From this article you will learn: what is rheoencephalography( abbreviated REG), what place does this examination take in the diagnosis of neurological diseases, how is it conducted.
Indications for rheoencephalography
Rheoencephalography is a method for examining the central nervous system and evaluating cerebral blood supply based on the difference in electrical resistance of blood, spinal cordfluid, brain and other tissues. This examination is not the main one in neurological and neurosurgical practice, but at times it provides quite important information.
Reoencephalography is performed by neurologists, neurosurgeons and physicians of functional diagnostics.
Different tissues and fluids in the body have different electrical conductivity and resistance( impedance).This is the basis of the principle of
For example, brain tissue has less conductivity than blood. Since at the time of contraction of the heart( systole) the blood vessels of the brain are filled with blood, then when passing a weak high-frequency electric current through the head, the conductivity will be higher than during diastole( relaxation of the heart muscle) when the blood in the vessels of the brain is smaller. It is the graphical record of these oscillations of electrical conductivity and resistance called rheography. If this examination is performed on the central nervous system, it is called rheoencephalography.
Indications for Rheoencephalography
Traditional rheoencephalography allows you to evaluate the blood flow in the brain. This functional examination technique has found its application for diagnostics:
- of acute disorders of cerebral circulation;
- violations of the patency of the main vessels;
- of cerebral arteriosclerosis;
- of headache of vascular origin;
- increased intracranial pressure;
- craniocerebral injury;
- circulatory insufficiency in the vertebral and arterial system;
- pathology of carotid arteries.
Using rheoencephalography, it is possible to assess the state of the brain vessels in hypertensive disease. Use this method of examination and to determine the vascular response when choosing the appropriate method of treatment, to monitor its effectiveness.
Modern medicine has other, more accurate methods of examination( computer and magnetic resonance imaging), which allow you to get more accurate information. The advantage of rheoencephalography over these methods is its low cost and the possibility of longer monitoring.
The disadvantage of rheoencephalography is that it is very rare to establish an accurate diagnosis with it. You can detect some violation of blood supply, but it is possible to name its cause only with the use of other methods of examination.
The development of medical and computer technologies significantly increased the diagnostic capabilities of REG, but this method still did not take the leading place in neurological and neurosurgical practice.
Rheoencephalography is a safe examination that can be performed by almost anyone. Do not spend it only in the following cases:
- patient's refusal of examination;
- presence of wound electrodes, fungal, bacterial or parasitic skin lesions on site.
Preparation for the
procedure No special preparation is required for this survey. The patient should not smoke, drink alcohol, drink coffee before the procedure, as this affects the state of the intracerebral vessels and may distort the test results. It is necessary to avoid heavy physical and emotional loads.
If the patient is taking any medications, he should definitely tell the doctor about it. Some of them will need to be temporarily stopped - this applies to those drugs that affect the vessels of the brain.
is being tested Reoencephalography is performed using a special apparatus - a rheograph. Usually the recording of the rheoencephalogram is performed by the nurse, but the physician is already interpreting it as functional diagnostics, neurologists or a neurosurgeon.
During testing the patient is sitting or lying down. To his head, using an elastic band, attach electrodes, which are lubricated with a special gel to improve the electrical conductivity. During the rheoencephalography, some electrodes send electrical signals, while others - perceive them after passing through the brain tissue. These perceived signals are processed by a rheograph and output on a computer monitor or on paper in the form of a curve that displays the electrical conductivity of the tissues. The whole procedure takes a few minutes. Immediately after recording the rheoencephalogram, the patient can return to his normal activities.
Depending on which part of the brain you need to get information, the electrodes can be placed in different parts of the head.
Sometimes, to obtain more accurate results, pharmacological tests are performed-that is, a record of the rheoencephalogram before and after the administration of certain drugs. Most often, pharmacological tests are carried out with drugs that dilate the cerebral vessels - vinpocetine, nitroglycerin, nicotinic acid, papaverine. Sometimes such functional tests are also performed before and after physical exertion, before and after pressing the carotid artery on one side, with head inclinations in one direction. All these modifications allow us to identify spasm of the cerebral arteries and assess collateral blood flow( blood flow through the bypass arteries).
Additional possibilities of rheoencephalography were provided by its joint recording with ultrasound examination of the brain.
Decoding of the results
Diagnostic results of the REG are performed by physicians of functional diagnostics, neurologists or neurosurgeons. Not only the received pattern of the rheoencephalogram is taken into account, but also the clinical picture of the disease, the patient's age and other important factors.
The rising part of the curve( from the beginning of the rheographic wave to the point of its maximum rise)corresponds to the anacrotic phase of the pulse wave and has a rapid steep ascent. The descending part of the curve( from the top to the end of the rheographic wave) corresponds to the cataract phase of the pulse wave and is characterized by a slow descent. Therefore, most often the ascending and descending parts of the rheographic wave are called anacrotic and catactrotic phases of the REG.An additional tooth corresponding to the dicrotic wave of the pulse wave is also called dicrotic.
Modern rheographs and the use of digital technology allow for more detailed analysis, including the definition of various indicators that give doctors information about the state of the vessels of the brain.
The interpretation of the rheoencephalogram does not take much time. Most of the work is carried out by a computer program, doctors can give an opinion within a few minutes after the examination.
Advantages and disadvantages of rheoencephalography
The advantages of REG are considered to be its safety for the patient, the simplicity of the procedure, the possibility of performing the examination in almost any conditions, the possibility of a long-term monitoring of blood circulation in the brain.
Reoencephalography also has drawbacks:
- Low diagnostic value.
- Impossibility of precise determination of causes of circulatory disturbances in the brain. Impossibility of direct measurement of blood flow.
Many newer methods for examining the central nervous system are now available, which have high diagnostic value in detecting brain diseases( eg, MRI, CT).They almost completely replaced rheoencephalography from the clinical practice of neurologists and neurosurgeons.