Although no distinct cause has been determined, Parkinson’s disease is due to gradual loss of cells in an area deep within the brain called substantia nigra, which normally produces a chemical called dopamine. Once produced, dopamine travels to other portions of the brain.
One portion called the striatum is the coordination center for various brain circuits. As there is insufficient dopamine in the striatum, the chemical imbalance leads to the symptoms of Parkinson’s disease. Later in the disease, cells in other portion of the brain and nervous system also degenerate.
No one knows why this dopamine producing cells die. Scientists are exploring several theories including chemical reactions within the body, exposure to toxic substances and certain genetic factors. A new gene in certain families suffering from Parkinson’s disease known as “Parkin gene” has been identified to be the positive factor for Parkinson’s disease.
However this has been found to be positive in a small group of patients with young onset of Parkinson’s disease. The research is still going on to find out the real cause for Parkinson’s disease in large patient population