Causes
In Parkinson’s disease, certain nerve cells called neurons in the brain gradually break down or die. Many of the symptoms of Parkinson’s are due to a loss of neurons that produce a chemical messenger in your brain called dopamine. When dopamine levels decrease, it causes irregular brain activity, leading to problems with movement and other symptoms of Parkinson’s disease.
The cause of Parkinson’s disease is unknown, but several factors appear to play a role, including:
Genes. Researchers have identified specific genetic changes that can cause Parkinson’s disease. But these are uncommon except in rare cases with many family members affected by Parkinson’s disease.
However, certain gene variations appear to increase the risk of Parkinson’s disease but with a relatively small risk of Parkinson’s disease for each of these genetic markers.
Environmental triggers. Exposure to certain toxins or environmental factors may increase the risk of later Parkinson’s disease, but the risk is small.
Researchers also have noted that many changes occur in the brains of people with Parkinson’s disease, although it’s not clear why these changes occur. These changes include:
The presence of Lewy bodies. Clumps of specific substances within brain cells are microscopic markers of Parkinson’s disease. These are called Lewy bodies, and researchers believe these Lewy bodies hold an important clue to the cause of Parkinson’s disease.
Alpha-synuclein found within Lewy bodies. Although many substances are found within Lewy bodies, scientists believe that an important one is the natural and widespread protein called alpha-synuclein, also called a-synuclein. It’s found in all Lewy bodies in a clumped form that cells can’t break down. This is currently an important focus among Parkinson’s disease researchers. Researchers have found the clumped alpha-synuclein protein in the spinal fluid of people who later develop Parkinson’s disease.
