Article

When recording compound muscle action potentials, the active electrode
is traditionally placed over the muscle and the reference over the corresponding
tendon (belly-tendon recording). This placement assumes that the reference
electrode is electrically inactive. We report on the influence of reference
electrode placement on the compound muscle action potential recorded from the
flexor digiti minimi brevis. DESIGN: We recorded compound muscle action
potentials from the flexor digiti minimi brevis using belly electrodes, tendon
electrodes, and an electrode on the contralateral medial malleolus from 11
healthy subjects. We measured compound muscle action potential amplitudes and
onset latencies. RESULTS: Compound muscle action potentials recorded using
electrodes on a tendon and the contralateral medial malleolus had higher
amplitudes and shorter onset latencies than the compound muscle action potentials
recorded with the belly-tendon montage. CONCLUSIONS: When recording compound
muscle action potentials from flexor digiti minimi brevis, the influences of the
tendon "reference" electrode on latency and amplitude are large.
Electrodiagnositicians should consider the influences of the reference electrode
when assessing the lateral plantar nerve. This study may also inform us about the
influence of proximally innervated muscles on the compound muscle action
potential recorded in the limbs.

Langue : ANGLAIS