Input the pain characteristics and MRI findings to differentiate classical trigeminal neuralgia from secondary or idiopathic causes.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Differentiating the "worst pain known to humanity" to ensure the correct surgical intervention is selected.
Gatekeeping patients before offering Microvascular Decompression (MVD).
Section 2
Literature
Development
The ICHD-3 criteria mathematically split TN based on MRI findings. Previously, surgeons would blindly open the posterior fossa of anyone with facial pain hoping to find a compressing vessel. The classification now formally separates "Classical TN" (vessel visible) from "Idiopathic TN" (no vessel).
Section 3
Pearls/Pitfalls
The Danger of Idiopathic TN
If the MRI shows absolutely no compressing vessel, the patient has Idiopathic TN. Performing an MVD on these patients results in the surgeon desperately hunting for a vessel that isn't there, usually resulting in them "combing" the nerve to intentionally inflict trauma. These patients are far better served by a percutaneous balloon compression or Gamma Knife.
Section 4
Evidence Appraisal
Primary Reference
Trigeminal neuralgia: New classification and diagnostic grading for practice and research
