Sign and Symptoms
Parkinson is most frequently assessed on the basis of your current symptoms; these assessments cannot tell how the condition will evolve over time or how you will respond to treatment.
Classic diagnosis is made on the basis of whether symptoms are improved by adding levodopa.
In addition to a clinical assessment, your doctor or specialist may use one of two disability rating scales. The first scale is quite a simple scale: the Hoehn & Yahr, named after the two doctors who devised it in 1967.The Hoehn & Yahr scale allocates stages from 0 to 5 to indicate the relative level of disability you are experiencing.
The Hoehn & Yahr stages
No visible symptoms of Parkinson
Parkinson symptoms just on one side of the body
Parkinson symptoms on both sides of the body and no difficulty walking
Parkinson symptoms on both sides of the body and minimal difficulty walking
Parkinson symptoms on both sides of the body and moderate difficulty walking
Parkinson symptoms on both sides of the body and unable to walk
Importantly, the Hoehn & Yahr scale was devised to support the introduction of most current Parkinson treatments. It was intended to include the entire range of Parkinson states. Parkinson does not necessarily progress to the more advanced stages (stages 4 and 5).
A more detailed scale – the Unified Parkinson Disease Rating Scale (UPDRS) – has been widely used by specialists, particularly in research studies of new treatments. The UPDRS includes a wide range of assessments, using 42 questions divided into four main subsections:
- Mentation (ability to process thoughts), behavior and mood
- Activities of daily living (during both 'on' and 'off ' periods)
- Motor examination
- Complications of therapy (that have occurred in the last week)
In addition to assessing mobility, doctors can also use quality of life scales to gain a better understanding of how troublesome your Parkinson symptoms are and how you are feeling. The PDQ-39, so called because it is made up of 39 questions, is a quality of life questionnaire that has been developed specifically for Parkinson.
Together, these disability and quality of life scales can be used to help gauge Parkinson, its impact on daily life and its response to treatment.
Another important technique is functional imaging. Functional imaging provides structural images of the brain using techniques such as computed tomography (CT) or magnetic resonance imaging (MRI) scans. It is possible to look at images of the brain chemistry by administering tiny doses of radioactive substances that concentrate in specific parts of the brain.
These techniques are called positron emission tomography (PET) and single photon emission computed tomography (SPECT) PET and SPECT scans have mainly been used in research. Such images have helped scientists to identify exactly what areas of the brain, nerve cells and chemicals (neurotransmitters) are affected by Parkinson.
However, the more widely available SPECT scanning is now sometimes used clinically in certain patients in whom the diagnosis is uncertain.