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

Abstract

Background 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 MMN.

Assessing the upper motor neuron in amyotrophic lateral sclerosis using the triple stimulation technique: A multicenter prospective study

“…TMS intensity was set at 130% of the resting motor threshold. TST was performed as described in previous studies (Attarian et al, 2015(Attarian et al, , 2007(Attarian et al, , 2005Corazza et al, 2020;Deroide et al, 2007;Eusebio et al, 2007;Grapperon et al, 2019Grapperon et al, , 2014Rico et al, 2009;Sevy et al, 2018) in accord with the practical guidelines for diagnostic TMS of the International Federation of Clinical Neurophysiology (Groppa et al, 2012). This technique consists first of the delivery of a magnetic stimulation on the motor cortex, followed by a supra-maximal electrical stimulation at the wrist on the ulnar nerve, so that the descending corticomotoneuronal volley collides with the antidromic action potentials.…”

Motor Nerve Conduction Block Estimation in Demyelinating Neuropathies by Deconvolution

“…Thus, with the intent of extending the promising results shown in [ 19 ] to neuropathic patients with abnormal TD of the APs, in this paper SAW has been included in the deconvolution kernel. The method was then tested on experimental signals from both healthy subjects and pathological patients, with either Chronic Inflammatory Demyelinating Polyneuropathy (CIDP [ 1 , 7 , 26 , 27 , 28 , 29 , 30 ]) or Multifocal Motor Neuropathy (MMN [ 26 , 28 , 29 , 31 , 32 ]). Our results are expected to contribute to the discussion on guidelines [ 7 , 27 , 30 ] and the proposal of innovative methods for the assessment of CB [ 1 , 31 ].…”

“…The method was then tested on experimental signals from both healthy subjects and pathological patients, with either Chronic Inflammatory Demyelinating Polyneuropathy (CIDP [ 1 , 7 , 26 , 27 , 28 , 29 , 30 ]) or Multifocal Motor Neuropathy (MMN [ 26 , 28 , 29 , 31 , 32 ]). Our results are expected to contribute to the discussion on guidelines [ 7 , 27 , 30 ] and the proposal of innovative methods for the assessment of CB [ 1 , 31 ].…”

Técnica de ressíntese: descrição da técnica para identificação de bloqueios de condução e aplicações clínicas

“…A neuropraxia apresenta por definição um BC transitório (SEDDON, 1942;SUNDERLAND, 1951) DEROIDE et al, 2007), a ultrassonografia (USG) de plexo braquial (GOEDEE et al, 2019) e a ressonância nuclear magnética (RNM) de plexo braquial (GOEDEE et al, 2017). A incorporação de técnicas que aumentem a sensibilidade é interessante, bem como seu uso inclusive combinado (CORAZZA et al, 2020), e nesse contexto a ressíntese pode ser também uma opção interessante.…”