Efficacies of Treatments of Alzheimer’s Disease

Alzheimer’s disease (AD) is a common form of dementia. It is usually found among the elderly with an increasing likelihood of increasing age and is characterized by degenerating abilities to recall basic information and live independently. There is no known cure, but research has yielded an increased medical understanding of the issue and identified a number of effective treatment options.

Clinicians identify Alzheimer’s disease as opposed to normal aging or mild cognitive impairment through the measurement of mental faculties. Dementia as a whole is not particularly uncommon among the elderly. Dementia, “in broad figures, affects one person in 20 aged over 65 and one people in five aged over 80.” (Benbow, 2009). The frequency of dementia has brought it much scientific scrutiny. When testing a patient for Alzheimer’s disease, a clinician takes “measures of the ability to learn new information and to retain it over time as well as to benefit from external organization cues can differentiate AD patients from normal older adults.” (Au et al., 2003). Many people can report on the mental degeneration caused by Alzheimer’s, and the disease “is characterized by ineffective consolidation or storage of new information, a rapid rate of forgetting and a failure to benefit from organization and category cues.” (Au et al., 2003). Essentially, it becomes an issue of memory.

The disease is most infamous for its effects on memory. Many a child has had to deal with a grandfather who could not remember his name. Medically speaking, “[m]emory is the recording, retention and retrieval of information.” (Machado, et al., 2009). Memory serves as an umbrella term for all information and knowledge gained over the course of a lifetime. The form most devastated by Alzheimer’s disease, “explicit memory (EM), is the ability to consciously and directly recall or recognize recently processed information.” (Machado, et al., 2009). It is by the loss of this that a person loses their concept of who they are and the life they have lived. However, Alzheimer’s disease is more merciful, though not completely so, to implicit memory (IM), “the ability to improve task performance. It reflects the unconscious effects of previous experiences on subsequent task performance, without conscious recollection.” (Machado, et al., 2009). Implicit memory takes several forms. Among them, “procedural memory, the memory of how to perform physical tasks, is one aspect of implicit memory. Repetition learning, the passive, automatic learning of associations upon repeated exposure, is another.” (Broster et al., 2012). Whereas explicit memory refers to the conceptual aspect of memory, implicitly refers to the practical. Despite the rapid loss of explicit memory, “[t]he neurodegenerative pattern of AD progression and the dissociation of implicit and explicit memory enable patients to preserve some types of implicit memory.” (Machado, et al., 2009). Many programs used to treat Alzheimer’s involve reinforcing the implicit memory to compensate for the loss of explicit memory. In fact, performance improvements in implicit memory skills among Alzheimer’s patients are actually “similar to healthy controls. According to such facts, these dissociations account for a common clinical situation: AD patients who can accurately use a toothbrush while they can no longer name a picture of a toothbrush or describe the steps used.” (Machado, et al., 2009). Thusly, it is through the reinforcement of practical routines of life that an Alzheimer’s patient can retain some of their independence.

Alzheimer’s disease is among the last things a patient wants to hear from his or her doctor, and with good reason. The neurodegenerative condition is well known for reducing people to what was once called senility. In regards to the gross effect of the disease, Alzheimer’s patients exhibit “little improvement in acquiring information over repeated learning trials and that they were more likely to recall the most recently presented information in free-recall tasks. However, the main characteristic associated with memory impairment of AD is the rapid forgetting of information over time as compared to the normal elderly.” (Au et al., 2003). The disease is an alienating experience for the elderly patient. It is well known that many find themselves locked away in rest homes.

If the disease is caught early, it is generally because its effect on the rate of forgetting is relatively easy to pinpoint. In terms of actual numbers, “Hart et al. reported on faster than normal rates of forgetting in AD patients between 90 s and 10 min. Larrabee et al. also found accelerated forgetting within the 1st hr, even when AD and controls were matched on the rate of acquisition. The rate of forgetting was also found to be relatively unaffected by age and level of education.” (Au et al., 2003). The disease has shown itself to effect consistently across cultures. In keeping with observations made of Western patients, “the Chinese AD patients in the present study demonstrated marked impairment in total delayed recall. In particular, as compared to the normal controls, AD patients were found to have a significantly higher rate of forgetting in the first 10 min.” (Au et al., 2003). A decline in cognitive functions is the most obvious manifestation of Alzheimer’s. Another symptom of the disease is a dulling of the brain’s ability to effect movement. It is common to find “preserved motor-skill learning in AD patients although their overall performance levels in terms of reaction and movement time were always inferior to those of the controls.” (Tilborg et al., 2007). The impeding of movement further complicates the life of an Alzheimer’s patient. Despite the fact that several studies uncovered preserved procedural memory in Alzheimer’s patients, “their performance level in terms of reaction and movement time were inferior when compared with controls. However, when it takes the level of learning into account, the results are less consistent.” (Machado, et al., 2009). The symptoms of the disease are apt to compound upon one another, further disabling and disorienting the unfortunate patient.

There are varying degrees of the disease. According to Au et al., “[t]ests of episodic memory have been regarded as the most useful early detectors of Alzheimer’s disease (AD), while measures of lexical-semantic functions are among the best discriminator between mild and moderate to severe AD patients.” (2003). Along with measurements of language skills, measurements of several other factors can help distinguish between stages of the disease. In regards to the acquisition of information “as measured by learning across trials, mild AD patients were shown to perform better than moderate AD patients. However, in terms of retention, no significant differences were found between mild and moderate AD patients in total delayed recall and the rate of forgetting.” (Au et al., 2003). It is not uncommon to hear of intelligent, witty people losing their spark to the horrors of the disease.

However, there is hope for the well-being of those afflicted with the disease. When testing for Alzheimer’s, clinicians will also assess implicit memory “indirectly by measuring facilitation in performance (i.e. decreased processing time or increased accuracy) due to previous exposure to identical or related information. It has been consistently shown that procedural memory remains relatively preserved throughout the course of AD.” (Machado, et al., 2009). As previously mentioned, this is the key to preserving some aspects of an Alzheimer’s patient’s quality of life. In fact, with no variance of results attached to the variance of manners of testing, “the studies assessing Procedural Memory in AD patients showed positive outcomes. Indeed, Hirono et al. observed that patients with mild AD were able to acquire motor and perceptual as well as cognitive skills in various motor skills learning tasks.” (Machado, et al., 2009). Despite the brain’s ability to preserve certain aspects of itself from the ravages of the disease, the protection is certainly not perfect. The performance levels of Alzheimer’s patients “never reached the levels of healthy controls, demonstrated by their prolonged reaction and movement times. The AD patients’ level of learning also varied depending on the task to be performed. It suggests that visual feedback has a positive effect on their learning pace.” (Machado, et al., 2009). Despite these hurdles, advances have been made with regard to the actual treatment of the disease.

There are a variety of treatments available to Alzheimer’s patients to address the various effects of the illness. Due to the desire of elderly people to continue living independently for as long as possible, “they need to be able to maintain familiar and learn new practical skills. Although explicit or declarative learning methods are mostly used to train new skills, it is hypothesized that implicit or procedural techniques may be more effective in this population.” (Tilborg et al., 2007). Unfortunately, the illness so centered on the impediment of learning resists this treatment every step of the way. Benbow explains, “Dementia can be viewed as a terminal illness and people will deteriorate until they need help with all activities of daily living. There is no specific treatment for Alzheimer’s disease or vascular dementia, although drug treatments are available which are of benefit to some people.” (Benbow, 2009). Despite these drug treatments, most treatment comes in the form of specialized training to assist the patient in the usual activities of daily living (ADL).

The training in question is referred to as cognitive rehabilitation. “Cognitive rehabilitation (CR) is composed of techniques and strategies that aim for minimizing deleterious effects originated by lesion or dysfunction of cognitive functions. These functions are seen as support for primary mental activities, e.g., memory, attention, thought, language, logic reasoning, etc.” (Machado, et al., 2009). As an exercise of the physical body builds and reinforces muscle, cognitive rehabilitation relies on building up what remains of the patient’s life skills. To that end, “[c]ontemporary cognitive rehabilitation, especially when delivered alongside pharmacotherapy, has been shown to improve memory outcomes and delay dementia progression in patients with mild cognitive impairment (MCI) and early Alzheimer dementia (AD).” (Broster et al., 2012). Cognitive rehabilitation revolves around conditioning the patient to carry out tasks necessary for day-to-day life functions.

Cognitive rehabilitation takes many forms. In recent years, “two general intervention approaches and have been applied in AD patients with memory deficits. The first approach aims to work on the residual skills of compromised memory. The other one intends to work the intact memory to compensate for the deficits of the compromised memory.” (Machado, et al., 2009). If the implicit memory is still functional, the patient can be habituated to the basic necessities of daily life through a specialized regimen of repetition and conditioning. Thusly, “CR strategies are used to compensate for the deficits caused in the ADL. In relation to AD, the CR focuses on minimizing the existing deficits due to the deterioration of memory systems.” (Machado, et al., 2009). Another tactic that might allow a patient to retain the memory of their life involves reinforcing the link between the practical and the conceptual in therapy. In a typical case, “it is seen that patients in mild to moderate stages of AD firstly show degeneration of explicit memory, while implicit memory stays preserved for a longer time. In this way, recent studies have shown an increase in the use of rehabilitation strategies that establish an association between explicit and implicit memory.” (Machado, et al., 2009). Essentially, the goal is to keep the brain busy and the faculties it still has in as much use as possible, so that they do not deteriorate further.

Interested health professionals have devised several methods of ingraining the necessary information of everyday life into an Alzheimer’s patient. Exercises can be organized randomly, or in blocks. In random exercise, different tasks are performed one after another, whereas blocked exercise focuses on one task repeated several times over. In terms of effectiveness, “[e]arly evidence suggests that random practice might be most effective to acquire motor skills, whereas, during the acquisition of a specific motor-skill, performance benefits most from blocked practice.” (Machado, et al., 2009). It is a difficult operation to preserve the mental functions of a person with progressively steepening learning disability and memory impairment. One possible strategy of inducing an association between implicit memory and explicit memory is to “link nonverbalized implicit knowledge to conscious effort when individuals are exposed to different tasks.” (Machado, et al., 2009). Also important is preserving in the patient a sense of the world. Accordingly, one approach to the problem “intervenes through techniques like the Reality Orientation Therapy (ROT), which involves a continued and organized presentation of data. Its objective is creating environmental stimuli that have eased the temporal and spatial orientation of the patient.” (Machado, et al., 2009). Another important interest lies in preserving a sense of the life lived before the onset of Alzheimer’s. In this interest, a technique involving memory retention is called “reminiscent therapy (RT). RT aims to stimulate the recall of mnemonic information through figures, pictures, music, games and other stimuli related to patient youth.” (Machado, et al., 2009). Despite all of these noble attempts to ensure a degree of independence, simple explicit reinforcement should not be overlooked. To this end, one technique revolves around “external aids as agendas, notes, alarm clocks, posters and signals aiming to compensate for the memory deficits that cannot be directly faced.” (Machado, et al., 2009). Perhaps most interestingly, researchers believe emotional attachments to be exploitable in the interest of helping to anchor the patient in reality. This belief has a major behavioral basis in that “emotional content might improve memory outcomes is the persistent finding that, even in older adults, emotional content is remembered more accurately and/or more quickly than non-emotional content for both short and longer-term recall of visual images.” (Broster et al., 2012). The strength of emotional stimuli in keeping the patient associated with the world is “independently demonstrated for emotional stimuli of both positive valence and negative valence relative to non-emotional control, and it is demonstrated in research participants with early AD.” (Broster et al., 2012). When scientists tested hypotheses surrounding emotionally valenced stimuli of both the positive and the negatively valenced variety, “both types consistently increase memory performance better than non-emotional stimuli, and, for older adults, positively valenced stimuli tend to produce better results than negatively valenced stimuli.” (Broster et al., 2012). By these treatments and others, many people hope to improve the prognosis and quality of life of their afflicted loved ones.

Though there is no cure for Alzheimer’s disease, treatment has effected real positive change in the lives of many patients. When treating the disease’s disruption of motor skills, “[t]he preserved implicit learning ability in AD can be of use for physical therapists working with this elderly patient group. Physical therapists can call upon neuropsychologists to provide information on their patients’ learning capacities since they have quantitative measures at their disposal to assess a patient’s level of functioning.” (Tilborg et al., 2007). In fact, the learning of motor skills, despite the disease actively impeding motor skills, shows great promise in keeping afflicted people independent. Studies have shown that, despite the deterioration of explicit memory, “AD patients can learn new motor skills in an implicit way. It is, therefore, worthwhile to establish what would be the best way to train them.” (Tilborg et al., 2007). Individuals afflicted with Alzheimer’s disease are still capable of implicitly learning motor skills “to a certain extent and under specific conditions. The experimental research to date shows preserved implicit motor learning irrespective of the task used. Patients are capable of acquiring motor skills without awareness simply by repeated exposure, although their performances will not reach normal levels.” (Tilborg et al., 2007). Constant reinforcement is, of course, paramount to the success of these treatments. In fact, “[a]ll available studies show that AD patients learn best under constant practice conditions.” (Machado, et al., 2009). It is important that the training be repetitive and consistent. “According to Wilson, individuals with amnesic deficits in the episodic memory, as AD patients are not able to remember their own errors, thus they do not learn as subjects without memory deficits.” (Machado, et al., 2009). Thusly, techniques such as errorless learning have been effective in inducing learning retention in a patient. Ultimately, it all boils down to preserving muscle memory where mental memory fails.

It is believed that humans typically use their episodic memory of training and other relevant information to accurately perform a task while learning a skill. However, because AD patients have such difficulty with episodic memory, “constant practice is more effective due to repeated running of the same neural networks (NNs) and does not require an intact episodic memory. The second reason why random practice may be less effective is that other cognitive functions that play a role in random practice, e.g., the ability to divide attention, are affected in AD patients.” (Machado, et al., 2009). As a sad extension of this logic, everything an Alzheimer’s patient learns is restricted to familiar territory. Scientists have concluded, “AD patients can develop and access a NN in training situations that emphasize movement consistency. However, they do not form the NNs needed to successfully achieve a movement when the environmental demands change because they are unable to encode and to store the different types of information about a motor pattern.” (Machado, et al., 2009). The issue here is that Alzheimer’s patients have great difficulty generalizing motor skills. Because of this, “training has to take place in an environment that closely resembles the one in which the skill is going to be used and presumably with tools used by the AD patient in his or her daily life.” (Tilborg et al., 2007). For example, if a patient is to learn how to use a toaster, she must be trained on the same make and model of toaster she will use at home.

Despite the advances made in therapy, treatment cannot end with the individual patient. These people are human beings and are just as much social animals as any other human specimen. Accordingly, another effective route of rehabilitation involves integration with society. Surprisingly, studies have shown that “people with dementia could successfully teach students how to prepare recipes. They suggest that such success may impact on the quality of life and feelings of self-worth as well as contributing to more rewarding social interactions.” (Benbow, 2009). It is well-known that solitary confinement will easily break the most hardened criminals. Similarly, keeping Alzheimer’s patients completely separate from society will do much more harm than good. As the human body is a system rather than a collection of parts, “[i]nvolvement in other learning opportunities may involve people in being more active physically which will impact their physical and mental health. If they make more social contacts it might reduce social isolation and loneliness: this may increase the likelihood of having close confiding relationships and a supportive social network with resulting benefits to mental health.” (Benbow, 2009). Healthy stimulation is a major key in the treatment of Alzheimer’s patients.

Alzheimer’s disease is a complicated situation. It devastates memory and impedes movement and is certainly isolating to any person who has to suffer through it and to anyone who loves this person. It is in the best interest of any healthy individual that Alzheimer’s patients are treated with compassion, as it cannot be guaranteed that any healthy individual will not develop it in the future.

References

Au, A., Chan, A. S., & Chiu, H. (2003). Verbal learning in Alzheimer’s dementia. Journal of the International Neuropsychological Society, Volume 9, 263-375.

Benbow, S. M. (2009). Older people, mental health and learning. International Pyschogeriatrics, 2009, 299-804.

Broster, L. S., Blonder, L. X., & Jiang, Y. (2012). Does emotional memory enhancement assist the memory-impaired? Frontiers in Aging Neuroscience, Volume 4, 1-6.

Machado, S., Cunha, M., Minc, D., Portella, C. E., Velasques, B., Basile, L. F., Cagy, M., Piedade, R., & Ribeiro, P. (2009). Arq Neuropsiquiatr, Volume 67, 334-342.

Tilborg, I. A. D. A. H., Scherder, E. J. A., & Hulstijn, W. (2007). Neruopsychol Rev, Volume 17, 203-212.