Clinical Rating Scale for Tremor (CRST)
The Clinical Rating Scale for Tremor (CRST) is a standardized instrument to assess the severity and functional impact of tremor, particularly in conditions such as Essential Tremor and Parkinson’s Disease.
It is divided into three parts:
Part A: Tremor Localization / Severity (max 32 points)
| Item | Description | Score (0–4) |
|---|---|---|
| Rest tremor | Face, lips, chin, tongue, hands | |
| Postural tremor | Arms outstretched | |
| Kinetic tremor | Spiral drawing, pouring water | |
| Intention tremor | Finger-to-nose | |
| Total Part A |
Part B: Specific Motor Tasks (max 36 points)
| Task | Description | Score (0–4) |
|---|---|---|
| Handwriting | Legibility, steadiness | |
| Drawing spiral (right) | Circle symmetry and amplitude | |
| Drawing spiral (left) | Circle symmetry and amplitude | |
| Pouring water | Between two cups | |
| Total Part B |
Part C: Functional Disabilities (max 20 points)
| Activity | Description | Score (0–4) |
|---|---|---|
| Speaking | Intelligibility | |
| Feeding | Use of utensils, spillage | |
| Hygiene | Tooth brushing, shaving | |
| Dressing | Buttons, zippers | |
| Working/social activities | Ability to perform tasks or socialize | |
| Total Part C |
Total CRST Score: 0 to 88
Interpretation:
- 0 = No tremor
- 1–20 = Mild tremor
- 21–40 = Moderate tremor
- >40 = Severe tremor impacting daily activities
Applications: Used in clinical trials and treatment evaluation, including:
- Medication response
- Deep Brain Stimulation (DBS)
- Focused Ultrasound Thalamotomy (FUS)