bluuebunny/crossref_metadata_2025 huggingface dataset:
Neuroleptic malignant‐like syndrome induced by metoclopramide
Authors: Samie M. Reza
Published: January 2005

A prompt recognition of neuroleptic malignant‐like syndrome is essential because of its high morbidity and mortality. A similar condition is described associated with metoclopramide, an agent with dopamine receptorblocking properties. An increased index of suspicion for early diagnosis of this condition and adjustment of metoclopramide dosing in patients with renal failure are emphasized.
Blepharospasm accompanying hypoxic encephalopathy
Authors: Palakurthy Prasad R. , Iyer Vasudeva
Published: January 2005

Severe bilateral blepharospasm with left hemiplegia occurred in a 50‐year‐old woman, who developed cardiac arrest following ventricular aneurysmectomy. The blepharospasm was present constantly, even during sleep, and increased during attempts at voluntary eye opening. CT scan revealed multiple hypodense areas involving basal ganglia bilaterally and the right perisylvian area. The blepharospasm improved gradually over a 6‐month period, although the left hemiplegia remained unchanged.
PHNO, a novel dopamine agonist, in animal models of parkinsonism
Authors: Koller William , Herbster Gregory , Gordon John
Published: January 2005

PHNO, a naphthoxazine compound, was investigated in animal models of central dopaminergic activity. The drug in doses of 5–300μg/kg when administered subcutaneously, or transdermally, induced stereotypic behavior in rats which was blocked by haloperidol but not by reserpine pretreatment. In rats with unilateral 6‐hydroxydopamine lesions of the substania nigra PHNO induced dose‐dependent contralateral turnings. The drug caused emesis in dogs and hypothermia in mice. PHNO bound to D‐2 dopamine receptors in the rat striatum. Chronic injection with PHNO did not induce behavioral super‐sensitivity of increase dopamine receptor density. These data indicate that PHNO is a direct acting dopamine agonist that is highly potent. PHNO differs from other dopaminergic drugs and may be useful in the treatment of Parkinson's disease.
A double‐blind evaluation of ciladopa in Parkinson's disease
Authors: Weiner William J. , Factor Stewart A. , Sanchez‐Ramos Juan , Berger Joseph
Published: January 2005

We evaluated 32 patients with Parkinson's disease in a double‐blind, parallel group, placebo‐controlled study with ciladopa (a troponylpiperazine derivative). The dosages administered were 5 mg b.i.d. and 15 mg b.i.d. Significant improvement was found in the gait scores and in the total disability scores in the high dose group (p<0.05). In addition, there was a trend toward improvement, though not significant, in the bradykinesia and rigidity scores in the high dose group and in the disability scores in the low dose group. Four patients in the low dose group and five patients in the high dose group decreased their Sinemet doses while no patients increased their Sinemet dose. There were no adverse effects observed in this study. These findings suggest that ciladopa may be an efficacious agent in Parkinson's disease. The low incidence of adverse effects with this agent suggests that higher doses may be utilized and may prove to be more effective.
Levodopa‐induced regional cerebral blood flow changes in normal volunteers and patients with Parkinson's disease
Authors: Montastruc J. L. , Celsis P. , Agniel A. , Demonet J. F. , Doyon B. , Puel M. , Marc‐Vergnes J. P. , Rascol A.
Published: January 2005

Single photon emission computed tomography was used to measure regional cerebral blood flow in six normal subjects and 12 patients with Parkinson's disease, before and after acute oral administration of levodopa. The drug induced a significant increase in cerebral blood flow both in controls and patients. Before levodopa, there was no significant difference between the groups, either in flow values or in their pattern. The clinical effects of levodopa were not related to the hemodynamic changes. The results suggest that measuring the flow response to levodopa is not appropriate to demonstrate variations in central dopaminergic receptor sensitivity in man.
The effect of intracerebroventricular infusion of (+)‐4‐propyl‐9‐hydroxynapthoxacine (PHNO) through a totally implanted drug delivery system in rats with dopamine deficiency
Authors: de Yebenes Justo G. , Fahn Stanley , Jackson‐Lewis Vernice , Mena Maria Angeles
Published: January 2005

Rats with experimentally induced DA deficiency were trated with intracerebroventricular administration of (+)‐4‐propyl‐9‐hydroxynaphthoxacine (PHNO) through a totally implanted chronic delivery system which delivered PHNO, 0.9μg/h, continuously for up to 2 weeks. Rats with 6‐OH‐DA induced unilateral nigrostriatal lesion showed, after PHNO infusion, a potent and persistent contralateral turning behavior (8–11 turns/min) which was not present in vehicle‐infused animals. The intensity of spontaneous and apomorphine‐induced rotation did not decrease after 2 weeks of continuous infusion, suggesting that tolerance to PHNO or to other dopamine agonists did not develop. The magnitude of the spontaneous turning behavior in PHNO‐infused animals correlated well with the baseline response to apomorphine (r = 0.505, p < 0.025). Rats implanted with pumps delivering PHNO or vehicle were treated with reserpine, 0.5 mg/kg/day for 14 days. Vehicle‐infused, reserpinized animals had a severe akinesia and weight loss during the experimental period (motor activity, measured in counts per minute was reduced to 5–10% of baseline levels, and body weight to 50% of baseline levels). PHNO‐infusion partially restored activity to 60% of baseline counts and reduced the severity of weight loss. PHNO effects were observed for as long as the infusion was maintained. No side effects were observed. Intracerebroventricular infusion of PHNO may be an alternative experimental approach to untreatable motor fluctutations in Parkinson's disease.
Torticollis following radiation therapy
Authors: Landan Ivan , Cullis Paul A.
Published: January 2005

A patient with adenocarcinoma in the apical portion of the lung producing a Pancoast's syndrome developed torticollis a few months after receiving a course of radiation therapy (5,040 rad) to his upper chest and neck. We describe this case, in which local radiation fibrosis of the neck muscles and perhaps segmental demyelination of the 11th cranial nerve resulted in peripheral nervous system lesion causing torticollis.
The effect of carbidopa on plasma and muscle levels of L‐dopa, dopamine, and their metabolites following L‐dopa administration to rats
Authors: Rose S. , Jenner P. , Marsden C. D.
Published: January 2005

Administration of L‐dopa (L, 4‐dihydroxyphenylalanine) (200mg/kg p.o.) to rats produced elevated plasma and muscle concentrations of both L‐dopa and 3‐O‐methyldopa (3‐OMD). This effect was potentiated by simultaneous administration of carbidopa (25 mg/kg p.o.) both L‐dopa and 3‐OMD accumulated in muscle after administration of L‐dopa with or without carbidopa. Elevated dopamine levels were detected in both muscle and plasma after treatment with L‐dopa alone. Concurrent administration of carbidopa only diminished dopamine levels in plasma, and the duration of raised dopamine levels in muscle was increased. Carbidopa administration had no effect on the elevated plasma concentrations of 3,4‐dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) caused by L‐dopa administration. In muscle, carbidopa treatment tended to prolong the duration of raised metabolite levels. Muscle appears to accumulate L‐dopa at a site where decarboxylation is not totally prevented by concurrent carbidopa administration, and where dopamine is not degraded as actively as in other tissues. The muscle sink for L‐dopa may influence the plasma profile of the amino acid, which has implications for the therapeutic response to L‐dopa in Parkinson's disease.
Chorea and dystonia: A remote effect of carcinoma
Authors: Albin Roger L. , Bromberg Mark B. , Penney John B. , Knapp Robert
Published: January 2005

A 45‐year‐old women with an acquired multifocal neurologic syndrome, including chorea, dystonia, cerebellar dysfunction, multiple cranial neuropathies, and pure sensory neuropathy, was found at autopsy to have oat cell carcinoma. Neuropathologic examination revealed serveral features typically associated with remote effects of malignancy on the nervous system. We believe that this is the first described case of chorea as a remote effect of malignancy.
Decrease of serotonin‐S2 receptors in temporal cortex of patients with Parkinson's disease and progressive supranuclear palsy
Authors: Maloteaux J. M. , Laterre E. C. , Laduron P. M. , Javoy‐Agid F. , Agid Y.
Published: January 2005

The number of serotonin‐S2 receptors was decreased in the temporal cortex of patients with Parkinson's disease and progressive supranuclear palsy (PSP). There was no significant modification of these receptors in the frontal cortex or in the hippocampus and putamne in both diseases. The decrease in mumber of receptors in PSP was unexpected, because the cerebral cortex is thought to be spared in this disease. There was no correlation between the decrease in number of serotonin‐S2 receptors and the degree of dementia in Parkinson's disease, suggesting that these receptors are not directly involved in the deterioration of cognitive functions.
Correlation between facial involuntary movements and abnormalities of blink and corneal reflexes in Huntington's chorea
Authors: Agostino R. , Berardelli A. , Cruccu G. , Pauletti G. , Stocchi F. , Manfredi M.
Published: January 2005

Blink and corneal reflexes were studied in 11 patients with Huntington's chorea and the results compared with the severity of the disease. The latency of the R2 component of the blink reflex was delayed and the duration of R2 and of the corneal reflex (CR) prolonged. A greater habituation of the R2 component was found in the patients with involuntary movements in the face, and in some patients a long‐lasting depression of R2 was present. A correlation was found between: (a) severity of involuntary face movements and R2 and CR latency and (b) severity of involuntary movements in the neck and latency of R2.
Comparison between L‐Dopa and lisuride intravenous infusions: A clinical study
Authors: Ruggieri Stefano , Stocchi Fabrizio , Carta Angelico , Bravi Daniele , Bragoni Maura , Giorgi Luigi , Agnoli Alessandro
Published: January 2005

L‐Dopa is still the most effective drug for the treatment of Parkinson's Disease, but after 5 years or more of therapy fluctuations in motor performance and abnormal involuntary movements commonly appear. Continuous intravenous infusions of L‐Dopa abolish or strikingly reduce such fluctuations. Unfortunately, this is not suitable for daily treatment because of the low solubility of L‐Dopa. Lisuride is a potent dopamine agonist and is very soluble in water. In this study the clinical effects of L‐Dopa and lisuride continuous intravenous infusions were compared in a group of 20 fluctuating parkinsonian patients L‐Dopa controlled fluctuations in almost all the subjects, whereas only seven patients were continuously mobile while taking lisuride. Another seven patients showed a fluctuating response and the remaining six did not satisfactorily respond to lisuride. Dyskinesias were present in all patients during “on” phases, with both levodopa and lisuride treatment.
Dopamine and memory function in Parkinson's disease
Authors: Mohr Erich , Fabbrini Giovanni , Williams Jill , Schlegel Jerry , Cox Christiane , Fedio Paul , Chase Thomas N.
Published: January 2005

Response fluctuations in motor function, complicating long‐term dopaminomimetic therapy of Parkinson's disease, may extend to the cognitive realm. To evaluate the effect of levodopa treatment both on attention as well as acquisition and retrieval of memory tasks, parkinsonian patients were examined neuropsychologically both while medicated with levodopa/carbidopa (“on”) and when the medication's antiparkinsonian effect had worn off (“off”). Significant cognitive differences emerged only on the delayed recall of complex verbal materials, where patients when “on” performed better compared with their “off” state. Comparison of change scores across states (administration or withholding of levodopa/carbidopa between acquisition and retrieval, “off” to “on” to “off”), revealed no substantial differences as a function of dopaminomimetic therapy. These results support the view that slight changes in cognition are associated with dopaminomimetic therapy of Parkinson's disease, but that these changes may be task‐specific.
Volitional control of involuntary movements
Authors: Koller William C. , Biary Nabil M.
Published: January 2005

Voluntary suppressibility of abnormal movements is helpful in the classification of movement disorders because this ability appears to be a common component of tics. However, there has been no systematic study of voluntary suppressibility in other movement disorders. We have therefore assessed 146 patients with tremors and dyskinetic disorders as to their ability to suppress movements by mental concentration. Patients were videotaped while trying to stop their movements, and the length of time they could suppress their abnormal movements was recorded. One hundred percent (10 of 10) of patients with tics could suppress movements for an average of 2.5 min. Two percent (1 of 50) of essential tremor patients could suppress the tremor, and the tremor of 24% (12 of 50) was made worse by mental concentration. Eighty percent (4 of 5) of neuroleptic‐induced tremor could be improved mentally. Seventy percent (35 of 50) of patients with parkinsonian tremor could voluntarily diminish their tremor for an average of 48 s. Fifty percent (8 of 16) of chorea (tardive dyskinesia, Huntington's disease, postencephalitic) was reduced. Dystonia was suppressible in 20% (3 of 15). It is concluded that movement disorders besides tics can be voluntarily suppressed and that suppressibility should not be used to classify movement disorders. Tics, however, are easier to suppress and can be suppressed for a longer time.
CQP 201‐403 in Parkinson's disease: An open‐label pilot study
Authors: Pfeiffer Ronald F. , Herrera Leonel H. , Glaeske Carolyn S. , Hofman Ruth E.
Published: January 2005

The dopamine agonist, CQP 201–403, was administered to 10 patients in an open label fashion with rapid dosage escalation during hospitalization. Assessed over an average of 20 days, significant improvement occurred in bradykinesia, rigidity, and postural instability. Tremor did not occur in sufficient frequency in this group of patients to be accurately assessed. The most serious adverse effect encountered was prolonged confusion with psychosis. This study suggests that CQP 201‐403 may be of value in the treatment of Parkinson's disease.
Induction of chorea and dystonia in parkinsonian primates
Authors: Boyce S. , Clarke C. E. , Luquin R. , Peggs D. , Robertson R. G. , Mitchell I. J. , Sambrook M. A. , Crossman A. R.
Published: January 2005

Administration of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine in primates induced a parkinsonian syndrome that could be reversed by levodopa treatment. Animals quickly developed an apparent restlessness (“akathisia”) of the lower limbs after as little as five doses. After 4–10 weeks of regular levodopa therapy, animals developed “peak dose” choreiform movements in the lower limbs that spread, with time, to involve the upper limbs and orofacial musculature. With further treatment (5–21 months), animals developed “peak dose” dystonia that variably involved the limbs and orofacial musculature. These conditions represent novel models of levodopa‐induced chorea and dystonia in humans. They depend on the same underlying neuropathology and treatment regimen as their human counterparts. It is to be anticipated that these models of dyskinesia will be useful in determining the mechanisms underlying chorea and dystonia in humans and are ideally suited for experimental evaluation of new treatment strategies.
Neural mechanisms of dystonia: Evidence from a 2‐deoxyglucose uptake study in a primate model of dopamine agonist‐induced dystonia
Authors: Mitchell I. J. , Luquin R. , Boyce S. , Clarke C. E. , Robertson R. G. , Sambrook M. A. , Crossman A. R.
Published: January 2005

The neural mechanisms that mediate dystonia were investigated in a novel experimental primate model of dopamine agonist‐induced dystonia. This condition was produced by long‐term (15 months) dopamine agonist therapy of a macaque monkey that had been rendered hemiparkinsonian by unilateral infusion of 1–methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine into the right common carotid artery. The 2–deoxyglucose (2–DG) metabolic mapping technique was applied to the animal during the expression of active unilateral dystonia, and regional brain uptake of 2–DG was assessed autoradiographically. The results demonstrate that dystonia is associated with marked increases in 2–DG uptake in the constituent nuclei of the basal ganglia (caudate nucleus, putamen, medial and lateral segments of the globus pallidus) and in the subthalamic nucleus, but decreased uptake in the structures that receive output of the basal ganglia (ventral anterior/ventral lateral thalamic complex and lateral habenula). Based on these findings it is suggested that dystonia is characterized by increased activity in the putaminopallidal and pallidosubthalamic pathways, and decreased activity in the subthalamopallidal and pallidothalamic pathways.
Cortical mechanisms mediating asterixis
Authors: Artieda J. , Muruzabal J. , Larumbe R. , de Casasola C. García , Obeso José A.
Published: January 2005

We describe a patient with chronic renal failure who suffered multifocal action‐induced jerks. Electromyography (EMG) recorded the typical silence of asterixis. Back‐averaging the EEG activity preceding the EMG silent periods in the forearm showed a biphasic wave antedating the asterixis by 23 ms. Somatosensory evoked potentials (SEPs) after median nerve stimulation were pathologically enlarged on both hemispheres. Brain‐mapping of the biphasic wave preceding asterixis and the giant SEPs indicated a common origin in the sensorimotor cortex. This observation provides further documentation of a cortical origin for some types of asterixis in humans.
Choreoathetosis in acquired immune deficiency syndrome patients with cerebral toxoplasmosis
Authors: Maggi P. , de Mari M. , De Blasi R. , Arminise S. , Romanelli C. , Andreula C. , Zimatore G. , Angarano G.
Published: January 2005

The aim of our study was to evaluate both the incidence and the pathologic and clinical features of extrapyramidal disorders in a population of acquired immune deficiency syndrome (AIDS) patients with cerebral toxoplasmosis. Of 240 AIDS patients evaluated in the 1985–1994 period, 50 of them were diagnosed to have cerebral toxoplasmosis on the basis of the following criteria: occurrence of specific antibodies, computed tomography and/or magnetic resonance imaging (MRI), and regression of the symptoms after specific therapy. Three of 50 (6%) had hemichoreoathetosis. In the first case, the disorder began as a dyskinesia of the left hand that subsequently spread to the whole ipsilateral arm and assumed the features of choretic athetotic movements. The other two cases were characterized by left hemisomatic distal choreic movements. Therapy with pyrimethamine and sulfadiazine led to a complete recovery of the extrapyramidal signs in two cases and to improvement in the third. According to our observations, the onset of these movement disorders could not be related to the dimension of the lesion or to the edema, but to a specific localization in subthalamic nucleus, in subthalamic/pallidal, and pallidal/thalamic pathways. MRI seems the elective tool to perform a more accurate study of the anatomic areas involved in this pathway and to verify their integrity. Cerebral toxoplasmosis in AIDS can be considered as a new etiopathogenic cause of choreoathetosis.
Adult‐onset acid maltase deficiency: A postmortem study
Authors: Dimauro Salvatore , Stern Lawrence Z. , Mehler Mark , Nagle Raymond B. , Payne Claire
Published: January 2005

In a postmortem study of a patient with adult‐onset acid maltase deficiency (AMD), morphological abnormalities were confined to skeletal muscle and consisted of a vacuolar myopathy. Acid maltase activity, however, was approximately 6% of normal in muscle, liver, and brain, and 3% of normal in heart. Kinetic characteristics, and inhibition by antibodies and Zn++, showed that the residual activity was “authentic” acid maltase. Neutral maltase activity was normal in muscle and liver, but decreased in brain (55% of normal) and heart (19% of normal). Although the relative decrease of acid maltase was similar in different tissues, absolute residual activity was lowest in skeletal muscle: this may explain the selective involvement of this tissue in late‐onset AMD.
Sural nerve conduction study in the rat: A new technique for studying experimental neuropathies
Authors: DeJesus C. P. V. , Towfighi J. , Snyder D. R.
Published: January 2005

An electrophysiologic technique for studying sensory fibers in the rat sural nerve is described. The conduction velocity of the sural nerve in rats is much slower than in humans, probably because of the lack of large myelinated nerve fibers in rats. An experimental neuropathy (induced by hexachlorophene) that predominantly causes a myelin disorder produced a slowing of sural nerve conduction velocity and a potential of normal amplitude and duration. An experimental neuropathy (induced by zinc pyrithione) that primarily causes axonal degeneration produced a sensory potential of lower amplitude and shorter duration that had a normal conduction velocity.
Myasthenia gravis: Review of diagnosis and management
Authors: Patten Bernard M.
Published: January 2005

Although the cause of myasthenia gravis is still unknown, its pathogenesis appears clear: immunologic attack on synaptic receptors in muscle causes receptor deficiency, decreased miniature endplate potentials, and decrements in the compound action potentials evoked from muscles on repetitive stimulation of peripheral nerves. In addition to the involvement of skeletal muscle, some MG patients may manifest subtle alterations of the function of heart, lung, smooth muscle, and CNS, indicating that this is truly a systemic disorder. Modern therapy involves adjusting treatment to the needs of individual patients. Anticholinesterases, calcium, ephedrine, potassium, and germine partially correct the defect in neuromuscular transmission; prednisone, ACTH, cytotoxic drugs, antilymphocyte serums, gamma globulin, thoracic duct drainage, plasmapheresis, and thymectomy partially modify the abnormalities of the immune system.
Isometric tension from rotary stimulation of fast and slow cat muscles
Authors: Lind Alexander R. , Scott Petrofsky Jerrold
Published: January 2005

In cats anesthetized with α‐chloralose, different populations of motor units in soleus, plantaris, and medial gastrocnemius muscles were stimulated in rotation through surgically divided groups of ventral roots. As a result, smooth muscular contractions were obtained at low frequencies of rotary stimulation, and maximal tetanic tensions were induced at frequencies within the upper range of voluntary contractions. The frequencies necessary to induce maximal tetanic contractions were lower for slow‐twitch muscles than for fast‐twitch muscles. It is speculated that the primary benefit resulting from asynchronous stimulation of the muscles is in the engagement of the tendon, which permits motor units to exert their tension without having to overcome a major portion of the elastic damping.
Actin‐containing microprocesses in the fusion of cultured chick myoblasts
Authors: Huang Helena L. , Singer Robert H. , Lazarides Elias
Published: January 2005

Scanning electron microscopic studies of myoblasts from 11‐to 13‐day‐old chick embryonic breast muscle cultred on collagen‐coated glass coverslips showed six stages of development into multinucleated myotubes: (1) growth of flattened, spread‐out cells for 20–30 hr following initiation of monolayer cultures; (2) extension of microprocesses (1–150 μm) from cells that have become spindle shaped; (3) contact and adherence of microprocesses from adjacent cells; (4) thickening of fused processes; (5) approximation of the cells; and (6) coalescence of the cells to form a spindle‐shaped myotube. When the calcium‐ion concentration in the growth medium was lowered‐either by increasing the concentration of ethylene‐glycol‐bis (aminoethyl ether) N, N'‐tetraacetate (EGTA) or by decresing the concentration of free calcium ion used‐the number of microprocesses present on the cells was reduced. Presumably, however, these microprocesses could still fuse together, provided that the calciumion concentration was greater than 160 μM. Indirect immunofluorescence assay with actin‐specific antibody indicated that actin is a major component of the myoblasts' microprocesses. Cytochalasin B (5μg/ml) caused the microprocesses to retract within 15 min and the myoblasts to round up and detach from the glass substrate. This was presumably caused by the action of the drug on actin filaments.
The entrapment neuropathies
Authors: Nakano Kenneth K.
Published: January 2005

This article discusses various entrapment neuropathies as well as their clinical features and treatment. In most patients with compression neuropathies, diagnosis and therapy can be effected early if a careful neurologic examination as well as x‐ray and electrodiagnostic (EMG and nerve conduction) studies are performed when the patient initially presents with symptoms.
Late‐onset X‐linked recessive spinal and bulbar muscular atrophy
Authors: Ringel Steven P. , Lava Neil S. , Treihaft Marc M. , Lubs Mary L. , Lubs Herbert A.
Published: January 2005

A family is described in which five males have late‐onset facial weakness, dysarthria, dysphagia, and slowly progressive proximal weakness. Electrodiagnostic studies and muscle biopsy were compatible with spinal muscular atrophy. This family appears quite similar to several previously reported families with late‐onset X‐linked recessive spinal and bulbar muscular atrophy. Because of the relative homogeneity of this particular phenotype of spinal muscular atrophy, a single metabolic derangement was sought. Three obligate carriers were studied, and no abnormality was detected. A further family with this condition is briefly discussed.
On the occurrence of striated muscle within the spinal leptomeninges
Authors: Lipow Kenneth , Horoupian Dikran S. , Raine Cedric S.
Published: January 2005

A clinically normal adult male rabbit was found to possess fascicles of muscle fibers within the leptomeninges over the spinal cord at L6, L7, and S1. The finding is believed to be purely incidental and unrelated to any experimental procedure. Morphologically, the fascicles had the characteristics of striated muscle; and, while most were of normal dimensions, several were made up of small fibers 4–10 μm in diameter. Motor endplates, capillaries, and endomysial and perimysial connective tissue were also present. Axons myelinated by Schwann cells were associated with the normal bundles but were absent from the bundles of small fibers. In such bundles, large, unmyelinated axons predominated, some of which lacked ensheathment while others were invested by perineurial‐type cells. The observation of incidental intraleptomeningeal skeletal muscle probably reflects a rare developmental anomaly. Its occurrence in humans is also discussed.
Neurophysiological investigation of subclinical and minimal toxic neuropathies
Authors: Le Quesne Pamela M.
Published: January 2005

In the investigation of subclinical or minimal toxic neuropathies, selection of the proper electrophysiological test depends largely on the nature of the condition being studied. Examples are given of several toxic disorders, and their features are discussed in relation to the appropriate electrophysiological measurement.
Electromyographic assessment of central motor disorders
Authors: Wiesendanger Mario , Rüegg Dieter G.
Published: January 2005

Experimental procedures are described that were designed to assess central motor disorders quantitatively. Initially delineated is a study of triggered ballistic movement performed in a reaction‐time situation. The reciprocal triphasic EMG pattern recorded in an antagonistic muscle pair was clearly abnormal in Parkinsonian patients; increased duration, diminished synchronization of motor units, and a tendency for coactivation of agonist and antagonist muscles and for action tremor were observed. Transport time of elbow movement was prolonged, particularly in a choice reaction‐time situation. Rapid, passive displacements of the forearm combined with excitability measurements of hindlimb motoneurons in monkeys revealed the existence of a transcortical loop that may contribute to increased muscle tone in Parkinsonian patients.
Early changes in chlorphentermine myopathy of rat studied by freeze fracturing
Authors: Schmalbruch Henning
Published: January 2005

Chlorphentermine interferes with the metabolism of phospholipids. When administered to the rat in daily doses for 5 days, it causes necrosis of muscle fibers that are rich in mitochondria. Before the onset of necrosis, the following characteristics of freeze‐fractured muscle preparations were observed: multilayered lipid globules and single‐layered lipid membranes without membrane particles; different stages of exocytosis of lipid through the plasma membrane of the muscle fibers; and areas of plasma membrane that were devoid of particles of intramembranous proteins. These latter areas may arise secondary to exocytosis, to fusion of lipid vesicles with the plasma membrane, or to a direct action of chlorphentermine on the membrane. It is not known whether these areas give rise to membrane defects and fiber necrosis.
HLA, anti‐DNA, and complement in myasthenia gravis
Authors: Christiansen Frank T. , Houliston John B. , Dawkins Roger L.
Published: January 2005

Twenty‐seven patients (18 females and 9 males) with myasthenia gravis were HLA‐A, ‐B, ‐C, and ‐D typed, and the results were analyzed with relation to evidence of immunodeficiency, thymic disease, and associated autoimmune processes. An association of A1, B8, and DRW3 appeared to identify a group of 8 females with higher mean anti‐DNA, lower mean C4, and lower mean E. coli antibody titer than other females in whom CW4 (with or without BW35) was common (6 of the remaining 10 females were in this category). Antiacetylcholine receptor (anti‐AChR) autoantibody and reduced serum lgM and isohemagglutinin titers were not clearly related to particular HLA specificities. These results suggest that HLA‐A1, ‐B8, ‐DRW3, and ‐CW4 may be related to associated phenomena rather than playing a major role in the development of anti‐AChR and myasthenia gravis.
Hypoxanthine‐guanine phosphoribosyltransferase activity of blood and muscle in duchenne dystrophy
Authors: Neerunjun Joseph S. , Allsop Jennifer , Dubowitz Victor
Published: January 2005

Hypoxanthine‐guanine phosphoribosyltransferase (HGPRT) activity was measured in red cells and in skeletal muscles of normal and Duchenne subjects. [8‐14C] hypoxanthine was used as substrate, and 5‐phospho‐α‐D‐ribose 1‐diphosphate (PRPP) was used as the ribose‐5‐phosphate donor. The [8‐14C] inosine monophosphate (IMP) formed was separated by high‐voltage electrophoresis, and radioactivity was measured by liquid scintillation counting. HGPRT activity in Duchenne and normal red‐cell hemolysates was similar, but such activity was significantly higher in Duchenne than in normal muscle homogenates. Red cells of both normal and Duchenne subjects had significantly higher enzyme activity than did skeletal muscles. It is suggested that increased HGPRT activity may be involved in enhancing protein synthesis by increasing intracellular levels of purine ribonucleotides.
Neurotrophic control of skeletal muscle phospholipids
Authors: Fernandez Hugo L. , Dorman Robert V. , Festoff Barry W.
Published: January 2005

The phospholipid composition of rat gastrocnemius muscles was assessed one to nine days after sciatic nerve transection was performed either close to the muscle (5–8 mm from the point of entrance of the nerve into the muscle for short‐stump nerve sections) or far from it (30–35 mm central to the nerve's point of entrance for long‐stump nerve sections). In both instances, denervation did not cause striking changes in total phospholipid content but resulted in a selective loss of 1,2‐diacyl‐sn‐glycero‐3‐phosphorylethanolamine (phosphatidyl ethanolamine, GPE). The quantity of GPE in denervated muscles was found to be significantly less than that in controls (p<0.01) within one day for short‐stump preparations, as compared to three days for long‐stump preparations. Also, direct comparison of short‐ and long‐stump GPE values showed significant differences (p<0.01) at all times from the first to the fifth day following denervation, with no difference detected thereafter. These results imply that maintenance of skeletal muscle GPE involves a neurogenic influence which is independent of nerve‐evoked muscle activity. This conclusion may help us understand neuromuscular diseases in which perturbation of phospholipid components has been implicated.
Amplitude of the surface electromyogram during fatiguing isometric contractions
Authors: Lind Alexander R. , Petrofsky Jerrold S.
Published: January 2005

Five volunteer subjects held isometric handgrip contractions at specific submaximal tensions until the required tension could no longer be maintained. At the start of those contractions, the amplitude of the surface electromyogram (EMG) was linearly related to the tension exerted; the amplitude of the EMG increased linearly throughout these sustained contractions by a constant amount—about 30% of the maximum. During sustained contractions, brief, intermittent maximal efforts showed that strength declined linearly at all tensions. At 25% maximal voluntary contraction (MVC), there was a linear fall in the EMG amplitude associated with the brief maximal efforts, but the fall in strength was more rapid than the fall in EMG amplitude. At 70% MVC, there was no fall in the EMG amplitude in response to the brief maximal efforts, while the muscle strength fell linearly.
Cylindrical spirals in human skeletal muscle
Authors: Carpenter Stirling , Karpati George , Robitaille Yves , Melmed Calvin
Published: January 2005

Muscle biopsies from two patients revealed that numerous type 2 fibers contained large abnormal areas filled with cylindrical spirals. The cytochemical profile of these cylindrical spirals was sufficiently characteristic that they could be distinguished from tubular aggregates. Their electron microscopic appearance was unmistakable. Their origin and significance are uncertain. The diverse nature of the patients' conditions (cramps and malignancy, and an unusual form of spinocerebellar degeneration) indicate that these abnormal structures are not disease specific.
Reinnervation of rat extensor digitorum longus muscles after free grafting
Authors: Carlson Bruce M. , Wagner Kenneth R. , Max Stephen R.
Published: January 2005

Free grafts of the extensor digitorum longus (EDL) muscle of the rat are invaded by regenerating nerve fibers during the second postoperative week. Neuromuscular junctions are established during the third week. Levels of choline acetyltransferase (CAT) activity parallel the invasion of the graft by nerve fibers, but this activity never returns to control levels. We conclude that incomplete reinnervation of free muscle grafts may be a factor in the failure of such grafts to reattain the mass of control muscles.
New muscle transplant method produces normal twitch tension in dystrophic muscle
Authors: Law Peter K. , Yap John L.
Published: January 2005

Grafting newborn muscle is an innovative method of muscle transplant. This method overcomes hypoxia in the deeper fibers and facilitates reinnervation and revascularization of the grafted muscle fibers, thus promoting the survival and development of the characteristics of the donor muscle. The result achieved is superior to that obtained from mature muscle grafts or from minced muscle transplants. When an intact soleus from a 1‐day‐old normal mouse was grafted into a recipient soleus of a 20‐day‐old dystrophic C57BL/6J‐dy2J mouse, the actively developing normal graft helped to improve the structure and function of the dystrophic muscle. When compared to the intact dystrophic solei, the test dystrophic muscles five to six months after operation showed increases in cross‐sectional area, in wet weight, in twitch and tetanic tension, and in the number of muscle fibers with high resting membrane potentials. This is the first procedure to have raised the muscle twitch tension in an adult dystrophic mouse to the normal level.
Treatment of denervated muscle by gangliosides
Authors: Caccia M. R. , Meola G. , Cerri C. , Frattola L. , Scarlato G. , Aporti F.
Published: January 2005

Short‐duration cooling of the nerve to the extensor digitorum longus muscle of the rat in vivo induced partially reversible denervation of the muscle and atrophy in the type 2 muscle fibers. Increases in cyclic adenosine monophosphate, cyclic guanosine monophosphate phosphodiesterase, adenylate cyclase, and guanlate cyclase were observed in the denervated muscle. Treatment with gangliosides of the bovine brain cortex seemed to improve the excitability of the surviving motor units and to encourage recovery of neuromuscular trophic control, but it did not affect the nerve conduction velocity or the contractile properties of the denervated muscle.
Trichinosis: Clinical report and histochemistry of muscle
Authors: Gross Brian , Ochoa José
Published: January 2005

A 35‐year‐old woman contracted severe trichinosis which was atypical in that it lacked a gastrointestinal prodrome and periorbital edema, and in that eosinophilia developed only late in the course of the illness. The patient developed an incapacitating myositis as well as complications of encephalopathy, myocarditis, and retinal hemorrhages, resulting in severe debilitation of more than two and one‐half months' duration. Muscle histochemistry illustrated previously unreported features.
The afferent influence on the voluntary firing range of individual motor units in man
Authors: Hannerz Jan , Grimby Lennart
Published: January 2005

The firing ranges of 50 normal anterior tibial or short toe extensor motor units in sustained isometric voluntary contraction were studied in electromyographic recordings. The afferent inflow was decreased by compression of the sciatic nerve, thereby blocking large afferents before alpha efferents. Motor units with low minimum and low maximum rates before blockade had higher minimum and maximum rates on blockade. Some motor units with high minimum and maximum rates before blockade had a lower minimum but an unchanged maximum rate on blockade. The firing range recorded for both types of motor unit on blockade was also recorded for all tonically firing motor units during early reinnervation after traumatic lesion to the muscle nerve in 14 patients. It is concluded that both facilitating and inhibiting proprioceptive afferent activity is involved in the differentiation of motor unit firing ranges in sustained isometric voluntary contraction.
A new regional curare test of the elbow flexors in myasthenia gravis
Authors: Horowitz Steven H. , Krarup Christian
Published: January 2005

Electrical and mechanical responses of the elbow flexors (EFs) and the adductor pollicis muscle (ADP) were evoked in 31 patients with myasthenia gravis (MG). Thirteen patients with moderate or severe involvement showed a decrement during trains of repetitive stimuli in both muscle types, greater in the proximal ones than in the distal one. Seven of 18 patients with mild generalized or ocular MG showed abnormalities in the EFs, and 4 patients showed abnormalities in the ADP. A regional curare test was performed in the EFs of 11 patients with borderline or no abnormalities in the EFs and the ADP. All patients were more sensitive to curare than were control subjects; in 2, a decrement outside the range of controls could only be provoked in the partly curarized muscle during posttetanic exhaustion. Excitation‐contraction coupling, as evidenced by the staircase phenomenon and after correction for blockade of fibers, was abnormal in 5 of 31 patients in the EFs, and in 11 patients in the ADP. In both muscles, the action potential was a more sensitive criterion of abnormality than the mechanical response. The decrement in the action potentials during 3/sec stimuli gave the largest diagnostic yield.
Role of plasma membrane defect of skeletal muscle in malignant hyperthermia
Authors: Gallant Esther M. , Godt Robert E. , Gronert Gerald A.
Published: January 2005

Halothane, at clinical concentrations, depolarizes the plasma membrane of skeletal muscle from Poland China pigs susceptible to malignant hyperthermia but does not affect the resting membrane potential of muscle from normal Poland China pigs, mice, or frogs. The depolarization is reduced or partially reversed in the presence of dantrolene sodium. We suggest the possibility that malignant hyperthermia may be initiated by this abnormal depolarization of skeletal muscle by halothane.
Recovery from central core degeneration of the tenotomized rat soleus muscle
Authors: Baker James H. , Hall‐Craggs E. C. B.
Published: January 2005

The soleus muscle of the rat undergoes degenerative changes after tenotomy. The effects are maximal one week postoperatively, after which follows a period of recovery. Muscle histology eventually returns to normal six weeks after tenotomy. Recovery is effected by means of peripheral myofibril splitting and de novo synthesis of myofibrils within the central portion of the fiber.
Neuralgic amyotrophy manifesting as anterior interosseous nerve palsy
Authors: Rennels Glenn D. , Ochoa José
Published: January 2005

Neuralgic amyotrophy may present as a picture of anterior interosseous nerve palsy. In such a case, rather than a lesion of the nerve in the forearm, we offer indirect evidence of a lesion in the brachial plexus affecting discrete fiber bundles destined to form the anterior interosseous nerve.
Autosomal recessive generalized myotonia
Authors: Zellweger H. , Pavone L. , Biondi A. , Cimino V. , Gullotta F. , Hart M. , Ionasescu V. , Mollica F. , Schieken R.
Published: January 2005

Four cases of autosomal recessive generalized myotonia are reported. Attention is drawn to the fact that this condition represents a disease entity distinct from the myotonia congenita of Thomsen, which is transmitted as an autosomal dominant trait. The clinical features of the two conditions are similar, apart from minor quantitative differences. The family history is the major tool for the differential diagnosis. The possibility of the detection of heterozygotes by electromyography is discussed.
A new variant of late‐onset myophosphorylase deficiency
Authors: Kost Gerald J. , Verity M. Anthony
Published: January 2005

McArdle disease classically presents in childhood or adolescence. Rarely does it become symptomatic for the first time in late adulthood, with the onset of progressive muscle wasting and weakness. Our patient is unusual in that despite a life of physical vigor, she developed immobilizing cramps, stiffness, and muscle swelling abruptly at age 60. She had no previous symptoms of muscle disease. The diagnosis was indicated by the ischemic forearm test, which produced muscle contracture and no rise in venous lactate levels, and confirmed by histochemical, electrophoretic, and biochemical studies that showed complete absence of myophosphorylase. This case defines a new variant of the late‐onset type and raises important questions about compensatory mechanisms, inheritance patterns, and etiological factors in myophosphorylase deficiency.
Abnormal myomuscular junctions and AChE in a congenital neuromuscular disease
Authors: Bormioli S. Pierobon , Lücke S. , Angelini C.
Published: January 2005

We studied a patient with a congenital neuromuscular disease clinically characterized by ophthalmoplegia, slight limb muscle weakness, and normal electromyography. In the muscle biopsy, there were frequent examples of interdigitation of areas of muscle and extracellular spaces giving a fragmented appearance to muscle fibers. These structures resemble myomuscular junctions; acetylcholinesterase activity was present in the vicinity of these structures and on the muscle cell surface.
Characterization of ATPase in sarcoplasmic reticulum from two strains of dystrophic mice
Authors: Neymark Michael A. , Kopacz Stephan J. , Lee Chaun‐Pu
Published: January 2005

The ATPase activities and phosphoenzyme levels have been determined in sarcoplasmic reticulum (SR) membranes prepared from two animal models of muscular dystrophy, myodystrophic (myd/myd) and strain 129 dystrophic (129 dy/dy) mice. In both myd/myd and 129 dy/dy SR membranes, the basal ATPase activities are elevated above control levels, while the Ca‐dependent ATPase activities are normal. The addition of 0.1% Triton X‐100 not only lowers the basal ATPase activity of myodystrophic control SR membranes by 60%, but also lowers the elevated basal ATPase activity of myd/myd SR membranes to a similar level. The Ca‐dependent ATPase activities of myodystrophic control and myd/myd SR membranes are increased approximately threefold by the addition of Triton. The addition of 0.1% Triton X‐100 lowers the basal ATPase activities of 129 control and 129 dy/dy SR membranes to similar levels, but stimulates the Ca‐dependent ATPase activity of 129 dy/dy SR membranes to a level that is only 60% of that of 129 control SR membranes. The level of phosphoenzyme intermediate is decreased approximately 15% in myd/myd SR membranes and approximately 30% in 129 dy/dy SR membranes.
Ca‐activated neutral protease and its inhibitors: In vitro effect on intact myofibrils
Authors: Sugita Hideo , Ishiura Shoichi , Suzuki Koichi , Imahori Kazutomo
Published: January 2005

SDS gel electrophoresis of troponin and myosin extracted from chicken myofibrils pretreated with Ca‐activated neutral protease showed a pattern similar to that observed in the muscles of patients with Duchenne muscular dystrophy, that is, a decrease in troponin‐l and troponin‐C with relative preservation of troponin‐T and degradation of the heavy chain of myosin. Also, α‐actinin and troponin‐C were released from myofibrils. Two inhibitors of Ca‐activated neutral protease, leupeptin and E‐64, inhibited the degradative action of Ca‐activated neutral protease on intact myofibrils in vitro.
Peripheral neuropathy in spinocerebellar degenerations
Authors: McLeod J. G. , Evans W. A.
Published: January 2005

Nerve conduction studies have been performed in 19 subjects with hereditary spinocerebellar degenerations other than Friedreich ataxia. Clinically, they may be classified as olivopontocerebellar atrophy or cerebello‐olivary degeneration. In 9 patients, sensory conduction was abnormal, and in the whole group there was a significant impariment of sensory conduction and mild slowing of motor conduction in the lateral popliteal nerve. Sural nerve biopsies were performed on 5 patients. In 3 cases there was a mild to moderate reduction of myelinated fibers of all diameters; unmyelinated fibers were normal. In 1 patient from a kindred with a spinocerebellar degeneration in which the inheritance was autosomal dominant, neuropathological findings at autopsy confirmed the clinical diagnosis of the Menzel type of olivopontocerebellar atrophy; thee was degeneration of dorsal root ganglion and anterior horn cells as well as of myelinated fibers of all diameters in the sural nerve.