The global parkinsonian summary score is a composite measure of parkinsonian signs. The score is the average of 4 separate domains calculated from a 26-item modified version of the motor portion of the United Parkinson's Disease Rating Scale (mUPDRS)*:

1. Bradykinesia
2. Gait
3. Rigidity
4. Tremor

A trained nurse clinician administers the modified motor portion of the mUPDRS. Bradykinesia is based on 8 items: right and left finger taps, fist clench, pronation-supination, and leg agility. Parkinsonian gait is based on 6 items: arising from a chair, shuffling gait, body bradykinesia, turning, posture, and postural stability. Rigidity is based on 5 items, one for neck and each of the four extremities. Tremor is based on 7 items: resting tremor of chin-jaw and all four extremities, and action-postural tremor of both hands.

The nurse clinician rates each item (see individual domains for scales). The domain score for each sign is calculated by adding the ratings for the individual items within each domain, dividing by the maximum possible score for the domain, then multiplying by 100. The global parkinsonian summary score ranges from 0 to 100 and is calculated by averaging the four domain scores. A higher summary score reflects expression of more severe Parkinsonian signs.

Notes: The modifications to the mUPDRS are minor and are intended to make the scale more applicable to persons without PD and easier for non-physicians to administer and score.

These measures have high inter-rater reliability and short-term temporal stability and are reproducible in men and women in aging and dementia from a variety of cohorts.