What is Parkinson’s Disease?
Parkinson’s disease (PD) is a chronic, neurodegenerative disease that primarily affects movement. The cause of PD is unknown, and although there is presently no cure, there are treatment options including medication and surgery to manage its symptoms. An estimated 500,000 to 1 million people in the US are living with Parkinson’s disease and the National Institute of Neurological Disorders and Stroke (NINDS) estimates that Parkinson’s disease carries an annual cost of over $5.6 billion to our society.
Symptoms of Parkinson’s Disease include:
- Tremor (shaking) – begins in hands and/or fingers of one limb
- Pill-rolling tremor – rubbing of the thumb and forefinger
- Slowed movements – reduction in ability to move
- Shuffling gait – dragging of feet when walking
- Muscle stiffness – limits range of motion and causes pain
- Speech changes – slurred words and low speech volume
- Writing changes – illegible handwriting
- Stooped posture and balance problems
- Fatigue – may precede motor symptoms
- Excessive daytime sleepiness (EDS) – including sudden “sleep attacks”
How is Parkinson’s Disease Linked to Mitochondrial Dysfunction?
Parkinson’s disease has been linked to mitochondrial dysfunction, where problems with the energy-producing mitochondria in cells can contribute to the development and progression of the disease. Parkinson’s disease results from a deterioration of the neurons (nerve cells) in the region of the brain called the substantia nigra. These neurons normally produce the neurotransmitter dopamine that sends signals to the basal ganglia, a mass of nerve fibers that helps initiate and control patterns of movement. Dopamine functions in the brain as an inhibitor of nerve impulses and is involved in suppressing unintended movement. When dopamine-producing (dopaminergic) neurons are damaged or destroyed, dopamine levels drop and the normal signaling system is disrupted. In both primary and secondary parkinsonism, the physiological effects of this deterioration do not manifest until roughly 60 to 80 percent of dopaminergic neurons are destroyed.