Other trigeminal autonomic cephalgias (TAC), intractable

This code signifies a severe, persistent, and difficult-to-treat form of trigeminal autonomic cephalgia (TAC) that does not respond adequately to standard therapies. TACs are a group of primary headache disorders characterized by unilateral head pain accompanied by ipsilateral autonomic symptoms such as conjunctival injection, lacrimation, nasal congestion, rhinorrhea, forehead and facial sweating, miosis, and ptosis. This specific code is for TACs other than cluster headache, paroxysmal hemicrania, or SUNCT/SUNA.

Use this code when documentation clearly indicates a diagnosis of a trigeminal autonomic cephalgia (e.g., hemicrania continua, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing [SUNCT], or short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms [SUNA]) that is explicitly stated as "intractable" or "refractory to treatment." The patient's medical record should detail failed attempts at various therapeutic interventions.

• Ensure the documentation specifies "intractable" or "refractory" for the TAC; otherwise, a non-intractable code should be used.
• Distinguish from other specific TACs like cluster headache (G44.00x-G44.02x) or paroxysmal hemicrania (G44.03x), which have their own codes.
• Always review the full clinical picture to confirm the specific type of TAC and its intractability.