Bright Light Therapy A Treatment Option for Alzheimers Disease - Essay Example

Bright Light Therapy - A treatment option for Alzheimer's disease Bright Light Therapy - Introduction and Application In 1985, N. E. Rosenthal was the first to present the therapeutic benefit of bright artificial light in the treatment of winter depression. As per the challenging hypothesis set forth by Rosenthal, lengthening of the daily photoperiod can effect a remission of winter depression. This was the beneficial research, which gave birth to a new remedy for diseases and disorders existent since decades. Bright light therapy is a treatment option which functions in the management, prevention and treatment of disease or disorder by exposing the patient to intense levels of light. The light therapy system that meets recommendations consists of a set of fluorescent bulbs installed in a box with a diffusing screen, and set up on a table at which the patient can sit with comfort for the treatment duration. The treatment involves mainly the sitting of the patient in proximity to the light box, with lights on and eyes open. It is not recommended to look straight at the light, since it may prove to be hazardous to the sensitive eyes. It is always a good practice to make an arrangement for the person to engage self in other activities, like reading, writing, eating, or perhaps some other areas of preference or desire. As a rule of thumb, the direction of the head and body should be toward the lights, and the concentration of the mind and eyes should be set on the objects that gain illumination from the bright light and not on the light itself. The treatment duration, depends of the type of disease or disorder demanding management or cure and the severity associated with that condition, and also the equipment in use. The treatment session varies and may last from 15 minutes to three hours, once or twice a day. The different types of illumination sources include common electric light bulb (least effective), fluorescent strip lighting (more efficient), and full spectrum lighting (costly but effective). Full spectrum light bulbs are made to try to imitate natural sunlight, and like sunlight, they also produce UV rays. Full spectrum bulbs, usually have a Color Rendering Index (C.R.I.) of 90 or above (Outdoor light has a CRI of 100) and a Kelvin temperature of 5,000 or above. Thus, it competes natural sunlight in effectiveness to heal. Full spectrum light can be presented as being having a purple or a bluish cast. The innovation in the technology usage in companies has advantaged the light box by provision of blocking the hazardous UV rays through diffuser screen. The progress of technology towards positivity has offered to the market effective systems using cool-white, triphosphor and bi-axial lamps. The point of importance is that the intensity of light emitted should match that of light outdoors shortly after sunrise or before sunset. The health benefit imparted by the bright light therapy has several known physiological effects. However, its mechanism of action is still not very clear. The human blood consists of a hormone called melatonin which is sensitive to light. This melatonin hormone which is abnormally increased at certain times of day gets rapidly decreased by exposure to light. Depending on time of bright light exposure, the internal clock of the body which controls daily rhythms of hormone secretion, body temperature, and sleep patterns gets shifted ahead or is delayed. These physiological time shifts can be the probable basis of the observed health benefit that results from light exposure. The intensity of light can also be responsible to amplify the day-night difference in these rhythms. Research into the exact mechanism of action of light exposure is in action. A number of researches have approved the associated efficiency of bright light to help mange and treat patients with even long histories of SAD. A clear beneficial effect of the treatment is observed a short span of a week, or even sooner. However, the symptoms return back to the same level and in the same period of time after the withdrawal of the light therapy. It therefore becomes crucial to continue the therapy for the whole period of existent winter. A short interruption in the treatment schedule is usually without any significant loss of gained positive effect. In the beginning of the light treatment a small minority of patients may complain of side effects including mild headaches, nausea, eyestrain and irritation. However, a few days of habitual treatment overcomes theses minor adverse effects. The most hazardous side effect, which occurs quite rarely with light therapy, is to switch to an overactive state. During this state of over activity, the patient may find significant difficulty in sleeping, feel restless or speedy. In old age, the optimum functioning of the circadian timing system is lost and this process is even more aggravated in Alzheimer's disease. The disturbances in rest-activity rhythm are significant and disabling symptoms in Alzheimer's disease (AD). Nighttime sleep is greatly fragmented and the daytime activity experiences the negativity of disease by the result of several episodes of napping. In most institutional environments, light levels are not to the required mark and therefore can be considered to insufficient to maintain the circadian clock for the whole day. With the associated side effects and the lack of required efficiency of pharmacological agents in the correction of day-night disturbances, non-pharmacological (bright light therapy) treatments have gained significant importance. Bright light therapy (BLT) is also gaining increasing importance as an additional therapeutic in the management and treatment of circadian rhythm disturbances in demented patients. Even though it is associated with low rate of side-effects is low, special attention is required while treating new groups of Alzheimer's disease patients. Occupational Therapy - Introduction and Advantage Occupational therapy, a skilled treatment option helps patients gain independence in all areas of their lives. It provides patients with the "skills for the job of living" necessary for existence of life with independence and satisfaction. The important services with which the occupational therapist usually benefits the society include: To provide customized treatment programs so as to help improve the patient's ability to perform daily activities To provide comprehensive home and job site evaluations with recommendations for adaptation To perform skills assessments and treatment To recommend for adaptive equipment and train for usage To provide rich guidance to family members and caregivers regarding the steps to be followed to help make the patient independent. Patients suffering from a number of diseases and disorder gain the benefit of better health from the efforts of occupational therapist. The conditions that add health by means of occupation therapy include work-related injuries, limitations following a stroke or heart attack, arthritis, multiple sclerosis, Alzheimer's, schizophrenia, post-traumatic stress, eating disorders, burns, spinal cord injuries, or amputations, broken bones or other injuries from falls, sports injuries or accidents, vision or cognitive problems. Alzheimer's disease, a progressive, degenerative disease that makes its presentation in middle-age attacks the brain and results in impaired memory, thinking and behaviour. The patients often suffer from disturbances in circadian (daily) rhythm. This negatively affects the important body functions such as sleep cycles, temperature, alertness and hormone production. Other disabling symptoms that prove problematic to both the patient and the family members include impaired sleep and nocturnal restlessness. These, sleep-wake rhythm disturbances in Alzheimer's patients make a prominent need on family members and is one of the most significant reason for institutionalization. It has also been known by study and observation that patients of Alzheimer's disease often fail to benefit their biological clocks with good level of light and required physical activity. The disturbances improve on increasing the intensity of environmental light, which, through the retinohypothalamic tract, activates the suprachiasmatic nucleus (SCN), the biological clock of the brain. Bright light therapy is an intervention that is associated with occupational therapy. The family members may benefit by participation in the weekly group meetings led by an occupational therapist on means to manage the many jobs that make up the family members "job of living." Additional occupational therapy services that hold benefit in the treatment of Alzheimer's disease include an assessment of the home environment. This results in detailed modifications to add more safety to the environment, help in location of items and label the essential regions or commodities. This adds to the independence of the Alzheimer's patient. The occupational therapist also provides valuable suggestions to the family members of the patient so as to increase ability in the care giving tasks and make it more manageable. It also helps to predict and prepare for the Alzheimer patient's functional decline. Thus, in so doing the occupational therapist also educates the patient and the family member about the therapeutic benefit incurred by the new, emerging, bright light therapy and thereby enjoys a stand of prominence in the treatment of Alzheimer's disease via bright light therapy. We conducted a systematic review for the purpose of determining, from the available literature, whether the bright light therapy, an important occupational therapy intervention helps improve the outcome for Alzheimer's patients. Six studies were included in the review, of which 3 were randomized controlled trials. Literature Search - Alzheimer's disease and Bright light treatment Literature search was done on the electronic database: Pubmed (1985-January 2005). The search was restricted to English language publications involving Humans and Animals and included the following terms: bright light treatment, Alzheimer's disease, light therapy, bright light, and bright light therapy. The search terms that were found to be most useful were Alzheimer's disease and bright light treatment. Other sources of publications included, "related articles" that were identified through Pubmed. All of the retrieved abstracts and titles were reviewed to determine eligibility and relevance. In total 110 abstracts and titles were obtained through electronic search, of these 6, full text papers were deemed most relevant and were retrieved. Thus, 6 unique studies met the inclusion/exclusion criteria of this review. Literature Review- Alzheimer's disease and Bright light treatment Ancoli-Israel (2003a) and colleagues performed a randomized clinical trial to investigate whether light exposure can consolidate sleep and strengthen circadian rhythms in severe Alzheimer's disease patients. It was observed by these experts that sleep in the nursing home environment is fragmented to a very high level, may be partly due to decreased light exposure. The results of their study brought to knowledge that both morning and evening bright light resulted in more consolidated sleep at night. The measurements that authenticated the observation were made using wrist actigraphy. It was also found that evening light also held the efficiency to increase the quality of the circadian activity rhythm and this was measured using a 5-parameter extended cosine model (amplitude, slope of the curve, acrophase, nadir, and relative width of the peak and trough). It was observed that an increase in the exposure of light all through the day and evening is likely to have a significant positive effect on sleep and on circadian rhythms in patients with dementia. It was therefore proposed that nursing homes should consider increasing ambient light in multipurpose rooms where Alzheimer's patients usually spend much of their time. Dowling (2005b) and colleagues used a randomized clinical trial to determine the effect of timed bright light treatment for rest-activity (circadian) disruption in institutionalized patients with Alzheimer's disease. The experimental groups received either morning (9.30-10.30 am) or afternoon (3.30-4.30 pm) bright light exposure (> or = 2500 lux in gaze direction) Monday through Friday for 10 weeks. The control group received usual indoor light (150-200 lux). Actigraphy was used to determine the daytime wake, nighttime sleep, and rest-activity parameters. In order to test the primary study hypotheses, repeated measures analysis of variance was used. The study was completed by seventy institutionalized subjects with Alzheimer's disease of mean age 84. No significant differences in actigraphy-based measures of nighttime sleep or daytime wake were found between groups. Subjects in either experimental light condition evidenced a significantly (p < 0.01) more stable rest-activity rhythm acrophase over the 10-week treatment period compared to the control subjects whose rhythm phase delayed by over two hours. The study did not ascribe the efficiency to the developing bright light therapy for the treatment of nighttime sleep or daytime wake. However, administration of one-hour of bright light in either the morning or afternoon may show significant improvement as additional adjunct to the circadian pacemaker to facilitate entrainment for the whole day. In another study, Dowling (2005a) and colleagues performed a randomized, placebo-controlled, clinical trial to test the effectiveness of morning bright light therapy in reducing rest-activity (circadian) disruption in institutionalized patients with severe Alzheimer's disease. A total of 46 subjects with mean age of 84 years were recruited from two large, skilled nursing facilities in San Francisco, California. The subjects who meet the NINCDS-ADRDA (National Institute of Neurological and Communicative Disorders and Stroke--the Alzheimer's disease and Related Disorders Association) AD diagnostic criteria were only included for the study. The experimental group received one hour (09:30-10:30) of bright light exposure (> or = 2500 lux in gaze direction) Monday through Friday for 10 weeks. The control group received usual indoor light (150-200 lux). Nighttime sleep efficiency, sleep time, wake time and number of awakenings and daytime wake time were assessed using actigraphy. Circadian rhythm parameters were also determined from the actigraphic data using cosinor analysis and nonparametric techniques. Repeated measures analysis of variance (ANOVA) was used to test the primary study hypotheses. Although significant improvements were found in subjects with aberrant timing of their rest-activity rhythm, morning bright light exposure did not induce an overall improvement in measures of sleep or the rest-activity in all treated as compared to control subjects. The results brought to knowledge that only subjects with the most impaired rest-activity rhythm respond significantly and positively to a brief (one hour) light intervention. Asayama (2003) and his team performed a double blind study of melatonin effects on the sleep-wake rhythm, cognitive and non-cognitive functions in Alzheimer type dementia. A total of nine subjects were administered a placebo (PLA), and 11 given melatonin (3 mg) (MLT). The mean age was 79.2+/-6.4 (17 females and 3 males). The drugs were given at 20: 30 each day for 4 weeks. The research scholars checked sleep time and activity by Actigraph through one week before and the 4th week after drug administration. Cognitive and non-cognitive functions were evaluated with the clinical dementia rating scale (CDR), and Mini Mental State Examination (MMSE), and the Alzheimer's Disease Assessment Scale (ADAS). They recorded with success Actigraph data from 18 patients (PLA8, MLT10). The mean sleep time change ratio and SD of the administration of PLA in the night was-0.2+/-13.7%, and MLT was 33.2+/-37.6%. The mean activity counts and SD of the administration of PLA in the night was 29.8+/-77.0%; in MLT it was-44.9+/-21.9%. Melatonin significantly prolonged the sleep time (p=0.017) and decreased activity (p=0.014) in the night (21: 00-6: 00) in the MLT group, although no significant difference in sleep time or activity in the daytime (6: 00-21: 00) was recognized between the two groups. In comparison with ADAS cognition score changes, the mean change and SD in the PLA was 0.3+/-3.7; in MLT it was-4.3+/-3.6 points. In comparison with ADAS non-cognition score, the mean change and SD in the PLA group was-0.8+/-1.0, in the MLT group it was-4.1+/-2.2 points. There were also significant differences between the PLA and the MLT groups in the comparison with the score improvement of ADAS cognition (p=0.017) and non-cognition (p=0.002), otherwise there was no significant difference in improvement of MMSE between both groups. Melatonin administration had effect to improve sleep time and night activity, but no significant effect to improve daytime naps and activity. Although melatonin administration might has less strong effect on circadian rhythm than morning bright light therapy, cognitive and non-cognitive functions were improved. Melatonin seemed to be useful for care of the Alzheimer type of dementia patients. Ancoli-Israel S (2003b) and colleagues studied the effect of light on agitation in institutionalized patients with severe Alzheimer disease in a large sample of patients with severe dementia. A total of ninety-two patients were randomly assigned to morning bright light, morning dim red light, or evening bright light. Agitation was rated by research staff who observed the patients every 15 minutes throughout the treatment period and by caregivers at one time-point before and one time-point after treatment. The results showed that morning bright light delayed the acrophase of the agitation rhythm by over 1.5 hours. Bright light was associated with improved caregivers' ratings but had little effect on observational ratings of agitation. It was concluded that though the result that light shifted the peak of the agitated behavior might be eneralizable to patients with milder forms of Alzheimer's disease, the fact that agitation was not ameliorated might not be. Because the suprachiasmatic nucleus (SCN) of patients with severe AD is likely to be more degenerated, and the circadian activity rhythms deteriorate as the disease progresses, it is still possible that patients with more intact SCNs, that is, patients with mild or moderate Alzheimer's disease, might benefit from light treatment even more than those with severe Alzheimer's disease. Van Someren (1999) and the research team studied whether bright light therapy held the claimed efficiency to improve sensitivity to its effects on rest-activity rhythms in Alzheimer patients by application of nonparametric methods. The data of recently published positive and negative reports on the effect of bright light on actigraphically assessed rest-activity rhythms in demented elderly were reanalyzed using several statistical procedures. It was demonstrated that the light-induced improvement in coupling of the rest-activity rhythm to the environmental zeitgeber of bright light is better detected using nonparametric procedures. Cosinor, complex demodulation, and Lomb-Scargle periodogram-derived variables are much less sensitive to this effect because of the highly nonsinusoidal waveform of the rest-activity rhythm. Guidelines for analyses of actigraphic data are given to improve the sensitivity to treatment effects in future studies. Discussion & Conclusion The systematic review of the English literature revealed that in the 6 studies of bright light therapy considered here, it can be said to be of value in the management and treatment of Alzheimer's disease. The review identified small but significant effect sized for the efficacy of bright light therapy, as an occupational therapy intervention for Alzheimer's disease patients. It was noted that the amount of evidence with respect to specific interventions is limited. The sample size of most of the studies was too small to confirm the efficiency of bright light treatment. Well-designed, placebo-controlled, randomized studies with a large sample sized clinical trials are required to prove efficiently the efficiency of bright light therapy in the management and treatment of Alzheimer's disease. Bright light therapy, a therapy that is developing each growing day, can be an essential area for patient education and family members counseling. The benefits of exposing the Alzheimer's patient to the bright light can help add more health to his/her present state of condition. Thus, the occupational therapist may assist regarding bright light therapy as an activity that can aid in the physical and mental development of the Alzheimer's patient. By providing right light treatment to the patient, the occupational therapist may help correct the biological clock of the patient. For severely impaired patients of Alzheimer's disease the "job of living" requires basic skills such as remembering the art and need of eating, speaking, and interacting with family members and friends. Patients of Alzheimer's disease suffer from sleep-wake rhythm disturbances those results in an essential demand on caregivers. This is one of the most significant reasons for institutionalization. The above reviewed several studies have studied and found the beneficial effect of bright light therapy in the improvement of disturbances in the circadian rhythm For the recovery of the Alzheimer's patient it is essential for him to gain good night sleep, have the disturbances in the circadian rhythm eliminated. It is essential to bring to practice the bright light therapy so that the patient can work on essential tasks, he/she would need to manage by self. Looking at all the above presented review of papers as evidence, exposure to bright light seems to be a useful treatment supplement in Alzheimer's patients, when suffering from delusions or agitation. However, steps should be taken to check, whether exposure to high light intensity in demented patients is not resulting in the development of agitation or increase in the intensity of agitation. References Ancoli-Israel S, Gehrman P, Martin JL, Shochat T, Marler M, Corey-Bloom J, Levi L. (2003a) Increased light exposure consolidates sleep and strengthens circadian rhythms in severe Alzheimer's disease patients. Behav Sleep Me, 1(1) p.22-36. Ancoli-Israel S, Martin JL, Gehrman P, Shochat T, Corey-Bloom J, Marler M, Nolan S, Levi L. (2003b) Effect of light on agitation in institutionalized patients with severe Alzheimer disease. Am J Geriatr Psychiatry, 11(2) p.194-203 Asayama K, Yamadera H, Ito T, Suzuki H, Kudo Y, Endo S. (2003) Double blind study of melatonin effects on the sleep-wake rhythm, cognitive and non-cognitive functions in Alzheimer type dementia. J Nippon Med Sch, 70(4) 334-41. Dowling GA, Hubbard EM, Mastick J, Luxenberg JS, Burr RL, Van Someren EJ. (2005a) Effect of morning bright light treatment for rest-activity disruption in institutionalized patients with severe Alzheimer's disease. Int Psychogeriatr. 17(2) p.221-36. Dowling GA, Mastick J, Hubbard EM, Luxenberg JS, Burr RL. (2005b) Effect of timed bright light treatment for rest-activity disruption in institutionalized patients with Alzheimer's disease. Int J Geriatr Psychiatry, 20(8) p.738-43. Van Someren EJ, Swaab DF, Colenda CC, Cohen W, McCall WV, Rosenquist PB.(1999) Bright light therapy: improved sensitivity to its effects on rest-activity rhythms in Alzheimer patients by application of nonparametric methods. Chronobiol Int, 16(4) p.505-18. Read More