Guillain-Barre syndrome (GBS), Miller Fisher syndrome (MFS) and Bickerstaffâs brainstem encephalitis (BBE) are immune-mediated disorders with overlapping clinical features. Anti-GQ1b IgG antibody is detected at variable frequencies, up to 95% in MFS, 26% in
GBS and 66% in BBE. In vitro studies of MFS have demonstrated anti-GQ1b IgG
antibody-mediated presynaptic damage at the neuromuscular junction. This mechanism may be responsible for some of its clinical manifestations. Repetitive nerve stimulation (RNS) is a validated electrophysiological technique for assessing neuromuscular transmission. Incremental
responses to RNS are characteristic of neuromuscular transmission defect at the presynaptic region, as reported in the Lambert-Eaton myasthenic syndrome (LEMS) and botulism. Significant correlation of increment with anti- GQ1b IgG antibody titer strengthened the role this antibody plays in presynaptic neuromuscular transmission defect.
Last date updated on July, 2014