IHS has set strict criteria for TN and include the following (Singh, 2015):
• A – Paroxysmal attacks of pain lasting from a fraction of a second to 2 minutes, affecting one or more divisions of the trigeminal nerve and fulfilling B and C
• B – Pain has at least 1 of the following characteristics: 1) intense, sharp, superficial, or stabbing; or 2) precipitated from trigger areas or by trigger factors
• C – Attacks stereotyped in the individual patient
• D – No clinically evident neurological