====== 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)