude that anunequivocally positive edrophonium test alone is not necessarily diagnostic of MG and that the diagnosis of MG should be based on the clinical features together with edrophonium‐responsiveness and other laboratory findings.
Long‐duration polyphasic motor unit potentials in myopathies: A quantitative study with pathological correlation
Authors: Uncini Antonino , Lange Dale J. , Lovelace Robert E. , Solomon Murray , Hays Arthur P. 
Published: January 2005

AbstractIn most myopathies, the duration of motor unit action potentials (MUAPs) is shorter than normal. However, polyphasic MUAPs of duration longer than 20% of the control mean, (long‐duration polyphasic potentials, or LDPPs) may be seen. We therefore analyzed the incidence and meaning of LDPPs using quantitative MUAP analysis in 41 patients with different myopathies. The mean duration of all potentials was reduced in only 64% of patients because LDPPs increased the mean. When only simple potentials were considered, however, the mean duration was decreased in 95% of patients. This observation confirms the need to exclude LDPPs when calculating the mean duration of MUAPs for diagnosis. We found LDPPs most often in chronic polymyositis and in one patient with Becker Muscular Dystrophy. LDPPs are attributed to desynchronization of single‐fiber potentials within the MUAP and may be due to slow conduction in regenerating muscle fibers.
Twitch response in a myopathy with impaired relaxation but no myotonia
Authors: Quinlan John G. , Iaizzo Paul A. , Gronert Gerald A. , Lambert Edward H. 
Published: January 2005

AbstractA patient with slow muscle relaxation but without accompanying motor unit or myotonic electrical activity had a unique staircase twitch response to repeated nerve stimulation. During 1‐Hz stimulation, twitches recorded by measurement of the ankle dorsiflexor group displayed progressively increasing relaxation times with successive stimuli (37% increase) unlike the progressively decreasing relaxation time of the normal response (12–37% decrease). The response may be diagnostic of this unusual myopathy; the test methods are noninvasive and easily tolerated.
Electrophysiological and histological follow‐up study in 15 Friedreich's ataxia patients
Authors: Santoro Lucio , Perretti Anna , Crisci Claudio , Ragno Michele , Massini Riccardo , Filla Alessandro , De Michele Giuseppe , Caruso Giuseppe 
Published: January 2005

AbstractA clinical and electrophysiological follow‐up was carried out for 3 to 7 years on 15 patients with Friedreich's ataxia (FA). Sural nerve biopsy was performed once in all patients, and a second time 6–7 years later in three of them. Clinical worsening and progression of disturbance were evaluated according to IAP and IACR scales. Sensory orthodromic conduction along median and tibial nerves was typical of FA and did not change between first and last examinations, nor were there morphological changes between the first and the second sural nerve biopsies. Peripheral nerve involvement is thought to be a result of defective development of the largest neurons and to remain stable from a very early stage of the disease; the clinical worsening may then be due to a progressive involvement of the pyramidal tracts and the cerebellar pathways.
Serum parvalbumin, an indicator of muscle disease in murine dystrophy and myotonia
Authors: Jockusch Harald , Friedrich Gudrun , Zippel Monika 
Published: January 2005

AbstractThe soluble Ca++ ‐binding protein parvalbumin (PV) is highly concentrated in fast muscle fibers of the wild type mouse. Employing Sandwich ELISA, we have shown that PV is present in the serum of normal mice and that its level is indicative of the disease status of muscle. Elevated PV levels were found in mice with X‐linked dystrophy (mdx) and reduced levels in myotonic (ADR) mice. Serum creatine kinase (CK) levels were elevated in mdx and normal in ADR mice. Because myotonic mouse muscle has a strongly reduced PV content, the reduced PV serum levle in ADR mice indicated that serum PV is derived from skeletal muscle. Serum PV in mdx mice, in which muscle PV content is close to normal, is a measure of the necrosis of fast muscle fibers. Serum levels of PV and CK were not significantly elevated in heterozygous (mdx/+) carrier females. Serum PV in Duchenne patients was below the limit of detection.
The electrophysiologic profile of Dejerine–Sottas disease (HMSN III)
Authors: Benstead Timothy J. , Kuntz Nancy L. , Miller Robert G. , Daube Jasper R. 
Published: January 2005

AbstractElectrophysiologic studies in 11 patients with Dejerine‐Sottas disease (hereditary motor and sensory neuropathy type III, HMSN II) showed median and ulnar motor nerve conduction velocities less than 6 m/sec in all but 1 patient. Marked temporal dispersion without conduction block was present in all patients. Uniform slowing in adjacent motor nerves was consistent with other studies of inherited neuropathies, although marked temporal dispersion may make HMSN III more difficult to distinguish from acquired neuropathies than other hereditary conditions. The electrophysiologic features of HMSN III patients were significantly different from a series of patients with other hereditary neuropathies chosen because of very slow nerve conduction velocity.
To what extent is hindlimb suspension a model of disuse?
Authors: Michel Robin N. , Gardiner Phillip F. 
Published: January 2005

AbstractThe extent to which the remaining active or passive components of musclemechanical stress not associated with weightbearing are involved in preserving muscle morphological and functional characteristics in the rodent hindlimb suspension model is not known. Such information would be relevant to the construction of appropriate countermeasures for the disuse atrophy associated with muscle unloading. This question was addressed by superimposing 2 weeks of hindlimb suspension and neuromuscular quiescence, achieved by the chronic neural application of the sodium channel blocker tetrodotoxin. A major portion of the muscle size characteristics of the fast anti‐gravity gastrocnemius and plantaris, and the functional characteristics of the plantaris, were maintained by the full range voluntary activity remaining after suspension. Muscle mass of the slow soleus was compromised regardless of this residual activity. Indeed, for fast ankle extensors, hindlimb unloading resembles more closely a model of normal usage than of disuse, but forslow extensors this condition appears to be extremely detrimental.
Rats immunized with cholinergic synaptosomes: A model for Lambert‐Eaton syndrome
Authors: Chapman Joab , Rabinowitz Ruth , Korczyn Amos D. , Michaelson Daniel M. 
Published: January 2005

AbstractLambert‐Eaton myasthenic syndrome (LEMS) is an autoimmune disorder characterized by reduced acetylcholine release at the neuromuscular junction. We report a model of the disease developed by active immunization of rats with purely cholinergic nerve terminals (synaptosomes) isolated from the Torpedo electric organ. Electromyographic studies of neuromuscular transmission in these rats showed a weak initial response followed by a pronounced incremental response to paired supramaximal stimuli (8 msec apart). There was no such response in control rats. There was no evidence of a postsynaptic transmission deficit in the synaptosomes immunized rats. We conclude that immunizing rats with Torpedo cholinergic nerve terminals causes a specific presynaptic dysfunction and may serve as a model for the study of LEMS.
Critical review of gangliosides and thyrotropin‐releasing hormone in peripheral neuromuscular diseases
Authors: Bradley Walter G. 
Published: January 2005

AbstractThe lack of effectve therapy for many of the chronic neuromuscular diseases such as amyotrophic lateral sclerosis, hereditary motor sensory neuropathy (Charcot—Marie–Tooth disease), spinocerebellar degenerations and idiopathic polyneuropathy has led to a search for substances that may stimulate peripheral nerve regeneration. Two such agents that have been proposed are gangliosides (mixed purified bovine brain gangliosides, Cronassial) and thyrotropin releasing factor (TRH). Studies on both of these agents were initially reported with enthusiasm to be successful, but later double‐blind controlled studies have failed to confirm these findings. This review provides critical analysis of the designs of studies of potentially effective agents in chronic neuromuscular diseases, and emphasizes the power of the placebo response, and the importance of designing placebos which are indistinguishable from the trial medication other than in the active effect.
Expression of a fast fiber enzyme profile in the cat soleus after spinalization
Authors: Jiang Bian , Roy Roland R. , Edgerton V. Reggie 
Published: January 2005

AbstractThis study was designed to determine the effects of reduced neuromuscular activity on the expression of proteins associated with contractile and metabolic functions and the size of single muscle fibers in the cat soleus. Adult cats were spinalized (Sp) at T12‐T13 and maintained in a healthy condition for 6 months. Some of the cats were trained to weight‐support (Sp‐WS) for 30 minutes per day beginning one month posttransection. Cross‐sectional area (CSA), succinate dehydrogenase (SDH), alpha‐glycerophosphate dehydrogenase (GPD), and myofibrillar adenosine triphosphatase (ATPase) activities were determined in a population of single fibers identified in frozen serial cross‐sections. Each fiber was categorized as either light or dark based on its staining density for qualitative myosin ATPase, alkaline preincubation (pH 8.75). The Sp (45%) and Sp‐WS (31%) groups had significantly higher percentages of dark ATPase fibers than control (<1%). All dark ATPase fibers were shown to react positively for a fast myosin heavy chain monoclonal antibody, while some of these fibers showed a reaction to both fast and slow myosin heavy chain antibodies. Overall mean fiber CSA were significantly smaller (∼25%) than control in both Sp groups. In the Sp‐WS, but not the Sp cats, the dark fibers were larger than the light fibers (P < 0.05), suggesting a preferential effect of postural training on the ATPase converted fibers. There were no significant differences among the three groups in any of the mean enzyme activities for either ATPase type fiber. However, there was a general tendency for the Sp cats to have elevated GPD and ATP activities per muscle; this appeared to be directly related to the percentage of fibers staining darkly for myosin ATPase. These data indicate that 6 months after spinalization some of the fibers of the slow muscle developed fast myosin staining patterns and oxidative and glycolytic enzyme profiles that are normally exhibited in fast fatigue‐resistant motor units. Periods of daily weight‐support appear to ameliorate some of these adaptations to spinalization. Further, the observation that SDH activities are maintained at control values in spinalized adult cats as well as in spinalized kittens (unpublished observations) suggest that, at least in the soleus, skeletal muscle fibers can maintain their oxidative potential even though there is a marked reduction in neuromuscular activity for 6 months.
A review of techniques employed to estimate the number of motor units in a muscle
Authors: Slawnych Michael P. , Laszlo Charles A. , Hershler Cecil 
Published: January 2005

AbstractBeing the smallest functional units under neural control, motor units play an integral role in muscle physiology. However, at the present time, there does not exit any widely accepted technique for quantifying or estimating the number of motor units in a muscle. Specifically, the existing techniques are the increment‐counting technique, a technique based on spike‐triggered averaging, and a macro‐EMG based technique which vary in invasiveness from noninvasive to highly invasive, respectively. We discuss each of these techniques, along with their associated shortcomings, in detail.
Inhibition of motoneuron discharge by peripheral nerve stimulation: An f response analysis
Authors: Fisher Morris A. 
Published: January 2005

AbstractF waves were recorded from the abductor pollicis brevis stimulating the median nerve at the wrist. These data were compared to responses obtained after preceding supramaximal stimulation of digital fibers of the second (II) finger or the median nerve at the wrist. The time between conditioning and test stimuli were 50 msec. Following conditioning stimuli, F wave latencies were significantly increased while F amplitudes, durations, and persistences were all decreased. Chronodispersion was not significantly affected. These changes were associated with increased repetition of individual F responses. The most prominent changes were found after stimulation of fibers of digit II but only at levels of stimulation supramaximal for the sensory nerve action potential. Some, but relatively limited, changes were present after stimulation of digital fibers of the fifth finger. The results are consistrent with afferent fiber, probably A delta, inhibition of antidromic motoneuron activation with associated decrease in central motor neuron pool excitability. The study also demonstrates that, except for chronodispersion, changes in F waves found with peripheral nerve injury may also occur due to physiological changes in the central nervous system.
Expression of sodium channel subtypes during development in rat skeletal muscle
Authors: Schotland Donald L. , Fieles William , Barchi Robert L. 
Published: January 2005

AbstractThis study contrasts the developmental patterns of expression of 2 subtypes of the voltage‐dependent sodium channel in rat muscle that are differentiated by their immunoreactivity with monoclonal antibodies raised to the purified muscle sodium channel protein. One subtype is found in the transverse tubular (T) system of slow twitch fibers as well as the plasma membrane of fast and slow twitch fibers in the anterior tibial and soleus muscles. The second is present in the plasma membrane in all fibers of both muscles. The transverse tubular subtype exhibits 2 immunocytochemical staining patterns within muscle fibers, reticular and homogeneous, which may represent labeling of the developing T tubular system and of a cytoplasmic pool of alpha subunits of the sodium channel respectively. The reticular pattern eventually disappears in fast twitch fibers but persists into the adult stage in slow twitch fibers. The homogeneous pattern is also seen with antibodies to the plasma membrane subtype and disappears in early development as immunoreactivity to both subtypes gradually appears in the surface membrane. A reticular pattern is never seen with the plasma membrane subtype. The factors that modulate the expression of these subtypes is unknown.
AAEM case report #21: Hemifacial spasm: Preoperative diagnosis and intraoperative management
Authors: Harper C. Michel 
Published: January 2005

AbstractA 75‐year‐old man developed progressive involuntary hemifacial spasm. Electrophysiologic evidence of abnormal cross‐transmission between neurons of the facial nerve was demonstrated. Electrodiagnostic studies were used to confirm the diagnosis preoperatively and determine the adequacy of vascular decompression of the facial nerve intraoperatively.
Why are slow and fast muscles differentially affected during prenatal undernutrition?
Authors: Ward Stephanie S. , Stickland Neil C. 
Published: January 2005

AbstractThe biceps brachii and soleus muscles (fast and slow twitch muscles, respectively) were taken from guinea‐pig fetuses, undernourished via maternal dietary intake to 60% of ad lib, and examined for differences from their controls. At birth, muscle fiber number was found to be reduced by 26% in the biceps brachii but was unaltered in the soleus muscle. An examination of the muscles at ages through gestation revealed that any reduction in fiber number was associated with a reduction in the secondary/primary fiber ratio. There was a stage in soleus myogenesis at which fiber number was significantly lower than the control. The deficit was corrected by the continuation of secondary fiber hyperplasia beyond the time of usual cessation. A similar delay was found in the biceps brachii but it did not enable recovery to a full complement of fibers. The difference between the 2 muscles was thought to be related to the relative proportions of primary fibers in the muscles, primary fiber development being apparently unaffected by undernutrition in utero.
Midbrain vs. pontine medial longitudinal fasciculus lesions: The utilization of masseter and blink reflexes
Authors: Hopf H. C. , Thömke F. , Gutmann L. 
Published: January 2005

AbstractMasseter (MR) and blink reflexes (BL) were investigated in 51 patients with internuclear ophthalmoplegia (INO) due to multiple sclerosis (28) and lacunar infarction (23). The MR was abnormal in 20 of 23 cases with bilateral INO and in 21 of 28 with unilateral INO. The R1 component of the BL (BL‐R1) was abnormal in 7 of 23 patients with bilateral INO and 10 of 28 with unilateral INO. Combined MR and BL‐R1 changes occurred in 8 of 28 cases with unilateral INO and 7 of 23 with bilateral INO. The findings provide evidence for a rostral/caudal localization of lesions within the medial longitudinal fasciculus causing INO on the basis of MR and BL‐R1 abnormalities. An abnormality limited to MR suggests a midbrain location in 58.8% of patients while abnormal BL‐R1 with or without an associated MR change suggests a rostral pontine location in 35.3%.
Myofibrillar disruption in the rabbit soleus muscle after one‐week hindlimb suspension
Authors: Anzil Archinto P. , Sancesario Giuseppe , Massa Roberto , Bernardi Giorgio 
Published: January 2005

AbstractRelevant muscle‐ and species‐specific differences may be found in the reaction of muscles to hindlimb suspension. This problem has been studied in 5 rabbits following a one‐week hindlimb suspension, and in 5 ground‐based controls. The soleus and the tibialis were prepared for light and transmission electron microscopy. In suspension the animals occasionally extended and flexed the hindlimbs, but, when standing still, their hindfeet were plantar‐flexed to an angle of 180°. In this position the length of the soleus was determined to be 35% less than in controls, whereas that of the tibialis was 30% more. Histologically, the tibialis fibers usually exhibited a preserved sarcomeric pattern, whereas soleus fibers displayed a regular sequence of areas of shortened sarcomeres, alternating with areas of myofibrillar disruption. These findings demonstrated that hindlimb suspension induces a focal breakdown of the soleus myofibrils, probably dependent on the reduced longitudinal tension of the suspended soleus and its phasic contractions against no load. It is conceivable that similar factors could also be responsible for soieus muscle atrophy induced by hypogravity as well as by other clinical conditions during which a stressful plantar flexion of the feet occurs against no load.
Basal lamina and superfast myosin expression in regenerating cat jaw muscle
Authors: Hoh Joseph F. Y. , Hughes Suzanne 
Published: January 2005

AbstractWe investigated the possible role of extracellular matrix in specifying the expression of superfast myosin during cat jaw muscle regeneration. Equal proportions of muscle tissue from jaw and limb were minced together after killing cellular elements from one source. We allowed the mince to regenerate in the bed of a fast limb muscle. Regenerates were analyzed immunocytochemically at 71 to 294 days after operation. Fibers in control regenerates containing live cells from both sources expressed fast, superfast or slow myosins, or a mixture of these myosins. In regenerates containing only one type of live cells, we detected only myosins appropriate to the live cells. Our results suggest that during regeneration the original extracellular matrix of jaw‐closing or limb muscle is unable to specify the expression of superfast or fast myosins, respectively; they point to the cellular elements, probably the satellite cells, as determinants of muscle specificity during regeneration.
Correlation of motor units with strength and spectral characteristics in polio survivors and controls
Authors: Rodriquez Arthur A. , Agre James C. 
Published: January 2005

AbstractThe purpose of this study was to determine whether quantitative motor unit analysis in postpolio individuals correlates with muscle strength, endurance, work capacity, or power spectral characteristics of surface EMG and to determine whether power spectrum differentiates postpolio from control subjects. This study was designed to compare these variables in 34 symptomatic postpolio, 16 asymptomatic postpolio, and 41 control subjects. Quantitative motor unit analysis of the quadriceps femoris muscle was performed using a concentric needle electrode. Isometric knee extension peak torque, endurance (time to exhaustion) at 40% of maximal torque, work capacity (tension time index), and recovery of force through 10 minutes postexhaustion were determined. Median frequency of the surface power spectrum was determined during the above testing. Power spectrum histograms were compared at the onset and termination of endurance exercise. Motor unit action potential variables did not correlate with isometric peak torque, tension time index, endurance time, recovery of strength, or with median frequency. Surface power spectrum did not differentiate postpolio from control subjects.