MDS-UPDRS Part III – Motor Examination
The clinician-administered motor examination in Parkinson’s disease. Total 0 to 132.
By Claire White
- Administered by a clinician or trained rater. The Movement Disorder Society runs a certificate program for raters.
- 18 examination items produce 33 scores, because most items are rated on each side of the body.
- Each score runs 0 to 4. The 23 non-tremor scores run 0 to 92, the 10 tremor scores run 0 to 40, and the Part III total runs 0 to 132.
- The score depends on medication state, so the ON or OFF state is recorded with the number.
- Published by the International Parkinson and Movement Disorder Society.
Psychometrics
Cronbach's alpha for the Part III total, from Goetz et al. (2008). Higher is better.
What does MDS-UPDRS Part III measure?
Part III is the examiner’s rating of the motor signs of Parkinson’s disease, performed with the person in front of them. Its 18 items fall into two groups. The 23 non-tremor scores, items 3.1 to 3.14, cover speech, facial expression, rigidity, finger tapping, hand movements, pronation and supination, toe tapping, leg agility, arising from a chair, gait, freezing of gait, postural stability, posture, and overall spontaneity of movement. The 10 tremor scores, items 3.15a to 3.18, cover postural, kinetic, and rest tremor, including the amplitude of rest tremor at each limb and how constant it is.
Most items are rated separately for the right and left side, which is why 18 items produce 33 numbers. The scale is licensed, so this page describes what Part III examines rather than reproducing its wording. The official form, with the exact instructions and the rating anchors, comes from the International Parkinson and Movement Disorder Society at movementdisorders.org.
What does an MDS-UPDRS Part III score mean?
Higher means more severe motor signs at the moment of the examination. A 2015 study of 452 people with Parkinson’s proposed three bands for the Part III total.
| Part III total | Severity |
|---|---|
| 0 to 32 | Mild |
| 33 to 58 | Moderate |
| 59 and above | Severe |
Part III is the number quoted most often on its own, in trials and in clinic letters, and it carries two conditions that travel with it. It is a snapshot, so it moves with medication state, and an ON score is only comparable with another ON score. And a single reading says less than a series. Change is read against a published threshold rather than by eye. In 728 paired assessments, clinicians judged 3.25 points of improvement and 4.63 points of worsening to be the smallest differences that mattered.
How MDS-UPDRS Part III is administered
- Administered by
- A clinician or trained rater
- Time to administer
- About 30 minutes for all four parts. No separate published figure for Part III.
- Equipment
- Pen and paper, and a chair the person can rise from
- Cost
- Free to take here.
- Published by
- International Parkinson and Movement Disorder Society
- Permission
- Required for each use, through the permission request form at movementdisorders.org
- Training required
- The Movement Disorder Society runs a certificate program for raters
- Age range
- Adults
- Available languages
- Official translations in more than 25 languages
Which conditions is MDS-UPDRS Part III used for?
Related instruments
- MDS-UPDRS Part IIThe same motor symptoms as the person reports them over the past week
- MDS-UPDRS Part IVDyskinesias and fluctuations, the reason an ON score and an OFF score differ
- Essential Tremor Rating Assessment Scale (TETRAS)Tremor in more detail, when the diagnosis is essential tremor rather than Parkinson's
- Parkinson's Disease Questionnaire (PDQ-39)Quality of life, which the motor examination does not capture
MDS-UPDRS Part III questions, answered
How is MDS-UPDRS Part III scored?
The examiner rates 18 items, but most of them are scored separately for each side of the body or each limb, which produces 33 numbers. Each is rated 0 to 4, where 0 is normal and 4 is severe. The 23 non-tremor scores, items 3.1 to 3.14, run from 0 to 92. The 10 tremor scores, items 3.15a to 3.18, run from 0 to 40. Added together the Part III total runs from 0 to 132.
What is a high MDS-UPDRS Part III score?
A 2015 study of 452 people with Parkinson's put 59 and above in the severe band, 33 to 58 in the moderate band, and 32 or less in the mild band. Those numbers are a description of where someone sits in the population studied, not a threshold for any decision, and they only mean anything alongside the medication state the score was taken in.
How much change in MDS-UPDRS Part III counts as meaningful?
About 3 points of improvement or about 5 points of worsening. In 728 paired assessments across 260 people, the smallest change clinicians judged clinically relevant was 3.25 points for improvement and 4.63 points for worsening. The two thresholds are not symmetrical, so a 4-point improvement and a 4-point decline are not the same size of event.
Does medication state change the MDS-UPDRS Part III score?
Yes, and it is the single biggest source of confusion about this number. The examination captures one moment, so an ON score taken an hour after a levodopa dose and an OFF score taken before the first dose of the day can differ substantially in the same person on the same morning. The state is recorded alongside the score, and ON and OFF scores are compared with like.
Who can administer MDS-UPDRS Part III?
A clinician or trained rater. Unlike Parts I and II, it cannot be self-completed, because it involves examining rigidity, gait, and postural stability directly. The International Parkinson and Movement Disorder Society runs a certificate program that trains and tests raters, and clinical trials generally require it.
Where does the official MDS-UPDRS Part III form come from?
From the International Parkinson and Movement Disorder Society, which holds the copyright and publishes the form at movementdisorders.org. Anyone administering it themselves requests permission through the form on that site. This page describes what Part III examines rather than reproducing the licensed form.
Evidence, psychometrics and provenance
Part III is one of the four parts of the MDS-UPDRS, published in 2008 by Goetz and colleagues for the International Parkinson and Movement Disorder Society. It is the most used single measure in Parkinson’s motor trials, which is why it is also the part with the most independent work behind it, including a dedicated study of how much change counts.
- Test-retest reliability
- ICC above 0.85 for each part's total (Martinez-Martin et al., 2013)
- Factor structure
- Comparative fit index above 0.90 for Part III (Goetz et al., 2008)
- Meaningful improvement
- 3.25 points, from 728 paired assessments (Horvath et al., 2015)
- Meaningful worsening
- 4.63 points, from the same cohort (Horvath et al., 2015)
References
- 1.Goetz CG, Tilley BC, Shaftman SR, et al. Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS): scale presentation and clinimetric testing results. Mov Disord. 2008;23(15):2129-2170.
- 2.Martinez-Martin P, Rodriguez-Blazquez C, Alvarez-Sanchez M, et al. Expanded and independent validation of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). J Neurol. 2013;260(1):228-236.
- 3.Martinez-Martin P, Rodriguez-Blazquez C, Alvarez M, et al. Parkinson's disease severity levels and MDS-Unified Parkinson's Disease Rating Scale. Parkinsonism Relat Disord. 2015;21(1):50-54.
- 4.Horvath K, Aschermann Z, Acs P, et al. Minimal clinically important difference on the Motor Examination part of MDS-UPDRS. Parkinsonism Relat Disord. 2015;21(12):1421-1426.
- 5.Luo S, Zou H, Goetz CG, et al. Novel approach to Movement Disorder Society-Unified Parkinson's Disease Rating Scale monitoring in clinical trials: longitudinal item response theory models. Mov Disord Clin Pract. 2021;8(7):1083-1091. (Source for the non-tremor and tremor item split and their score ranges.)
- 6.International Parkinson and Movement Disorder Society. MDS-UPDRS: rating scale, permission request form, translations, and rater certificate program. movementdisorders.org.
- 7.Shirley Ryan AbilityLab. Rehabilitation Measures Database: MDS-UPDRS. Administration, cost, and per-part internal consistency, citing Goetz et al. (2008).
This assessment uses a validated instrument and is reference information, not a diagnosis. The MDS-UPDRS is copyright the International Parkinson and Movement Disorder Society. This page describes the scale and does not reproduce it. Permission for each use is requested at movementdisorders.org.