A drop of >30% in the UPDRS-III score between 'Off' and 'On' medication states is a strong predictor of success for Deep Brain Stimulation surgery.
Motor Symptom Probe
Complete the motor audit by selecting the current severity of tremors, rigidity, and balance to determine the UPDRS stage.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Baseline and follow-up evaluation of Parkinson's disease motor severity.
The absolute gold-standard for determining if a patient will benefit from Deep Brain Stimulation (DBS) of the STN or GPi.
Section 2
Literature
Development
The Unified Parkinson's Disease Rating Scale (UPDRS) was developed to standardize research. Part III specifically isolates the motor exam (Tremor, Rigidity, Bradykinesia). Functional neurosurgeons realized that if a patient's UPDRS-III score improved drastically (e.g. >30%) when they took levodopa (their "On" state), then a DBS electrode would cure them. If the score did not change with dopamine, DBS would fail.
Section 3
Pearls/Pitfalls
The Levadopa Challenge
A DBS practically provides the patient with their "best medicated On-state" 24 hours a day without the dyskinesias. Therefore, if a symptom (like postural instability or freezing of gait) remains severe during the UPDRS "On" test, DBS will NOT fix it, and the patient must be warned.
Section 4
Evidence Appraisal
Primary Reference
Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS): scale presentation and clinimetric testing results
