Parkinson’s disease is a progressive nervous system disorder that affects movement. Symptoms start gradually, sometimes starting with a barely noticeable tremor in just one hand. Tremors are common, but the disorder also commonly causes stiffness or slowing of movement.

Parkinsonian syndromes can be divided into two types according to their origin:

Primary or idiopathic, where the cause of cell death is not fully understood; and secondary or acquired, where the disease can be linked to various kindsof offending agents such as drugs, toxins, infection, tumor etc.

Idiopathic Parkinson’s disease can have a hereditary basis or it can be sporadic in nature. A related group of disorders “Atypical Parkinsonism” represents wider distribution of the process of degeneration involving other critical areas of the brain. One of the diseases in this group is known as multiple system atrophy.

Symptoms

Parkinson’s signs and symptoms may include:

Tremor. A tremor, or shaking, usually begins in a limb, often your hand or fingers. You may a rub your thumb and forefinger back-and-forth, known as a pill-rolling tremor. Your hand may tremor when it’s at rest.

Slowed movement (bradykinesia). Over time, Parkinson’s disease may slow your movement, making simple tasks difficult and time-consuming. Your steps may become shorter when you walk. It may be difficult to get out of a chair. You may drag your feet as you try to walk.

Rigid muscles. Muscle stiffness may occur in any part of your body. The stiff muscles can be painful and limit your range of motion.

Impaired posture and balance. Your posture may become stooped, or you may have balance problems as a result of Parkinson’s disease.

Loss of automatic movements. You may have a decreased ability to perform unconscious movements, including blinking, smiling or swinging your arms when you walk.

Speech changes. You may speak softly, quickly, slur or hesitate before talking. Your speech may be more of a monotone rather than with the usual inflections.

Writing changes. It may become hard to write, and your writing may appear small.

Causes

Parkinson’s disease/ Parkinsonian syndrome is caused by a loss of nerve cells in the part of the brain called the substantia nigra. Nerve cells in this part of the brain are responsible for producing a chemical called dopamine. Dopamine acts as a messenger in the nervous system, and helps control and co-ordinate body movements. If these nerve cells become damaged or die, the amount of dopamine in the brain is reduced. This means that the part of the brain controlling movement cannot work so well, which causes movements to become slow and abnormal. The loss of nerve cells is a slow process. The level of dopamine in the brain falls over time. Only when 80% of the nerve cells in the substantia nigra have been lost, will the symptoms of Parkinson’s disease appear and gradually become more severe. Most people with Parkinson’s disease have idiopathic disease (having no specific known cause). Possible factors associated with the Parkinson’s disease are:

Familial occurrence in small number of patients
Environment factors have been associated with an increased risk of Parkinson’s including:
i. Pesticide exposure
ii. Head injuries
iii. living in the rural area or farming
iv. Air pollution related to road traffic

Diagnosis

Diagnosis of Parkinson’s disease is essentially a clinical diagnosis from information derived from medical history and neurological examination. There is no imaging or laboratory test that can identify the disease. Brain scans are sometimes used to rule out disorders that could give rise to similar symptoms

Complications

Parkinson’s disease is often accompanied by these additional problems, which may be treatable:

Thinking difficulties. You may experience cognitive problems (dementia) and thinking difficulties. These usually occur in the later stages of Parkinson’s disease. Such cognitive problems aren’t very responsive to medications.

Depression and emotional changes. You may experience depression, sometimes in the very early stages. Receiving treatment for depression can make it easier to handle the other challenges of Parkinson’s disease.

You may also experience other emotional changes, such as fear, anxiety or loss of motivation. Doctors may give you medications to treat these symptoms.

Swallowing problems. You may develop difficulties with swallowing as your condition progresses. Saliva may accumulate in your mouth due to slowed swallowing, leading to drooling.

Chewing and eating problems. Late-stage Parkinson’s disease affects the muscles in your mouth, making chewing difficult. This can lead to choking and poor nutrition.

Sleep problems and sleep disorders. People with Parkinson’s disease often have sleep problems, including waking up frequently throughout the night, waking up early or falling asleep during the day.

People may also experience rapid eye movement sleep behavior disorder, which involves acting out your dreams. Medications may help your sleep problems.

Bladder problems. Parkinson’s disease may cause bladder problems, including being unable to control urine or having difficulty urinating.

Constipation. Many people with Parkinson’s disease develop constipation, mainly due to a slower digestive tract.

You may also experience:

Blood pressure changes. You may feel dizzy or lightheaded when you stand due to a sudden drop in blood pressure (orthostatic hypotension).

Smell dysfunction. You may experience problems with your sense of smell. You may have difficulty identifying certain odors or the difference between odors.

Fatigue. Many people with Parkinson’s disease lose energy and experience fatigue, especially later in the day. The cause isn’t always known.

Pain. Some people with Parkinson’s disease experience pain, either in specific areas of their bodies or throughout their bodies.

Sexual dysfunction. Some people with Parkinson’s disease notice a decrease in sexual desire or performance.

Management

Treatment

Parkinson’s disease can’t be cured, but medications can help control your symptoms, often dramatically. In some later cases, surgery may be advised.

Your doctor may also recommend lifestyle changes, especially ongoing aerobic exercise. In some cases, physical therapy that focuses on balance and stretching also is important. A speech-language pathologist may help improve your speech problems.

Medications

Medications may help you manage problems with walking, movement and tremor. These medications increase or substitute for dopamine.

People with Parkinson’s disease have low brain dopamine concentrations. However, dopamine can’t be given directly, as it can’t enter your brain.

You may have significant improvement of your symptoms after beginning Parkinson’s disease treatment. Over time, however, the benefits of drugs frequently diminish or become less consistent. You can usually still control your symptoms fairly well.

Prevention

There is no definitive preventive strategy for Parkinson’s disease. Healthy life style and early diagnosis are helpful in disability limitation and care planning.

There are reports from large epidemiological studies suggest that a few life style factors provide protection against the disease. However, these are not recommended for prevention of Parkinson’s disease.

References:

www.nlm.nih.gov
www.ninds.nih.gov
www.pdf.org
www.parkinson.org
www.nhs.uk