Biomedical subjects

Gulapar Phongsamart

Publications and source records attributed to Gulapar Phongsamart.

2 recordsLinked to original sources

PubMed2003

Quantitative electromyography.

Quantitative EMG is an MUAP analysis technique providing objective information on the NEE. The concept and techniques are not new; however, with the advancement of computer technology, quantitative EMG is now more easily performed. The study requires solid knowledge of basic neurophysiology and access to the appropriate instrument to provide smooth technique and accurate interpretation. Despite recent technical advances, the original MUAP parameters defined by Buchthal are still widely used today as reference values. It is increasingly recognized that many factors can influence the obtained parameters. The ability to measure something does not mean that it is fully understood. The future of quantitative EMG will depend on increased understanding of the physiologic and pathophysiologic significance of the detailed numeric parameters that are generated.

Action Potentials↗

PubMed2002

Effect of reference electrode position on the compound muscle action potential (CMAP) onset latency.

Compound muscle action potential (CMAP) onset latency is interpreted to reflect the arrival time at the muscle of impulses in the fastest-conducting motor nerve fiber. However, we have observed that the position of the reference or indifferent electrode (E2) affects CMAP onset latency. Motor nerve conduction studies (NCS) of the median, ulnar, and deep ulnar motor (DUM) nerves on 20 normal hands were performed using both traditional bipolar and experimental monopolar (referenced to the contralateral hand) montages. As the position of E2 was altered, the CMAP onset latency varied 0.1-0.5 ms for the median NCS, 0.1-0.3 ms for the ulnar NCS, and 0.1-1.5 ms for the DUM NCS. This study demonstrates that E2 recorded potentials are significant and vary with positioning, affecting motor onset latency. This has implications both for reference values and the physiologic interpretation of the CMAP waveform.

Action Potentials↗