Mechanism of Tremor in Parkinson's Disease

Uncontrollable shaking is a primary symptom associated with Parkinson's disease. It usually starts in the hands or fingers before moving on to affect other body parts like the arms, legs, jaw or face.

Tremor

• The involuntary shaking or trembling that accompanies Parkinson's disease is a result of repetitive contraction and relaxation of muscles.

Cause

• The death of nerve cells in the region of the brain called the substantia nigra is the root cause of Parkinsonian tremor. These cells are responsible for the production of the important brain chemical dopamine.

Mechanism

• Dopamine transmits signals from the substantia nigra to the corpus striatum for smooth body movement. When dopamine level is low, the nerves fire sporadically, causing trembling.

Considerations

• By the time Parkinson's symptoms appear, 60 to 80 percent of the dopamine-producing cells may have already been destroyed.

Theories/Speculation

• While nerve cell death is directly responsible for Parkinson's tremors, the process that kills the cells is less understood. Suspects are mitochondrial stress, inflammation, oxidative stress and protein buildup in the brain.