摘要:

AbstractThree cases of chronic distal sensorimotor neuropathy are described in patients with neurofibromatosis. One had type 2 or central neurofibromatosis with a chromosome 22 deletion; the precise form of the disease was not established in the other two. A striking clinical feature was a diffuse nodular enlargement of the peripheral nerves. Nerve biopsies from all three cases demonstrated the presence of neurofibromatous pathology. Neurofibromatous neuropathy constitutes a rare manifestation of neurofibromatosis, related to diffuse neurofibromatous changes in the peripheral nerves.

ISSN:0148-639X    

DOI:10.1002/mus.880130202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThirty‐two patients with a mononeuropathy multiplex associated with a systemic necrotizing vasculitis were studied. The main abnormality was a loss of motor and sensory axons confirmed by electrophysiological and histological methods. A conduction block was observed in five patients, but only one was at a usual site of compression. Based on previous pathological studies and the experimental data in human and animals, the mechanism of the block is proposed to be ischemic. It is suggested that a conduction block in one nerve in a neuropathy with two or more individual nerves affected and with electrophysiological features of axonal degeneration may be due to a vasculiti

ISSN:0148-639X    

DOI:10.1002/mus.880130203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe expression of MHC class I and II molecules on cultured rat and human Schwann cells (SCs) was studied to determine whether these molecules could be synthesized by SCs in the absence of T cells. Normal rat and human SCs in vitro expressed low levels of class I MHC, but this was markedly increased by incubation with interferon gamma (IFN‐γ). Untreated SCs of rat or human origin did not express detectable class II MHC molecules, but after 48 hours incubation with IFN‐γ 100 U/ml, 20% of rat SCs and 90% of human SCs were class II positive. Immunoelectron microscopy confirmed the surface expression of MHC molecules on SCs and demonstrated class II MHC within endocytotic vesicles. These findings provide further evidence for an immunological role for SCs as antigen presenting cells or as targets for cytotoxic T

ISSN:0148-639X    

DOI:10.1002/mus.880130204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractTo assess the effects of thallium on the conduction velocities of faster and slower nerve fibers, the distribution of conduction velocities in sensory fibers of the median nerve was examined in a patient with acute thallium poisoning 2 and 11 months after the onset of symptoms. In the first examination, the patient showed evidence of a distal sensorimotor neuropathy and had an elevated urinary thallium concentration (3.5 mg/L); the conduction velocities of faster fibers were below the normal lower limit, whereas those of slower fibers were within normal limits. At the second examination, the conduction velocities of all faster and slower fibers increased and were within normal limits: clinical signs and symptoms of neuropathy almost disappeared. It is concluded that the conduction velocities of faster fibers significantly decrease in an early stage of acute thallium poisoning and recover following recuperation from the poisoning; those of slower fibers are minimally affected and then improve.

ISSN:0148-639X    

DOI:10.1002/mus.880130205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe earliest horseardish peroxidase (HRP) neuronal labeling (the fastest retrograde transport) was determined by histochemical techniques at various intervals after intramuscular HRP injection in wobbler mice and normal littermates. In the clinically impaired forelimb system, the retrograde transport rate was 150–170 mm/day in wobbler mice and 170–230 mm/day in controls. However, there was no statistical difference between the two groups. The neuronal HRP accumulation at the early intervals was significantly less in wobbler mice than controls, suggesting that the amount of HRP transport was dminished in each axon. For the clinically intact hindlimb nerves, the rate was normal in wobbler mice, but the amount of neuronal HRP was significantly increased. Retrograde axonal transport appeared to be affected in a differential fashion, depending on the extent of dise

ISSN:0148-639X    

DOI:10.1002/mus.880130206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractSurgical resection of a lipomyelomeningocele carries a risk of injury to nerve roots in the cauda equina. We have devised a technique for combined spinal evoked potential and peripheral nerve compound action potential recording for intraoperative monitoring of this surgical procedure. We report the results of six cases where this technique was used. In each case, the monitoring prevented resection of viable neural tissue, and all six patients were neurologically unchanged postoperatively.

ISSN:0148-639X    

DOI:10.1002/mus.880130207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effects of motor denervation on levels of phosphorylase kinase isozymes and phosphorylase were investigated in rat epitrochlearis, hemidiaphragm, and soleus muscles. Amounts of the proteins were measured after quantitative immunoprecipitation and found to be decreased by as much as 70% 2 weeks after denervation. Unexpectedly, denervation had little, if any, effect on the relative proportions of the two phosphorylase kinase isozymes. Phosphorylase and phosphorylase kinase were decreased by essentially the same extent after denervation, and the effects of denervation were comparable in all three muscles. The decreases in these enzymes explain, at least in part, the marked alterations in glycogen metabolism that occur after motor denervation.

ISSN:0148-639X    

DOI:10.1002/mus.880130208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractPrior to definitive diagnosis, electrodiagnostic studies are often requested in patients with polymyalgia rheumatica to evaluate complaints of muscle aching, tenderness, and weakness. These studies are generally normal, although rare reports of electromyographic abnormalities in polymyalgia rheumatica exist. Two patients with polymyalgia rheumatica and electro diagnostic findings consistent with diffuse denervation are described. Following steroid treatment, both patients experienced impressive clinical and electromyographic improvement. To explain this improvement, we hypothesize a steroid‐responsive microvascular arteritis resulting in ischemic damage to axons of motor nerve terminal branche

ISSN:0148-639X    

DOI:10.1002/mus.880130209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractMyotubes prepared from mice with muscular dysgenesis (mdg) were used to further elucidate the putative role of inositol triphosphate (InsP3) in excitation‐contraction (E‐C) coupling of skeletal muscle. The mdg mutation is characterized by an uncoupling of the E‐C coupling. InsP3production in normal andmdg/mdgmyotube cultures and its relation to the levels of cytosolic free calcium were analyzed. Basal and ATP‐stimulated levels of InsP3were equal in normal andmdg/mdgmyotube cultures. In contrast, the transient increases of cytosolic free calcium inmdg/mdgmyotubes in culture were generally much lower than those in normal ones. This suggests that the defect in dysgenic myotubes does not rest on the InsP3formation but on the InsP3‐triggered transduction of excitation and/or the induction of calcium release from intern

ISSN:0148-639X    

DOI:10.1002/mus.880130210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractForty patients with ALS underwent cortical magnetic stimulation. Twelve had marked pseudobulbar signs; in these motor evoked potentials (MEPs) could not be elicited. Mean MEP latencies in the others, who had predominantnantly lower motor neuron signs, measured 23.3±2.1 msec (thenar), 18.7±5.3 msec (EDC), and 13.4±2.9 msec (biceps), respectively. These values were significantly longer (P>0.001) compared with normal values (n=35), which measured 20.2±1.6, 14.2±1.7, and 9.4±1.7 msec, respectively. MEP amplitude was often markedly reduced (less than 15% of the M wave) compared with a normal mean of 39.5±13.0%. Overall abnormal MEPs (delayed, absent, or reduced in amplitude) approached 100%. It is argued that measuring central motor delay, which was not significantly different in the patients compared with normals, is subject to error

ISSN:0148-639X    

DOI:10.1002/mus.880130211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY