Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Jan;43(1):31-6.
doi: 10.1002/mus.21843.

Activity-dependent Conduction Block in Multifocal Motor Neuropathy


Activity-dependent Conduction Block in Multifocal Motor Neuropathy

Dirk C G Straver et al. Muscle Nerve. .


Previous studies suggested that activity-dependent conduction block (CB) contributes to weakness in multifocal motor neuropathy (MMN). Obtaining more robust evidence for activity-dependent CB is important because it may be a novel target for treatment strategies. We performed nerve conduction studies in 22 nerve segments of 19 MMN patients, before and immediately after 60 seconds of maximal voluntary contraction (MVC) of the relevant muscle. We employed supramaximal electrical stimulation, excluded nerves with marked axonal loss, and adopted criteria for activity-dependent CB. Per segment, the segmental area ratio [area proximal compound muscle action potential (CMAP)/area distal CMAP] was calculated and, per nerve, total area ratio (area CMAP at Erb's point/area distal CMAP) was obtained. MVC induced no changes in mean area ratios and induced no activity-dependent CB. In segments with CB before MVC, the MVC induced increased duration prolongation. In MMN, MVC induced temporal dispersion but no activity-dependent CB.

Similar articles

See all similar articles

Cited by 3 articles

Publication types