iMAX: un nouvel outil pour l'évaluation de l'excitabilité des axones moteurs (une étude prospective multicentrique)

peer reviewe

Analyse fonctionnelle et structurale du faisceau corticospinal au cours de la sclérose latérale amyotrophique

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocSudocFranceF

Monitoring the short-term effect of intravenous immunoglobulins in multifocal motor neuropathy using motor unit number index

International audienc

Detection of proximal conduction blocks using a triple stimulation technique improves the early diagnosis of Guillain-Barre syndrome

Objective: Current diagnostic electrophysiological criteria can miss the early stages of Guillain-Barre syndrome (GBS). We evaluated the diagnostic efficiency of the triple stimulation technique (TST) in highlighting proximal conduction blocks (CBs) in patients who do not meet the electrophysiological criteria for GBS. Methods: All patients with a diagnosis of clinical GBS referred to our center between September 2014 and January 2016 were included in the study. For patients who did not fulfill the electrophysiological criteria of GBS, we performed the TST examination. Results: Among the 44 included patients, 86% fulfilled the electrophysiological criteria of GBS during the initial nerve conduction study (NCS). The six remaining patients had proximal CBs revealed by TST examination. Therefore, a combination of a conventional NCS and the TST allowed 100% of the patients to be electrophysiologically diagnosed. Conclusions: TST is useful for the diagnosis of GBS in association with NCS, particularly in the early stages of the disease. (C) 2017 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved

Detection of proximal conduction blocks using a triple stimulation technique improves the early diagnosis of Guillain-Barre syndrome

Objective: Current diagnostic electrophysiological criteria can miss the early stages of Guillain-Barre syndrome (GBS). We evaluated the diagnostic efficiency of the triple stimulation technique (TST) in highlighting proximal conduction blocks (CBs) in patients who do not meet the electrophysiological criteria for GBS. Methods: All patients with a diagnosis of clinical GBS referred to our center between September 2014 and January 2016 were included in the study. For patients who did not fulfill the electrophysiological criteria of GBS, we performed the TST examination. Results: Among the 44 included patients, 86% fulfilled the electrophysiological criteria of GBS during the initial nerve conduction study (NCS). The six remaining patients had proximal CBs revealed by TST examination. Therefore, a combination of a conventional NCS and the TST allowed 100% of the patients to be electrophysiologically diagnosed. Conclusions: TST is useful for the diagnosis of GBS in association with NCS, particularly in the early stages of the disease. (C) 2017 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved

GLOBAL MOTOR UNIT NUMBER INDEX SUM SCORE FOR ASSESSING THE LOSS OF LOWER MOTOR NEURONS IN AMYOTROPHIC LATERAL SCLEROSIS

International audienceIntroduction: We propose a motor unit number index (MUNIX) global sum score in amyotrophic lateral sclerosis (ALS) to estimate the loss of functional motor units. Methods: MUNIX was assessed for 18 ALS patients and 17 healthy controls in 7 muscles: the abductor pollicis brevis (APB), abductor digiti minimi (ADM), tibialis anterior (TA), deltoid, trapezius, submental complex, and orbicularis oris. Results: MUNIX was significantly lower in ALS patients than in healthy controls for the APB, ADM, TA, and trapezius muscles. The MUNIX sum score of 4 muscles (ADM + APB + trapezius + TA) was lower in ALS patients (P=0.01) and was correlated with clinical scores. Discussion: The global MUNIX sum score proposed in this study estimates the loss of lower motor neurons in several body regions, including the trapezius, and is correlated with clinical impairment in ALS patients

Combination of serum and CSF neurofilament-light and neuroinflammatory biomarkers to evaluate ALS

International audienceAbstract This monocentric prospective study of patient suffering from Amyotrophic lateral sclerosis (ALS) aims to evaluate the prognosis and diagnostic potential of both Neurofilament-Light (Nf-L) and neuroinflammatory biomarkers in serum and CSF. Candidate markers levels were measured using multiplex method in serum of 60 ALS patients, 94 healthy controls of 43 patients suffering from Inflammatory Peripheral Neuropathies (IPN). A comparative CSF analysis was performed for 20 ALS and 17 IPN patients. Among the altered biomarkers, CSF Nf-L level remains the best marker of ALS severity, while serum levels correlate strongly with disease progression. The combination of Nf-L and ICAM-1 concentrations in the CSF and IFN-γ concentration in the serum differentiate ALS patients from IPN patients with improved sensibility and specificity relative to individual biomarkers. A cutoff value of 0.49 for the fitted values of these 3 biomarkers discriminate ALS from IPN patients with a specificity of 100% (78.20–100%) and a sensibility of 85.71% (57.19–98.22%) with an AUC of 0.99 ± 0.01. The measure of Nf-L and neuroinflammatory biomarkers in CSF and serum can be useful biomarkers panel in the differential diagnosis of ALS

iMAX: un nouvel outil pour évaluer l'excitabilité des axones moteurs périphériques (une étude prospective multicentrique)

iMAX: un nouvel outil pour évaluer l'excitabilité des axones moteurs périphériques (une étude prospective multicentrique) iMAX: a new tool for the assessment of motor axon excitability (a multicenter prospective study) Objectifs The aim of this study was to validate by a multicentric approach a new electrodiagnostic technique called iMAX to evaluate the peripheral motor axons excitability. Matériel / Patients et méthodes iMAX (the lowest intensity allowing a maximal response) and two other excitability parameters, iUP and threshold were prospectively derived from three nerves (median, ulnar and fibular) in four university centers (Liège, Marseille, Fraiture and Nice). iMAX procedure was applied in 28 healthy volunteers and 32 patients with a demyelinating (CIDP, GBS, CMT1a) or axonal peripheral neuropathy. Résultats The iMAX parameters of healthy volunteers were not significantly different in the four centers. The test-retest reproducibility was good (Spearman's correlation coefficient > 0.5). Upper limits of normal were established using the 95th percentile. Comparison of the results between volunteers and patient groups indicated significant increases in iMAX parameters especially with the CMT1a and CIDP groups. In CMT1a, iMAX abnormalities were homogeneous at the three stimulation sites, which was not the case for CIDP. Discussion - Conclusion The iMAX procedure is reliable and allows to demonstrate disorders of motor axons excitability. The iMAX technique should prove useful in routine clinical practice as it is a fast (5'), non-invasive procedure, easily applicable without dedicated software or devices

iMAX: A new tool for assessment of motor axon excitability. A multicenter prospective study.

[en] OBJECTIVE: This study was undertaken to establish by a multicentric approach the reliability of a new technique evaluating motor axon excitability. METHODS: The minimal threshold, the lowest stimulus intensity allowing a maximal response by 1 mA increments (iUP) and then by 0.1 mA adjustments (iMAX) were prospectively derived from three nerves (median, ulnar, fibular) in four university centers (Liège, Marseille, Fraiture, Nice). iMAX procedure was applied in 28 healthy volunteers (twice) and 32 patients with Charcot-Marie-Tooth (CMT1a), chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barré syndrome (SGB) or axonal neuropathy. RESULTS: Healthy volunteers results were not significantly different between centers. Correlation coefficients between test and retest were moderate (> 0.5). Upper limits of normal were established using the 95th percentile. Comparison of volunteers and patient groups indicated significant increases in iMAX parameters especially for the CMT1a and CIDP groups. In CMT1a, iMAX abnormalities were homogeneous at the three stimulation sites, which was not the case for CIDP. CONCLUSIONS: The iMAX procedure is reliable and allows the monitoring of motor axon excitability disorders. SIGNIFICANCE: The iMAX technique should prove useful to monitor motor axonal excitability in routine clinical practice as it is a fast, non-invasive procedure, easily applicable without specific software or devices

Comparison of MRI and motor evoked potential with triple stimulation technique for the detection of brachial plexus abnormalities in multifocal motor neuropathy

International audienceBackground: Conduction blocks (CB) are the diagnostic hallmark of multifocal motor neuropathy (MMN). Conventional nerve conduction studies cannot detect CB above Erb's point. Our purpose was to compare the performance of the motor evoked potential with triple stimulation technique (MEP-TST) and MRI in the detection of abnormalities of the brachial plexus.Methods: Examinations were performed on 26 patients with MMN (11 definite, 6 probable, 9 possible), of whom 7 had no CB. Results: MEP-TST detected proximal CB in 19/26 patients. Plexus MRI showed T2 hyperintensity in 18/26 patients, with nerve enlargement in 14/18. A combination of both techniques increased the detection rate of brachial plexus abnormalities to 96% of patients (25/26).Conclusions: MEP-TST and MRI have high sensitivities for detecting brachial plexus abnormalities. A combination of the two techniques increases the detection rate of supportive criteria for the diagnosis of MM