brain, spinal cord, and nerve disorders
Parkinson Disease (PD)
Causes of Parkinson Disease
In Parkinson disease, synuclein (a protein in the brain that helps nerve cells communicate) forms clumps called Lewy bodies in nerve cells. Lewy bodies consist of misfolded synuclein. Synuclein can accumulate in several regions of the brain, particularly in the substantia nigra (deep within the cerebrum) and interfere with brain function. Lewy bodies often accumulate in other parts of the brain and nervous system, suggesting that they may be involved in other disorders. In Dementia With Lewy Bodies and Parkinson Disease Dementia , Lewy bodies form throughout the outer layer of the brain (cerebral cortex). Lewy bodies may also be involved in About 10% of people with Parkinson disease have relatives who have or have had the disease. Also, several gene mutations that can cause Parkinson disease have been identified. There is growing evidence that Parkinson disease is part of a more widespread disorder. In this disorder, synuclein accumulates not only in the brain but also in nerve cells in the heart, esophagus, intestines, and elsewhere. As a result, this disorder causes other symptoms such light-headedness when a person stands up, constipation, and difficulty swallowing, depending on where synuclein accumulates. Many other disorders and drugs can cause symptoms similar to those of Parkinson disease. Parkinson disease is sometimes hard to diagnose in older people because aging causes some of the same symptoms. 