Determinants and clinical application of muscle fibre conduction velocity.

Contains fulltext : 52347.pdf (publisher's version ) (Open Access)A muscle fibre can be excited by electrical stimulation using a needle electrode. Action potentials elicited this way will be conducted through the muscle fibre and can be recorded at some distance with a second needle electrode. This way, muscle fibre conduction velocity can be estimated. In the present study we have investigated the determinants of conduction velocity in healthy subjects and in patients with various neuromuscular disorders. Our main result was a linear relationship between conduction velocity and fibre diameter that we demonstrated in both groups, using data obtained from muscle biopsies. Furthermore, we evaluated the diagnostic value of the technique to measure muscle fibre conduction velocity with needle electrodes. Our findings showed that the diagnostic value was similar to those of the reference techniques, which were electromyography and muscle biopsy. In some myopathies, such as mitochondrial myopathies, channelopathies, and early motor neuron disease, our technique rendered superior results. In conclusion, this thesis contributes to the knowledge of muscle fibre physiology, and clarifies the use of an invasive technique to measure conduction velocity in electrodiagnosis.RU Radboud Universiteit Nijmegen, 14 december 2007Promotores : Zwarts, M.J., Stegeman, D.F. Co-promotor : Schelhaas, H.J.166 p