There is no “one way” to diagnose Parkinson’s disease (PD). However, there are various symptoms and diagnostic tests used in combination. One of the most important things to remember about diagnosing PD is that there must be two of the four main symptoms present over a period of time for a neurologist to consider a PD diagnosis.
Four Main Motor Symptoms of PD:
- Shaking or tremor
- Slowness of movement, called bradykinesia
- Stiffness or rigidity of the arms, legs or trunk
- Trouble with balance and possible falls, also called postural instability
How does your doctor make a PD diagnosis?
The bedside examination by a neurologist remains the first and most important diagnostic tool for patients suspected of having PD. When questions arise, some newer imaging modalities such as PET and DAT scans may aid diagnosis, when performed by an expert in neuroimaging. DATscan is FDA-approved for differentiating PD from essential tremor, but it cannot distinguish between PD and parkinsonian subtypes. A neurologist will make the diagnosis based on:
- A detailed medical history and physical examination.
- A detailed history of your current and past medications, to make sure you are not taking medications that can cause symptoms similar to PD.
- A detailed neurological examination during which a neurologist will ask you to perform tasks to assess the agility of arms and legs, muscle tone, your gait and your balance.
- You may notice that a neurologist records your exam into a table, called United Parkinson’s Disease Rating Scale (UPDRS). UPDRS is a universal scale of PD symptoms and it was created to comprehensively assess and document the exam of the patient with PD and be able to compare it with patient’s future follow up visits, or to communicate about the progression of the PD symptoms in each patient with other neurologists.
- Visit the International Parkinson and Movement Disorder Society for their version of the UPDRS.
- The response to medications (that imitate or stimulate the production of Dopamine) causing a significant improvement in symptoms is how the diagnosis of PD is made clinically.