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Background
Biofeedback can be defined as a training technique that utilizes monitoring instruments to detect and amplify internal physiological processes, and presents this ordinarily unavailable information by audio and / or visual means to patients. This information is usually displayed in a quantitative manner and used by the patients to learn specific tasks.
Urinary Incontinence
Urinary incontinence (UI) affects people of all ages especially elderly women. Among adults, there are 4 prevalent types of UI: (i) stress incontinence (closure problem), (ii) urge incontinence (storage problem), (iii) overflow incontinence, and (iv) mixed stress and urge incontinence. In women, stress incontinence is generally caused by an incompetent urethral mechanism which arises from damage to the sphincter(s) or weakening of the bladder neck support that typically occurred during childbirth. Some women develop stress incontinence as a consequence of multiple anti-incontinence procedures resulting in a condition known as intrinsic urethral sphincter deficiency In man, stress incontinence is usually a consequence of operations for benign prostatic hypertrophy or prostatic carcinoma Urge incontinence is usually associated with an over-activity of the detrusor muscle. When the involuntary contraction of the detrusor muscle is associated with a neurological deficit, it is known as detrusor hyperreflexia. On the other hand, when detrusor over-activity is not associated with any neurological deficit, it is labeled as detrusor instability (unstable bladder). Overflow incontinence may be due to an underactive detrusor muscle or obstruction of the urethra. In men, overflow incontinence associated with obstruction is usually due to prostatic hyperplasia. Urethral obstruction in women may occur as a consequence of anti-incontinence operation or severe prolapse of the uterus or relaxation of the anterior vaginal wall with cystocele or cystourethrocele.
It is now generally accepted that behavioral techniques, because of their relatively non-invasive and low risk approaches, have become the first line treatment for UI. Other techniques that may be used in combination with behavioral therapies include biofeedback, vaginal cone retention and electrostimulation even though the effectiveness of the latter in the treatment of certain types of UI is still unproven. The next step of treatment for UI is drug therapy followed by surgical interventions which include periurethral bulking injection of collagen.
Pelvic muscle exercises can aid in strengthening the voluntary periurethral and pelvic muscles needed to maintain urinary continence since contractions of these muscles raise the urethral pressure. Indeed, this form of exercise is indicated for women with stress incontinence, men with incontinence following prostatic surgery, and patients with urge incontinence. Depending on the type of UI, patients are taught to contract the pelvic floor muscles, relax the detrusor and the abdominal muscles, and/or contract the sphincters. Biofeedback has been suggested to be useful in teaching patients with UI pelvic muscle exercises because it relays to them whether they are contracting the right muscle(s) and provides positive reinforcements as they acquire the skill during training sessions.
There is sufficient evidence that biofeedback-assisted pelvic muscle exercise (e.g. Kegel's exercise) is a safe and effective method for the treatment of stress incontinence, urge incontinence, and mixed stress and urge incontinence. The Agency for Health Care Policy and Research (AHCPR)'s clinical practice guideline on urinary incontinence in adults states that biofeedback used in combination with other behavioral treatments such as pelvic muscle exercises and bladder training, can be useful in the reduction of symptoms associated with urinary incontinence.
Chronic Constipation
Constipation is one of the most common gastrointestinal complaints in the United States affecting at least 10% of the general population, and 25% of the elderly. It is not a disease, but a symptom of various diseases/disorders of mixed etiologies and mechanisms. According to the report of an international workshop on the subject, constipation is defined as the occurrence of 2 or more of the following symptoms in the previous 12 months (without the use of laxatives): (i) fewer than 3 bowel movements per week, (ii) excessive straining during at least 25 % of bowel movements, (iii) a feeling of incomplete evacuation after at least 25 % of bowel movements, and (iv) passage of hard or pellet-like stool during at least 25 % of bowel movements (Whitehead, et al., 1991). Causes for constipation may be colorectal (e.g. malignancy, diverticular disease, pelvic floor dysfunction, and anal fissure), drug-induced (e.g. opiate analgesics, calcium and aluminum-containing antacids, antidiarrheal agents, antidepressants, and antihistamines), metabolic/endocrine (diabetes mellitus, hypothyroidism, hypercalcemia, and pregnancy), and neurogenic (multiple sclerosis, Parkinson's disease, cerebral tumors, and Hirschsprung's disease). Other possible causes include irritable bowel syndrome, inadequate dietary fiber, and psychosocial problems.
There are two major causes for chronic constipation: (i) colonic inertia, and (ii) pelvic floor outlet obstruction (PFOO). The former is known as slow-transit constipation, and is characterized by a delay in the movement of food residues through the colon. It is usually treated with total abdominal colectomy with ileorectal anastomosis. The latter is also known as anismus, pelvic floor dyssynergia, paradoxical puborectalis contraction, pelvic outlet syndrome, and spastic pelvic floor syndrome, and is characterized by inability or difficulty to expel stool from the rectosigmoid region. Pelvic floor outlet obstruction is a functional disorder of evacuation involving the external anal sphincter and pelvic floor voluntary musculature in which the muscles contract, rather than relax. This results in the anal canal being kept tightly closed during straining at attempted defecation. Symptoms of PFOO include incomplete rectal evacuation, prolonged straining at defecation, digital manipulation of the rectum, and constipation. The diagnosis of PFOO is often established by means of anorectal and pelvic floor function tests such as balloon expulsion test (simulated defecation), evacuation proctography (defecography), anorectal manometry, scintigraphic expulsion of artificial stool, sphincter/puborectalis electromyogram, as well as measurement of rectoanal angle. Biofeedback has been used successfully to teach patients with this disorder to relax the sphincteric and pelvic floor musculature.
There is sufficient evidence that electromyographic (EMG) biofeedback is safe and effective in the treatment of patients with chronic constipation due to pelvic floor outlet obstruction. Electromyographic biofeedback has been shown to improve chronic constipation secondary to pelvic floor outlet obstruction by changing the anorectal angle, improving rectal sensation, and enhancing relaxation of the pelvic floor and sphincter musculature.
Fecal Incontinence
Fecal incontinence (FI) is relatively common in the elderly and children. There are many causes for FI including injuries or diseases of the spinal cord, congenital anorectal malformations, accidental injuries to the rectum and anus, aging, diabetes mellitus, tumors, post obstetrical injuries, and post anorectal surgeries. Fecal continence relies on several factors: (i) mental function, (ii) stool volume and consistency, (iii) colonic transit, (iv) rectal distensibility, (v) anal sphincter function, (vi) anorectal sensation, and (vii) anorectal reflexes. Dysfunction/abnormality of any of these factors, alone or in combination, can result in FI. Normal anal sphincter activity depends on a functional sphincter mechanism consisting of the internal anal sphincter (IAS), the external anal sphincter (EAS), and the puborectalis muscles. The passage of stool into the rectum causes rectal distention resulting in reflex relaxation of the IAS. During this relaxation, FI will ensue unless the EAS is simultaneously contracted voluntarily.
There are various methods for the treatment of FI including behavioral therapies, drug therapies, as well as surgical intervention. For the past three decades, various biofeedback techniques have been used in the management of FI. In particular, EAS biofeedback training has been shown to be effective in treating FI. This technique teaches patients to increase the strength of contraction of their EAS in response to rectal distention. The major outcome measures deemed important in assessing the usefulness of biofeedback for the management of patients with FI are restoration of continence or reductions in the frequency of incontinence, and long term results.
There is evidence that biofeedback techniques are safe and effective in the treatment of patients with fecal incontinence, especially those who have some degree of rectal sensation and ability to contract the sphincter voluntarily. Biofeedback training has been demonstrated to restore continence or reduce the frequency of incontinence in patients with fecal incontinence with satisfactory long term results.
Terra et al (2006) evaulated the outcome of pelvic floor rehabilitation in a large series of consecutive patients with FI caused by different etiologies. A total of 281 patients (252 females) were included. Data about medical history, anal manometry, rectal capacity measurement, and endo-anal sonography were collected. Subgroups of patients were defined by anal sphincter complex integrity, and nature and possible underlying causes of FI. Subsequently patients were referred for pelvic floor rehabilitation, comprising 9 sessions of electric stimulation and pelvic floor muscle training with biofeedback. Pelvic floor rehabilitation outcome was documented with Vaizey score, anal manometry, and rectal capacity measurement findings. Vaizey score improved from baseline in 143 of 239 patients (60 %), remained unchanged in 56 patients (23 %), and deteriorated in 40 patients (17 %). Mean Vaizey score reduced with 3.2 points (p < 0.001). A Vaizey score reduction of greater than or equal to 50 % was observed in 32 patients (13 %). Mean squeeze pressure (+5.1 mm Hg; p = 0.04) and maximal tolerated volume (+11 ml; p = 0.01) improved from baseline. Resting pressure (p = 0.22), sensory threshold (p = 0.52), and urge sensation (p = 0.06) remained unchanged. Subgroup analyses did not show substantial differences in effects of pelvic floor rehabilitation between subgroups. The authors concluded that pelvic floor rehabilitation leads overall to a modest improvement in severity of FI, squeeze pressure, and maximal tolerated volume. However, only in a few patients, a substantial improvement of the baseline Vaizey score was observed. They noted that further studies are needed to identify patients who most likely will benefit from pelvic floor rehabilitation.
A Cochrane review on biofeedback and/or sphincter exercises for the treatment of FI in adults, Norton and colleagues (2006) concluded that the limited number of identified trials together with their methodological weaknesses do not allow a definitive assessment of the possible role of anal sphincter exercises and biofeedback therapy in the management of people with FI. These researchers found no evidence of biofeedback or exercises enhancing the outcome of treatment compared to other conservative management methods. While there is a suggestion that some elements of biofeedback therapy and sphincter exercises may have a therapeutic effect, this is not certain. They stated that larger well-designed trials are needed to enable safe conclusions.
Suitable candidates for this treatment modality are patients who have some degree of rectal sensation and ability to contract the sphincter voluntarily. First line approaches including behavior modification (e.g. dietary manipulations and/or changes in bowel habit, and prevention of fecal impaction/constipation by regular use of laxatives and/or enemas) and pharmacotherapies (e.g. loperamide/Imodium, or diphenoxylate with atropine/Lomotil, Diarsed, and Reasec) should have been tried and failed.Children with fecal incontinence secondary to myelomeningocele are not good candidates for the use of biofeedback in treating their incontinence.
Headache
It is estimated that 50 million Americans suffer from headache. Headaches can be classified into 4 distinct categories--vascular, tension, traction, and inflammatory. Vascular headaches include migraine and cluster which probably arise from the abnormal functioning of the vascular system or the brain's blood vessels. Tension (muscle contraction) headaches are caused by the tightening of muscles of the head, face and neck. Traction and inflammatory headaches refer to those that are caused by inflammation, traction and displacement of the pain sources of the head. Pathological conditions such as hematomas, aneurysm, brain tumors, or brain edema can lead to traction headaches; while diseases of the eye, ear and sinus can give rise to inflammatory headaches. The most prevalent type of vascular headache is migraine. It is now generally accepted that about one in eight adults in the developed countries has migraine headaches. Women are affected two to three times more than men. This disorder predominantly affects young adults and the peak incidence is between the age of 25 and 34. There are two major types of migraine headaches-- (i) migraine with aura (classical migraine) which accounts for 15 to 18% of all migraine episodes, and (ii) migraine without aura (common migraine) which accounts for 80% of all migraine attacks. Some individuals suffer from both types of migraine at different times.
The treatment of choice for frequent migraine sufferers is usually pharmacologic prophylaxis. Avoidance strategies (loud noises flashing lights, stress and certain foods) also constitute a very important first line approach in managing migraine. Biofeedback training with or without relaxation techniques have also been shown to be effective in treating migraine and tension headache.
In particular, thermal biofeedback training has been shown to be effective in treating migraine headache. This technique teaches patients to increase the temperature of their fingers. Supposedly, dilatation of the peripheral blood vessels in the hand is associated with reduced blood flow in the regions of the supra-orbital and superficial temporal arteries, although the exact mechanism by which thermal biofeedback improves migraine headaches is still unclear. For the management of tension headache, electro-myographic (EMG) feedback has been employed primarily. Moreover, it has been shown that the combination of thermal and EMG biofeedback has been effective in the control of migraine, tension, and mixed migraine and tension headache. Furthermore, it has been reported that relaxation techniques can produce improvements in headache.
Available evidence indicates that biofeedback techniques (thermal, EMG, and temporal blood volume pulse biofeedback), with or without other behavioral therapies (relaxation and cognitive training), are safe and effective methods for the treatment of migraine and tension headache. This therapeutic modality has no side effects and does not preclude other options. Unlike migraine and tension headache, there is a lack of published data concerning the safety and effectiveness of biofeedback in the management of cluster headache.
Before enrolling in a biofeedback program, patients should be examined by a physician to ensure that their headaches are not due to pathological conditions such as hematomas, aneurysm, brain tumors, brain edema, or diseases of the eye, ear and sinus. They should also be willing and motivated to learn and practice the specific tasks needed to correct / improve their problems. First line approaches, including avoidance of precipitating stimuli and pharmacologic prophylaxis, should have been tried and failed.
Neuromuscular Rehabilitation
Among patients who survive longer than 1 month following stroke, it has been estimated that 10% of them experience almost complete spontaneous recovery, and another 10% do not benefit from any type of therapy. It is the remaining 80% of stroke survivors with significant neurological deficits and physical disabilities who may benefit from rehabilitation. The principal goal of stroke rehabilitation is to improve the functional abilities of these patients, thus affording them greater independence in activities of daily living and improving their quality of life. Conventional modalities of stroke rehabilitation comprise various combination of range of motion and muscle strengthening exercises, mobilization activities, and compensatory techniques. Other therapies include neurophysiological/developmental based methods in which the therapeutic program incorporates neuromuscular re-education techniques. In this regard, biofeedback has been used for neuromuscular rehabilitation. Among biofeedback techniques employed in neuromuscular rehabilitation, EMG biofeedback is the most common one. It is often utilized by stroke patients for facilitation of contraction (strength) and relaxation of spasticity (inhibition). Electromyographic biofeedback has also been used to treat patients with spasmodic torticollis and patients with muscular atrophy resulting from surgery.
The goals of EMG biofeedback in neuromuscular rehabilitation is two-fold: (i) relaxation of muscles, or (ii) recruitment of muscles. Relaxation of muscles is usually performed under one of two conditions -- either muscles are trained to relax as a consequence of hyperactivity that may be stress or work related, or they are trained to relax as a result of hyperactivity caused by central nervous system dysfunction (e.g. patients with spasticity due to stroke or traumatic brain injury). Recruitment of muscles is generally carried out under conditions requiring increased output for movement generation or strength. A typical application of muscle recruitment using EMG biofeedback is in the activation of muscles that have been weakened as a result of a variety of reasons (e.g. patients with joint/ligament repair or immobilization of limb segment).
There is sufficient evidence that EMG biofeedback is safe and effective for (i) neuromuscular rehabilitation in patients who suffered from strokes and traumatic brain injury. In contrast, there is insufficient evidence that EMG biofeedback is effective as a rehabilitation modality for patients with spinal cord injury, and in patients with spasmodic torticollis. Additionally, although there is limited evidence that EMG biofeedback is effective in enhancing (i) the return to full active extension of the operated knee, and (ii) recovery peak torque of the quadriceps femoris muscle following knee surgeries, there is little data on how these physiological improvements translated into improved functional outcomes.
Candidates for EMG biofeedback should be disabled and have not benefited from conventional forms of therapy.Patients should have some volitional motor activity, but are unable to use it in any meaningful manner. Ideal candidates should have no receptive aphasia and should be motivated and committed to the therapy.
Raynaud's Disease
Raynaud's syndrome is a painful vasospastic disorder affecting most frequently the digits of the upper extremity, usually triggered by cold and/or emotional stress. When these symptoms are secondary to the presence of other causes such as vascular injury, and exposure to drugs and chemicals, or diseases, this disorder is known as Raynaud's phenomenon. On the other hand, when these symptoms occur without an associated disease, it is called Raynaud's disease (RD). Clinical manifestations of this disorder usually occur between the ages of 20 and 40 years. Moreover, women are more likely to be affected than men (approximately 4 to 1 ratio).
Treatments of RD include avoidance of precipitating factors, wearing of heavy clothing, protecting not only the hands and feet, but also the face and trunk to avoid reflex vasospasm, and drug therapy. For most patients with RD, the drug of choice is a calcium channel blocker. For patients with very severe RD, surgery may have immediate benefits, but long term results have been disappointing. Another approach for the management of RD is biofeedback. Thermal (finger temperature) biofeedback is the most commonly used biofeedback mode for the treatment of RD. Studies have shown that finger temperature biofeedback is effective in reducing the frequency and severity of vasospastic attacks in patients with RD. The major outcome measures deemed important in assessing the usefulness of thermal biofeedback for the management of patients with RD are reductions in frequency and intensity of attacks, and long term results.
Available evidence indicates that thermal (finger temperature) biofeedback is safe and effective for the treatment of Raynaud's disease. Treated patients showed a reduction in the frequency and severity of attacks with satisfactory long term results. First line approaches including avoidance of precipitating stimuli and pharmacotherapies should have been tried and failed.
Tinnitus
Tinnitus is defined as the aberrant perception of noise or sound without any external stimulation. Tinnitus presents as an aberrant and often disabling ringing, buzzing, clicking, or roaring sounds in the ears. Tinnitus may be unilateral or bilateral and has equal prevalence in women and men and is most prevalent between the ages of 40 and 70. Occasionally, it can also occur in children. Periodic bouts of mild, high-pitched tinnitus lasting for several minutes are common in normal-hearing individuals. Severe and persistent tinnitus can interfere with sleep and the ability to concentrate, causing great psychological distress. In extreme cases, patients with severe chronic tinnitus may consider suicide. Tinnitus can be classified into two types: (i) subjective tinnitus, and (ii) objective tinnitus.
Subjective tinnitus, which is more common, is only audible to the patient. It may arise from some types of electrophysiological disturbance anywhere in the auditory system -- the external ear canal, tympanic membrane, ossicles, cochlea, auditory nerve, brainstem or cerebral cortex. The underlying causes of subjective tinnitus include otological (presbycusis, noise-induced hearing loss, Meniere’s disease, or chronic otitis media), metabolic (diabetes, thyroid diseases, hyperlipidemia, or zinc deficiency/vitamin deficiency), pharmacological (aspirin compounds, non-steroidal anti-inflammatory drugs, caffeine, nicotine, aminoglycosides, or antidepressants), neurological (whiplash, skull fracture/closed head trauma, multiple sclerosis, or following meningitis), psychological (depression or anxiety), as well as infectious and neoplastic (syphilis, acoustic neuroma, autoimmune diseases, or acquired immune deficiency syndrome) disorders.
Objective tinnitus, the less common type of tinnitus, usually refers to noises that can be heard by an examiner. The physician must put his/her ear against the patient’s ear or use a stethoscope against the patient’s external auditory canal. Objective tinnitus usually has a vascular (arteriovenous malformations/shunts, arterial bruits, hypertension, arteriosclerosis, venous hums, or aneurysms) or mechanical (eutaschian tube dysfunction, temporomandibular joint disease, palatal myoclonus, or idiopathic stapedal muscle spasm) origin.
The management of patients with tinnitus often depends on the severity of the condition. If the patient’s activities of daily living are not affected by tinnitus, treatment options include counseling, reassurance, and/or behavioral and dietary modifications (avoidance of excessive noise, nicotine, salt, and caffeine). All medications should also be evaluated to eliminate ototoxic drugs. If the tinnitus interferes with the patient’s sleep and his/her activities of daily living, treatment options include habituation therapy and pharmacotherapy. However, it should be noted that no drug has been approved by the Food and Drug Administration for the specific treatment of tinnitus.
Another therapeutic modality is biofeedback. The major outcome measures that are deemed important in assessing the effectiveness of biofeedback in treating tinnitus are suppression or reduction of tinnitus severity and/or frequency. Reviews on tinnitus indicated that biofeedback is an useful treatment modality for patients with severe tinnitus. Studies have reported that electromyographic (EMG) or thermal biofeedback training alone or supplemented with relaxation techniques is effective in treating patients with severe subjective tinnitus.
Appropriate candidates for biofeedback for tinnitus should not have a medically correctable cause of tinnitus, and have tried and failed conservative treatments including counseling andreassurance, behavioral and dietary modifications, masking devices and drug therapy.Patients taking medications for other medical problems known to have a side effect of tinnitus, such as aspirin, Vasotec (Enalapril Maleate), etc., are generally not appropriate candidates for biofeedback, nor are patients with active ear disease, or patients with psychiatric problems such as schizophrenia, depression, hysteria, or hypochondria.
Temporomandibular Joint Syndrome
Temporomandibular joint disorders, also known as temporomandibular pain dysfunction syndrome (TMPDS), or myofascial pain dysfunction syndrome (MPD or MPDS), are a collective term for a variety of problems affecting the jaw's joints, muscles, and surrounding tissues. These terms are often confused with myofascial pain dysfunction (MPS), myofascial syndrome, and myofascitis which refer to body pain and autonomic phenomena associated with trigger points. Temporomandibular joint disorders are characterized by pain in the preauricular area, TMJ, or masticatory muscles ; limitation or deviation in mandibular motion ; and clicking/popping sounds during opening or closing of the jaw (crepitus). The causes of TMJ disorders range from emotional stress, orthodontic problems, degenerative disease that may produce arthritic conditions, to trauma/injury to the head or neck. Signs and symptoms of TMJ disorders usually increase in frequency and severity from the age of 20 to 50. These disorders are generally self-limiting or fluctuate over time, and pain seems to decrease markedly by the sixth decade of life. It is estimated that approximately 5 % of this patient population requires medical care.
Because of their variable etiologies, TMJ disorders have been treated with different approaches including behavioral therapies, physical therapy, pharmacotherapy, occlusal appliance therapy, as well as surgery. Behavioral therapies often entail removal of causative factors, if known, to prevent continued damage. These include biofeedback, counseling the patients to lower the frequency of clenching, bruxing, and unhealthy oral habits, as well as reducing stress via identification of behaviors that result in clenching and muscle pain. Physical therapy includes the use of vapocoolant sprays, moist heat, massage, and cold packs to tender muscles, and general physical exercise to decrease the focus on excessive use of the jaw muscles. Pharmacotherapy consists of the use of muscle relaxants such as diazepam and cyclobenzaprine, hypnotics such as florazepam, analgesics such as aspirin and ibuprofen, and antidepressants such as amitriptyline and desipramine. Occlusal appliance therapy is the use of TMJ appliances such as bite splint, night guard, occlusal orthopedic appliances and occlusal splint to alleviate jaw movement habits and reduce the frequency of diurnal and nocturnal clenching habits. Most patients with TMJ disorders attain good relief of symptoms with these noninvasive, conservative treatment methods. In general, there is a 70 to 90 % rate of success with the use of occlusal appliances. All of the above-mentioned modalities are reversible except for surgery. Temporomandibular joint surgery is considered to be an irreversible treatment. It should be considered only when all noninvasive conservative methods of treatment have been exhausted and there is conclusive evidence that the pain and dysfunction are due to major structural changes.
Among biofeedback techniques used to treat TMJ disorders, electromyographic (EMG) biofeedback is the most common one. This technique usually entails teaching patients to reduce muscle (the masseter and/or the temporalis, frontalis muscles) activity and produce physical relaxation of the muscles of the jaw. Many studies have reported that EMG biofeedback is effective in treating TMJ disorders.
The use of electromyographic (EMG) biofeedback for the treatment of temporomandibular joint (TMJ) disorders has been shown to be safe and effective. Appropriate candidates are thosewho have been diagnosed to have TMJ disorders. Patients history should be the prime indicator for biofeedback. Patients should be willing and motivated to learn and practice the specific tasks needed to correct/improve their problems.
Hypertension
It is estimated that about 65 million adult Americans have been diagnosed to be hypertensive. Moreover, 90% of all hypertension cases are classified as essential, primary, or idiopathic hypertension -- the exact etiology of the condition is unknown. Essential hypertension is among the most common diagnosis for patients visiting offices of physicians, accounting for 4% of visits. The Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure considered an individual 18 years or older to be hypertensive if the average of two or more diastolic blood pressure (DBP) readings on at least two subsequent visits is 90 mm Hg or above, or when the average of multiple systolic blood pressure (SBP) measurements on two or more subsequent visits is consistently higher than 140 mm Hg.
The main objective of antihypertensive therapy is to lower the overall cardiovascular risk. Pharmacological treatments for hypertension are available in many forms that range from diuretics, beta-blocking agents, ganglionic blockers, postganglionic neuronal depletors, centrally acting postsynaptic alpha-adrenergic agonists, alpha-adrenergic receptors inhibitors, to vasodilators including hydralazine, minoxidil, angiotensin-converting enzyme inhibitors, and calcium antagonists. Nonpharmacological treatments of hypertension mainly entail changes in lifestyle and diet which include weight reduction, moderation in alcohol and caffeine intake, smoking cessation, exercise, sodium restriction, dietary supplement of potassium, calcium, or magnesium. Cognitive behavioral techniques such as biofeedback, relaxation, and meditation have also been employed for the treatment of hypertension.
The Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure has published evidence-based guidelines on the treatment of hypertension. This report and its predecessors were initiated by the National High Blood Pressure Education Program Coordinating Committee which includes member organizations such as the American Academy of Family Physicians, American College of Cardiology, American College of Physicians, American College of Preventive Medicine, American Medical Association, American Society of Hypertension, National Hypertension Association, Inc., and National Stroke Association, as well as federal agencies such as the Agency for Health Care Research and Quality, the Centers for Medicare and Medicaid Services, and National Heart, Lung, and Blood Institute. The current report states that biofeedback techniques have been evaluated in short term and long term controlled studies with little effect beyond that observed in the control groups. The Committee concluded that the available literature does not support the use biofeedback in the management of hypertension.
Attention-Deficity Hyperactivity Disorder
Attention deficit hyperactivity disorder (ADHD) is one of the most common and serious neurobehavioral disorders among children with a prevalence of 1 to 5%. This disorder is characterized by developmentally inappropriate degrees of inattention, impulsiveness, and hyperactivity which are frequently manifested at home, in school, and in social situations. For approximately half of the cases, the onset is usually before school age, yet the disorder is often not recognized until the child starts schooling. Most children with ADHD often perform poorly at school. Academically, adolescents with ADHD are generally 2 years behind their normal counterparts. It has been demonstrated that 30 to 50% of individuals with ADHD continue to manifest the symptoms in adulthood.
The cause of ADHD is unknown, however, many theories have been proposed to explain the etiology of hyperactivity. Some authorities have suggested that there is a metabolic dysfunction in the brain, whereas others believe that the noradrenergic and dopaminergic systems are involved in the pathophysiology of ADHD. Other factors that may be associated with the etiology of ADHD are heredity, toxic substances, as well as prenatal and perinatal risks.
There are 3 major approaches in treating ADHD: (i) pharmacotherapy, (ii) behavior modification, and (iii) cognitive behavioral techniques. The drugs most frequently employed in treating this disorder are psychostimulants such as methylphenidate hydrochloride (Ritalin), dextroamphetamine sulfate (Dexedrine), and pemoline (Cylert), with Ritalin being the treatment of choice. Behavior modification is used not only to address hyperactivity and impulsiveness of patients with ADHD, but also to train them to learn adaptive behaviors such as directing attention, self-cueing, and inhibitory processes. Cognitive behavioral techniques are utilized to train patients to develop more reflective organized strategies for learning, as well as to teach them to think before acting for reducing their impulsiveness. Components of behavior modification and cognitive behavioral approaches may include positive reinforcement, limiting hyperactive behaviors by time-out procedures, and parental training to teach them the appropriate ways to attend to, ignore, and reward target behaviors.
Biofeedback and/or relaxation training have been used to reduce hyperactivity and impulsiveness as well as to increase attention to task in patients with ADHD. The rationale proceeds from the belief that muscular tension and inability to relax not only contribute to but also exacerbate symptoms of hyperactivity. The assumption is that when hyperactive patients learn how to maintain muscular tension at low levels, a reduction in hyperactivity will ensure. Many forms of biofeedback have been utilized including electromyogram (EMG), electroencephalogram (EEG), galvanic skin resistance, and skin (surface) temperature.
Most studies that suggested biofeedback is effective in treating this disorder were uncontrolled case series with small numbers of patients. Oftentimes it is unclear whether these patients were truly afflicted by this disorder. On the other hand, there were reports that raised serious questions regarding the effectiveness of biofeedback in treating hyperactivity. More importantly, few studies have shown that the initial treatment successes would result in lasting benefits after the treatment ended.
Anxiety Disorders
Anxiety is a normal, adaptive, emotional response which can be an effective stimulus for improving performance. However, chronic anxiety is a maladaptive, irritating, and debilitating condition which may impair social as well as occupational functioning. Anxiety is manifested in many ways with the principal psychological symptoms being fear, excessive worrying, and avoidance. Other symptoms are hypervigilance, autonomic hyperactivity, motor tension, and easy fatigability. Anxiety disorders often surface with depression. In fact, mixed states of anxiety and depression are probably the most common psychiatric problem seen by primary care physicians. Many medical, neurological, and toxicological disturbances can mimic anxiety disorders. These include endocrine disorders, cardiovascular and respiratory disorders, neurological problems, infectious diseases, tumors, and medications.
Anxiety disorders can be classified into 2 major groups: (i) panic disorders, and (ii) generalized anxiety disorder (GAD). Panic disorders are episodic with attack-like symptoms, with the principal feature being the sudden, unexpected, and often overwhelming fear accompanied by somatic symptoms such as dyspnea, palpitations, and faintness. Unlike panic disorders, GAD is a persistent state of anxiety. The cardinal feature of adults with GAD is unrealistic anxiety regarding 2 or more life circumstances such as groundless worrying about one's finances, and possible mishaps to one's offsprings for 6 months or longer. In children and adolescents with GAD, this may emerge as anxiety concerning academic, athletic, and social performance. The prevalence of GAD, which is more common in young women, ranges from 25 to 64 per 1,000. The age of onset is variable, but most frequently is in the 20s and 30s. In patients who seek assistance from health care professionals, women outnumber men by 2 to 1. It is unclear whether there is a familial or hereditary basis for GAD.
Nonpharmacological interventions such as cessation of caffeine, alcohol, and drugs of abuse, combined with vigorous exercises are usually the initial steps in treatment of GAD. Cognitive behavioral therapies including relaxation training, biofeedback, and desensitization that aim at teaching patients methods to reduce anxiety are employed for more severe cases. When GAD is severe enough to warrant pharmacotherapy, SSRIs are the agents of choice.
The 3 most common types of biofeedback in the treatment of GAD are electromyogram (EMG), electroencephalogram (EEG), and heart rate (HR). Many investigators have claimed that biofeedback alone or in combination with other therapies was effective in treating anxiety disorders. In contrast, others have reported that this method was not effective or not any better than other behavioral techniques in controlling GAD. Very few studies actually used biofeedback independently of other treatment techniques. The majority of the studies reported the use of biofeedback in combination of relaxation training in treating this disorder. To determine the effectiveness of biofeedback alone in treating generalized anxiety disorder, studies should include separate treatment groups of biofeedback and relaxation training (or other techniques) as well as a placebo control group. Additionally, it is unclear whether biofeedback/relaxation skills learned in the laboratory setting can be transferred to social situations. More importantly, few studies have shown that the initial treatment successes would result in lasting benefits after the treatment ended.
Fibromyalgia
Fibromyalgia, also known as fibrositis, is characterized by the constant presence of widespread musculoskeletal pain, sleep disturbance, morning stiffness, chronic fatigue, poor endurance, and exhaustion following minimal effort, and is often associated with headache and irritable bowel syndrome. Currently, there is no laboratory test to diagnose fibromyalgia. According to the American College of Rheumatology, the diagnosis of fibromyalgia can be rendered if patients have widespread pain for 3 months and pain in response to palpation at 11 of the 18 identified tender point sites. Pain is considered widespread when all of the following are present: (i) pain in the left and right side of the body, (ii) pain above and below the waist, and (iii) axial skeletal pain -- cervical spine, anterior chest, thoracic spine, or low back. The 18 tender point sites are located bilaterally at the following 9 areas: (i) occiput -- suboccipital muscle insertions, (ii) low cervical -- anterior aspects of the intertransverse spaces at C5 - C7, (iii) trapezius -- midpoint of the upper border, (iv) supraspinatus -- above the scapula spine near the medial border, (v) second rib -- second costochondral junctions, just lateral to the junctions on upper surfaces, (vi) lateral epicondyle -- 2 cm distal to the epicondyles, (vii) gluteal -- upper outer quadrants of buttocks in anterior fold of muscle, (viii) greater trochanter -- posterior to the trochanteric prominence, and (ix) knee -- medial fat pad proximal to the joint line.
It is estimated that 3 to 6 million individuals in the United States may be afflicted with fibromyalgia, and approximately 15 to 20 % of patients seen in a rheumatology practice have this disorder. Approximately 80 to 95 % of all cases are women, usually between the ages of 30 and 60 years. Fibromyalgia is also found in children between the ages of 5 and 17 years, primarily white females, but the prevalence of this disorder in this age group is unknown. On the other hand, fibromyalgia is seldom seen in elderly patients (between the ages of 70 and 90 years), suggesting that symptoms may improve with time. The exact cause of fibromyalgia is still unclear, and presently there is no cure for this disorder. Spontaneous improvement may occur in mild cases whereas recalcitrant cases need comprehensive treatment. There are a number of methods in the management of fibromyalgia. These incluud: (i) education of patient and family on current knowledge of fibromyalgia, (ii) myofascial therapy including heat, massage, stretching and trigger point injections, (iii) improvement in sleep quality with medications or via avoidance of aggravating environmental factors, (iv) fitness program with aerobic conditioning, and (v) psychological intervention through stress management and coping strategies. In addition, authorities have recommended a multidisciplinary approach that entails (i) therapy for associated diseases, (ii) lifestyle modifications, and (iii) pharmacotherapy.
There is insufficient evidence that biofeedback is effective in treating patients with fibromyalgia. Randomized controlled studies with large sample size are needed to ascertain the effectiveness of this treatment modality.
Visual Disorders
An abnormality in either the sensory or motor component of the visual system may lead to a variety of visual disorders. Many optometrists have employed vision therapies to treat these problems. While some vision therapies are concerned with the perceptual aspects of the sensory component of vision, most vision therapies deal with dysfunctions in the motor component. Vision therapy usually encompasses a wide variety of non-surgical methods including eye exercises, eye patches, penlights and mirrors, prisms and lenses, as well as computerized devices that provide feedback to patients to improve their visual problems by programming activities directed at stimulating proper function or building compensating systems to alleviate insufficiencies.
Since the 1970's, biofeedback has been employed for the management of various ophthalmic problems such as oculomotor training for the correction of strabismus, nystagmus, amblyopia, refractive error reduction, and control of blepharospasm. Early biofeedback techniques for treating visual disorders centered on the utilization of electromyography (EMG) to monitor the frontalis muscle as a means of monitoring eye position. Although the use of EMG on extraocular muscles is rather straightforward, it is compromised by powerful signals from the facial muscles and by the imprecision introduced by the electrodes. Presently, the application of ophthalmic biofeedback usually involves direct monitoring of the eyes. There are several methods to achieve this goal including television systems, electromagnetic coil monitoring, electro-oculography (EOG), and photoelectro-oculography (PEOG).
The Accommotrac Vision Trainer is a high speed infrared optometer that provides biofeedback training of accommodation. The primary goal is to train patients to achieve better control of voluntary accommodation to improve functional myopia although it is claimed that this equipment can also be used to treat early presbyopia and latent hyperopia. This device records the vergence of light reflected from the retina at a rate of 30 to 40 times per second, and the signal is converted into an auditory tone which increases in pitch and rate as accommodation decreases. The subject receives immediate auditory feedback through headphones concerning his/her accommodative status. The signals can also be heard by the experimenter through an external speaker. Training takes place in a dark room with the subject watching a small amorphous green fixation light which can be presented at various dioptric settings.
Because of a lack of objective data, the effectiveness of biofeedback in the treatment of visual disorders such as nystagmus, strabismus, amblyopia, and blepharospasm remains unclear. Although some studies have suggested biofeedback may be useful in the treatment of various visual disorders, almost all reports were either in-house publications, abstracts of conference proceedings, case studies, or uncontrolled studies with small sample sizes. When sound experimental studies with control groups, randomization, masking, and statistical analysis have been conducted, biofeedback has not been demonstrated to be effective in the treatment of visual disorders. More research with better experimental design and large sample size is needed to ascertain the effectiveness of biofeedback in the treatment of visual disorders, and the long-term effectiveness of any improvement.
Seizures
Epilepsy, one of the most common neurological disorders, is characterized by seizures that usually occur repeatedly over months or years without consistent provoking factors. The principal treatment modality for epilepsy is pharmacotherapy. The main objective is to protect patients from having seizures without interfering with normal cognitive function, or in children with development of normal intellectual function, without producing adverse side effects. Approximately 70% of patients with epilepsy can be satisfactorily managed by pharmacotherapy. The remaining patients appear to be resistant to medications or develop undesirable side effects. For patients who have intractable seizures despite adequate treatment with appropriate antiepileptic drugs, surgery may be their last hope.
A nonpharmacological intervention for intractable seizures is EEG biofeedback. Electroencephalography is the recording of the electrical currents generated spontaneously from nerve cells in the brain using electrodes placed usually on the scalp. Electroencephalographic biofeedback entails the monitoring of brain wave activity associated with different mental states. There were studies, usually uncontrolled with small number of subjects, that reported the successful treatment of epileptic seizure disorders through biofeedback training of various EEG patterns, especially a 12 - 16 Hz EEG pattern also known as sensorimotor rhythm. However, there have been very few controlled studies with large sample size that included long-term follow up to ascertain the improvements, if any, of EEG biofeedback in the treatment of patients with intractable seizures.
Based on frequency and amplitude, EEGs commonly comprise 4 types of brain waves -- beta, alpha, theta, and delta (in order of frequency from fastest to slowest). Beta waves (above 13 Hz) predominate when the cerebrum is engaged with sensory stimulation or mental activities. Alpha waves (8 to 13 Hz) characterize EEGs of individuals who are awake, in a relaxed, non-attentive state, but with eyes closed. Theta waves (4 to 7 Hz) generally represent EEGs of individuals who are in a state of drowsiness. Delta waves (less than 4 Hz) are normally observed in individuals who are in deeper stages of sleep. The aim of EEG biofeedback in treating seizures is to train patients to increase the desired alpha waves (to enhance the 12 - 16 Hz sensorimotor rhythm in the EEG) and/or decrease the undesired theta and delta waves.
There is insufficient scientific evidence to support the effectiveness of EEG biofeedback in the management of patients with intractable seizures. Studies that claimed EEG biofeedback to be effective were uncontrolled case studies involving small number of subjects.
Back Pain
Chronic low back pain is one that lasts for more than 3 months. Treatments of chronic LBP include bed rest, traction, wearing of spinal braces and other movement-restricting appliances, exercises, heating or cooling modalities, massage, chiropractic manipulation, pharmacotherapies such as non-steroidal anti-inflammatory drugs, muscle relaxants, non-narcotic analgesics, narcotic analgesics, and psychotropic medications, as well as surgeries such as discectomy/discotomy, laminectomy/laminotomy, therapeutic injections, spinal fusion, spinal osteotomy, and neuroablative procedures. Behavior therapy and behavior modification techniques have also been employed in the management of patients with chronic LBP. One of the behavioral therapies used is EMG biofeedback. This technique is often used to improve lumbar paraspinal muscle strength, sometimes in conjunction with the upper trapezius and frontalis muscle groups.
The outcome measures deemed important in assessing the effectiveness of EMG biofeedback for the treatment of patients with chronic LBP are resolution or reduction of pain, decreases in the use of pain medications, and increases in functional activity level.
The effectiveness of electromyographic (EMG) biofeedback in the treatment of patients with chronic low back pain (LBP) has not been established. Although biofeedback may reduce the activity of paraspinal muscles, there are conflicting data regarding the effectiveness of EMG biofeedback in the treatment of patients with chronic LBP.
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