- Electroneurography - indications and contraindications for the test
- Electroneurography - how to prepare for the examination?
- Electroneurography - what is the test?
Electroneurography is a neurological test aimed at assessing the function of peripheral nerves. Therefore, ENG is helpful in the diagnosis of many diseases of the nervous system. What is an electroneurographic examination and what are the indications for its performance?
Electroneurography( ENG ) is aneurological testaimed at assessing the function of peripheral nerves - motor and sensory fibers. It is helpful in the diagnosis of many diseases of the nervous system, because it helps to locate damaged nerves, determine the size of pathological changes, differentiate their nature, and determine the dynamics of the disease process in the examined nerve. Therefore,electroneurographic examinationcan be used in the diagnosis of, for example, diseases with muscle atrophy, sensory disturbances, and after injuries of peripheral nerves.
Electroneurography - indications and contraindications for the test
The indications for the examination are symptoms of peripheral nerve damage, suspected myasthenia gravis or postoperative treatment due to myasthenia gravis. ENG can also be used to assess the rate of growth or regression of peripheral nerve damage.
Contraindications for electro-neurographic examination are an implanted electric pacemaker or metal elements in the heart (e.g. an artificial valve) or in the examined area of the body.
Electroneurography - how to prepare for the examination?
On the day of the examination, you should only wash the part of the body you are examining. It is contraindicated to use creams, ointments or lotions on the skin in the area where the test will be performed.
Directly before the examination, inform the person carrying out the procedure about the medications you are currently taking.
ImportantPeople taking oral anticoagulants (anticoagulants) should start using low molecular weight heparin 3 days before the test, of course with the prior consent of the attending physician. Patients with myasthenia gravis should not take anti-myasthenia drugs on the day of the test.
Electroneurography - what is the test?
Electroneurography involves stimulating the examined nerves with a current of very low intensity (0-100 mA), frequency (2 Hz) and short duration (0.2 ms), and then measuring the speedConducting an electrical stimulus through these nerves by means of surface electrodes placed on the body. A first (stimulating) electrode is placed over the nerve to be stimulated. In turn, the second electrode (receiving) is placed over the appropriate muscle for a given nerve. When the motor or sensory fibers are stimulated, the muscles contract and a very weak current flows. The receiving electrode then registers the stimulation of the muscle. In the course of the test, the speed of conduction through the peripheral nerves is measured, which is determined by the following parameters: electric impulse conduction time, i.e. the time from the moment of current activation to the appearance of a response, and the difference in the distance between the points of stimulation and the delay in the muscle response. The test takes 10 to 60 minutes. The result in the form of a description with an attached graph (a record of the electrical activity of the nerve) is provided to the patient immediately after the end of the test.