What is Parkinson’s Disease?

Parkinson’s Disease patient with hands shaking, making it difficult to hold a mug in her hands

Parkinson’s Disease (PD) is a disorder of the central nervous system that affects movement. Nerve cell damage in the brain causes dopamine (a neurotransmitter made in one’s brain that plays a role as a “source of rewards”, and plays a part in many body functions, such as movement, memory, movement, mood, and attention) levels to drop, leading to the symptoms seen in Parkinson’s patients. Parkinson’s Disease often starts with tremors in one hand, and then progresses to other parts, and causes slow movement, stiffness, and a loss of balance.

Symptoms of PD can be motor-related as well as non-motor. While the obvious motor-related symptoms are the ones recognized earliest, e.g. slowed movements (bradykinesia), tremors while muscles are at rest, lead pipe rigidity and cogwheel stiffness (stop-and-go movement akin to the seconds hand on a clock), there are non-motor symptoms as well such as orthostatic hypotension (low blood pressure when standing up), constipation, depression, anosmia (a lack of smell), and sleep problems.

While several risk factors have been recognized as increasing the chance of getting PD, such as exposure to pesticides, the only confirmed cause of PD is genetic. About 10% of cases of PD originate in people who had either one or both parents suffering from PD. Seven different genes have been linked to PD, of which 3 are linked to early-onset Parkinson’s Disease. The rest of the patients’ cause is idiopathic (which means that their cause is unknown). Parkinson’s Disease is not contagious, which means you can’t contract it from someone suffering from the disease.

To determine if one has Parkinson’s Disease, several tests can be done, such as a computerized tomography (CT) scan, genetic testing, magnetic resonance imaging (MRI), or a positron emission tomography (PET) scan.

While there are no known cures currently for Parkinson’s Disease, there are several ways to improve the symptoms of PD, such as deep brain stimulation (which involves implanting a medical device that delivers a mild electrical current to a part of one’s brain), and some experimental stem cell-based treatments which may or may not work for one’s particular condition. Medications can also treat PD, in one of several ways such as adding dopamine, dopamine agonists (simulating dopamine), dopamine metabolism blockers that prevent dopamine from breaking down, levodopa (precursor to dopamine) metabolism inhibitors, and adenosine (helps when levodopa is reduced) blockers that help reduce how much the body uses up adenosine.

Scientists are trying to harness gene editing to find an actual cure for Parkinson’s Disease, but this is still a work-in-progress.