EMG - EEG (ElektroMiyelography)

What is EMG?

EMG examination is used to measure the functions of peripheral nerves in the body. Sensory nerves and movement nerves can be examined separately.

EMG is the abbreviation of the term electromyography. It is a muscle examination in which the electrical activity that causes the contraction of the muscles is monitored and interpreted. The contraction of the muscles occurs thanks to the electrical potentials known as Motor Unit Action Potentials (MUAP) created in the muscles by the excitatory potentials transmitted from the brain through the nerves.

The amount of contraction increases with increasing number and frequency of MUAPs. Examination of MUAPs in cases where the muscles are not or contracted, whether their shape or frequency is within normal limits, or electrical activities that are not normally encountered are the variables examined to determine the problems in the muscles. In daily use, EMG examination means a set of tests including nerve examination as well as muscle examination.

What is the Role of EMG in Diagnosing Diseases?

Although EMG does not replace direct examination methods, it guides these methods.

Why is it requested?

EMG and nerve conduction examinations are an indirect method used to diagnose anterior horn cells, nerve roots, nerve networks, terminal nerves, neuromuscular junction and muscle diseases of the spinal cord, respectively, and due to its ease of application, it is often used alone and sometimes with other auxiliary methods (eg, imaging techniques). , blood biochemistry) leads to the most definitive diagnosis or directs the physician to other methods for diagnosis (eg biopsy, direct visualization of the problematic area with surgery). It is often used to measure how much nerve and muscles are damaged in painful situations and sensation defects caused by back and neck hernias, compression of the end nerves at certain points, in some cases where arm and leg weakness are seen, in limited or widespread muscle wasting.

How is EMG done?

Needle electrodes are used in EMG examination for the diagnosis of muscle problems. That's why it is also called needle EMG. Usually concentric needles are used. These needles are turned into recording electrodes by placing a very thin wire inside the known injector needles. When a needle attached to the device is first seen, it arouses fear of being electrocuted. However, no electrical stimulation is given in the needle EMG examination. It is used only for recording normal or abnormal electrical activity in muscles. The tip of the needle is inserted directly into the investigated muscle. MUAPs or other electrical activities created by the stimuli sent from the brain for the contraction of that muscle in the muscle area close to the needle tip are amplified by very special amplifiers and monitored on the screen of the device. In addition to the visual examination, the same signals are made audible by the loudspeaker and make a significant contribution to the evaluation of the doctor who performs the examination.

How long is the review?

It is always necessary to examine more than one nerve and muscle in a body region. Since the method can be painful due to the method of application, the practitioner avoids unnecessary interventions by limiting the examination with the help of his knowledge and experience. Sometimes, the reviews that seem limited and planned to be short can be expanded according to the data obtained during the application. Since separate examination plans are applied for each patient in EMG, it is difficult to talk about a standard examination period, but this period can extend from 30 minutes to 2 hours. During this period, the patient's assistance to the doctor as much as possible will ensure that the examination is healthier and will prevent unnecessary prolongation.

Electroencephalography or EEG is a method that measures the electrical monitoring of brain wave activity. Since no electric current is given to the patient, no pain or pain is felt. The recording obtained with an electroencephalogram is also called an electroencephalogram (EEG). This technique, which is called electroencephalography or "brain electrocution", was developed by the German psychiatrist Hans Berger in 1929. In EEG, the shooting is done by placing small electrodes on the scalp, that is, by sticking them with a conductive substance called "paste". The electrical potential changes between these two electrodes are recorded on the computer and the result is interpreted by the specialist, and the patient is given the necessary information. In the examination of the obtained recording, based on the deviations from the normal, many working disorders of the brain (e.g. epilepsy) can be diagnosed. The human nervous system contains about 10 billion nerve cells. Most of them are located in the brain, the rest in the spine and other parts of the body, in the corresponding nerves. Each brain cell is connected with 5,000-50,000 nerve cells. Nerve fluxes are carried along nerve fibers and cause electrical waves in the brain. These electrical waves can be measured on the scalp. While EEG abnormality may not be demonstrated in every patient with clinical seizure, EEG abnormality may be observed in individuals who do not have seizures or epilepsy. In patients with seizures or epilepsy, an average of 70% abnormality can be observed in EEGs between seizures. For adults, it is necessary to clean the hair one day before coming to the shoot. For sleep EEG recording, the sick person may need to be sleepless for 24 hours. In children, shooting is usually done while asleep. For this, medication can be given before the shooting, and it is recommended that the child be put to bed late and lifted early for the shooting to be easier.