Clinical Work: Treatment of Neurological Disorders using EEG
Biofeedback
Simplified, the term 'biofeedback' means to 'feed back' to the patient, information about their 'biological' functions. In biofeedback, information about the patient's involuntary biological function (brain activity, heart rate, muscle tension, skin conductance or temperature) is picked up by sensors (surface electrodes), electronically amplified, and then fed back to the patient and clinician in a recognizable format (audio tone, visual graph or audio-visual game), and the patient then learns to make appropriate voluntary changes to the biological function (through operant conditioning) and to adjust its measurements to a desired level. In many cases biofeedback treatments can reduce the need for medications such as Ritalin for ADD, muscle relaxants, anti-depressants, blood pressure and anxiety medications, and may even enable a patient to discontinue their medication completely. Five types of biofeedback are based on the five types of biological functions that can be recorded and subsequently trained. These are:
EEG Biofeedback or Neurofeedback
The electroencephalogram measures brain electrical activity. The brain emits electrical signals of various frequencies (see EEG) and a few of these waves have been directly tied to specific disorders or mental states. For example, alpha waves are commonly observed during relaxed and restful states, therefore some researchers believe that patients can suffering from anxiety and insomnia (characterized by predominating theta wave states) can obtain relief from their symptoms by learning to increase their alpha wave activity. Similarly beta waves are commonly observed during alert and focused states therefore it is believed that patients suffering from ADHD (characterized by predominating alpha, delta and theta wave states) can improve concentration by learning to increase their beta wave activity. In addition, epileptics have found relief by monitoring waves produced during seizures. As technology advances, EEG biofeedback may be used for other neurological diseases. This form of feedback is discussed in greater detail below.
EMG Biofeedback
The electromyogram (EMG) measures muscle tension. Two electrodes are placed on the skin over the muscle to be monitored. Some of the most common muscles used are the frontalis (the 'frowning' muscle in the forehead), the masseter (the jaw muscle), and the trapezium (the shoulder muscles that hunch when an individual is stressed). EMG biofeedback machines have been utilized to rehabilitate patients paralyzed by stroke or suffering from cerebral palsy. Even when a person has no sensation in a paralyzed limb and cannot move it voluntarily, the EMG electrodes can often detect some electrical activity in the muscles. The EMG biofeedback machine then amplifies the electrical sound emitting from the paralyzed limb and as the patient becomes aware of the activity, his or her nervous system may stimulate more muscle activity. Eventually, new nerve endings may grow in the affected muscles and the patient may regain some mobility. More often EMG is used to promote relaxation in muscles that have become tense in response to stress. When the EMG electrodes detect electrical activity in the muscles related to muscle tension, the machine gives off a signal such as a colored light or sound. In this way, the individual can see or hear continuous monitoring of their muscle activity and begin to focus on what the activity, and therefore, the tension feels like. As they become more aware of this internal process, they will begin to recognize in their daily life when tension starts to build. They can then use the techniques learned in the biofeedback training to control the tension before it gets worse. EMG has been used for the treatment of tension headaches, backache, neck pain, and bruxism as well as in the stress related illnesses such as asthma and ulcers.
ECG or HRV Biofeedback
The electrocardiogram measures the heart's response to emotional, mental, and physical stress, and its ability to bounce back to a relaxed and better functioning state. It helps for general relaxation, and cardio vascular distress. A sensor is attached to the individual's finger, and a computer interface allows you to see your heart rhythms on the screen, which appear like ocean waves, or lines that move up and down. Irregular, ever-changing waves mean that things easily upset you, whereas smooth waves mean that you are able to stay calm in stressful situations.
GSR or EDR Biofeedback
Electrodermal Response (EDR) or Galvanic skin response (GSR) measures electrical conductance in the skin, which is associated with the activity of the sweat glands. A very slight electrical current (unnoticeable to you) is run through your skin. The machine measures changes in the salt and water in your sweat gland ducts. The more emotionally aroused you are, the more active your sweat glands are and the greater the electrical conductivity of your skin. GSR is effective in treating phobias, anxiety, excessive sweating, and, at times, stuttering since these emotions will affect your skin's conductivity. It is used as a lie detection test. Athletes use this technique to prepare for games - to make sure that they are not too anxious or have pre-game jitters.
Temperature Biofeedback
Temperature biofeedback device monitors skin temperature and can be helpful in certain circulatory disorders. Reynolds disease is an example that can be benefited by this technique. Usually, a sensor is attached to your foot or to the middle or small finger of your dominant hand. When you are tense or anxious, your skin temperature drops as blood is redirected inward to muscles and internal organs. Like monitoring muscle tension, measuring skin temperature is a useful tool in learning how to manage stress. This method may also reduce the frequency of migraine headaches, and is also used to promote relaxation.
Neurofeedback
Neurofeedback, also called EEG biofeedback, is form of biofeedback in which the electrical activity of the brain is measured by scalp electrodes and then 'fed back' to the patient in the form of a sound, display or vibration. Through guided techniques, the patient is able to learn how to significantly increase or decrease the brain waves to the desired frequency bands. The learning paradigm used is known as operant conditioning: if brain activity changes in the direction desired by the clinician, a positive feedback or 'reward' is given to the individual, and if it regresses, either a negative feedback or no feedback is given, depending on the protocol. Rewards can be as simple as a change in pitch of a tone or as complex as a certain type of desired movement of a character in a video game.
The brain emits electrical signals of various frequencies ranges (see EEG for a full description) and a few of these waves have been directly tied to specific disorders or mental states. Thus researchers in the field have proposed a number of 'brainwave goals'. Generally, these goals are based upon descriptions of abnormal EEG patterns or on results from a QEEG. A popular goal is the increase of electrical activity in the SMR (12Š18 Hz) band and a decrease of electrical activity in the Theta (4Š8 Hz) and/or Beta2 (22Š28 Hz) bands. It is widely believed that the various neurofeedback methods may benefit the treatment of patients with epilepsy, ADD/ADHD, learning disabilities and stroke/ischemia by enabling the achievement of these brainwave goals.
For instance, research has shown significant differences in the type of predominant brain waves found among children and adults diagnosed with ADD. Specifically, people with ADD are found to produce more 'slow' brain waves (alpha, delta and theta) that are associated with decreased arousal and have difficulty producing 'fast' brain waves (beta) that are associated with increased arousal, better concentration and enhanced performance. Because they possess a decreased state of brain arousal, children and adults with ADD are constantly seeking outside stimuli making it difficult to remain focused on any one task. Through neurofeedback, the patient is able to learn to significantly increase brain waves in the beta band, which are compatible with stronger attentional focus and enhanced mental performance. The patient learns to attain this 'brainwave goal' automatically, and this skill is then maintained in everyday life. EEG biofeedback has physiological effects similar to those created by medication, but has no side effects, is non invasive, painless, and often provides long lasting results.
Other Neurofeedback Techniques
The 'Low Energy Neurofeedback System' (LENS) uses an electromagnetic field as the carrier wave for the feedback. With this method, the EEG leads serve as bi-directional conduits for both the brainwaves and the feedback signals. This neurofeedback method is distinct in that the duration of treatment for ADD/ADHD, depression, PTSD, TouretteÕs, and seizures is claimed to average a fewer amount of sessions, and the system settings and electrode site selection change from client to client, and for any client, change from time to time. However, the same range of side effects that occur with traditional neurofeedback appear more rapidly.
'Sensory Prompting' uses sensory stimuli to entrain EEG rhythms. One method of neurofeedback with sensory prompting involves the use of rhythmic stimuli. Medical EEG testing commonly includes intense, repetitive light stimulation at various frequencies to test for seizures. Some research indicates that computer programs or hardware that generate repetitive stimuli various frequencies are able to stimulate the brain and alter the brain's frequency via a much more subtle audio or visual stimulus. Other research counters these claims. Probably the best summary at this time is that entrainment does occur in many but not all individuals, and that the result may have a transitory influence on the dominant subjective state reported by that person. There is some small-group study research to suggest that light-sound stimulation is clinically useful to some extent, however, this will not always induce relaxation. Another method of neurofeedback with sensory prompting involves the use of binaural beat audio frequencies. If the left ear is presented with a steady tone of 500 Hz and the right ear a steady tone of 510 Hz, these two tones will combine in the brain and the difference, 10 Hz, will be perceived by the brain as a beat frequency. It is claimed that such binaural beat frequencies are an effective stimulus for brainwave entrainment, since the ears cannot hear sounds that are or a low enough frequency to be useful for brain stimulation. However there is still not enough scientific evidence to suggest that balancing the left and right cerebral hemispheres will induce any benefit.
Length of Treatment
A typical minimal length of treatment is 10 sessions. Frequently the average is 15-30 sessions, but this can vary widely based on patient response. Neurofeedback sessions work best when treatment is scheduled 2-3 times a week for most. This rate can be accomplished by sessions in the same day with short breaks in between sessions. The body learns to change best with sessions closer together. Biofeedback sessions may be scheduled once a week. This commitment can allow the patient to obtain a powerful, lasting skill that creates long term change. A neurofeedback practitioner will ask you to visit your physician before beginning treatment in order to check for disease related causes of the presenting symptom. For example: before assuming that headaches are being caused by stress, it would be important to rule out the presence of any tumors.
History
In 1924, Hans Berger connected a pair of electrodes to a patient's scalp and detected a small current by using a delicate galvanometer. Initially, this led him to outline a theory on how thoughts could be telepathically propagated by radiating brainwaves. However, this theory did not hold, since brainwaves are subject to the inverse square law and jump to infinitesimally small amounts when moved away from the scalp. Nonetheless, BergerÕs discovery enabled a new and measurable connection between the body and mind using these scalp measurements. As delicate recording equipment and sophisticated electronic amplifiers developed, the brain signal or electroencephalogram (EEG) became a significant clinical tool for neurophysiologists.
In the 1940s and 1950s, these EEG signals became the fundaments of neurofeedback, which was seen as a revolutionary way to study the mind and its capabilities. Later, in the 1960 and 1970s, neurofeedback was popularised by the work of Joe Kamiya and Elmer Green, among others. In 1968, Kamiya published a study on the efficacy of alpha training in 'Psychology Today'. In the first part of his study, subjects were asked to keep their eyes closed, and when a tone sounded to say whether they thought they were in alpha. They were then told whether they was correct or wrong. Initially subjects would get about fifty percent correct, but eventually some subjects would develop the ability to distinguish between states and be correct a highly significant percentage of the time. In the second part of the study, subjects were asked to go into alpha when a bell rang once and not go into alpha when the bell rang twice. Once again some subjects were able to enter the state on command for a significant percentage of the time. Since alpha states are connected with relaxation, such alpha training had the possibility to alleviate stress and stress-related conditions. Thus neurofeedback appealed greatly to the social movements of the 1960s, when altered states were a lifestyle, and research on alpha brain waves appealed more to the pop-culture fascination than to the more conservative scientific community. In 1973, Elmer Green took a portable psychophysiological lab to India to study a selection of holy men. All of these men possessed the incredible ability to control their heart rate, blood flow, and other autonomic functions and, according to GreenÕs results, all of them generated alpha waves continuously while doing so. Despite these highly compelling claims, the universal correlation of high alpha density to a subjective experience of calm can not be assumed. Visuomotor activity appears to be of primary importance in alpha neurofeedback, and the generation of alpha with the eyes open and the lights on can yield different results if the procedure is carried out with the eyes closed or in total darkness. Hence alpha states do not seem to have the universal stress-alleviating power as the early expectations indicated.
Subsequently, in the 1980Õs and 1990Õs, the work of Barry Sterman, Joel F. Lubar and others has indicated a higher efficacy for beta training, specifically the sensorimotor rhythm (SMR). The SMR is the rhythmic activity between 12 and 16 Hz that can be recorded from an area near the sensorimotor cortex. It is found in waking states and is very similar, if not identical, to the sleep spindles that are recorded in the second stage of sleep. Studies have shown that enhancement of sensorimotor activity through operant conditioning designed to increase SMR is an anticonvulsant process and is therefore an effective treatment for epilepsy. This SMR training has been used in the treatment of epilepsy, attention deficit disorder, hyperactive disorder, and other mood disorders. Sterman has conducted several studies into the treatment of epilepsy using SMR training. He research has shown that monkeys and cats that have undergone SMR training have elevated thresholds for the convulsant chemical monomethylhydrazine. This suggests that SMR is associated with an inhibitory process in the motor system and therefore increasing SMR through operant conditioning increases the ability to control seizures. Most recent neurofeedback studies have involved the treatment of most severe epilepsy patients, where anticonvulsant drug therapy was unable to control their seizures. In this most severe group of patients, it was found that beta and SMR training on average produces a 70% reduction in seizures. In these severe cases of medically intractable epilepsy, biofeedback has been able to facilitate greater control of seizures in 82% of patients. Lubar has addressed attention disorders using essentially the same protocol. His research indicates that by inhibiting motor function, input function, which relates to attention, is also inhibited. LubarÕs protocol, which has been adopted by most practitioners as the standard protocol for treating patients with attention disorders, is to inhibit both 2-10 Hz slow waves (alpha and theta) as well as 19-22 Hz waves and encouraging activity in the 12-19 Hz range. This procedure has been supported since alpha activity is known to decrease during cognitive functions and to be inversely related to metabolism. LubarÕs hypothesis is that the ADD brain has a decreased metabolism and decreased blood flow to the subcalossol cortex. These problems are countered by the inhibition of alpha. Lubar has published 10-year follow-ups on cases and found that in about 80% of patients, neurofeedback can substantially improve the symptoms of ADD and ADHD, and that these changes are maintained. Currently, treatment for attention disorders is the most common application of neurofeedback. However, the treatment is also effective in the treatment of traumatic head injuries and sleep disorders as well as epilepsy.
More recently, within the last 5-10 years, neurofeedback has taken a new approach in taking a second look at deep brain states. Alpha-theta training has been used in the treatment of alcoholism and other addictions, post-traumatic stress disorder and the dysphoric disorders of women-musicians and psychopathic offenders. During this therapy, when the alpha wave amplitude is crossed over by the rising amplitude of theta waves, the state is called the alpha-theta crossover state and is associated with resolution of traumatic memories. This low frequency training differs greatly from the high frequency beta and SMR training that has been practiced for over thirty years and is more reminiscent of the original alpha training of Elmer Green and Joe Kamiya. Beta and SMR training can be considered a more directly physiological approach, strengthening sensorimotor inhibition in the cortex and inhibiting alpha patterns, which slow metabolism. On the other hand, alpha-theta training derives from the psychotherapeutic model and involves accessing of painful or repressed memories through the alpha-theta state. The physiological mechanisms behind these therapies are very unclear, but the theory is that repressed memories and unresolved traumas exert a stress on the brain that interferes with normal operation. EEGs of alcoholics have revealed an inability to produce the alpha waves generally associated with feelings of relaxation and comfort. However, following the use of alcohol, theta and alpha waves increase, since drowsiness and relaxation are common effects of alcohol. Therefore, alcoholics may be self-medicating their abnormal level of low frequency waves. Studies have demonstrated a high efficacy of alpha-theta therapy in treating alcoholism. Peniston and Kulkosky found that while alcoholics in a control group receiving standard treatment showed significant increases in beta-endorphin levels as a result of stress caused by abstinence from alcohol, alcoholics receiving the alpha-theta treatment did not. On four-year follow-ups only 20% of the traditionally treated group of alcoholics remained sober, compared with 80% of the experimental group who received neurofeedback training. Despite these results alpha-theta treatment remains relatively unexplained physiologically and must deal with the vagaries of the repressed memories and dreams. Therefore, it continues to straddle the boundary between psychotherapy and the more physiologically specific high frequency neurofeedback.
Controversy
Neurofeedback during clinical trials has attempted to remediate certain mental problems by conducting an assessment and then attempting to train specific changes in order to normalize the EEG and improve mental function. This technique has been proposed for the treatment of epilepsy, ADHD and various other diseases and disorders. Some researchers have proposed that this form of operant conditioning of EEG may produce lasting positive functional changes. Indeed, numerous practitioners have actively lobbied against psychiatric medication in general, and Ritalin in particular, in favour of neurofeedback methods for the treatment of narcolepsy and ADHD. However, the subject of training the brain using brainwaves is still strongly contended by some researchers. One line of research has attributed observed benefit in function to the placebo effect. Another line of research has argued that brain function is highly complex and specific to certain loci within the brain, so although certain physical and mental activities are indeed associated with certain brainwaves, general entrainment to a single frequency or state will be unsatisfactory and ineffective. Indeed several ADHD experts, most notably Russell Barkley, state that any form of neurofeedback is ineffective and that research supporting it is, to date, sloppy and inconclusive.
Measuring the brain's EEG activity is a standard procedure in medicine, and can give interesting indicators of how the brain works. However, the issue of whether EEGs can be used to balance the cerebral hemispheres, induce relaxation, improve mental functioning, or change or benefit the brain in any way is still inconclusive and controversial. Although there are several studies that clearly demonstrate such benefits, more research is needed to determine whether neurofeedback can, indeed, be considered a reliable form of treatment.
Therapeutic Applications of Neurofeedback
The therapeutic applications listed below have grouped according to the level of research and/or clinical data that is currently available. The inclusion of certain therapeutic applications in the third grouping is also based on the need for professionals to be aware of their potential for side effects. It should be noted that these groupings will most likely be subject to revision as the literature on neurofeedback continues to expand.
Syndromes with Published Evidence of Effectiveness using Neurofeedback
Addiction, Anxiety, Attention Deficit Disorder (ADD)/ Attention Deficit Hyperactivity Disorder (ADHD), Depression, Posttraumatic Stress Disorder and Sleep Disorders.
Syndromes with Clinical Reports of Effectiveness using Neurofeedback
Attachment Disorder, Autoimmune Dysfunction, Borderline Personality Disorder, Chronic Fatigue Syndrome, Chronic Pain, Cognitive Decline in the Elderly, Dissociative Identity Disorder, Eating Disorder, Obsessive-Compulsive Disorder, ParkinsonÕs Disease, Traumatic Brain Injury and Tourette's Syndrome.
Syndromes that are Current Experimental Applications for Neurofeedback
Autism, Conduct Disorders, Epilepsy, Fetal Alcohol Syndrome, Learning Disabilities, Migraine, Pre-Menstrual Syndrome and Stroke.
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