What is "parkinson's disease"

Palsy \Pal"sy\, n.; pl. Palsies. [OE. palesie, parlesy, OF. paralesie, F. paralysie, L. paralysis. See Paralysis.] (Med.) Paralysis, complete or partial. See Paralysis. ``One sick of the palsy.''
--Mark ii. 3.

Bell's palsy, paralysis of the facial nerve, producing distortion of one side of the face; -- so called from Sir Charles Bell, an English surgeon who described it.

Scrivener's palsy. See Writer's cramp, under Writer.

Shaking palsy, (Med.) paralysis agitans, a disease usually occurring in old people, characterized by muscular tremors and a peculiar shaking and tottering gait; now called parkinsonism, or Parkinson's disease.

Parkinson's \Parkinson's\, Parkinson's disease \Parkinson's disease\prop. n. A disease causing parkinsonism, a degenerative nervous disorder; sometimes used loosely as a synonym for parkinsonism. More precisely, parkinson's disease is the term for the underlying physiological disorder and parkinsonism is the term for the set of symptoms associated with the disease. See parkinsonism.

Syn: paralysis agitans, Parkinsonism, Parkinson's disease syndrome, shaking palsy.

Parkinson's disease is the most common form of parkinsonism, a group of disorders that are the result of the loss of dopamine-producing brain cells.
--Mayo Clinic (Report, 1999)

According to the National Parkinson's Foundation (NPF), 1 million Americans -- including former heavyweight boxing champion Muhammad Ali, U.S. Attorney General Janet Reno, and television and film star Michael J. Fox -- are affected by Parkinson's disease.
--Mayo Clinic (Report, 1999)

1877, from French maladie de Parkinson (1876), named for English physician James Parkinson (1755-1824), who described it (1817) under the names shaking palsy and paralysis agitans.

Parkinson's disease (PD) is a long term disorder of the central nervous system that mainly affects the motor system. The symptoms generally come on slowly over time. Early in the disease, the most obvious 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".

The cause of Parkinson's disease is generally unknown, but believed to involve both genetic and environmental factors. Those with a family member affected are more likely to get the disease themselves There is also an increased risk in people exposed to certain pesticides and among those who have had prior head injuries while there is a reduced risk in tobacco smokers and those who drink coffee or tea. The motor symptoms of the disease result from the death of cells in the substantia nigra, a region of the midbrain. This results in not enough dopamine in these areas. The reason for this cell death is poorly understood but involves the build-up of proteins into Lewy bodies in the neurons. Diagnosis of typical cases is mainly based on symptoms, with tests such as neuroimaging being used to rule out other diseases.

There is no cure for Parkinson's disease. Initial treatments is typically with the antiparkinson medication levodopa, with dopamine agonists being used once levodopa becomes less effective. As the disease progresses and neurons continue to be lost, these medications become less effective while at the same time they produce a complication marked by involuntary writhing movements. Diet and some forms of rehabilitation have shown some effectiveness at improving symptoms. Surgery to place the microelectrodes for deep brain stimulation has been used to reduce motor symptoms in severe cases where drugs are ineffective. Evidence for treatments for the non-movement-related symptoms of PD, such as sleep disturbances and emotional problems, is less strong.

In 2013 PD was present in 53 million people and resulted in about 103,000 deaths globally. Parkinson's disease typically occurs in people over the age of 60, of which about one percent are affected. Males are more often affected than females. When it is seen in people before the age of 40 or 50, it is called young onset PD. The average life expectancy following diagnosis is between 7 and 14 years. The disease is named after the English doctor James Parkinson, who published the first detailed description in An Essay on the Shaking Palsy, in 1817. Public awareness campaigns include World Parkinson's Day (on the birthday of James Parkinson, 11 April) and the use of a red tulip as the symbol of the disease. People with parkinsonism who have increased the public's awareness of the condition include actor Michael J. Fox, Olympic cyclist Davis Phinney, and late professional boxer Muhammad Ali.