The Sunnybrook Facial Grading System (SB-FGS) is a widely recognized and comprehensive tool used to objectively assess and grade the severity of facial nerve paralysis, offering a standardized method to track patient recovery or deterioration over time.
Understanding the Sunnybrook Facial Grading System
The SB-FGS provides a structured approach to evaluate facial function by breaking it down into distinct components, making it easier to quantify the impact of conditions like Bell's Palsy or other facial nerve injuries. Its design allows clinicians to generate a numerical score that reflects the overall status of facial nerve recovery.
Components of the System
The system is composed of 13 distinct items that are carefully observed and scored. These items are categorized into three main areas:
- Resting Symmetry (3 items): This section evaluates the appearance of the face when completely at rest, assessing for any asymmetry. Examples include the resting position of the eyebrow, eye opening, and corner of the mouth.
- Voluntary Movement (5 items): This part assesses the patient's ability to perform specific facial expressions and movements on command. These typically include:
- Eye closure (gentle and forced)
- Brow lift
- Nasal flare
- Smiling
- Lip pucker/snarl
Each movement is graded based on the extent and quality of movement compared to the unaffected side.
- Synkinesis (5 items): Synkinesis refers to involuntary facial movements that occur concurrently with voluntary movements. For example, when a patient attempts to smile, their eye might involuntarily close. This section identifies and quantifies the presence and severity of such uncoordinated movements.
Scoring Methodology
Scoring in the Sunnybrook system involves assigning values based on categorical answering scales for each of the 13 items. These individual scores are then used to calculate various overall metrics, providing a detailed picture of facial nerve function:
- SB Composite Score: This is the primary overall score, ranging from 0 to 100. A higher composite score indicates better facial nerve function and symmetry, with 100 representing normal function.
- Subscores: To provide more granular insight, specific subscores are also calculated:
- Resting Symmetry Subscore: Ranges from 0 to 20. This subscore specifically quantifies the symmetry of the face at rest.
- Voluntary Movement Subscore: Ranges from 20 to 100. This reflects the extent and quality of volitional facial movements.
- Synkinesis Subscore: Ranges from 0 to 15. This score quantifies the presence and severity of synkinetic movements. A lower synkinesis score indicates less involuntary movement and better recovery.
Summary of Scoring Ranges:
| Score Type | Range (Minimum - Maximum) | Interpretation (Higher Score) |
|---|---|---|
| SB Composite Score | 0 - 100 | Better overall function |
| Resting Symmetry | 0 - 20 | Better resting symmetry |
| Voluntary Movement | 20 - 100 | Better voluntary movement |
| Synkinesis | 0 - 15 | Worse (indicates more synkinesis) |
Note: For the Synkinesis subscore, a higher number indicates greater severity of synkinesis, meaning less favorable recovery in this aspect.
Practical Application
To effectively use the Sunnybrook Facial Grading System, a clinician typically follows these steps:
- Patient Preparation: Ensure the patient is relaxed and in a well-lit environment. Explain the assessment process clearly.
- Observation at Rest: Carefully observe the patient's face for any asymmetry without them making any expressions. Score the 3 resting symmetry items.
- Voluntary Movement Assessment: Instruct the patient to perform specific facial movements on command (e.g., "Please close your eyes gently," "Now, smile as wide as you can"). Observe and score the 5 voluntary movement items, comparing the affected side to the unaffected side.
- Synkinesis Assessment: While the patient performs voluntary movements, specifically look for any accompanying involuntary movements. Score the 5 synkinesis items based on their presence and severity.
- Score Calculation: Based on the individual item scores, calculate the composite score and the three subscores. This often involves a standardized formula or specialized software.
- Documentation and Interpretation: Record the scores accurately. These scores provide an objective measure that can be used to:
- Monitor progress: Track changes in facial function over time, especially during rehabilitation.
- Guide treatment: Inform therapeutic decisions and adjustments.
- Communicate effectively: Provide a standardized language for healthcare professionals to discuss patient status.
- Research: Facilitate research on facial nerve paralysis outcomes and interventions.
By providing a detailed and quantifiable assessment, the Sunnybrook Facial Grading System aids healthcare professionals in understanding the nuances of facial nerve recovery and optimizing patient care. For more information on facial nerve disorders and their assessment, you can consult reputable medical resources like the National Institute of Neurological Disorders and Stroke.
