Neurodegenerative Disease: An Interdisciplinary Approach

Introduction

Neurodegenerative disease (ND) is a broad medical term used to describe a range of conditions that primarily affect the neurons in the human brain. For example, Alzheimer’s disease, Parkinson’s disease, prion diseases, motor neuron disease, Huntington’s disease, spinocerebellar ataxia, spinal muscular atrophy, and more. The population of the United States is aging, and an ever-increasing number of Americans are afflicted with NDs. Unfortunately, the pathophysiological mechanisms of many of these diseases remain unknown. What is primarily known is neurons, termed building blocks of the nervous system, are electrically excitable cells that transmit and integrate information, acting as affecter cells of nerve cells, muscle, or gland cells. When neurons become damaged or die, they cannot be replaced or reproduce to compensate for the loss. Therefore, the degeneration of these crucial cells often causes problems with movement, or mental functioning, leading to an often slow and painful death. These diseases affect many areas of a patient’s life and their loved ones. For instance, Amyotrophic Lateral Sclerosis (ALS) is characterized by the degeneration of upper and lower motor neurons. One discipline involved in the natural sciences, the biology of the disease affects the upper motor neurons, these direct lower motor neurons to produce movements such as walking or chewing. Subsequently, lower motor neurons control movement in the arms, legs, chest, face, throat, and tongue. Another discipline under natural sciences is psychology, the effect the disease has on the mind and behavior of a patient. For example, ND patients might have higher comorbidity of depression compared to others in their age bracket. Finally, focusing on the humanities, the patient families are affected by sociology factors. Often, the patient feels like a burden to the primary caregiver, and the caregiver can undergo extreme amounts of stress. In summary, to accurately assess the effects of NDs on a patient’s life, an interdisciplinary approach is imperative.

Biology

The lack of knowledge of the pathophysiological mechanisms of neurodegenerative diseases impacts the efficacy of a timely diagnosis, accurate prognosis, and effective treatment. Specifically, the average diagnostic delay, or time from onset of symptoms to diagnosis of ALS, is about a year. The diagnosis is based mostly on clinical and electrodiagnostic evaluation, such as an electromyography (EMG) (to determine the electrical activity of muscle fibers), which can be challenging in the early stages of the disease. Four domains have been identified to predict subsequent cognitive impairment and ND; data patterns of memory and performance, cardiovascular factors, genetic markers, and brain activity (Nilsson, 2006). A gradual impairment in the performance of memory testing might be an indicator of preclinical dementia. But, to analyze the decline, there must first be an assessment of typical memory decline, since a deterioration is also a common finding in healthy aging. Further, studies show that brain abnormalities, mainly white matter lesions, have an association with blood pressure and negatively impact brain function. Also, many genetic markers that correlate with neurodegeneration are involved with protein folding. For instance, misfolding of prions, and other proteins might aggregate in and around neurons, to form structures like amyloid plaques. Additionally, it is essential to consider how biologically determined factors that induce various experience-based factors could counter structural brain changes. The complexity of this model demonstrated that one single marker should not be used as a significant predictor. Future research should identify individuals who have multiple of the previously listed biomarkers. However, many challenges or limitations arise when performing this research. For example, many of the studies must be longitudinal, but often experience a significant decrease in sample size when more limits or specifications are added to a cohort. Therefore, while studies exist on the clinical diagnosis and predicting factors of ND, there are many obstacles to achieve substantial findings.

Recent research investigates the importance of personal medical history when evaluating a patient’s risk for ND. A study performed by LoBue and others sought to identify a possible relationship between traumatic brain injury (TBI) history and the advancement of mild cognitive impairment (MCI) to Alzheimer’s Disease (AD), the most common ND (2018). One would hypothesize that following multiple episode of TBIs experienced, an individual might experience a more rapid or accelerated progression from MCI, a transitional stage, to AD by increasing the pathological burden. This study involved 2,719 subjects with MCI obtained from the National Alzheimer’s Coordinating Center (NACC), an extensive database of standardized clinical and neuropathological research data. Traumatic brain injury was defined, including a loss of consciousness without chronic deficit occurring greater than one year before the diagnosis of MCI. Subsequently, survival analyses determined if the history of TBI predicted progression from MCI to AD, and random regression models were used to see if the history predicted the rate of decline. The researchers concluded that TBI history was not significantly associated with progression to a diagnosis of Alzheimer’s disease, and TBI history was a nonsignificant predictor for the rate of decline. However, mild cognitive impairment was diagnosed with a mean of about three years earlier in patients with TBI history. Therefore, the incidence of a traumatic brain injury might reduce the threshold for the onset of MCI and certain neurodegenerative conditions. The previously described studies that focus on the biology of NDs showcase the complexities of determining the pathophysiological mechanisms, diagnosing the diseases, identifying significant predictors, and compiling a final cohort to study.

Psychology

The progression of a disease such as Alzheimer’s disease, results in an individual’s impairment of cognitive functions, including memory and comprehension. This effect is often debilitating and can lead to a patient being institutionalized in long-term care (LTC) facility, such as a nursing home. Thus, a patient is experiencing behavioral and psychological symptoms of dementia (BPSD) that are affected by internal and external changes. Interestingly, a study set out to determine the effectiveness of built environment interventions in managing BPSD among the residents in LTCs (Soril et al., 2014). To accomplish this, Soril et al. conducted a systematic review of the literature published from 1995 to 2013. The built environment is commonly described as the constructed physical surroundings where a patient performs activities of daily living (ADL). A specific example of a built environment intervention could include the addition of a new object, construction of an outdoor area, or relocation to an entirely novel living environment. The results of the systematic review concluded that of the three categories of intervention; change of existing physical space, the addition of physical objects, and type of living environment, only one cohort of patients reported improvements in BPSD. The patients that demonstrated improvements in BPSD was a redesign of physical spaces. Conversely, the individual addition of physical objects showed no difference, and the novel living environment sample exhibited a decreased or no difference in BPSD. Therefore, there is inconclusive evidence to suggest which built environment intervention is clinically superior in long-term care settings. Further studies are required to demonstrate the feasibility and effectiveness of responses about the patient’s physical surroundings.

While there is not much evidence for the support of physical surroundings in improving a patient with NDs’ experience, there may be evidence for the help of loved ones. For instance, a neurodegenerative disease affects not only the ill individual but also their partner, parents, children, and friends. Correctly, one study verified the effectiveness of the couple’s treatment in models of rehabilitation wherein the partner often becomes the primary caregiver (Ghedin et al., 2017). The goal of treatment is to decrease the stress on both parties during this time of shifting roles, particularly in emotional and sexual intimacy, and to allow the ailing one to attain some degree of autonomy. Several studies have shown that the caregivers’ quality of life is miserable and inversely proportional to the burden of the caregiver. Fourteen patients affected by NDs and their spouses participated in emotionally focused couple therapy (EFT). EFT is an evidence-based approach for helping partners to their emotions of fear, sadness, and loneliness. Further, the therapists work in three phases; cycle de-escalation, restructuring interactional positions, and integration. Ultimately, the goal of EFT is to create and strengthen secure attachment bonds between couples so they can share their feelings and face uncertainty and life-threatening situations in the context of illness. The researchers measured the quality of life and relationship satisfaction for both partners before treatment and after treatment. The results show an improvement in the quality of life, couple adaptation, and couple contentment. Through the expression of the underlying feelings of fear, guilt, shame, and sadness, it is possible to give each spouse a partner that offers support, therein, easing the caregiver burden and patient’s guilt. Further studies should increase the sample size, which subsequently decreases the margin of error, producing significant findings.

Sociology

Sociology helps to explain the impact that fatal, progressive diseases have on family relations. The nature of cognitive deterioration exerts a unique stressor, which significantly affects an individual’s relationships. In addition to the patient coping or possibly attempting to cover the memory loss, the illness also exerts a disruptive influence on families. A study conducted in 1993 examined the decisions to place a person in LTC as a function of caregiver stress (Aneshensel, Pearlin, & Schuler). In this research, three annual interviews were performed with a sample size of 555 caregivers, who are a parent or spouse of a patient with AD. All of the patients were cared for at home, but 192 were later placed in institutional care, and 146 passed away. The results showed an evident competition of conflicting interests of family members. Such as the cessation, or end of in-home care significantly reduces role-related stress. However, patients who are hospitalized in an LTC facility are more likely to die than those who remain at home. There may be many possible reasons for this shift in mortality when institutionalized; for instance, the individual may feel isolated from their loved ones, or the change in routine hurts their disease. The interests of the caregiver and patient are not equally met with in-home care or an LTC placement. One might infer that this quandary adds a higher amount of stress, burden, and anguish of having a loved one with an ND. Further studies should include more research into social pressure with a focus on the well-being of the person exposed to stress and consequential health-relevant outcomes. This improvement could apply to the chronically ill person suffering from ND and the health outcomes of the caregiver. A longitudinal study might reveal that due to the chronic stress, the once health caregiver develops a disorder.

As previously established, the cost of community obligation and care for the fatally ill increases the caregiving burden on families with members who have NDs. Also, societal norms and expectations differ depending on ethnicity. Ethnicity is just one factor that influences caregiving duties. For instance, a considerable amount of previous research that focuses on Black families presents an interesting dichotomy; an unstable, disorganized nature of Black nuclear families indicated by the percentage of single-parent families or Black families with extensive ties to extended family and a broader sense of familial responsibility compared to White families. These differences might stem from economic disadvantage among Blacks or differences in Black and White norms of family obligation. A particular study used data from interviews with 78 parents and 70 siblings of patients with mental illness scheduled for release from a mental hospital (Horwitz & Reinhard, 1995). One hypothesis could be there are no ethnic differences in caregiving duties between Black and White parents. Secondly, Black parents will report less burden from their caregiving duties than White parents. This hypothesis would imply that although both ethnicity’s parents might provide comparable levels of caregiving-their responsibilities might be more normative for Black, thus, more arduous for Whites. Thirdly, Black siblings will report more extensive caregiving duties than White siblings. Lastly, Black siblings will feel less burdened by their caregiving duties than White siblings. Due to the expectation that Blacks have a greater sense of familial obligation, sibling caregiving might be more normative. The results of this study only add to the contradictory nature of findings regarding Black families and extended families. The findings indicate that Black and White parents have equal caregiving duties, although White parents report significantly more caregiver burden. Similarly, Black siblings identify more caregiving responsibilities than White siblings but also report less burden. There are many limitations to this study; for example, the sample size of Black parents and siblings is minimal. Contrastingly, the study controlled for income, gender, age, diagnosis, perceived stigma, and residence when considering these ethnic differences. In summary, the results indicate that ethnicity can be a vital factor affecting levels of caretaking for those with serious mental illness, such as NDs.

Conclusion

While this analysis of neurodegenerative disease paints a bleak picture for individuals diagnosed with these terrible afflictions and their families, there may be strategies to delay the onset of symptoms or prevent NDs. Smith analyzed healthy cognitive aging and behavioral prevention strategies that could help maintain high levels of cognition (2016). These strategies could also reduce the burden-medical, social, and economic, associated with aging and diseases that often accompany it. Specifically, brain health and cognitive resilience begin in utero. Also, there are antipoverty, perinatal health, preschool education, physical education, and education enrichment programs that are all a part of a national dementia prevention strategy. However, more considerable resources must be directed to behavior research. One avenue to pursue this could be the National Institutes of Health (NIH), expanding its research on cognitive disorders of aging, which could be approached from a biology, psychology, and sociology perspective. This research would provide a comprehensive and informed view of the patient and patient-family care. While there is no perfect treatment of these ruthless diseases, an ideal treatment would be developed on a case-by-case basis using an interdisciplinary approach. Every individuals’ needs are different, and this is imperative to remember when treating someone who appears to be slowly losing their individuality. Firstly, there should be increased resources for patients and families. This could be in the form of patient education, i.e., keeping the patient informed throughout the process to reduce their stress as much as possible. Besides, access to therapy is imperative to lessen the burden on the patient and improve their relationship with their loved ones; therapy could also be beneficial to ease the burden of guilt that comes with the cessation of caregiving. Finally, continued communication between patients and their families after institutionalization and communication between LTC facilities and families could both be beneficial for the health of all parties involved. Secondly, education is the easiest way to empower somebody to make informed decisions and restore a semblance of autonomy or power a patient once had. This education could include early signs if NDs, prevention, predictive markers, or even simple ways to sharpen cognitive function daily. While previous research exists across many subdisciplines of ND, there are many established limitations. Further research could be done to investigate the economic strain family experiences when a loved one is diagnosed with these diseases. Also, there are many laws and public policies that show a total disregard for human-centered health care but are solely focused on financial gain. Another possible topic is the ethical obligation a caregiver faces when deciding to institutionalize a loved one. At what point is harm being done to both parties, or when is it better for a caregiver in the long run to cease care. Above all, it is imperative that those with positions of power, such as physicians studying the pathophysiological mechanisms, psychologists focused on built environments, and sociologists studying ethnicity and NDs, all remember to involve humanness in healthcare.

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