What is Parkinson's Disease?
Parkinson's disease (PD) is a deficiency of the production of the neurotransmitter dopamine in the brain, resulting from the loss of dopamine-producing brain cells (neurons) due to the accumulation of the protein alpha synuclein. Once a significant loss of the dopamine-producing neurons has occurred, then the physical symptoms of Parkinson's disease can manifest.
Common Symptoms of PD
The cardinal physical or motoric symptoms of Parkinson's disease include:
- Tremor
- slowness of movement (bradykinesia)
- stiffness (rigidity)
- changes in gait/balance and posture oftentimes characterized by shuffling, imbalance, and stooped posture
Other motor symptoms can include decreased facial expression (masked facies or hypomimia) and low voice volume (hypophonia) due to slowness and stiffness of the facial and swallowing musculature. However, not everyone with Parkinson's disease will necessarily manifest all of these physical symptoms.
Non-motor symptoms
There is also increasing recognition of the non-motor symptoms that can be prevalent in Parkinson's disease. Some of the most common non-motor features of PD include acting out of dreams during sleep (REM sleep behavior disorder or RBD), decreased sense of smell (hyposmia), chronic constipation, changes in urinary function, changes in blood pressure regulation, and changes in mood and/or memory. Sometimes, such symptoms can present even up to decades in advance of the overt physical manifestations of PD.
How is Parkinson's Disease Diagnosed?
Parkinson's disease is diagnosed clinically (based off a history and examination that is suggestive of PD) performed by a medical professional. In cases in which there remains clinical ambiguity about an underlying diagnosis of PD, there are ancillary tests that can be considered to aid in the diagnosis of a Parkinsonian condition. These include the DaTscan (dopamine transporter scan) as well as emerging tests for PD via a spinal tap (lumbar puncture) or skin testing.
Do the Symptoms Change Over Time?
Parkinson's disease is a progressive disorder, meaning that the inherent dopamine production from the brain in those with PD continues to decline over time. As a result, some of the symptoms of PD can become more apparent over time, or features that were not present at the time of diagnosis can manifest as the disease evolves.
Medications
Given that PD is a dysfunction of dopamine in the brain, the medications currently used in the treatment of PD all seek to alter the dopaminergic system in the brain (although different medications work via different mechanisms to accomplish this).
Other Treatments
There are also treatments including Deep Brain Stimulation Surgery (DBS), Focused ultrasound (FUS), and Duopa pump which can aide in the symptomatic management of select PD patients that meet certain clinical indications for such interventions.
Non-pharmacological modalities which help with PD include physical, occupational, and speech therapy, and we cannot overemphasize enough the importance of exercise. Furthermore, there are always ongoing clinical trials at any given point in time aiming to improve upon existing medications and therapies, innovate new treatments, and, hopefully one day soon, provide a breakthrough that helps slow down or reverse the progression of PD.
Content provided by Ronak Vora, D.O.
Movement Disorder Specialist
Member, PEP4U Board of Directors