1,721,012 research outputs found
Transcranial magnetic stimulation as a new tool to control pain perception
Full text linkTreatment for chronic pain is frequently unsuccessful or characterized by side-effects. The high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been suggested in the management of refractory chronic pain. Various studies have shown that HF-rTMS sessions of long-duration applied at primary motor cortex induce pain relief through mechanisms of plastic changes. Efficacy of rTMS mostly depends on stimulation parameters, but this aspect requires better characterization. A rationale to target other cortical areas exists. Current data are promising, but a careful analysis of stimulation settings and maintenance treatment design are need
Bilateral spike-and-wave dicharges in a hemi-deafferented cortex
No full textWe studied a patient with a history of absence attacks in childhood in whom an absence status with bilateral spike-and-wave discharges developed after a top-of-the-basilar syndrome. Surprisingly, even though the ischemic lesion involved the left thalamus alone, spike-and-wave discharges were recorded from the two hemispheres. Three days after antiepileptic treatment (sodium valproate 500 mg 3 times a day) began, electroenceplalographic recordings and consciousness became normal. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved
Atypical case of diaphragmatic pseudo myoclonus
No full textAbdominal muscles can be involved in rare conditions such as diaphragmatic myoclonus (also known as diaphragmatic flutter), which consists of brief involuntary, repetitive contractions of the diaphragm. The possible causes of this condition include neuronal reorganization after structural lesions in the central or peripheral
nervous system, pharmaceutical intake or metabolic dysfunctions. In this case report, accompanied by video documentation, we describe a subject with a iatrogenic movement disorder of the diaphragm
Synaptic potentiation induced by rTMS: effect of lidocaine infusion
No full textRepetitive transcranial magnetic stimulation (rTMS) delivered at various intensities and frequencies excites cortical motor areas. Trains of stimuli (at 5-Hz frequency, and suprathreshold intensity) progressively increase the size of motor evoked potentials (MEPs) and the duration of the cortical silent period (CSP) in normal subjects. Because antiepileptic drugs, acting mainly on sodium channels, depress MEP facilitation during rTMS, we suggested that rTMS trains facilitate the MEP size by inducing synaptic potentiation primarily involving voltage-gated sodium channels. The aim of this study was to evaluate the effect of lidocaine - a drug that acts selectively on sodium channels - on the rTMS-induced changes in cortical excitability. We tested the changes in motor threshold, MEP size, CSP duration evoked by focal rTMS and the M-wave amplitude in healthy subjects before and after lidocaine infusion. Lidocaine abolished the normal rTMS-induced facilitation of MEPs but left the other rTMS variables and the M-wave unchanged. Our results suggest that the MEP facilitation related to rTMS-induced synaptic potentiation results from an increase in cortical excitatory interneuron excitability that involves voltage-gated sodium channels
Duloxetine for the Treatment of Overactive Bladder Syndrome in Multiple Sclerosis: A Pilot Study
No full textOBJECTIVES: Overactive bladder (OAB) syndrome represents one of the main urinary disorders associated with multiple sclerosis (MS). At present, no widely accepted effective treatment is available. Duloxetine, an antidepressant acting as a selective serotonin-norepinephrine reuptake inhibitor, has been shown to be effective in the treatment of some symptoms of stress urinary incontinence and OAB because of etiology other than MS.The present study aims at establishing the efficacy and tolerability of duloxetine in the treatment of OAB in patients affected by remitting-relapsing MS and secondary progressive MS. MATERIALS AND METHODS: Twenty-three patients with MS, 13 of which with remitting-relapsing MS and 10 with secondary progressive MS, have been treated with duloxetine and placebo for a total period of 8 weeks during a single-blinded cross-over trial. At each programmed visit, patients have been screened for the following: (1) quantitative evaluation of maximal bladder capacity and postmicturition residual volume; (2) questionnaire administration to evaluate bladder disorder-Overactive Bladder Questionnaire, quality of life-Visual Analogue Scale-Quality of life, fatigue-Fatigue Severity Scale, and depression-Beck Depression Inventory. RESULTS: Three patients did not complete the study because of duloxetine-related adverse events. A statistically significant improvement in bladder disorder, as measured by OAB-Q, has been observed after duloxetine treatment compared with both basal levels and placebo with values of 21.8 ± 1.1 versus 34.2 ± 1.2 (P < 0.0001) and 21.8 ± 1.1 versus 30.1 ± 1.7 (P < 0.003), respectively.In addition, a decrease in postmicturition residual volume has also been observed compared with basal level (6.8 ± 3.2 ml vs 38.1 ± 12.2 ml, P = 0.06) together with an improvement in quality of life (7.1 ± 0.5 vs 6.3 ± 0.4, P = 0.07). Both these changes were close to being statistically significant. CONCLUSIONS: It emerges from this study that duloxetine might become an effective therapeutic alternative to be investigated in a larger number of MS patients for the treatment of OAB. Duloxetine should be considered a first-choice drug in the treatment of MS patients presenting both depression and OAB; in addition, it should also be considered as a suitable alternative or as concomitant treatment in MS patients with OAB but not experiencing depression Copyright © 2012 by Lippincott Williams & Wilkins
Effects of repetitive transcranial magnetic stimulation in a patient with fixation-off sensitivity
No full textAim of the present study was to evaluate the acute and long-term effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on focal epileptiform interictal EEG activity in a patient with fixation-off sensitivity and partial epilepsy. Real and sham rTMS were delivered over the vertex. Two trains of 500 stimuli per day were delivered at 0.33 Hz frequency and threshold intensity for five consecutive days. The number of posterior EEG spikes and spike-and-wave complexes/min before and after the application of rTMS were compared in a blinded manner. In our patient, real-rTMS induced a long-lasting decrease in the number of posterior EEG spikes and spike-and-wave complexes/min. Despite the limitations of a single case report, our study confirms that low-frequency rTMS significantly reduces interictal focal epileptic activity over time
Enhanced brain motor activity in patients with MS after a single dose of 3,4-diaminopyridine
No full textBackground: 3,4-Diaminopyridine (3,4-DAP), a potassium (K+) channel blocker, improves fatigue and motor function in multiple sclerosis (MS). Although it was thought to do so by restoring conduction to demyelinated axons, recent experimental data show that aminopyridines administered at clinical doses potentiate synaptic transmission. Objective: To investigate motor cerebral activity with fMRI and transcranial magnetic stimulation (TMS) after a single oral dose of 3,4-DAP in patients with MS. Methods: Twelve right-handed women (mean ± SD age 40.9 ± 9.3 years) underwent fMRI on two separate occasions (under 3,4-DAP and under placebo) during a simple motor task with the right hand. FMRI data were analyzed with SPM99. After fMRI, patients underwent single-pulse TMS to test motor threshold, amplitude, and latency of motor evoked potentials, central conduction time, and the cortical silent period; paired-pulse TMS to investigate intracortical inhibition (ICI) and intracortical facilitation (ICF); and quantitative electromyography during maximal voluntary contraction. Results: FMRI motor-evoked brain activation was greater under 3,4-DAP than under placebo in the ipsilateral sensorimotor cortex and supplementary motor area (p < 0.05). 3,4-DAP decreased ICI and increased ICF; central motor conduction time and muscular fatigability did not change. Conclusion: 3,4-DAP may modulate brain motor activity in patients with MS, probably by enhancing excitatory synaptic transmission
Excitatory and inhibitory after-effects after repetitive magnetic transcranial stimulation (rTMS) in normal subjects
No full textEffects of transcranial magnetic stimulation on the H reflex and F wave in the hand muscles
No full textObjective: In 14 healthy subjects, we studied the effects of transcranial magnetic stimulation (TMS) on the excitability of spinal motoneurons in the abductor pollicis brevis muscle (ABP), by testing the F wave and H reflex. Methods: TNIS pulses were delivered with the subjects at rest and at various motor threshold (Mth) intensities. Electrical stimuli were delivered to the median nerve at the wrist at two different intensities. High-intensity pulse was used to evoke an F wave and low-intensity paired pulse to evoke an H reflex in the ABP muscle. The effects of TNIS were studied using a conditioning-test paradigm. The tests F wave and H reflex were conditioned by TMS (120% Mth) at various interstimulus intervals (ISIs) (30-100 ms) and intensities (90-200% Mth). Results: At 30 ms but not at ISIs from 40 to 100 ms, conditioning TNIS (120% Mth) significantly increased the F-wave area. At the 30 ms ISI, conditioning TNIS at 120% Mth intensity significantly increased the F-wave area whereas higher intensities (140-180% Mth) did not. At 200% Mth intensity, the F-wave area decreased significantly. At 30 and 40 ms ISIs, conditioning TNIS at 120% Mth significantly reduced the H-reflex area. At 50-100 ms ISIs, the H-reflex area almost matched the control value. At the 30 ms ISI, conditioning TNIS at greater than or equal to 100% Mth intensity significantly decreased the H-reflex area. Conclusions: In conclusion, our findings suggest that the distinct changes in the TMS-conditioned F wave and H reflex reflect changing excitability in the motoneuronal populations activated by the cortical input. (C) 2003 International Federation of Clinical Neurophysiology. Published by Elsevier Science Ireland Ltd. All rights reserved
Attention influences the excitability of cortical motor areas in healthy humans
No full textWe investigated whether human attentional processes influence the size of the motor evoked potentials (MEP) facilitation and the duration of the cortical silent period (CSP) elicited by high-frequency repetitive transcranial magnetic stimulation (rTMS). In healthy subjects we assessed the effects of 5 Hz-rTMS, delivered in trains of 10 stimuli at suprathreshold intensity over the hand motor area, on the MEP size and CSP duration in different attention-demanding conditions: "relaxed," "target hand," and "non-target hand" condition. We also investigated the inhibitory effects of 1 Hz-rTMS conditioning to the premotor cortex on the 5 Hz-rTMS induced MEP facilitation. F-waves evoked by ulnar nerve stimulation were also recorded. rTMS trains elicited a larger MEP size facilitation when the subjects looked at the target hand whereas the increase in CSP duration during rTMS remained unchanged during the three attention-demanding conditions. The conditioning inhibitory stimulation delivered to the premotor cortex decreased the MEP facilitation during the "target hand" condition, leaving the MEP facilitation during the other conditions unchanged. None of the attentional conditions elicited changes in the F wave. In healthy subjects attentional processes influence the size of the MEP facilitation elicited by high-frequency rTMS and do so through premotor-to-motor connections. © 2007 Springer-Verlag
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