How is the Guillain-Barré Syndrome (GBS) disability score calculated?

GBS Disability Score Calculation

The GBS disability score is a 7-point ordinal scale (0-6) that assesses functional motor disability based on the patient's ability to walk and perform activities of daily living, with 0 being healthy and 6 being death. 1, 2

The Scale

The GBS disability score grades are:

• Grade 0: Healthy state 1
• Grade 1: Minor symptoms and capable of running 1
• Grade 2: Able to walk ≥5 meters without assistance but unable to run 1
• Grade 3: Able to walk ≥5 meters with assistance (walker or stick) 1
• Grade 4: Bedridden or chair-bound (unable to walk ≥5 meters even with assistance) 1
• Grade 5: Requiring assisted ventilation for at least part of the day 1
• Grade 6: Death 1

Clinical Application

The score is determined by direct clinical assessment of the patient's current functional motor status, not by calculation from other parameters. 1, 2

Key Assessment Points:

• Walking ability is the primary determinant—specifically whether the patient can walk 5 meters independently, with assistance, or not at all 1
• Ventilatory status automatically places patients at grade 5 if mechanical ventilation is required, regardless of walking ability 1
• The score is typically assessed at multiple time points: admission, nadir (peak disability), 2 weeks, and at follow-up intervals (1,3,6 months) 3, 4

Prognostic Significance

A GBS disability score ≥3 at presentation (unable to walk independently) is the threshold used in most treatment trials to identify patients requiring immunotherapy. 1

Specific Prognostic Applications:

• Score at 2 weeks after entry is a key predictor in the Erasmus GBS Outcome Score (EGOS) for predicting inability to walk at 6 months 3
• Score at nadir strongly predicts recovery—lower scores at nadir correlate with better recovery to independent walking 4
• Score at admission helps stratify patients for monitoring intensity and treatment decisions 4

Important Clinical Caveats

The GBS disability score focuses exclusively on motor function and does not capture sensory symptoms, pain, fatigue, or autonomic dysfunction—all of which significantly impact patient outcomes and quality of life. 1

• Approximately 35-40% of patients experience persistent pain, 60-80% have fatigue, and 6-7% develop anxiety or depression despite favorable motor recovery 1
• Alternative outcome measures like the Rasch-built Overall Disability Score (RODS), Overall Neuropathy Limitations Scale (ONLS), and Fatigue Severity Scale (FSS) provide more comprehensive assessment but are more complex 1
• The score's simplicity makes it practical for bedside use and clinical trials, but clinicians should recognize its limitations in capturing the full disease burden 1