One scale to rule them all: New guidance standardizes carpal tunnel syndrome grading

Carpal tunnel syndrome (CTS) is the most common nerve compression disorder, yet clinicians have been grading its severity using a fragmented mix of 12 different systems — with no consistent standard in sight. New guidance from the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) aims to change that by recommending a single, validated tool: the Bland neurophysiologic grading scale.

The Bland scale classifies CTS into seven grades (0–6), ranging from normal to extremely severe, based on progressively worsening nerve conduction abnormalities. It was selected through a consensus-based Delphi process involving neurologists, orthopedic surgeons, and plastic surgeons, who evaluated all 12 existing scales against criteria including validity, objectivity, and clinical relevance.

Key Takeaways:

• Grades 0–2 may be managed non-operatively (splinting, steroid injections)
• Grades 3–4 warrant surgical consultation before further nerve degeneration
• Grades 5–6 should also be referred for surgery, but patients should be counseled that full recovery is less likely

Why it matters: A survey of over 1,250 clinicians found that while more than 70% routinely grade CTS severity, only 43% base it solely on nerve-conduction findings and 27% use no formal system at all. Standardizing around the Bland scale could bring consistency to electrodiagnostic labs worldwide, improve treatment decisions, and set clearer expectations for patients.