Evaluating Disease Severity
This article is excerpted from the APDA's booklet, Coping With Parkinson's Disease
One of the first questions many patients ask about is the severity of their disease. To evaluate the severity, an examination in the physician's office is necessary. However, the examination may not reveal a patient's ability to perform outside the office and carry out the activities of daily living.
For example: patients frequently say that when they see their physician, they are at their best-not a true indication of their overall daily performance. Most physicians familiar with PD are aware of this discrepancy and do not base decisions regarding treatment solely on one office observation.
In addition. the patient's age may further complicate the picture thus, the 80-year-old patient may not be as independent as the comparably afflicted 40-year-old patient.
Rating Scales
Scales rating the severity of PD are based on an evaluation of the symptoms. and may assign a weighted numerical value to each symptom. The scales differ in which symptoms are evaluated and the value assigned to each.
Among the more frequently used scales are the:
In the Hoehn and Yahr Scale. the disease is divided into five stages
Stages 0-II are mild disease; Stage III is moderate disease; Stages IV and V are marked or advanced disease. There are gray areas between the successive stages.
Complementing these rating scales are functional disability scales that rate the patient's ability to perform activities of daily living. These scales assign a weighted value to a particular activity, such as walking, eating, dressing. hygiene, speaking: and then grade the patient's degree of disability.
For patients who experience daily oscillation changes in performance, physicians assess the daily number of hours patients spend in their "on" (good) period and the number of hours they spend in their "off" (bad) period. Such a determination is made by instructing patients with these oscillations to keep a daily diary of both the number of hours they are ''on" and the number 'off." Through such a diary, the physician gains a better understanding of the patient's overall performance. Since reports on the degree of the patient's disability may differ between the patient and the family, it is useful for the physician to question both.
None of the currently used means of evaluating PD measures a patient's initiative, determination, spirit, or drive-all qualities which can transcend the patient's disability.