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Motor Conduction Velocities (motor + conduction_velocity)
Selected AbstractsAbstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 76JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003D Pareyson The X-linked form of Charcot-Marie-Tooth disease (CMTX) is associated with mutations in the Connexin 32 gene (Cx32) and is the second most common CMT subtype after CMT1A, in which the 17p11.2 duplication is the underlying molecular defect. CMTX is characterized by no male-to-male transmission, intermediate motor conduction velocities (MCV), and more severe disease in males. In our series of CMT patients, we found 9 different Cx32 mutations in 11 families. Overall there were 26 patients, 13 males and 13 females, aged 11,76 yrs. Age at onset ranged considerably (1,60 yrs), but symptoms began earlier in males (mean 15.4 yrs, 77% within age 20) than in females (mean 25 yrs). All patients were autonomous, but disease severity was greater in males, while 4 female carriers were asymptomatic. Pain and tremor were frequent complaints. Two patients had Babinski sign and one had rest tremor. Nerve conduction studies were performed in 23 patients (13 males, 10 females). Upper limb motor conduction velocities (MCV) ranged between 25 and 57 m/s, and were slower in males (25,48 m/s) than in females (34,57 m/s). MCV were in the upper range of CMT1 (25,38 m/s) in 10/13 males but only in 3/10 females. In some cases, nerve conduction slowing was non-uniform within single nerves, and one female patient had a previous diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy. There was considerable asymmetry of involvement between different nerves. The median nerve was often more severely affected than the ulnar nerve, and not only in females, as previously reported, but also in males. Therefore, it appears unlikely that this asymmetry is accounted for by a Lyonization phenomenon. Subclinical abnormalities of central nervous system as revealed by multimodal evoked potential studies were found in 8/10 patients. Expression of Cx32 in the brain is the likely explanation of this finding that confirms previous non-systematic observations. We found seven missense and two nonsense mutations (one novel mutation). Two families presented distinct mutations at the same codon (Arg164), while the Arg22Stop and Arg220Stop mutations were each found in two unrelated cases. Partially supported by a grant from the Italian Ministry of Health to F.T and D.P. (Progetto Ricerca Finalizzata ICS 030.3/RF00.174). [source] Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 57JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003D Cocito BACKGROUND: Since 1991, five sets of electrophysiological criteria for CIDP have been reported. However, until now, receiver operator characteristic (ROC), such as sensitivity and specificity, of only AAN criteria were investigated, showing a high specificity, but intermediate sensitivity. The application of these criteria may be useful in clinical trials, but is inadequate in clinical practice, since they preclude immunomodulating treatment in patients who do not meet them. OBJECTIVE: 1) to evaluate the ROC and predictive value of five different electrophysiological criteria for CIDP (AAN, INCAT, Rotta et al, Nicholas et al. and Saperstein et al.); 2) to identify the most informative electrophysiological features indicative of demyelination by mean of the likelihood ratio; 3) to determine, in our series of cases, a set of minimal electrophysiological criteria (albeit aspecific) enough sensitive for CIDP diagnosis. PATIENTS AND METHODS: 20 patients with sensorimotor polyneuropathy, progressive for at least 2 months, with weakness in least two limbs and documented improvement in strength in response to immunotherapy. Other potential causes were excluded, including diabetes and IgM paraproteinemia with or without anti-MAG reactivity. Twelve patients with axonal polyneuropathy associated with diabetes and 12 patients with amyotrophic lateral sclerosis were included as controls. Nerve conduction studies (NCS) were evaluated according to all five sets of NCS criteria and ROC was calculated. Likelihood ratio for CIDP was evaluated for each set of NCS criteria and for presence of each of the following features in different number of nerves: motor conduction velocities (MCV), conduction blocks/temporal dispersion, distal motor (DML) and F-wave latencies (FWL). MCV, DML and FWL were considered indicative of demyelination if decreased or increased as suggested by AAN criteria. Results will be discussed. [source] AUTOMIC FAILURE AND NORMAL PRESSURE HYDROCEPHALUS IN A PATIENT WITH CHRONIC DEMYELINATING INFLAMMATORY NEUROPATHYJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002M. Laurą A 75-year-old man with HCV hepatitis developed at the age of 70 presented with rest and action tremor localized at both hands and progressive cognitive impairment with memory loss. Four years later he begun to complain of progressive fatigue, occasional falls, numbness at the extremities and orthostatic hypotension. One month after admission, he rapidly worsened with inability to walk, mainly because of autonomic failure. Neurological examination revealed gait disturbances, including a wide base of support and short stride, slurred speech, reduction of upward gaze, rest and action tremor at both hands, intrinsic hand muscle and anterior tibialis muscle wasting and weakness on both sides, absent deep tendon reflexes, loss of vibration sense at lower limbs, and bilateral pes cavus. Routine laboratory studies, autoantibodies, thyroid function, neoplastic markers and immunoelectrophoresis were normal. Cryoglobulins were absent, whereas CSF protein content was increased (142 mg/dl). Autonomic nervous system investigation detected severe orthostatic hypotension. Nerve conduction studies showed absent sensory potentials and a marked reduction of compound motor action potential amplitudes and of motor conduction velocities. A sural nerve biopsy revealed remarkable onion bulb-like changes, endoneurial and perivascular infiltrations of inflammatory cells. Psychometric tests showed mild cognitive impairment. Brain MRI was consistent with normotensive hydrocephalus. The findings indicated the presence of chronic inflammatory demyelinating polyneuropathy, autonomic nervous system involvement and normal pressure hydrocephalus. A condition of multiple system atrophy (MSA) might be taken into account, even if somatic peripheral nerve involvement may rarely occur in MSA. Moreover the normal pressure hydrocephalus could be due to the high protein content in CSF (Fukatsu R et al., 1997). [source] POSTIRRADIATION LUMBOSACRAL RADICULOPLEXOPATHY: IMPROVEMENT AFTER IMMUNE THERAPYJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000A. Bersano A delayed progressive impairment of peripheral nervous system including brachial and lumbosacral radiculoplexopathy is a well-known complication of local radiotherapy. No treatment for this infrequent complication is currently available. Recently, improvement after treatment with high dose immunoglobulin (IVIg) has been reported in some patients, suggesting either an immune-mediated inflammatory nerve damage induced by irradiation or a dysimmune neuropathy (CIDP-like) misdiagnosed as a postirradiation disease. We report on two patients who developed motor lumbosacral radiculoplexopathy several years after local radiotherapy. The first patient (ZA) is a 49 y.o. man developing a progressive proximal>distal weakness and hypotrophy of lower limbs, 20 years after radiotherapy of lumbosacral region for seminoma. Electrophysiological studies showed markedly reduced motor conduction velocities (CV) and prolonged F-wave latencies in lower limb nerves. The second patient (BF), is a 52 y.o. woman who developed progressive left brachial plexopathy and distal>proximal weakness and hypotrophy of lower limbs 12 years after a first course of toracoascellar and lumbar irradiation for Hodgkin lymphoma followed by a second course of cervicoclavicular irradiation for tumor recurrence 7 years later. Electrophysiological studies showed markedly reduced CMAP amplitudes and proportionally reduced CV in motor nerves. No sensory impairment was detected in both patients. CSF protein was elevated in both patients while cells were normal. On the assumption of a possible dysimmune origin of the disease, patient ZA underwent high dose intravenous steroid treatment, while patient BF, who had previously deteriorated after steroids, was treated with IVIg. After treatment, patient ZA became able to walk with less waddling, to rise from the floor and climb stairs without support, and to run. Improvement was less consistent in patient BF, whose right leg strength improved even if she still needed bilateral support to walk. The improvement observed in both patients supports the hypothesis that, at least in some patients, an immune-mediated mechanism may underlie postirradiation radiculoplexopathy. [source] CLINICAL AND IMMUNOLOGICAL FEATURES AND RESPONSE TO IVIg IN PATIENTS WITH CLINICALLY TYPICAL MULTIFOCAL MOTOR NEUROPATHY BUT NO OVERT CONDUCTION BLOCKJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2000E. Nobile-Orazio Multifocal motor neuropathy (MMN) is characterized by progressive asymmetric limb weakness usually predominant in the upper limbs associated with conduction block (CB) in motor but not sensory nerves. There are, however, occasional patients with clinically typical MMN in whom no CB can be detected. Whether these patients differ from patients with MMN and CB remains unclear. Since 1991, we have observed 24 patients with the typical clinical features of MMN. In 20 of them (14 men and 6 women), electrophysiological studies disclosed the presence of CB in at least one motor nerve. In four (all women), no evidence of CB could be detected in examined nerves even if three had some features of demyelination, including asymmetric reduction of motor conduction velocities (1 patient) or prolonged or absent F wave latencies (3 patients). Three of them had markedly reduced or absent proximal and distal CMAP amplitudes in some nerves. The mean age of onset of MMN was similar in patients with (41.5 years, range 21,70) and without CB (41.5 years, range 24,57). The mean duration of the disease at the time of our first visit was longer in patients without CB (18.5 years, range 13,25) than in those with CB (6.3 years, 3 months,25 years); only 3 patients with CB had a duration of the disease longer than 10 years. All patients without CB had a predominant or exclusive impairment of upper limbs compared with 18 (90%) of those with CB. The mean Rankin score before therapy was slightly worse in patients without (2.5) than with (2.2) CB. Anti-ganglioside antibodies were found in 1 patient without CB (25%) and in 8 (40%) with CB. All but 2 patients with CB (90%) consistently improved with IVIg. All patients without CB also improved with IVIg, but only one did so consistently. In conclusion, patients with the typical clinical presentation of MMN but no overt CB are clinically and immunologically indistinguishable from those with MMN and CB. The longer duration of the disease and frequent axonal impairment in patients without CB may explain the lower efficacy of IVIg in these patients than in those with CB. [source] Resolution of alcoholic neuropathy following liver transplantationLIVER TRANSPLANTATION, Issue 12 2004Edward Gane Between 10 and 20% of adult liver transplants are performed for end-stage alcoholic liver disease. Severe extrahepatic end-organ damage from alcoholism (cardiomyopathy, pancreatitis, central nervous system injury, and neuropathy) is widely regarded as an absolute contraindication to liver transplantation, despite a lack of data on the effect of transplantation on these complications. We describe such a patient who presented with decompensated alcoholic liver disease and moderately severe peripheral neuropathy. Both his liver failure and neuropathy progressed despite 9 months abstinence and intensive nutritional support. By 12 months post-transplant, however, this patient had regained almost normal muscle strength, with associated recovery in sensory and motor conduction velocities. Direct alcohol toxicity, nutritional and vitamin deficiencies, and liver failure were all likely etiologic factors in this patient's neuropathy. In conclusion, this case suggests that peripheral neuropathy in a patient with alcoholic cirrhosis may resolve following liver transplantation and should not constitute a contraindication to transplantation, even when it is disabling. (Liver Transpl 2004;10:1545,1548.) [source] Schwann cell myelination occurred without basal lamina formation in laminin ,2 chain-null mutant (dy3K/dy3K) miceGLIA, Issue 2 2001Masahiro Nakagawa Abstract The laminin ,2 chain is a major component of basal lamina in both skeletal muscle and the peripheral nervous system. Laminin ,2 chain deficiency causes merosin-deficient congenital muscular dystrophy, which affects not only skeletal muscles, but also the peripheral and central nervous systems. It has been reported that the formation of basal lamina is required for myelination in the peripheral nervous system. In fact, the spinal root of dystrophic mice (dy/dy mice), whose laminin ,2 chain expression is greatly reduced, shows lack of basal lamina and clusters of naked axons. To investigate the role of laminin ,2 chain and basal lamina in vivo, we examined the peripheral nervous system of dy3K/dy3Kmice, which are null mutants of laminin ,2 chain. The results indicate the presence of myelination although Schwann cells lacked basal lamina in the spinal roots of dy3K/dy3K mice, suggesting that basal lamina is not an absolute requirement for myelination in vivo. Immunohistochemically, the expression of laminin ,4 chain was increased and laminin ,5 chain was preserved in the endoneurium of the spinal root. Laminin ,4 and ,5 chains may play the critical role in myelination instead of laminin ,2 chain in dy3K/dy3Kmice. In addition, the motor conduction velocity of the sciatic nerve was significantly reduced compared with that of wild-type littermate. This reduction in conduction velocity may be due to small axon diameter, thin myelin sheath and the patchy disruption of the basal lamina of the nodes of Ranvier in dy3K/dy3Kmice. GLIA 35:101,110, 2001. © 2001 Wiley-Liss, Inc. [source] Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 43JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003S Amadio Study aim: the Ebf gene family has been implicated in several developmental processes, ranging from B-cell development to neuronal differentiation. As the murine Ebf2 gene is expressed in numerous sites of nervous system, Ebf2-null mice develop hypogonadotropic hypogonadism, due to defective migration of gonadotropin releasing hormone-synthesizing neurons, and a peripheral neuropathy as well. Therefore, we aimed to study whether electrophysiological tests would be able to detect abnormalities of peripheral nerve function. Methods: 2 groups of mice were studied, which consisted of 8 Ebf2-/- mice and 9 age-matched controls. The sciatic nerve was stimulated at the ankle and at the ischiatic notch; the compound motor action potential (cMAP) was recorded from the paw muscles with a pair of needle electrodes to measure the motor conduction velocity (MCV). Results: MCV mean values were lower in Ebf2-/-(21.8 m/sec; SD 2.9) than in controls (35.2 m/sec; SD 2.6) and the difference was significant (p < 0.001). The mean cMAP amplitude was also decreased in Ebf2-/-(6.2 mV; SD 2.7) as compared to controls (9.3 mV; SD 2.6, p < 0.05). Conclusions: electrophysiological tests demonstrated a sharp decrease of sciatic MCV in Ebf2-/- mouse, as consequence of defective axon sorting, segmental dysmyelination and axonal damage revealed by pathological study. [source] ANTI-SULFATIDE IgM ANTIBODIES DETECTED IN A PATIENT DIAGNOSIS OF MOTOR NEURON DISEASEJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2002Article first published online: 11 MAR 200 D'Avino C., Del Corona A., Bacci A., Calabrese R., Siciliano G. Department of Neuroscience-Clinical Neurology-University of Pisa-Italy Case report. The patient, a 66-year-old man with a 5-year diagnosis of diabetes mellitus, in Sep. 2000 started complaining of language disturbances as rhinolalia. In Jan. 2001, because of generalized fatigue and difficulties in walking, he was hospitalized in Internal Medicine and a diagnosis of diabetic angiopathy and neuropathy was made. Since discharge patient clinical conditions gradually deteriorated and a neurological evaluation showed tongue atrophy, dysarthria, dysphagia, fasciculations in the four limbs, increased deep tendon reflexes with bilateral foot clonus and paraparetic spastic deambulation. He underwent spinal MRI that showed mild arthrosic abnormalities in cervical spinal cord and limb EMG that showed denervation spontaneous activity with neurogenic MUAP modifications, with normal sensory and motor conduction velocity. MEP showed bilateral pyramidal track involvement. A significantly increased anti-sulphatide IgM antibodies titer (1:32,000) in the serum was detected. The diagnosis at discharge was "probable motor neuron disease" and the patient is under riluzole therapy at the moment. Discussion. Anti-sulfatide IgM antibodies are currently associated with several subtypes of peripheral neuropathy. In most cases it is a chronic dysimmune sensory or sensorimotor neuropathy in which electrophysiological and morphological studies are usually con- sistent with a predominant demyelination frequently associated with prominent axonal loss. Although rare, an association between motor neuron disease and IgM anti-sulfatide has been described in a recent paper by Latov and coworkers that reviewed electrophysiologic, morphologic and laboratory data of 25 patients with elevated antisulfatide antibodies. It seems interesting to follow-up the clinical course of the patient, the response to therapy and its correlation to antibodies titer, while the opportunity of high dose IVIg therapy is under discussion at the moment. [source] Sural nerve biopsy may predict future nerve dysfunctionACTA NEUROLOGICA SCANDINAVICA, Issue 1 2009S. Thrainsdottir Objective,,, Sural nerve pathology in peripheral neuropathy shows correlation with clinical findings and neurophysiological tests. The aim was to investigate progression of nerve dysfunction over time in relation to a baseline nerve biopsy. Methods,,, Baseline myelinated nerve fiber density (MNFD) was assessed in sural nerve biopsies from 10 men with type 2 diabetes, 10 with impaired and 10 with normal glucose tolerance. Nerve conduction and quantitative perception thresholds were estimated at baseline and follow-up (7,10 years later). Results,,, Subjects with low MNFD (,,4700 fibers/mm2) showed decline of peroneal amplitude (P < 0.02) and conduction velocity (P < 0.04), as well as median nerve sensory amplitude (P < 0.05) and motor conduction velocity (P < 0.04) from baseline to follow-up. In linear regression analyses, diabetes influenced decline of nerve conduction. MNFD correlated negatively with body mass index (r = ,0.469; P < 0.02). Conclusion,,, Low MNFD may predict progression of neurophysiological dysfunction and links obesity to myelinated nerve fiber loss. [source] | ||||||||||