1. Detection of the defect
2. Determination of degree of affection of the disturbed functions (full or partial conductivity trouble)
3. Determination of stages and nature of pathological process (denervation, reinnervation)
Superficial (global, epicutaneous or total EMG) is a method of registration and study of biopotentials of muscles at rest and at self-produced tension by detection of bioelectric activity with the help of superficial electrodes from skin surface above the motor point. This method is non-invasive and painless, it helps to estimate electric activity of muscles globally, i.e. totally.
Needle (or local EMG) is a method of registration and studying of bioelectric activity of motor fibers and motor muscle units by needle electrodes at rest and at self-produced tension. This method is invasive and painful, but it helps to identify the mechanisms of work of the nervous and muscular system, which can be not identified correctly by superficial EMG.
EMG stimulation is a method of registration and studying of bioelectric activity of the muscles caused by activation of a nerve at any place or by activation of the receptors of neurons by electric or mechanical stimulus. Registration of evoked (by stimulation) activity of the muscle is carried out either by epicutaneous or needle electrodes depending on the research problem, muscle depth and on the necessities to exclude an activity of induction from adjacent muscles .
An important disadvantage of the electrophysiological diagnostics methods (electric diagnostics and ENMG) - there is no opportunity to characterize and visualize relative positions of space occupying lesion, nerve trunk and surrounding tissues that is important for making a decision about surgical treatment.
Using ultrasonic examination (USE) and magnetic resonance imaging (MRI) we can visualize the tumor, and to establish relative positions with nerve trunk and surrounding tissues.
Ultrasonic examination is widespread method of diagnostics, it helps to visualize a space occupying lesion and to study the topographic anatomy relations of the tumor