The influence of active electrode placement on CMAP amplitude
| Autor: | Mark B. Bromberg, Teresa Spiegelberg |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Wave form
Neural Conduction Polyradiculoneuropathy Action Potentials Recording electrode Humans Muscle Skeletal Mathematics Motor Neurons Extensor digitorum brevis Electromyography Foot business.industry General Neuroscience Amyotrophic Lateral Sclerosis Electrical engineering Active electrode Hand Axons Electrodes Implanted Compound muscle action potential Electrophysiology Amplitude Motor point Neurology (clinical) business Biomedical engineering |
| Zdroj: | Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control. 105:385-389 |
| ISSN: | 0924-980X |
| DOI: | 10.1016/s0924-980x(97)00037-4 |
| Popis: | The compound muscle action potential (CMAP) is a measure of the number of axons in a nerve. Placement of the active recording electrode over the motor point of a muscle is thought to give the maximal response, but there is considerable variation in amplitude among initially negative CMAP wave forms. Ten examiners of varied training backgrounds and experience placed the active electrode as they usually do over the thenar, hypothenar, abductor hallucis, and extensor digitorum brevis muscles in the same normal subject. There was variability of the CMAP amplitude recorded over each muscle; the lowest value recorded from a muscle was 57% of the maximum value, and the lowest median value was 77%. There was no relation between examiner background or level of training and recording the maximal response. Higher amplitude CMAPs were associated with steeper wave form slopes, but the range of correlations between amplitude and slope was 0.42 to 0.92. We conclude that when it is important to record the maximal CMAP response, empirical assessment by moving the active electrode is necessary. |
| Databáze: | OpenAIRE |
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