[Magnetic stimulation motor evoked potential in patients with Guillain-Barré syndrome].

In 27 patients with Guillain-Barré syndrome (GBS), motor evoked potentials (MEP) were compared with electromyography (EMG), nervous conduction velocity (NCV), F wave and somatosensory evoked potentials (SEP). The positive rate of MEP was 74%, and 83% of EMG. The findings of MEP were consistent with pathological changes of demyelination and clinical distribution of muscle weakness. A good correlation between abnormal MEP and degree of muscle weakness (P < 0.01) was noted. MEP should be regarded as an objective index for diagnosis, differential diagnosis, followup and effect of therapy. MEP is painless and can be done easily and repeated.