Parkinson's Disease Research Paper

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Pathophysiology

Research Paper - Parkinson’s Disease
7/20/13

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Parkinson’s disease (PD) is a common neurodegenerative disorder second to Alzheimer’s disease in prevalence (1). PD is marked by rigidity, a tremor at rest, unstable posture, and bradykinesia. Incident rates of PD increase with age the earliest occurring around 40 years with a significant increase after 60 years (7). Approximately 1 in 272 people have PD in the United States though it is believed that there are many undiagnosed, or improperly diagnosed individuals who have PD (7). The population with PD and increasing efficiency in diagnosis coupled with longer lifespans pose a potential burden on the individuals and health care system for their cumulative costs.
In addition to pain from their resting tremor the resulting stiffness is another early indicator of PD, most frequently found in the shoulder.
When these limbs are moved by another individual a “cogwheel rigidity” (difficult movement initially, then a period of less resistance repeating) is often noted (8). This rigidity may be found in the wrists, ankles, neck, shoulder, or hips. Studies found that the presence of stiffness were associated with increased development of PD (8).

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Bradykinesia is the slowness of movement, a common clinical trait in which PD causes. This is

the most common symptom of basal ganglia disorders which causes difficulty in numerous aspects of planning movement through its execution (8). These symptoms first appear in daily activities and decreased reaction times. Further development of bradykinesia causes increased difficulty with fine motor skills (eg, tying shoes, penmanship) (7). Changes in the ability to swallow cause an individual to drool accompanied by lack of facial expression. Of all signs and symptoms of PD, bradykinesia is best explained by dopamine deficiency (8). Bradykinesia is not consistent as it depends heavily on
Parkinson’s disease is noted by the degeneration of dopamine producing neurons. Dopamine is a neurotransmitter in the brain that is involved in rewards and pleasure, many addictive drugs simulate its effects. Dopamine is an organic catecholamine chemical, produced in the basal ganglia and of which epinephrine and norepinephrine are made from the dopamine base. Degeneration is found in the basal ganglia’s substantia nigra and dorsal stratum where α-synuclein point mutations or misfolds decreases dopamine production (8). This results in uncontrolled excitatory or inhibitory flow in the basal ganglia.
Dopamine moderates and individuals response by moderating the amount of effort needed to achieve an action. The decreased amounts of dopamine in PD patients create an atmosphere within the body where to achieve an action larger amounts of effort are required. However, with a large stimulus of the sympathetic nervous system an action can easily be achieved. Changes to the α-synuclein production varies in the individual with PD (2); younger patients degradation of the substantia nigra occurs over a longer time period than older patients (2). These differences are believed to be the difference of dementia’s