EMG - Examinations of the peripheral nervous system and muscles
To examine the peripheral neuromuscular system, electromyography (EMG) or a nerve conduction study (NCS) is often used to clarify any errors. These tests will shed light on muscle function and the conduction of the nerves, respectively. Usually the physician will carry out both tests on the individual patient in different combinations to obtain as unambiguous a picture as possible, and thereby correctly diagnose the patient.
During an EMG test, electrical activity from muscles in the body is registered, which is used to assess whether muscle impairment is due to disturbances in the motor neurones, the motor nerve fibres, or in the muscle cell itself.
Physiology
The motor unit in the muscle constitutes the smallest unit in the muscle that can be controlled by will-power. A motor unit consists of a bundle of muscle fibres controlled by a single motor neuron. The number of muscle fibres in a motor unit depends on the size of the muscle and can vary from just a few in the smallest muscles, for example around the eye, to several thousand in the large muscle groups in the legs.
Registering the muscle’s electrical activity is carried out using different types of electrodes, including surface electrodes, as well as different types of needle electrodes, which are placed directly in the muscle. The choice of electrodes depends on the actual test, but a concentric or monopolar needle is usually used for routine EMGs.
The EMG test involves registering electrical activity when at rest, with gentle contraction, and finally under normal contraction.
Ambu Neuroline Needles for EMG
The Ambu Neuroline Concentric is a needle with a silver wire inside the needle (the active electrode) and a shaft of metal (used as the reference electrode). By placing a ground electrode on the patient, the physician can obtain a very precise measurement, since the active electrode (the silver wire) and the reference electrode (the cannula) are very close to each other.
The Ambu Neuroline Monopolar is a needle where the tip of the needle is used as the active electrode and the rest of the needle is isolated. A surface electrode, which functions as the reference electrode, is placed above the muscle to be examined, and the ground electrode is typically also placed nearby.
The Ambu Neuroline Inoject range comprises single patient EMG needle electrodes for injections with Botulinum Toxin. Our new Neuroline Inoject provides superior performance in terms of ease of penetration, reduction of friction and a better grip, with an reduced patient discomfort during EMG and injection procedures.
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Ambu Neuroline
Monopolar Needle
Ambu Neuroline
Concentric Needle
Ambu Neuroline
Inoject Needle
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