Health Conditions

What causes it?

The cause of Parkinson's disease remains a mystery. The consensus among medical professionals is that it probably results from a combination of genetic and environmental factors. Idiopathic Parkinson's disease is caused by the gradual loss of neurons in the substantia nigra. The substantia nigra is the region of the brain that controls movement; particularly automatic movements such as arm swinging while walking. When nerve cells in this area become impaired and die, production of a chemical in the brain called dopamine, which aids in transmitting signals, decreases. The result is impaired movement.

Although Parkinson's disease is caused by degeneration limited to the substantia nigra, other degenerative diseases and some medications can produce secondary parkinsonism. Medications that can cause symptoms of Parkinson's disease include antipsychotics (mesoridazine [Serentil], thioridazine [Mellaril], chlorpromazine [Thorazine], perphenazine [Trilafon], fluphenazine [Prolixin], trifluoperazine [Stelazine], haloperidol [Haldol], thiothixene [Navane], risperidone [Risperdal]), antiemetics (prochlorperazine [Compazine]), gastrointestinal antimotility drugs (metoclopramide [Reglan]), and drugs that lower blood pressure such as reserpine (Serpasil). Drug-induced parkinsonism must be ruled out before the diagnosis of Parkinson's disease is made.