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Conduction Study (conduction + study)
Kinds of Conduction Study Selected AbstractsNear-nerve needle sensory and medial plantar nerve conduction studies in patients with small-fiber sensory neuropathyEUROPEAN JOURNAL OF NEUROLOGY, Issue 9 2008K. Uluc Background and purpose:, The aim of this prospective study was to show and compare the rate of large-fiber involvement with near-nerve needle sensory (NNNS) nerve conduction study (NCS) and with medial plantar NCS recorded with surface electrodes in a group of patients who had clinically pure small-fiber sensory neuropathy (SFSN) with reduced intra-epidermal nerve fiber density in skin biopsy and with normal routine NCS. Methods and results:, The study included 19 patients with clinically pure SFSN with normal routine NCS results and 17 healthy volunteers. Routine NCS, skin biopsy, medial plantar NCS and NNNS NCS were performed. NNNS NCS data were evaluated both by using univariate analysis methods and by using a multivariate analysis method, principal components analysis (PCA). Eight patients (42%) had abnormal results for medial plantar NCS with surface electrodes. Seven patients (37%) had abnormal results for NNNS NCS with PCA, whilst only four patients with univariate analysis. We found a significant correlation between intra-epidermal nerve fiber densities, medial plantar NCS and PCA results of NNNS NCS. Conclusions:, This study showed that large-nerve fibers are also involved in some patients with pure SFSN and medial plantar NCS can accurately diagnose neuropathy without a need for NNNS NCS in patients with normal routine NCS. [source] Seronegative myasthenia gravis: comparison of neurophysiological picture in MuSK+ and MuSK, patientsEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2006L. Padua The aim of this study was to compare the neurophysiological and clinical pictures of a large sample of seronegative myasthenia gravis (SNMG) patients with and without anti-MuSK antibodies. Fifty-two consecutive SNMG patients were retrospectively evaluated. They had undergone an extended neurophysiological evaluation: repetitive nerve stimulation (RNS), single fiber EMG (SFEMG), and electromyography (EMG) with nerve conduction study. A muscle biopsy was performed in 11 of 52 patients, the edrophonium test in 44 of 52 patients and anti-AChR antibodies and anti-MuSK antibodies were tested in all patients. Anti-MuSK antibodies were detected in 25 SNMG patients (48.1%). The number of women in the MuSK+ group was significantly higher (P = 0.01) than in the MuSK, group. Seronegative MuSK+ patients are more severely affected and the deficit often involves the bulbar and the respiratory muscles. No statistically significant differences were observed in the edrophonium test between MuSK+ and MuSK, groups. The RNS test was abnormal in a significantly higher number of MUSK, patients than MUSK+ patients (P < 0.00001). With regard to SFEMG data, MuSK, patients were characterized to have more severe neurophysiological pattern. Our observations showed several differences between the clinical and neurophysiological pictures of MUSK+ and MUSK, patients. [source] Magnetically evoked motor potentials in demyelinating and axonal polyneuropathy: a comparative studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2000H. Takada We investigated the value of magnetically evoked motor potentials (MEPs) for the differentiation of demyelinating and axonal polyneuropathies. The study population comprised 107 patients, with polyneuropathy verified by electromyography (EMG) and nerve conduction study (NCS), who had also been examined by means of MEP. MEPs were evoked by magnetic stimulation of the cortex and the spinal roots and were recorded from three upper limb muscles and two lower limb muscles bilaterally. From the EMG/NCS results 53 patients were characterized as having primary demyelination (demyelinating patients) and 54 as having axonal involvement (axonal patients). Demyelinating patients were classified as acute (acute inflammatory demyelinating polyradiculoneuropathy: AIDP ) or chronic (chronic inflammatory demyelinating polyradiculoneuropathy: CIDP ) according to the duration of illness. A series of indices were calculated from MEP results. One demyelinating patient and two axonal patients had normal MEPs. The MEPs of the demyelinating patients showed significantly longer peripheral conduction times, larger interside differences and lower amplitudes than the axonal patients. The central conduction index and the amplitudes upon cortical stimulation were significantly higher in patients with CIDP than in those with AIDP. Peripheral conduction time prolonged by more than 85% in at least one of the 10 muscles studied or a peripheral conduction index of above 9.4 were pathognomonic for demyelination . By combining all criteria 75% of the patients could be categorized as CIDP vs. AIDP in accordance with the EMG/NCS diagnosis. Likewise, 83% were categorized correctly as demyelinating versus axonal according to the EMG/NCS data. [source] Congenital hypomyelination neuropathy in a newborn infant: unusual cause of diaphragmatic and vocal cord paralysesJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 2 2002JS Hahn We report a case of congenital hypomyelination neuropathy presenting at birth. The infant had generalized hypotonia and weakness. There was decreased respiratory effort along with a right phrenic nerve and left vocal cord paralyses. Tongue fasciculations were present. Deep tendon reflexes were absent in the upper extremities and hypoactive (1+) in the lower extremities. Magnetic resonance imaging of the head revealed no intracranial abnormalities, including normal cerebral myelination. Nerve conduction study showed absence of motor and sensory action potentials in the hands when the nerves in the upper limbs were stimulated. A motor response could be elicited only in the proximal leg muscles. Needle electromyography study was normal in the proximal limb muscles, but showed active denervation in the distal muscles of the arm and leg. These findings were thought to be consistent with a length-dependent sensorimotor peripheral polyneuropathy of axonal type with greater denervation of the distal muscles. A biopsy of the quadriceps muscle showed mild variability in fiber diameter, but no group typing or group atrophy. The muscle fibers showed no intrinsic abnormalities. Biopsy of the sural nerve showed scattered axons with very thin myelin sheaths. There was also a nearly complete loss of large diameter myelinated fibers. No onion bulb formations were noted. These findings were thought to be consistent with congenital hypomyelination neuropathy with a component of axonopathy. DNA analysis for identification of previously characterized mutations in the genes MPZ, PMP22, and EGR2 was negative. Several attempts at extubation failed and the infant became increasingly ventilator-dependent with increasing episodes of desaturation and hypercapnea. He also developed increasing weakness and decreased movement of all extremities. He underwent surgery at 2 months of age for placement of a gastrostomy tube and a tracheostomy. He was discharged from the hospital on a ventilator at 6 months of age. The infant was 13 months old at the time of submission of this report. Although he appears cognitively normal, he remains profoundly hypotonic and is on a home ventilator. There was no evidence of progressive weakness. Congenital hypomyelination neuropathy is a rare form of neonatal neuropathy that should be considered in the differential diagnosis of a newborn with profound hypotonia and weakness. It appears to be a heterogeneous disorder with some of the cases being caused by specific genetic mutations. [source] Electrophysiological Changes In Diabetic Neuropathy: From Subclinical Alterations To Disabling AbnormalitiesJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000M. Baba Clinical spectrum of diabetic neuropathy is variable; it may be asymptomatic, but once established, it becomes irreversible and disabling. Some investigators suggested that earliest change in diabetic nerve function is alteration in axonal excitability due to alterations in ion conductance of axon membrane, although these functional changes of ion channels necessarily cause permanent damage or degeneration of nerve fibers. Among various parameter of nerve conduction study in diabetics, prolonged F-wave latency in the peroneal and tibial nerve seems the commonest abnormality in asymptomatic patients. Decrease in amplitude of compound sensory action potential of sural nerve is another earlier abnormality, which is, then, accompanied by a fall in motor amplitude of peroneal and tibial nerves in advanced patients. In disabled patients no motor response is often elicited in the legs. Previous electrophysiological studies could not make clear if central axons were involved or not in diabetic neuropathy. Recently, our group has demonstrated that somatosensory central conduction from the spinal cord to the sensory cortex is delayed in diabetics as well as in the peripheral conduction, which might be partly responsible for the irreversible clinical presentation of diabetic neuropathy. [source] ROSS SYNDROME: CLINICAL AND LABORATORY EVALUATION OF TWO CASESJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000G. De Joanna We describe two males, aged 41 and 55, come to our observation complaining of heat intolerance, abnormal increase in body temperature with minimal exercising, reduced sweating and, generalized fatigability; one of them had distal paresthesias. Neurologic evaluation showed bilateral Adie's tonic pupil and an absence of deep-tendon jerks. A diagnosis of Ross' Syndrome was advanced. Autonomic tests, nerve conduction study, H-reflex, computerized termoregulatory and pain thresholds, laser CO2 cortical evoked potentials, and skin biopsy were performed. One of them performed a histamine test and hand photopletismography resulted positive for sympathetic impairment, and pilocarpine pupil test that showed a parasympathetic denervation hypersensitivity. The following tests gave the same results in both patients: parasympathetic and most sympathetic tests were normal. Sympathetic skin response was absent and Minor test showed an almost complete absence of sweating. Sweating was possible only in two or three small areas. Positive pilocarpine test suggested a postganglionic involvement of sympathetic nervous system. Sensitive and motor nerve conduction velocities were normal, while H-reflex was not detectable. Termoregulatory and pain thresholds were abnormal. Laser CO2 cortical evoked potentials showed the absence of C fibre potentials, whereas A-, fibres response was abnormal in one of them. Hairy skin biopsy showed a definite reduction of sweat glands and of small vessel innervation; glabrous skin biopsy performed in one of them showed a reduced number of Meissner corpuscles. These findings suggest that in Ross' Syndrome the degenerative process can involve, besides the autonomic fibres, myelinated somatosensory fibres also. [source] Peripheral neuropathy associated with leflunomide: is there a risk patient profile?,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 1 2007Karin Martin pharmD Abstract Purpose (i) To monitor the potential clinical neurotoxic symptoms in patients treated with leflunomide in daily practice and (ii) to describe the characteristics of patients presenting with this peripheral nervous system symptoms. Method All patients treated with leflunomide between May 2000 and April 2003 and followed in the rheumatology department of the University Hospital participated in the study. Data concerning treatment patterns with leflunomide, demographic and disease characteristics were obtained from clinical charts. Neuropathy was diagnosed with nerve conduction study (NCS). Cases of neuropathy were described and then compared to other patients using univariate analyses. Results One hundred and thirteen patients were included in the study. M/F sex ratio was 0.45. Mean age at start of treatment was 55.6 years (range,=,27,81). During the study period, eight incident cases of peripheral neuropathy and two cases of worsening of preexisting neuropathy were reported (incidence: 9.8%). Compared with other patients, neuropathy cases were older (69 vs. 54 years, p,=,0.0006), more often diabetic (30% vs. 2.9%, p,=,0.009) and more often treated with potentially neurotoxic drugs (20% vs. 1.9%, p,=,0.039). At least one risk factor (potentially neurotoxic drug or diabetes) was found in 50% of patients with neuropathy versus 4% of patients without neuropathy (56% PPV, 96% NPV). Conclusion Cases of toxic neuropathy have been observed during treatment of rheumatoid arthritis with leflunomide. Their occurrence seems to be associated with known risk factors. Careful monitoring of the patient's neurological status during leflunomide treatment is therefore mandatory. Copyright © 2006 John Wiley & Sons, Ltd. [source] A randomized controlled trial evaluating an alternative mouse or forearm support on change in median and ulnar nerve motor latency at the wristAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2009Craig F. Conlon MD Abstract Background The purpose of this study was to determine the effects of an alternative mouse and/or a forearm support board on nerve function at the wrist among engineers. Methods This randomized controlled intervention trial followed 206 engineers for 1 year. Distal motor latency (DML) at baseline and follow-up was conducted for the median and ulnar nerves at the right wrist. Results One hundred fifty-four subjects agreed to a nerve conduction study at the beginning and end of the study period. Those who received the alternative mouse had a protective effect (OR,=,0.47, 95% CI 0.22,0.98) on change in the right ulnar DML. There was no significant effect on the median nerve DML. The forearm support board had no significant effect on the median or ulnar nerve DML. Conclusions In engineers who use a computer for more than 20 hr per week, an alternative mouse may have a protective effect for ulnar nerve function at the wrist. No protective effect of a forearm support board was found for the median nerve. Am. J. Ind. Med. 52:304,310, 2009. © 2009 Wiley-Liss, Inc. [source] Chronic inflammatory demyelinating polyradiculoneuropathy in children: characterized by subacute, predominantly motor dominant polyeuropathy with a favorable response to the treatmentACTA NEUROLOGICA SCANDINAVICA, Issue 5 2010H. Y. Jo Jo HY, Park M-G, Kim D-S, Nam S-O, Park K-H. Chronic inflammatory demyelinating polyradiculoneuropathy in children: characterized by subacute, predominantly motor dominant polyeuropathy with a favorable response to the treatment. Acta Neurol Scand: 2010: 121: 342,347. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives,,, Chronic inflammatory demyelinating polyradiculopathy (CIDP) is less well-studied in children than in adults, probably due to its relative rarity. This study was performed in order to characterize the clinical features of CIDP in children. Materials and methods,,, Twenty-eight patients with CIDP who were followed up for more than 1 year were included, and were divided into a child (n = 7, age <16) and an adult group (n = 21, age ,16). Then, we have assessed the initial progression pattern, clinical course, and serial nerve conduction findings in each patient. Finally, differential features in child and adult group were analyzed. Results,,, Distinguishing features in the child group include subacute progression within less than 2 months, predominant motor system involvement in lower extremities, and marked improvement in response to immune modulating therapy. Our study also suggested that serial nerve conduction study may be useful in assessing the effectiveness of the treatment in children. Conclusions,,, Our study showed that children with CIDP have some distinguishing features from adults in terms of clinical course and response to treatment. [source] | ||||||||||