Parkinsons Disease

Overview

Parkinson's disease is a progressive neurological disorder that impacts the nervous system and interferes with the functioning of the nerves. As a result, body parts controlled by nerves are affected, and their normal function is interrupted. It is most commonly found in patients older than 60.

The primary target of Parkinson's disease is a specific area of the human brain called the basal ganglia. The disorder causes deterioration of the basal ganglia and results in the loss of control over areas controlled by the part. 

During the body's normal functioning, the brain releases certain chemicals called neurotransmitters to monitor and control the communication of the neurons or brain cells. Dopamine is one such neurotransmitter, and it is essential to generate the 'fight or flight response of the body. It is responsible for bodily functions like movement, sleep, behaviour, attention and arousal.

Parkinson's disease causes a reduction in the dopamine levels released by the brain. In turn, the body lacks sufficient neurotransmitters to send electrical impulses to the body, resulting in delayed movements and loss of cognitive functions.

While Parkinson's can be controlled using medications, the disorder worsens with time. Hence, it is crucial to consult a doctor during the early stages and start treatment early.

Types of Parkinsonism:

Parkinsonism is the umbrella term covering ailments that have symptoms similar to Parkinson's disease. The condition covers five types of conditions, namely:

1. Idiopathic Parkinsonism

Parkinson's disease, also known as idiopathic Parkinsonism, is the most common disorder. It is characterised by the loss of nerve function in body parts caused due to a reduction in dopamine. Since dopamine helps provide electrical signals to enable motility and other functions of the body, Parkinson's is synonymous with symptoms like delayed responses, loss of balance, impaired senses and stiff muscles that restrict movement.

2. Vascular Parkinsonism

This type of Parkinsonism is known to cause damage to the part of the brain controlling the motility of the body. The reason for this damage is usually tiny strokes that damage the nerve function of a specific portion of the brain. The symptoms resemble that of idiopathic Parkinsonism, but the cause here is different. While idiopathic Parkinsonism occurs due to a gradual loss or damage of nerve cells that impact dopamine production, vascular Parkinsonism can be credited to small strokes that build up damage over time and affect cognitive function.

The blood vessels in the brain are responsible for ensuring no interruption in blood flow to the region that controls the body’s motor skills. However, small strokes cause damage to these vessels and affect the flow of blood to the deep centres of the brain. Alternatively, vascular Parkinsonism can also occur due to constricted blood vessels or the formation of fatty plaques in the arteries.

3. Drug-Induced Parkinsonism

Among all the types, drug-induced Parkinsonism is the only one that does not occur due to a natural disruption in the body. It is a non-degenerative type that arises due to the effects of drugs that block dopamine production.

Overall, it is similar to idiopathic Parkinsonism in terms of symptoms. However, a neurosurgeon can address it more quickly by reducing the dosage of the drug causing the condition.

4. Multiple System Atrophy (MSA)

MSA impacts two systems – one that controls movement and the other that controls actions like blood pressure and digestion. It is a progressive disorder similar to Parkinson's and gradually reduces the functioning of the nerve cells in the spinal cord and brain.

5. Progressive Supranuclear Palsy (PSP)

Hailed as an uncommon brain disorder, PSP results in significant problems caused by loss of control in body movements, coordination and clear thinking. It is a progressive disease that causes loss of balance and difficulty in managing eye movement. Left untreated for a long time, PSP can cause severe pneumonia and lead to swallowing problems that can contribute to choking.

Symptoms: 

The symptoms usually emerge slowly; as the disease progresses, non-motor symptoms become more common. Early symptoms are tremors, rigidity, slow movement, and difficulty with walking. Problems may also arise with cognition, behaviour, sleep, and sensory systems. Parkinson’s disease dementia is common in advanced stages.

Causes and Risk factors:

The causes of Parkinson’s disease are not fully understood, but they are believed to involve a combination of genetic and environmental factors. Some of the factors that may increase the risk of developing Parkinson’s disease include:
•    Genetic mutations: About 10 to 15% of Parkinson’s cases are caused by inherited gene defects that affect the function or survival of dopamine-producing neurons in the brain12. Some of the genes that have been linked to Parkinson’s disease are SNCA, LRRK2, GBA, PARK2, and PINK13.
•   Environmental exposures: Certain chemicals, toxins, or infections may damage the dopamine-producing neurons or trigger an inflammatory response in the brain. Some of the environmental factors that have been associated with Parkinson’s disease are pesticides, herbicides, metals, solvents, head trauma, and viral infections14.
•   Aging: The risk of Parkinson’s disease increases with age as the dopamine-producing neurons naturally decline over time. The average age of onset for Parkinson’s disease is 60 years, but some people may develop it earlier or later15.
The exact mechanism of how these factors interact to cause Parkinson’s disease is still unknown, and more research is needed to understand the complex pathogenesis of this disorder. However, some of the possible mechanisms that have been proposed are oxidative stress, mitochondrial dysfunction, protein aggregation, neuroinflammation, and impaired autophagy.
 

Complications:

Being a progressive disease, Parkinson's worsens with time. If it is detected near the onset, it can be controlled through medication and physical therapy. If none of these methods work, surgery is also viable.

However, untreated Parkinson's disease can ultimately deteriorate the brain within ten to fifteen years and cease all brain functions. It can also lower the patient's life expectancy and cause early death due to a complete shutdown of the brain. Unmanaged Parkinson's is also known to cause health hazards like pneumonia, choking and severe injuries.

The Hoehn and Yahr scale usually denotes the intensity of Parkinson's disease. It represents the stages of Parkinson's on a scale of 1 to 5. The initial stage denotes the early onset of Parkinson's, two and three points mean mid-stage, and the last two indicate severe Parkinson's.

Prevention:

Although Parkinson's disease cannot be prevented, some lifelong habits may help to reduce the risk.

Avoiding toxins:
People should exercise caution when using potentially toxic chemicals, such as herbicides, pesticides, and solvents.

Individuals should, whenever possible, take the following steps:

• Reduce pesticide and herbicide use. 

• Use alternatives to products that contain known toxins, like paraquat.

• Taking precautions, such as wearing protective clothing, when they cannot be avoided.

Avoid head trauma:
To prevent traumatic brain injury, individuals can take the following steps:

• Wear protective headgear during contact sports.

• Use a helmet when cycling or motorcycling.

• Use a seatbelt when driving.

• Seek medical attention for concussion and avoid future risks until cleared by a doctor.

Exercise:
Regular physical exercise may prevent or treat Parkinson's disease, according to a 2018 review (Trusted Source). The authors state that physical activity can help maintain dopamine levels in the brain.

Dietary factors:
Some dietary choices may also help lower the risk of Parkinson's disease and other conditions. According to research, the following may be helpful:

Turmeric: Turmeric is a mild spice that can be added to curries, soups, teas, and other dishes. It contains curcumin, which is an antioxidant. One laboratory study suggests that it may help reduce the risk of Parkinson's disease by preventing oxidative stress and alpha-synuclein protein clumping.

Flavonoids: Research indicates that flavonoids may reduce the risk of Parkinson's disease. Flavonoids can be found in berries, apples, vegetables, tea, and red grapes.

Avoid aldehydes: Some cooking oils, such as sunflower oil, can produce toxic chemicals known as aldehydes when heated and reused. Potatoes fried in previously used cooking oils may contain high levels of aldehydes.

When to Consult a Doctor?

Initial symptoms synonymous with Parkinson's disease may usually be mild. As a result, they may be challenging to detect and make it difficult to receive timely medical attention.

Some common signs should convince patients to consult a doctor immediately.

• Early symptoms

Tremors in the finger, hand or chin; minor loss of smell, inability to sleep, stiff muscles making it difficult to perform an unrestricted movement, constipation, constant dizziness or fainting episodes

• Age

Parkinson's disease is common in elderly patients, especially individuals nearing sixty. For these patients, it is important to schedule regular medical check-ups to assess overall health and discover discrepancies to weed them out. Younger people can also choose regular health check-ups to detect Parkinson's disease or other ailments.

Diagnosis

The symptoms of Parkinson's disease can overlap with multiple other conditions, making it difficult for neurologists to make a diagnosis with symptoms alone. Although there is no specific test to detect Parkinson's disease, neurologists employ several tests to rule out other disorders.

Some of the tests utilised are as follows.

• Lab tests

Sometimes, the neurologist may ask for a blood sample to rule out other conditions like abnormal thyroid hormone levels or liver damage.

• Imaging tests

Standard tests like MRI or CT scans help rule out additional conditions like strokes or brain tumours to confirm the diagnosis. Sometimes, neurologists may ask for a dopamine transporter (DAT) scan to identify the amount of dopamine in the body and diagnose Parkinson's disease.

Along with these tests, a neurologist analyses the patient's symptoms, medical history and neurological and physical examinations to confirm Parkinson's disease.

Treatment

Parkinson's disease is a chronic condition that cannot be cured completely. However, it can be managed with regular neurologist consultations and self-care. Here are some ways to manage the disease.

• Homecare

For individuals with Parkinson's disease, it is essential to remain physically active by engaging in exercises like running and stretching to gain more flexibility and balance. Activity is also believed to increase muscle strength and improve coordination between body parts. Additionally, getting uninterrupted sleep and avoiding caffeine, tobacco, and alcohol is vital.

• Medication

Neurologists prescribe carbidopa-levodopa during the initial stages to confirm the diagnosis. If a patient's condition is improved after taking this medication for a few days, the diagnosis of Parkinson's disease is confirmed. Neurologists may further prescribe levodopa and carbidopa to increase dopamine production in the brain to manage the condition. People with Parkinson's disease can take anticholinergic drugs such as trihexyphenidyl, benztropine, orphenadrine, procyclidine, and biperiden. These medications are thought to be equally effective.

• Surgical Treatment

While neurologists attempt to manage the disorder using medications, they may suggest surgery if the previous treatment is ineffective. The standard surgical method employed is deep brain stimulation, where the surgeons implant an artificial device into the patient’s brain. This device aims to provide an electrical current directly to some brain regions and compensate for the lack of dopamine production.

• Alternative management

The research on Parkinson's has allowed for the development of a new method called Duopa. Though it is not a widely used procedure, it involves a gel of carbidopa-levodopa to be directly delivered to the intestine to reduce the absorption and ensure the maximum amount of the mixture reaches the brain. The surgical process is conducted by creating an incision in the abdomen through which a tube is inserted. The tube acts as a pump to deliver Duopa to the intestine directly.

Additional information:

The scope of PD is global, affecting about 6.2 million people worldwide as of 2015. It is more common in older people, with the average age of onset being 60 years. However, some people may develop PD at a younger age, which is called early-onset PD. The disease affects both men and women, but men are slightly more likely to have it than women. The prevalence and incidence of PD vary by region, ethnicity, and socioeconomic status. The disease significantly burdens individuals, their families, and the health care system, affecting the physical, psychological, social, and economic aspects of life.