Diagnosis is usually based on physical observation and questioning of the patients, but can sometimes involve scanning methods. The following is a summary of the main means of diagnosing and assessing Parkinson's Disease :

The most commonly used symptom questionnaire is the Unified Parkinson Disease Rating Scale (UPDRS). The UPDRS was developed to address the need for a comprehensive Parkinson's Disease measurement tool. It encompasses earlier rating scales : Hoehn and Yahr staging scale, and the modified Schwab and England activities of daily living scale. In monotherapy, a “Total UPDRS” score is the combined sum of parts I, II, and III: 0 (not affected) to 176 (most severely affected). In adjunct therapy, part IV is included. Part IV contains 11 questions and the scale can range from 0 to 23. For an understanding of the UPDRS go to UPDRS.

HOEHN AND YAHR

The Hoen and Yahr characterises patients according to a scale of five stages of severity, from Stage 1, which is mild, to Stage 5, which is incapacitated. For the questionnaire go to the Hoehn and Yahr scale.

SCHWAB AND ENGLAND

The Schwab and England Activities of Daily Living assesses patients in terms of their degree of independence concerning their functions - with a range a percentages from 100% to 0%. Rating can be assigned by the rater or the patient. For the questionnaire go to the Schwab and England.

PDQ39

The PDQ39 assesses the quality of life. The PDQ-39 is the most widely used Parkinson's Disease specific measure of health status. It contains thirty nine questions, covering eight aspects of quality of life. Scores on the PDQ range from 0 to 100, with higher scores reflecting greater problems. For the questionnaire go to PDQ 39.

PDQL

The PDQL is a self administered measure that contains 37 items contained in four sub-scales : parkinsonian symptoms, systemic symptoms, social functioning. An overall scale can be derived, with a higher score indicating better perceived quality of life. For the questionnaire go to the PDQL.

SCANNING METHODS

SPECT SCAN

A single-photon emission computerized tomography (SPECT) procedure allows the analysis of the function of your internal organs. SPECT is used as an aid in diagnosing Parkinson's Disease as it can show decreased dopamine activity. Although it is often claimed to show the extent of the loss of the dopaminergic neurons (the cells involved in Parkinson's Disease), it instead shows the level of activity in the existing cells.  A SPECT scan is a type of nuclear imaging test, which means it uses a radioactive substance and a special camera to create three-dimensional images that show how your organs work. Most SPECT scans involve two steps : receiving a radioactive dye and using a SPECT machine to scan a specific area of the body. Before undergoing the SPECT scan, patients receive a radioactive substance through an injection or through an intravenous (IV) infusion into a vein in the arm. The health care team position patients on a table in the room where they undergo the SPECT scan. Most SPECT scans take 30 to 90 minutes. For more information go to SPECT scan. DaTSCAN  is the name of a solution used for injection in SPECT scans. For more information go to DatSCAN.

 

PET SCAN

The F-dopa PET scan is used as an aid in diagnosing Parkinson's Disease as it can show decreased dopamine activity in the basal ganglia. Although it is often claimed to show the extent of the loss of the dopaminergic neurons (the cells involved in Parkinson's Disease), it instead shows the level of activity in the existing cells.  Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer) that is introduced into the body on a biologically active molecule. It will take approximately 30 to 60 minutes for the radiotracer to travel through your body and to be absorbed by the organ or tissue being studied. You will be asked to rest quietly, avoiding movement and talking. You will then be moved into the PET scanner and the imaging will begin. You will need to remain still during imaging. Actual scanning time is approximately 45 minutes. Images of tracer concentration in 3-dimensional space within the body are then reconstructed by computer analysis.  For more information go to PET scan.