アレイ電極により推定した咬筋の神経筋接合部の分布

抄録

The purpose of this study was to investigate the position of the myoneural junction (end-plate zone) which influence the myoelectric signals. Motor unit action potentials (MUAPs) were derived with multiple surface electrodes (electrode arrays) from the right and left masseter muscles of 18 healthy adults. Each potentials detected by 11 amplifiers showed the bidirectional propagation along the muscle fibers. The position of the end-plate zone on the muscle was estimated using spike triggered averaging method.
The findings obtained were as follows:
1. The masseter showed more activity at its lower than at its upper portion at 10-50% of the maximum voluntary contractions. The modification in the electrical activity was shown when the location of the electrodes was changed with respect to the end-plate zone of the muscle.
2. The propagation of the MUAPs along the muscle fibers was detected in the lower portion of the masseter muscle at the low contraction level.
3. The position of the end-plate zone estimated was about 40-50 mm apart from the zygomatic arch.
4. The position of the end-plate zone was not centered but spread over along the muscle fibers.
5. It was concluded that this technique for estimating the end-plate zone became effective in the diagnosis of neuromuscular disorders.