Parkinson’s Disease, Essay Example

Parkinson’s disease is a progressive, degenerative neurological condition that impairs mobility and muscle control. The disease was diagnosed in 1817 by James Parkinson, who described it as ‘shaking palsy’ (Davie, 2008). Parkinson’s disease not only impacts the patient but their families and caregivers due to the progressive degenerative effect on motor functions. Similarly, the disease has caught the scientific community’s attention due to its prevalence in the global population due to aging and increased life span. This research paper aims to describe Parkinson’s disease from a scientific and analytical perspective. The first section examines the pathophysiology of the disease and the body systems affected. The author also studies what happens at the genetic level and the biochemical processes causing Parkinson’s disease. The author then uses economic theories to highlight the economic issues related to Parkinson’s disease in the analytical section. Finally, the author outlines statistical facts related to the condition and identifies the most favorable statistical processes to study and understand Parkinson’s disease.

Scientific perspective

Pathophysiology of Parkinson’s disease

Parkinson’s condition causes dopaminergic neurons to die from both endogenous and exogenous causes. The motor areas of the basal ganglia lose dopaminergic and motor function as a result of parkinsonism (Chatterjee et al., 2017). Research conducted in the 1950s revealed that the depletion of striatal dopamine causes motor symptoms of P.D. while the non-motor functions are linked to other neurotransmitters. More recent cellular and molecular research highlight that neuronal accumulation of Lewy bodies is the main contributor to Parkinson’s disease (Chatterjee et al., 2017). The prime constituent of Lewy bodies is alpha-synuclein which directly causes cytotoxic mechanisms that cause neurodegeneration. As a result, the condition leads to various motor disabilities, including akinesia, catalepsy, and dyskinesia. While the mechanisms underlying cellular death in Parkinson’s disease patients are unknown, there is strong evidence that progressive loss of mesodiencephalic dopaminergic (mDA) neurons, the brain’s main source of dopamine, as well as midbrain dopaminergic neurons (DA), is linked to movement impairment (Aarsland et al., 2007). While the causes of DA cell degeneration remain a mystery, oxidative stress, protein aggregations, decreased neurotrophic, and mitochondrial malfunction signaling are all thought to be contributors (Aarsland et al., 2007).

Symptoms of Parkinson’s disease

Perkison’s does not always exhibit tremors in its motor characteristics. However, several neurological characteristics are linked to P.D if a patient does not manifest phenotypic symptoms. They include multisystem atrophies, progressive supranuclear palsy, and corticobasal ganglionic degeneration. There are three motor manifestations of P.D. rigidity, bradykinesia, and the freezing phenomenon (Aarsland et al., 2007). Rigidity is characterized as resistance to passive movement of the limbs; bradykinesia is associated with slow movement and a decline in strength among patients. The freezing phenomenon refers to a transient and sudden inability to move while walking. This phenomenon occurs randomly and can last a few seconds to several minutes before it abates.

Parkinson’s disease patients are prone to cognitive and psychiatric issues such as dementia and sadness (Chatterjee et al., 2017). Patients have also been noted to have apathy, irritability, hallucinations, and delusions. Dementia is characterized as a cognitive manifestation of P.D. Dementia affects 28% of P.D. patients; however, it is more prevalent in older patients where it affects 65% of patients above 85 years of age (Chatterjee et al., 2017). Depression is also more common in P.D. patients who have signs of dementia and debilitating motor functions.

Other symptoms of Parkinson’s disease include BMS, hypomimia, dysphagia, scoliosis, camptocormia, and dysarthria. Burning mouth syndrome (BMS) is prevalent in 24% of patients with P.D. The condition is characterized by intraoral burning sensations in the mouth (Davie, 2008). Hypomimia and dysphagia are usually linked to nerve and muscle problems resulting in less facial muscular control and swallowing difficulties, respectively. A curved spine characterizes scoliosis, while camptocormia is defined as irregular spine flexion visible when standing or walking. Lastly, dysarthria is linked with nervous system damage, which results in impeded muscular control for speech.

Pathogenesis of Parkinson’s disease

Cell death is the most common pathological attribute of Parkinson’s disease, affecting about 70% of cells in the substantia nigra and pars compacta (Jankovic & Tan, 2020). In Parkinson’s disease, the neurotransmitter systems of the striatum and nucleus basalis, which are influenced by dopaminergic inputs from the substantia nigra and pars compacta, are altered (Jankovic & Tan, 2020). Several chemical changes inhibit motor function in P.D. patients. Boosted inhibitory GABAergic drive originating from the striatum and moving towards the peripheral regions of the Globus pallidus make the GPe and GPi hypoactive. Similarly, higher glutamatergic drive from the hyperactive subthalamic nucleus to GPi and SNpr are hyperactivated (Jankovic & Tan, 2020). As a result, the GPi and SNpr nuclei responsible for sending inhibitory signals to motor nuclei are overly inhibited, resulting in Parkinson’s disease.

Analytical perspective

Economic issues linked to Parkinson’s disease

Parkinson’s disease has a negative impact on a person’s life and is expensive to treat. Population projections forecast an increasingly unfavorable ratio between the elderly and caregivers. Additionally, Parkinson’s disease is more common as people get older. Besides the direct medical cost linked to P.D., the amplified demand for formal and informal care results in high non-medical costs while also creating a demand for highly trained informal caregivers (Findley, 2007). According to the WHO, Parkinson’s disease is responsible for 0.11% of all Diseases Adjusted Life Year (DALY), a measure of the combined effect of premature death and disability. Whetten Goldstein et al. (1997) conducted a cross-sectional study in the US, which found that Parkinson’s disease patients incurred a total yearly cost of $6115, while informal care provided by their spouses cost them 22 hours per week (Whetten-Goldstein et al., 1997). Another study by Ou et al., (2002) evaluated the direct and indirect costs of 127 Swedish patients to 8000 euros annually. These studies highlight that the burden of P.D. is significant (Ou et al., 2021).

Statistical facts related to Parkinson’s disease

Parkinson’s disease affects one million people in the US and ten million people worldwide (Davie, 2008). In the U.S, approximately 60,000 people are diagnosed with P.D. annually. The Global Study of Disease estimates that Parkinson’s disease is expected to double from 10 to 15 million by 2040, creating an enormous burden for society (Davie, 2008). P.D., which stands for Progressive Dementia, is the second most prevalent neurodegenerative disease, affecting people of all ages and with a prevalence ranging from 41 in 10,000 individuals in their fifties to more than 2000 people out of 100,000 over the age of 80. Thus, the rate of diagnosis increases with age. Furthermore, men are approximately 1.5 times more likely to be diagnosed with P.D. than women (Ou et al., 2021).

Economic theories and Statistical processes to analyze Parkinson’s disease

Several assessments in health economics theory are adopted to analyze P.D. A PD treatment is considered cost-effectiveness when health outcomes are worth the expenditure. Similarly, the incremental cost-effectiveness ratio (ICER) evaluates the cost of P.D. against the QALY gained (Findley, 2007). Healthcare stakeholders then determine whether the cost is cost-effective. Each country has its cut-off for P.D. that it considers cost-effective. The acceptable QALY is 50000, 30000, and 60000 in the U.S., U.K., and Norway, respectively. The core function of economic theory is to allow for planning, budgeting, and monitoring of P.D. within the healthcare sector. There are various guidelines for priority setting within the healthcare system. However, when these guidelines are weighted in terms of Quality-adjusted life year (QALY), they fail to meet the requirements of social justice and fairness because they do not take into account the severity of Parkinson’s, life-saving interventions, and standard of living (Findley, 2007). While QALY has the advantage of measuring life expectancy with the health state, it is criticized for overlooking health benefits to the patient.

Conclusion

This research paper aimed to offer more insight into Parkinson’s disease by adopting a scientific and analytical approach. In the first section, the author has established that degeneration of mesodiencephalic dopaminergic (mDA) neurons and the midbrain dopaminergic neurons (DA) is not the only link to movement impairment. Impaired neurotrophic signaling, protein aggregations, oxidative stress, and mitochondrial abnormalities have all been linked to P.D. There are numerous symptoms of P.D. whereby some present phenotypic characteristics while others do not. In the second section, the paper highlights that P.D. creates an enormous economic burden for the patient, caregivers, and society. Economics theories like QALY discriminate against P.D. while the ICER of P.D. is not universal but determined by each healthcare provider.

References

Aarsland, D., Emre, M., Lees, A., Poewe, W., Ballard, C., Montgomery, E. B., Miyasaki, J. M., & Gronseth, G. (2007). Practice Parameter: Evaluation and treatment of depression, psychosis, and dementia in Parkinson disease (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology, 68(1), 80–81. https://doi.org/10.1212/01.wnl.0000252956.34585.a6

Chatterjee, P., Roy, D., Bhattacharyya, M., & Bandyopadhyay, S. (2017). Biological networks in Parkinson’s disease: an insight into the epigenetic mechanisms associated with this disease. BMC Genomics, 18(1). https://doi.org/10.1186/s12864-017-4098-3

Davie, C. A. (2008). A review of Parkinson’s disease. British Medical Bulletin, 86(1), 109–127. https://doi.org/10.1093/bmb/ldn013

Findley, L. J. (2007). The economic impact of Parkinson’s disease. Parkinsonism & Related Disorders, 13, S8–S12. https://doi.org/10.1016/j.parkreldis.2007.06.003

Jankovic, J., & Tan, E. K. (2020). Parkinson’s disease: etiopathogenesis and treatment. Journal of Neurology, Neurosurgery & Psychiatry, 91(8), 795–808. https://doi.org/10.1136/jnnp-2019-322338

Ou, Z., Pan, J., Tang, S., Duan, D., Yu, D., Nong, H., & Wang, Z. (2021). Global Trends in the Incidence, Prevalence, and Years Lived with Disability of Parkinson’s Disease in 204 Countries/Territories from 1990 to 2019. Frontiers in Public Health, 9. https://doi.org/10.3389/fpubh.2021.776847

Whetten-Goldstein, K., Sloan, F., Kulas, E., Cutson, T., & Schenkman, M. (1997). The Burden of Parkinson’s Disease on Society, Family, and the Individual. Journal of the American Geriatrics Society, 45(7), 844–849. https://doi.org/10.1111/j.1532-5415.1997.tb01512.x