DIAGNOSIS OF PARKINSON'S DISEASE
Diagnosis is usually based on physical observation and questioning of the patients, but can sometimes involve scanning methods. The SPECT scan and the PET scan are the most accurate means of diagnosis. The following is a summary of the main means of diagnosing and assessing Parkinson's Disease :
UNIFIED PARKINSONS DISEASE RATING SCALEThe 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 ďTotal UPDRSĒ 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.
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.
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.
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.
an accurate aid in diagnosing Parkinson's Disease as it can show decreased
dopamine activity. 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 the patient on a table in the room where they undergo the SPECT scan. Most
scans can take 30 to 90 minutes. For more information go to
The F-dopa PET scan is an accurate aid in diagnosing Parkinson's Disease as it can show decreased dopamine activity in the basal ganglia.
Positron emission tomography (PET) is a nuclear medicine imaging technique which produces a three-dimensional image or map of functional processes in the body. It will take approximately 30 to 60 minutes for radiotracer to travel through your body and to be absorbed by the tissue being studied. You will then be moved into the PET scanner and the imaging will begin. 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.
The SIT, which is also known as UPSIT, consists of four self-administered test booklets, each containing ten stimuli for smell.
Loss of olfactory function (sense of smell) is common in Parkinson's Disease, and so is sometimes used as a means of diagnosis. Respondents pick from one of four multiple choices. For more information go to SIT. 'Sniffin' Sticks' is a test of nasal chemosensory performance based on pen-like odour dispensing devices. It comprises three tests of olfactory function, for odour threshold, odour discrimination and odour identification. The specificity of the 16-item identification test from Sniffin' Sticks (SS-16) when used in Parkinson's Disease was 89% to 90%, and there was a sensitivity of 81% to 85%.
Transcranial Sonography is a non-invasive, diagnostic technique that makes use of sound waves to create a digital image.
Sound waves are produced by a transducer. Strong, short electrical pulses from the ultrasound machine make the transducer ring at the desired frequency. Materials on the face of the transducer enable the sound to be transmitted into the body. The sound wave is partially reflected from layers between different tissues. The return sound wave vibrates the transducer, which turns the vibrations into electrical pulses. The electrical pulses then travel to the scanner where they are then transformed into a digital image. For more information go to Transcranial Sonography.
The eye-tracking system, the Mobile Eye Brain Tracker (EBT), is available for the detection of Parkinson-plus diseases.
Parkinson-plus syndromes have additional features that distinguish them from Parkinson's Disease. Different areas of the brain are involved in producing eye movements, and abnormalities that occur can be linked to dysfunction in certain areas of the brain. Results have shown that eye movements provide a more accurate early diagnosis than traditional clinical examinations. The Mobile EBT is non-invasive and costs less than regularly used imaging techniques. For more information go to Eye Brain Tracker.
The Parkinsonís KinetiGraph system consists of a sensor that is worn around the wrist of the patient to record data about their symptoms.
The system also uses a computer unit which receives that data and analyses it. The device remotely records data about a personís movement and via algorithms, provides a report for the their neurologist showing an objective measure of the presence and severity of bradykinesia and dyskinesi. The device also reminds the person when to take their Parkinsonís Disease drugs as prescribed by their medical practitioner. For more information go to Kinetigraph.
Mercury is a wearable wireless sensor being developed as a means of enabling home monitoring of the motion of people with Parkinson's Disease.
Patients wear wireless nodes equipped with sensors for monitoring their movement and physiological conditions. The basic approach is to capture data from each limb using wearable sensors. The patient wears up to eight sensors and recharges the sensors at night. A laptop in the patient's home stores the data. Data is then sent via the Internet to the clinic where it is processed. Signals are subject to extensive processing to evaluate the patientís motor function. For more information go to Mercury