The Rights of Persons with Disabilities Act, 2016 defines Parkinson’s disease as a progressive disease of the nervous system marked by tremor, muscular rigidity, and slow, imprecise movement, chiefly affecting middle-aged and elderly people. It is associated with degeneration of the basal ganglia of the brain and a deficiency of the neurotransmitter dopamine. It mainly affects the motor system.
As the disease worsens, non-motor symptoms become more common. The symptoms usually emerge slowly. Early in the disease, the most obvious symptoms are shaking, rigidity, slowness of movement, and difficulty with walking. Thinking and behavioral problems may also occur. Dementia becomes common in the advanced stages of the disease. Depression and anxiety are also common, occurring in more than a third of people with PD. Other symptoms include sensory, sleep, and emotional problems. The main motor symptoms are collectively called "parkinsonism", or a "parkinsonian syndrome".
Parkinson’s disease is a progressive disease. That means symptoms of the condition
typically worsen over time.
Many doctors use the Hoehn and Yahr scale to classify its stages. This scale divides
symptoms into five stages, and it helps healthcare providers know how advanced the
disease signs and symptoms are.
- Stage 1 Parkinson’s is the mildest form. It’s so mild, in fact, the person may not experience symptoms that are noticeable. They may not yet interfere with daily life and tasks. If the person does have symptoms, they may be isolated to one side of the body.
- Stage 2 Parkinson's is the progression of stage 1 to stage 2 can take months, or even years. Each person’s experience will be different. At this moderate stage, the person may experience symptoms such as:
- muscle stiffness
- changes in facial expressions
- Muscle stiffness can complicate daily tasks, prolonging how long it takes to complete them. However, at this stage, the person is unlikely to experience balance problems. Symptoms may appear on both sides of the body. Changes in posture, gait, and facial expressions may be more noticeable.
- Stage 3 Parkinson's In this middle stage, symptoms reach a turning point. While the person is unlikely to experience new symptoms, they may be more noticeable. They may also interfere with all daily tasks. Movements are noticeably slower, which slows down activities. Balance issues become more significant, too, so falls are more common. But people with stage 3 Parkinson’s can usually maintain their independence and complete activities without much assistance.
- Stage 4 Parkinson's is the progression from stage 3 to stage 4 brings about significant changes. At this point, the person will experience great difficulty standing without a walker or assistive device. Reactions and muscle movements also slow significantly. Living alone can be unsafe, possibly dangerous.
- Stage 5 Parkinson's is the most advanced stage, severe symptoms make around-the-clock assistance a necessity. It will be difficult to stand, if not impossible. A wheelchair will likely be required. Also, at this stage, individuals with Parkinson’s may experience confusion, delusions, and hallucinations. These complications of the disease can begin in the later stages.
This is the most common Parkinson’s disease stage system, but alternative staging
systems for Parkinson’s are sometimes used.
The exact cause of Parkinson’s is unknown. It may have both genetic and environmental
components. Some scientists think that viruses can trigger Parkinson’s as well. Low levels of dopamine and norepinephrine, a substance that regulates dopamine, have
been linked with Parkinson’s. Abnormal proteins called Lewy bodies have also been found in the brains of people with Parkinson’s. Scientists don’t know what role, if any, Lewy bodies play in the development of Parkinson’s.
While there’s no known cause, research has identified groups of people who are more
likely to develop the condition. These include:
- Sex: Men are one and a half times more likely to get Parkinson’s than women.
- Race: Whites are more likely to get Parkinson’s than African Americans or Asians.
- Age: Parkinson’s usually appears between the ages of 50 and 60. It only occurs before the age of 40 in 5-10 percent of cases.
- Family history: People who have close family members with Parkinson’s disease are more likely to develop Parkinson’s disease, too.
- Toxins: Exposure to certain toxins may increase the risk of Parkinson’s disease.
- Head injury: People who experience head injuries may be more likely to develop Parkinson’s disease.
Each year, researchers are trying to understand why people develop Parkinson’s.
Treatment for Parkinson’s relies on a combination of lifestyle changes, medications, and
Adequate rest, exercise, and a balanced diet are important. Speech therapy, occupational therapy, and physical therapy can also help to improve communication and self-care.
In almost all cases, medication will be required to help control the various physical and mental health symptoms associated with the disease.
Drugs and medication used to treat Parkinson’s disease
- Levodopa is the most common treatment for Parkinson’s. It helps to replenish dopamine. About 75 percent of cases respond to levodopa, but not all symptoms are improved. Levodopa is generally given with carbidopa. Carbidopa delays the breakdown of levodopa which in turn increases the availability of levodopa at the blood-brain barrier.
- Dopamine agonists can imitate the action of dopamine in the brain. They’re less effective than levodopa, but they can be useful as bridge medications when levodopa is less effective. Drugs in this class include bromocriptine, pramipexole, and ropinirole.
- Anticholinergics are used to block the parasympathetic nervous system. They can help with rigidity. Benztropine (Cogentin) and trihexyphenidyl are anticholinergics used to treat Parkinson’s.
- Amantadine (Symmetrel) can be used along with carbidopa-levodopa. It’s a glutamate blocking drug (NMDA). It offers short-term relief for the involuntary movements (dyskinesia) that can be a side effect of llevodopa.
- COMT inhibitors or Catechol O-methyltransferase (COMT) inhibitors prolong the effect of levodopa. Entacapone (Comtan) and tolcapone (Tasmar) are examples of COMT inhibitors. Tolcapone can cause liver damage. It’s usually saved for people who don’t respond to other therapies. Ectacapone doesn’t cause liver damage. Stalevo is a drug that combines ectacapone and carbidopa-levodopa inone pill.
- MAO B inhibitors or MAO B inhibitors inhibit the enzyme monoamine oxidase B. This
enzyme breaks down dopamine in the brain. Selegiline (Eldepryl) and rasagiline (Azilect) are examples of MAO B inhibitors. Patients need to talk with doctor before taking any other medications with MAO B inhibitors.
- They can interact with many drugs, including:
- St. John’s wort
- some narcotics
Over time, the effectiveness of Parkinson’s medications can decrease. By late-stage
Parkinson’s, the side effects of some medicines may outweigh the benefits. However,
they may still provide adequate control of symptoms.
Surgical interventions are reserved for people who don’t respond to medication, therapy, and lifestyle changes. Two primary types of surgery are used to treat Parkinson’s:
- During deep brain stimulation (DBS), surgeons implant electrodes in specific parts of the brain. A generator connected to the electrodes sends out pulses to help reduce symptoms.
- Pump-delivered therapy, In January 2015, the U.S. Food and Drug Administration (FDA) approved a pump-delivered therapy called Duopa. The pump delivers a combination of levodopa and carbidopa. In order to use the pump, your doctor will have to perform a surgical procedure to place the pump near the small intestine.
Statistics in India
As per the “Global, regional, and national burden of Parkinson's disease, 1990–2016: a
systematic analysis for the Global Burden of Disease Study 2016”, the prevalence in India
is 575,946 (range of 458,316 to 712,213). However, there are very few population-based studies determining the exact incidence and prevalence of PD in India.
In a door-to-door survey done in Bangalore district in South Karnataka in India in 2004, the prevalence rate of Parkinsonism was found to be 33 per 100,000 (crude prevalence) and 76 per 100,000 (age adjusted). Rural population had a higher prevalence compared to the urban population (41 vs 14). But it was less compared to other highly prevalent neurological disorders such as headache, epilepsy, stroke, and mental retardation.
rom a survey in Kolkata in 2006, the prevalence of Parkinsonism was found to be 45.82 per 100,000. In the state of Kashmir, the prevalence was 14.1 per 100,000, while the age adjusted prevalence was 134 per 100,000.
A survey, done in Parsi community in Mumbai, a small stable community, showed a prevalence of 192 per 100,000, which was higher compared to rest of the population. In a surveillance in old age homes in a Bangalore, there was very high prevalence of 17.6% (109/612 residents) of Parkinsonism. This may be due to unawareness of this disorder among the general population who do not avail the medical facilities at the appropriate time. As per another source, the incidence of PD in India is estimated to be 70 out of 100,000.