Parkinson's disease is a disorder of the brain that leads to shaking (tremors) and difficulty with walking, movement, and coordination.

Paralysis agitans; Shaking palsy

Parkinson's disease was first described in England in 1817 by Dr. James Parkinson. The disease most often develops after age 50. It is one of the most common nervous system disorders of the elderly. Sometimes Parkinson's disease occurs in younger adults, but is rarely seen in children. It affects both men and women.

In some cases, Parkinson's disease occurs in families. When a young person is affected, it is usually because of a form of the disease that runs in families.

Nerve cells use a brain chemical called dopamine to help control muscle movement. Parkinson's disease occurs when the nerve cells in the part of the brain that makes dopamine are slowly destroyed. Without dopamine, the nerve cells in that part of the brain cannot properly send messages. This leads to the loss of muscle function. The damage gets worse with time. The exact reason why the brain cells waste away is unknown.

Parkinson's in children may occur because the nerves are not as sensitive to dopamine. Parkinson's is rare in children.

The term "parkinsonism" refers to any condition that involves the types of movement changes seen in Parkinson's disease. Parkinsonism may be caused by other disorders (such as secondary parkinsonism) or certain medications.

The disorder may affect one or both sides of the body. How much function is lost can vary.

Symptoms may be mild at first. For instance, the patient may have a mild tremor or a slight feeling that one leg or foot is stiff and dragging.

Symptoms include:

• Automatic movements (such as blinking) slow or stop
• Constipation
• Difficulty starting or continuing movement, such as starting to walk or getting out of a chair
• Drooling
• Impaired balance and walking
• Lack of expression in the face (mask-like appearance)
• Loss of small or fine hand movements (writing may become small and difficult to read, and eating becomes harder)
• Muscle aches and pains (myalgia)
• Problems with movement
• Rigid or stiff muscles (often beginning in the legs)
• Shaking, tremors
  • Tremors usually occur in the limbs at rest, or when the arm or leg is held out
  • Tremors go away during movement
  • Over time, tremor can be seen in the head, lips, tongue, and feet
  • May be worse when tired, excited, or stressed
  • Finger-thumb rubbing (pill-rolling tremor) may be present
• Shuffling gait
• Slowed movements
• Slowed, quieter speech and monotone voice
• Stooped position

Other symptoms:

• Anxiety, stress, and tension
• Confusion
• Dementia
• Depression
• Fainting
• Hallucinations
• Loss of muscle function or feeling
• Memory loss
• Oily skin (seborrhea)