EEG measures the bioelectrical activities in the brain. Brain imaging can provide valuable information on the biological dimension of many psychiatric disorders, especially depression and panic disorder.
EEG is an important technique that allows psychiatric illnesses that are perceived as abstract, to become material, and thereby aids compliance with treatment. For a long time now, psychological health and illnesses have been accepted as brain disorders. The biological dimension of many psychiatric disorders, particularly of depression and panic disorder, can be verified by scientific research. The link between these disorders and certain biochemical irregularities in the brain can be demonstrated through laboratory studies. Because it is not possible to directly view the human brain or take a sample from it for analysis, as one would do with other organs, researchers use techniques that provide indirect information on the brain. Treatment based on measuring brain functions in adults, young patients and children has been a long-standing aim of psychiatry. We have discussed bioelectrical activities which are the final product of the biological process, with Psychiatrist Prof. Dr. Kemal Arıkan, who has important publications and studies on the subject of EEG.
– First of all we would like to know the meaning of EEG
EEG is the short version of “Electroencephalography” which in Greek means the picture of the brain’s electricity.
– Do we have to comprehend the brain system in order to understand an EEG?
It is essential to be informed about the anatomy and physiology of the brain.
– Does an EEG record brain activities?
The brain has many activities, the EEG records the bioelectrical activity of the brain. Nevertheless, an EEG also harbours a reflection of many of the other activities, like metabolic activities and similar.
– When was the EEG first used in psychiatry?
It started being used from the moment it was discovered. It goes back to the 1930’s, which means that it is in use for the past 70-80 years. In fact, the inventor of the EEG was a German psychiatrist called Hans Berger.
– What is the difference between the EEG used in neurology and the EEG used in psychiatry?
Technically they are the same, we are looking at the same function but from a different view point. Neurologists mainly look for epileptic and/or organic focal points, whereas psychiatrists focus on the differentness.
– Does the expression Quantitative EEG represent something different?
No. The only difference is that instead of the old conventional method of printing the EEG recording onto paper, here the printout of the recording is produced by a computer and is in digital format.
– What do we see on an EEG?
There are two main indicators in an EEG, these are frequency and amplitude. It is the deviation from the normal, that is then investigated.
– What is the value of EEG in psychiatry?
It is very valuable to psychiatry. It has unrivalled benefits in arriving at a diagnosis, a differential diagnosis, in following-up the course of the disease, in forecasting the response to medication, and in many other clinical and research areas.
– In which illnesses is it most useful?
In major psychiatric disorders in which there is a consensus on diagnostic standards, we have a sufficiently sensitive and specific bioelectrical profile, even if it is not 100%. Therefore it is useful in schizophrenia, depression, and almost every type of anxiety disorder and dementia.
– Since EEG does not provide a diagnosis, how does the clinician and the patient benefit from it?
It is used by the clinician as a diagnostic aid.
– Is EEG used widely in the world?
Yes. Particularly in Germany which is the birth place of the EEG, EEG is involved in more than 14% of all investigations.
– What is the situation in Turkey?
Real EEG came to our country at a later stage, however its use in psychiatry is slowly increasing and rising towards the levels in Europe and America.
– The hesitation that some clinicians show – is it because they are not sufficiently familiar with the subject?
I presume so.
-Does EEG materialize psychiatric complaints in the eyes of the patient? Does it help with compliance with treatment?
To know at least, that the illness has a physical factor is helpful.
– Does EEG provide guidance in psychiatric cases were emotion, cognition and behaviour are affected?
– Can we say that after EEG it has become possible to understand human psychology by means of scientific techniques?
The belief that human psychology can be understood by scientific methods goes back a lot further in time. EEG is one of the techniques that has strengthened that belief.
– Does it bring benefits and means to scientific research?
Its benefits in this regard are vast. EEG and evoked potentials, which is a type of EEG, have an application field in research.
-What is the difference of Sleep EEG?
Sleep EEG is recorded during sleep, whereas EEG is the name given to a recording made whilst the patient is awake. Sleep EEG has some technical characteristics. These are related to certain specific EEG patterns which cannot be detected whilst the person is awake.
– What are new developments related to EEG?
The most important development is the fMRI compatible EEG, which provides information on the anatomy that corresponds to functions. This technology is very rare in our country.
Brain Imaging in Depression
After it became clear that depression is a brain disorder, major studies have been carried out in order to understand the changes that occur in the brain in depression.
The areas on the right side of the brain deal with abstract notions like emotions, excitement, music and art, whereas the left half of the brain deals with functions like logic, reasoning, analysis, speech and calculations. The functions of the right half of the brain are more marked in women. When a woman goes shopping, she places more importance on aesthetic considerations, she wants things to be beautiful, nice. When a man is shopping, his priorities would involve the item being cheap, of good quality, and useful.
The first human response comes from his genetic make-up. If we improve ourselves, we can create a balance in our use of the two halves of the brain. Improving the functions of the brain areas related to logic requires more effort in women, whereas in men special effort and education is required to improve the brain areas related to emotions.
Link between Depression and the Brain
Depression is essentially a disorder of emotions. It is three times more common in women than in men. This is related to the fact that the areas of the brain that deal with emotions, are more active in women than in men.
Research revealed that brain functions are produced through electrical and chemical transmissions.
Today we can scientifically prove that a person suffering from depression has decreased levels of chemical transmitters like Serotonin, Noradrenalin and Dopamine in the brain. Serotonin first drew attention to itself when in the 1970’s it was proven that in people who have committed suicide, the level of a serotonin metabolite in the cerebrospinal fluid was 10 times lower than in normal cases.
Another point that stands out is, that in depression there is a slow-down in energy transfer in the brain.
As a result, the brain fails to carry out its information processing function to a full extent. We particularly see dysfunction in the areas that deal with the management of emotions.
A lack in secretions that are related to producing a feeling of joyfulness would explain symptoms like sorrow, sadness, loss of joy/happiness, sleep dysfunction, appetite problems, fatigue, reduced energy and difficulties in concentrating.
The importance of imaging
The increased success of drugs in psychiatry during recent years and the therapeutic ability of drugs to bring pharmacological improvements, has led to large investments being made in this field.
To reveal biological abnormalities in the brain is a complex and long process. There are certain methods yield good results in the diagnosis, treatment and progression of the illness.
Some markers only emerge during the illness (State Markers). There are other markers that are present both before and after the illness (Trait Markers). There is a wide variety of these markers, they are called state and trait markers. Measurements related to nerve cells, cerebrospinal fluid, drug levels in the blood, certain enzymes and hormones are some of the indicators.
Biological measurements that are sensitive, specific and display regional characteristics, are more valuable.
SPECT Scan: Substances marked with a radioactive material are used to measure blood circulation. It predominantly shows the cortex.
PET Scan: This is based on understanding the brains glucose and oxygen metabolism by mapping the brain with the help of radioactively marked tracers. With the help of substances that are the agonist of the marked serotonin it is possible to create a map of the serotonin and upper chemical transmissions in the brain.
Both of these techniques are special and expensive, and they are still not being used on a daily basis.
CEEG, MAP: Techniques like MR and BT show structural changes in the brain. In other words, they detect space-occupying tumoral abnormalities. In depression it is necessary to measure brain activities.
With Computer Based EEG (electroencephalography) brain activities can be recorded.
The great progress achieved in computer technology has made it possible to count the number of signals produced by our brain in one second, an information which is a valuable aid. Fast and slow signals (frequencies) produced by the brain are counted and mapped. This is called brain mapping. A headset is placed over the patient’s head and without administering any foreign substance into the body, the brain signals of the patient are measured and checked against the data stored in the data bank. This reveals the bioelectrical functions of the patient’s brain.
Before treatment, a bioelectrical map of the brain is produced. During the treatment period, depending on the patient’s needs, the measurements may be repeated after 1½, 3, 6 months. The first and last measurements are compared with one another in order to monitor if the abnormal changes in the brain have ceased.
If the patient responds well to treatment, the bio-efficacy of the drug will have been tested. If the values measured in the brain continue to be high, then it will be assumed that the patient’s predisposition to the illness is ongoing, and a continuation of the drug has to be more carefully considered.
As we can see, the more progress is made in technology, the easier it becomes to help in matters of a healthy brain and a healthy psychology.