Parkinson’s disease (PD) also known as idiopathic or primary parkinsonism, hypokinetic rigid syndrome (HRS), or paralysis agitans is a neurodegenerative brain disorder of the central nervous system (CNS). PD progresses slowly in most people, taking years for symptoms to develop and worsen. The motor symptoms of Parkinson’s disease result from the death of dopamine-generating cells in the substantia nigra, a region of the midbrain; the cause of this cell death is unknown. Dopamine is a chemical that relays messages between the substantia nigra and other parts of the brain to control movements of the human body. Dopamine helps humans to have smooth, coordinated muscle movements. When approximately 60 to 80% of the dopamine-producing cells are damaged, and do not produce enough dopamine, the motor symptoms of Parkinson’s disease appear. PD itself is not fatal, but complications from the disease are serious. The Center for Disease Control rated complications from PD as the 14th top cause of death in the United States.  There is currently no cure for Parkinson’s. Stem cell transplantation shows great potential for the management of Parkinson’s disease.
WHAT ARE THE SYMPTOMS
Parkinson’s disease symptoms and signs may vary from person to person. Symptoms often begin on one side of your body and usually remain worse on that side, even after symptoms begin to affect both sides. Parkinson’s disease affects movement, producing motor symptoms. Non-motor symptoms, which include autonomic dysfunction, neuropsychiatric problems (mood, cognition, behavior or thought alterations), and sensory and sleep difficulties, are also common. Parkinson’s signs and symptoms may include: :
- Tremor, or shaking, usually begins in a limb, often your hands or fingers. One characteristic of PD is a tremor of your hand when it is relaxed.
- Slowed movement (bradykinesia). PD may reduce ability to move and slow movement, making simple tasks quite difficult. A person’s stride may be reduced and they may drag their feet as they try to walk.
- Rigid Muscles. Muscle stiffness may occur in any part of the body and limit range of motion.
- Impaired posture and balance. Posture may become stooped and balance problems can occur.
- Speech changes. People suffering from PD may speak softly, quickly, slur, or hesitate before talking. Speech can become monotone, lacking usual inflections.
While there is no cure for Parkinson’s disease treatments aim to restore the proper balance of the neurotransmitters acetylcholine and dopamine by increasing dopamine levels. Symptoms of PD can often be controlled for years with medication. 
- Levodopa – Is the most prescribed drug. The body metabolizes it to produce dopamine. However, this is ineffective, because the brain blocks it from being used by the body. To suppress nausea and other side effects the drug is often given in conjunction with a separate drug called carbidopa.
- COMT inhibitors – Tolcapone (Tasmar) and entacpone (Comtan) are drugs taken with levodopa. They prolong symptom relief of the drug by blocking the action of an enzyme that breaks down levodopa.
- MAO-B inhibitors – Also block the action of an enzyme that breaks down dopamine. They may be taken alone early in PD or with other drugs as the disease progresses.
- Dopamine agonists – are dopamine-like drugs that directly imitate dopamine’s activity in the brain.
It is very important to maintain a daily exercise program and to remain socially active. In many Parkinson’s patients, a weakening of social ties because of physical difficulties can lead to depression. The American Parkinson Disease Association can provide information about support groups and exercise classes in your area valuable sources for companionship.