Parkinson’s disease (PD) tends to develop gradually, which is why it may take many months or even years for an individual to go through diagnosis. Making an accurate diagnosis of Parkinson’s, especially in its early stages can be difficult. There must be two of the four main symptoms (Tremors, Bradykinesia, Muscle Rigidity and Postural Instability) present over a period of time for a practitioner to consider a PD diagnosis.
Since there are no standard diagnostic tests for the disease, initiating diagnosis rests on the information provided by the person with Parkinson’s. Ideally, a neurologist who works with nervous system issues and is trained in movement disorders like Parkinson’s should carry out the diagnosis.
A neurologist makes the diagnosis based on physical examination, a detailed medical history, neurological examination and a detailed history of the individual’s current and past medications. During this detailed examination, an individual may be asked to perform certain tasks so that the existing agility of arms and legs, muscle tone, gait and balance can be checked . The neurologist will most likely ask the diagnosee to perform a number of physical exercises to detect any problems with movement. He may check if diagnosee’s expression is animated and arms are observed for tremor (either when they are at rest, or extended). How quickly an individual is able to regain balance or rise from a chair easily are other important factors to consider.
Sometimes, it may take time to diagnose the disease as regular follow-up appointments with neurologists could be recommended. A neurologist records the exam into a table, called United Parkinson’s Disease Rating Scale (UPDRS) – a universal scale of Parkinson’s symptoms. Through UPDRS, the neurologist is able to track the progression or decline (very rare) of the symptoms.
The Bedside Examination is the first and most important diagnostic tool for an individual suspected of having PD. Some imaging modalities such as Positron Emission Tomography (PET) scan, Magnetic Resonance Imaging (MRI), ultrasound of the brain, Single-Photon Emission Computed Tomography (SPECT) scan, and DaTscan may aid diagnosis. At times, the doctor may also prescribe blood tests to rule out other conditions that could be causing PD-alike symptoms. The additional testing helps the expert exclude other diseases such as stroke or hydrocephalus that mimic the appearance of PD.
Since people with PD don’t make enough of dopamine, the neurologist may ask the diagnosee to try Levodopa or the combination of Carbidopa-Levodopa, which temporarily restores dopamine action in the brain. A person’s good response to Levodopa may support the diagnosis of PD.