Parkinson’s Disease (PD) is an age-related multifactorial disease that is influenced by both genetic and environmental factors and is also the second most common neurodegenerative disease after Alzheimer’s (Antony, P., 2013). PD is a progressive neurodegenerative disease that is caused by the loss of neurons that produce the neurotransmitter dopamine. These dopaminergic neurons are located within the midbrain, specifically in the basal ganglia structure called the substantia nigra. Dopamine is regulated in the body and has the purpose of primarily regulating movement; however, has other purposes such as regulating attention, learning, and emotional responses. The beginning stage of Parkinson’s Disease is usually characterized by motor symptoms, such as resting tremors, rigidity, loss of balance, and masked facial expression and bradykinesia (linked to a shuffling gait and motor dysfunction). Later signs of PD that are not as significantly displayed are non-motor symptoms such as sleep disturbances, depression, constipation, and a “softer” voice (Antony, P., 2013). There is no known cure for Parkinson’s Disease; however, there are medications such as Carbidopa-Levodopa, otherwise known as Sinemet, which can reduce motor symptoms (tremors, slowness, and rigidity). Other treatment options that can reduce motor, as well as non-motor symptoms include exercise, physical therapy, and other non-traditional practices like LSVT BIG.
The cure for Parkinson’s Disease is still unknown as well as reasons why Parkinson’s Disease occurs in the human brain. PD is an age related disorder, there is a strong correlation with 1% of people older than 60 years affected, compared to people of 80 years of age rise up to 3% (Antony, P., 2013). PD is also linked genetically and there are about 28 distinct chromosomal sex genes that are related to Parkinson’s Disease (Antony, P., 2013). Environmental factors are also linked to Parkinson’s Disease. These environmental factors such as farm working, gardening, and occupational exposure to agricultural chemicals such as insecticides like paraquat and rotenone remain elusive regarding the pathogenesis of Parkinson’s Disease (Antony, P., 2013).
Although the reasons why Parkinson’s Disease occurs typically in the aging brain is unknown the roles of how the degradation of the dopaminergic receptors from Parkinson’s Disease is through the mechanism of the direct and indirect pathways. The role in muscle contraction from the brain is through the primary motor cortex which inputs the direct (stimulatory effect) and indirect (inhibitory effect) pathways to link through the lentiform nucleus of the brain. The putamen located in the lentiform nucleus uses these two pathways to connect to the thalamus and back into the primary motor cortex which allows the movement of muscles from the corticospinal tract. The substantia nigra located in the basal ganglia stimulates dopaminergic receptors to increase the stimulus of the direct pathway and inhibit the stimulus of the indirect pathway in the putamen by increasing the stimulus of both gabaergic neurons found in the putamen of the lentiform nucleus. This allows a stronger contraction of the agonist muscles and a weaker contraction of the antagonist muscles. This enhancement also allows for a smooth contraction without rigidity to occur when performing any kind of muscle movement. Nonetheless, there are also cholinergic receptors that do the opposite function of the dopaminergic receptors D1 (Direct) and D2 (Indirect). Parkinson’s Disease plays a role in this mechanism by degradation of these dopaminergic receptors. Without the optimal stimulus of these dopaminergic receptors, the cholinergic receptors will overcome them. With more acetylcholine than dopamine, there’s an imbalance causing the direct pathway to be inhibited, and the indirect pathway to be stimulated significantly (Segura-Aguilar, J., 2014). This imbalance of acetylcholine and dopamine causes the symptoms of rigidity and resting tremors found in people with Parkinson’s disease.
Parkinson’s Disease is not only involving the motor function for your body, but your non-motor function as well. Non-motor functions that are hindered through PD can be autonomic function, restful sleep, and cognitive ability. These dysfunctions caused by PD lower confidence in people diagnosed with PD and lower quality of life. There are medications that help suppress these dysfunctions; however, pharmacologic treatment for these impairments are often inadequately ineffective and cause intolerable side effects (Amara, W., 2017). Exercise prescription has shown to improve autonomic function, attenuate cognitive decline, and improve sleep and daytime drowsiness. These effects are shown to improve with the total population not just patients diagnosed with Parkinson’s disease. Compared to prescribing multiple medications, exercise prescription is shown to help symptoms for restless sleep, constipations, stiffness, as well as improving balance. The typical population diagnosed with Parkinson’s Disease are typically individuals above the age 60 (Antony, P., 2013). There are rare cases of individuals diagnose earlier; however, are very miniscule. For older populations according to ACSM Guidelines, intensity and duration of physical activity should be light at the beginning for individuals who are not as conditioned. Prescription should be tailored to individual’s with PD regarding what modalities and exercises should be prescribed because PD has chronic limitations. Motor symptoms, cardiac sympathetic denervation, low self-esteem, as well as risk of falling are all considering factors when prescribing exercise to a client with PD (Amara, W., 2017).
Nonetheless, these considerations can be implemented and ACSM’s prescription and testing to older specific populations and can be used with clients diagnosed with Parkinson’s Disease. Before exercise prescription is implemented with patients with Parkinson’s Disease as well as any specific older population, Exercise testing is used to show future improvement, as well as determining functional ability. A standardized test for older specific populations is the Senior Fitness Test (101). This test includes a 30s chair stand, arm curls, 8ft up and go, 6-minute walk, 2-min step, sit and reach, and back scratch. The total time to conduct the whole test is about 30 minutes. These multiple tests are used to evaluate the individual’s strength, flexibility, CRF, agility, and dynamic balance (Riebe, D., 2018). Another test that is good for implementing is the Usual Gait Speed Test. This test is used to analyze the clients gait (manner of walking). Individuals diagnosed with Parkinson’s disease have a shuffle gait, which is known for sliding their feet across the ground and have a hard time quickly starting and stopping movements such as walking.
Tailoring an Exercise program for a client with PD using the FITT principle should include Frequency, Intensity, Time, and Type of exercise. An important distinction between older adults and a younger population is their relative intensity (Riebe, D., 2018). Regarding aerobic exercise, older individuals should exercise for at least five days per week regarding moderate intensity (5-6) for at least 30 or more minutes of any modality that does not impose excessive orthopedic stress (Riebe, D., 2018). Individuals diagnosed with PD have sympathetic dysfunction, which is a major cause of cardiovascular dysregulation and occurs in at least 50% of patients (Amara, W., 2017). Pharmacologic therapies for OH have not been shown to improve cardiovascular dysregulation, and have shown to be associated with serious side effects such as ventricular hypertrophy (Amara, W., 2017). Nonetheless, aerobic training is important; however, older adults are prone to atrophy, specifically type 2 muscle fibers. Resistance training is known to counteract atrophy and shown to slow progression of deteriorating muscle fibers. When prescribing resistance training, older individuals should train at least 2 days per week starting with 8-10 exercises that are progressive weight bearing exercises and other strengthening activities that use major muscles groups at a light intensity and progressively increase as training continues (Riebe, D., 2018). Certain resistance training exercises are known to help with balance, which is crucial to older age specific populations, including those with PD. Increasing the proprioceptors ability and awareness of its surroundings will help reduce risk of fall and thus will reduce risk of injury.
Exercise is a beneficial, cost-effective, low-risk intervention that improves overall health and provides promise for both improving both motor and non-motor symptoms in PD. Nonetheless, there are other therapies that can help reduce the symptoms of Parkinson’s Disease such as physical therapy. Physical therapy provides help by focusing on the progressive motility issues that PD patients face on a day-today basis. Specific treatment goals are dependent on how long the patient has been diagnosed with PD and what stage he/she is classified in. Stage 1 is early symptoms of PD, this is shown with resting tremors, bradykinesia, a soft voice and masked facial expression. The goals of Stage 1 therapy are to focus on the prevention of inactivity, fear of falling and to improve physical capacity (Keus, S., 2008). Stage 2 is classified as the start of limitations in activities. The goals regarding stage 2 is the same as stage 1; however, also improve body posture, reaching and grasping, balance and gait (Keus, S., 2008). By this point of the stage, there is considerations of neurosurgery, specifically stimulation of the dopaminergic receptors or desensitization of the cholinergic receptors (Keus, S., 2008). The last stage or known as “late phase” has the same goals in mind as the previous stages; however, try to focus on vital functioning, prevention of pressure sores caused by imbalance and gait, as well as prevention of contractures.
Although physical therapy plays an immense role in those with PD, medications such a levodopa play a significant role as well. Levodopa is a metabolic precursor to dopamine and is able to be converted to dopamine in the brain (Manza, P., 2018). Supplementation of this medication that mimic’s or increases levels of dopamine in the brain should balance the effect of the cholinergic receptors overcoming the dopaminergic receptors. This increase in balance of the brain should reduce the motor symptoms of Parkinson’s Disease. Although, medications like levodopa have a lack of evidence to fully cure Parkinson’s Disease and fully reduce the symptoms of PD. As Parkinson’s Disease progresses further, it is harder for medications to help reduce symptoms and tend to only help early-on in beginning stages of PD (Manza, P., 2018). Other therapies that has been in the development to show to help with symptoms of PD is the Lee Silverman Voice Treatment (LSVT). This therapy was first in development in 1995 for the purpose of vocal loudness and vocal articulation for those with Parkinson’s Disease (McDonnell, M., 2017). LSVT-BIG therapy introduces concentrated training of amplified body and limb movements to the individual as well as vocally calling out queues when performing the movement. This therapy is an attempt to restore normal movement patterns and reduce motor symptoms of Parkinson’s Disease. A systematic review of the therapy was shown to be more effective than other interventions in improving motor functionality, especially motor symptoms linked to gait speed (McDonnell, M., 2017). However, there is limiting therapists certified for practicing LSVT-BIG and is not as common as typical physical therapy prescribed to patients with Parkinson’s Disease.
Future research into Parkinson’s Disease has been in development primarily on the genetic factors and finding out what causes the onset of Parkinson’s Disease. As well as what factors contribute to the disease. Many studies have been found of reducing symptoms of Parkinson’s Disease and future research in bettering everyday life with the disease since there has yet to be a cure. Examples such as handwriting therapy, speech therapy, and technological advances (Thomas, M., 2017). One of the technical advances is adding gyroscopes in utensils to counteract the resting tremors and rigidity when preforming movements. Parkinson’s Disease is a progressive neurodegenerative disease and will only get worse as time continues as the patient ages. However, it is key for the continuation of further research to implement new ideas to either help reduce symptoms, or finding the reasons why this disease occurs during aging. Once the understanding of how the disease appears, then a better understanding of how to detect and stop the disease will happen.