What techniques are used to conduct a brain examination: a description and information content
- 1 When you need to check vessels
- 2 Electroencephalography of the brain
- 3 Cerebral vascular reoencephalography
- 4 Angiography of cerebral vessels
- 5 Brain ultrasound
- 6 Conclusion
Currently, there are many methods to assess the condition of the arteries and veins, blood flow velocity, the presence of various obstacles in the path of blood flow. This ultrasound, electroencephalography, rheoencephalography, ultrasound, angiography. It is impossible to remember all the names of studies, but they are all effective and sometimes complementary.
When you need to check vessels
There are rare signs of impairment to the appearance of which a person does not pay attention. In hot weather, I lost my balance, my head became very sick – nothing, it will pass, because of the heat. I stood up sharply, flew in front of the eyes of the “fly” – this is also all right, I had to get up more slowly. The pressure has risen – of course, it will rise, the weather is changing so quickly. There are explanations and excuses for everything, but any of these signs may indicate a serious pathology.
With the following symptoms, an urgent need to consult a doctor:
- The headache pursues constantly, amplifies.
- Vision, speech, hearing deteriorate, there are incidents with the complete loss of these functions.
- Thought processes, memory, attention are broken.
- Changing the coordination of movements, possible loss of balance, the appearance of a shaky gait.
- There are cramps.
- A person loses consciousness or experiences a pre-unconscious state.
- Changes in intracranial, blood pressure.
- Appear “flies” before my eyes.
These symptoms indicate a pathology of the cerebral vessels. To exclude it, a medical examination may be prescribed. It includes both the basic procedure of checking the blood vessels for patency (called angiography), and ultrasound, rheoencephalography, and electroencephalography.
These methods are used to clarify head injuries, neck injuries, stroke, tumors, diseases associated with inflammation of the brain, thrombosis, atherosclerosis. Examination of the head is carried out before the operation on the vessels or after it.
Depending on the pathology, one or several types of research can be assigned. Many methods have limitations, so they are assigned in case of emergency.
Electroencephalography of the brain
EEG is a non-invasive method for studying the electrical activity of the brain, including under the influence of certain stimuli: light, sound, movement. Indirectly indicates a change in blood circulation, therefore, is not the main way to diagnose vascular disorders.
- vascular lesions;
- traumatic brain injury;
- inflammatory diseases.
Examination of the brain is carried out using a special device – an encephalograph, capable of recording the frequency of electrical oscillations from 0.5 to 100 Hz. Electrodes are put on the head, which pick up minimal brain signals. Signals go to the amplifier, increase in it by millions of times, are transmitted to the computer monitor as a graph – encephalogram. In children under 3 years old, research is conducted only during sleep or under light anesthesia.
The record reflects the fluctuations and rhythms of the electrical process that occurs in the nerve cells of the head:
- Alpha rhythm with a frequency of 8-14 hz, characterizing the state of rest.
- Beta rhythm 13-30 Hz, indicating depression and anxiety.
- Delta rhythm 0.5-3 Hz, typical for sleep.
- Theta rhythm 4-7 hz, characteristic of an adult in a dream and a child.
The predominance of alpha and beta rhythms, the same electrical activity in both hemispheres and the occurrence of only a local reaction to the stimulus are signs of a normal encephalogram. EEG does not give an anatomical picture of the structure of the vessels.
Prepare before encephalography. 2 hours before the procedure, you can not eat, for 12 hours you can not drink coffee, energy and should not smoke. Do not use hair styling products. The time that the procedure may take is 45-120 minutes.
Electroencephalography is not used in the period of exacerbation of mental disorders, with mental trauma, infectious diseases, injuries or wounds on the scalp. Without extreme need not carried out in children under 7 years.
Read also … For the diagnosis of which diseases is assigned Echo EG: the order of carrying out and decoding the results
Cerebral vascular reoencephalography
REG (rheoencephalography) is a non-invasive method for diagnosing cerebral vessels, recording the change in electrical resistance of vascular walls during the passage of a high-frequency pulse through them. It provides an opportunity to check the vessels of the head, their reactivity, tone, elasticity, resistance level of the vascular tissue, possible blockage and features of the blood supply.
REG is indicated for suspected diseases:
- vascular pathologies;
- circulatory disorders;
- vascular stenosis;
- clarification of the effects of drugs;
- traumatic brain injury.
Rheographs with the number of channels from 2 to 6, recording the corresponding number of vessels, are used for rheoencephalography. The patient is sitting or lying down. Electrodes are mounted on his head with rubber bands. Under them can be applied a special paste to improve skin contact and reduce resistance. Electrodes are attached depending on the vessel under study. So, if you need to check the internal carotid artery, the electrode is placed on the nose and the mastoid process.
Part of the electrodes sends electrical signals, others receive them and transmit them to the reograph. The latter processes and transmits to a monitor or a print in the form of a graph – rheoencephalogram. The procedure lasts a few minutes.
During the examination, the patient may be given a small dose of nitroglycerin under the tongue, papaverine or asked to change the position of the body, turn the head. These measures will allow you to see the change in tone and blood supply.
The advantage of rheoencephalography is simplicity, safety for the patient, the ability to monitor blood flow for a long time. Among the shortcomings note the inability to measure cerebral blood flow and determine the exact cause of circulatory disorders.
Before the study can not smoke, drink alcohol, coffee, energy drinks. If the patient is taking medication, this should be reported to the doctor. You may have to stop taking some.
Rheoencephalography is not assigned to children under 7 years old, as well as for wounds and injuries in the attachment sites of the electrodes.
Angiography of cerebral vessels
Angiography is the most accurate and most informative examination of cerebral vessels, followed by the administration of a contrast agent. It will allow you to learn about the functional state, the characteristics of blood flow, the change in vascular patency, the location of the violation.
In this study, the following pathologies are examined:
- arteriovenous malformation;
- vascular stenosis;
- vascular occlusion;
Angiography is also carried out in the postoperative period, to control the location of the clips installed on the vessels.
There are 3 methods of angiography: classical, CT angiography, magnetic resonance.
Classical and CT angiography is not performed in case of hypersensitivity to a contrast agent and anesthetics, impaired hemostasis, pathology of internal organs, acute infectious diseases, exacerbation of mental disorders, changes in thyroid function, pregnancy, lactation.
Classical (x-ray angiography)
As part of the procedure, the aorta, large vessels (carotid arteries) and small arteries are checked.
Preparation includes giving up alcohol for 2 weeks. 4 hours before the procedure is prohibited to buy and drink. In some cases, carry out hydration to facilitate the removal of a contrast agent from the body. Do x-ray and electrocardiogram. Perhaps the appointment of antihistamine drugs.
During the procedure, the patient is placed on a special table, fixed, connected to a heart monitor. A femoral (possibly carotid or vertebral) artery is punctured, a catheter is inserted into it, through which a contrast agent (mainly iodine) is injected, an examination is carried out. X-ray television captures everything that happens in the vessel. At the completion of the study, a dressing is applied to the puncture site for a day. In the absence of contraindications, it is recommended to drink as much water as possible.
Duration – 60-180 minutes, is performed only in the hospital. The advantage is the accuracy of the results. Disadvantages: invasiveness and radiation exposure.
This study is one of the types of computed tomography of the brain, but to obtain a clearer picture, a contrast agent is injected through the catheter into the cubital vein. It is carried out on an outpatient basis with the help of a computer tomograph. One week before the procedure, a creatinine test is taken.
The tomograph takes pictures in layers with the distance between the layers of about 1 mm in different projections. As a result, the doctor receives a lot of pictures, which are later combined into three-dimensional images of the structure of blood vessels. The study allows to combine images of arterial and venous blood flow.
Advantages of CT angiography: no shadows, highly informative. Disadvantages: invasiveness and X-ray irradiation.
An additional contraindication is third degree obesity.
Angiography of this type is a type of MRI. Instead of x-ray exposure, magnetic fields are used. With 4D-angiography not only get a three-dimensional image, but also visualize the dynamics of blood flow. In rare cases, the introduction of a contrast agent.
After the patient has removed the jewelry, the glasses are placed on the table and moved to a closed capsule. It is important to ensure the immobility, so if the study is carried out in small children, they make light anesthesia.
The time is 30 minutes. The procedure is carried out on an outpatient basis.
Advantages: no exposure, accuracy of information, the ability to conduct when sensitive to iodine-containing substances.
Contraindications include established pacemakers and metal-containing implants, heart failure, pregnancy, mental disorders, third-degree obesity, claustrophobia.
The basis of ultrasound (echoencephalography) is the principle of reflection of the signal from the brain structures from different angles. Ultrasound is a non-invasive study of the brain, allows you to get information about the features of the walls, vascular permeability, their diameter, the presence of atherosclerotic plaques, check the speed of blood flow.
Research is shown at suspicion on the following violations:
- cervical osteochondrosis;
- elevated cholesterol.
For some time before examining the vessels, it is recommended to exclude coffee, strong tea, energy, alcohol, avoid strong emotional stress.
Before the procedure, remove the jewelry from the head and neck. The patient is lying or sitting. It is important to ensure his peace. The doctor or nurse checks the head for the presence of deformities, hematomas and on the sides of the skin pre-lubricated with gel install ultrasonic sensors.
Among the advantages are simplicity, non-invasiveness, safety and the absence of contraindications. The main disadvantages are the inability to see the dynamics, the lack of accurate information about the blood circulation in small vessels and some vascular pathologies. In general, ultrasound can not replace angiography.
It has no contraindications. The duration of the procedure is 30-40 minutes. Ultrasound examination of a child under 1 year old is called neurosonography.
Usually ultrasound combined with Doppler. This combination allows you to get not only a static picture, but also the sound characteristics of the blood flow.
The basis of this diagnostic method is the reflection of the ultrasound beam from the blood cells. A special transducer sends signals to the blood vessels, they are reproduced at frequencies corresponding to the blood flow and are converted into sound signals. The changing frequency of the signal allows us to estimate the speed of flow, the direction of blood, the volume per second, to obtain information about the lumen, the size of the vessels, their resistance, the development of atherosclerotic stenosis.
During the procedure, the patient lies on the couch. A roller is placed under the head. A gel is applied to the skin and a special sensor is carried over the head, looking through and measuring all the vessels. Usually sensors are installed on the temples, above the eyes, on the back of the head. The doctor may also ask you to hold your breath or make some movement to evaluate a possible reaction.
This type of ultrasound combines two methods – directly ultrasound, which provides information about the anatomical structure of blood vessels, and Doppler, which allows to evaluate the cerebral blood flow.
A two-dimensional image of a blood vessel among the tissues, as well as signs of plaques, blood clots, thickening of the vessel walls, and their drawing are obtained on the screen. The vessel can be viewed both along and in cross section. Duration – 30-45 minutes.
The study includes 3 methods: ultrasound, Doppler and color Doppler mapping. In the process, vessels are examined, their wall thickness, resistance, while vessels are painted in a different color, depending on the speed of blood flow, and this is precisely what the study differs from duplex.
A variety of research methods that currently exist allows us to carry out an accurate diagnosis of vascular disorders in toddlers and adults, regardless of their condition and the presence of contraindications.
Some methods are informative in their own right, others are complex. Timely diagnosis of dangerous vascular diseases will help to avoid negative consequences.