The “Parkinson syndrome” or Parkinsonism actually refers to a number disorders and causes, including classic or idiopathic (cause unknown) Parkinson disease, genetic or familiar forms, environmental toxins (including medications), and rare atypical parkinsonisms such as progressive supranuclear palsy, multiple system atrophy, Lewy body dementia, and corticobasal degeneration. By far, the most common cause of Parkinsonism though is idiopathic Parkinson disease. The disorder is characterized by progressive tremor, stiffness, slowing of movement, and postural instability. Average age of onset is about 60 years, but rare cases are seen as early as 30 years old.
The hallmark of the disease includes progressive loss of cells in a region of the brain called the substantia nigra. These cells produce an important chemical, dopamine, which is needed for normal behavior. Unfortunately, by the time patients present to their doctor with symptoms nearly 50-70% of these dopamine producing cells have been lost. Therapies to date for Parkinson disease focus on “dopamine replacement” and are quite effective, but importantly treat only symptoms. As the disease progresses these therapies become less effective and are fraught with complications, resulting in significant morbidity. The need for novel therapeutic approaches to Parkinson disease is evident. These include potential neuroprotective strategies as well as treatments to address the non-motor aspects of Parkinsonism.