What is the treatment for Trigeminal Autonomic Cephalgia (TAC)?

Treatment of Trigeminal Autonomic Cephalalgias (TACs)

The treatment for trigeminal autonomic cephalalgias varies by specific subtype, with first-line treatments being verapamil for cluster headache, indomethacin for paroxysmal hemicrania, and lamotrigine for SUNCT/SUNA syndrome. 1

Classification and Diagnosis

TACs are a group of primary headache disorders characterized by:

• Unilateral pain in the trigeminal distribution
• Ipsilateral cranial autonomic features (tearing, conjunctival injection, rhinorrhea, etc.)
• Different attack durations and frequencies

The main TAC subtypes include:

1. Cluster headache (most common)
2. Paroxysmal hemicrania
3. SUNCT (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing)
4. SUNA (Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic symptoms)
5. Hemicrania continua

Treatment by TAC Subtype

1. Cluster Headache

Acute Treatment:

• 100% oxygen inhalation (high flow, 12-15 L/min via non-rebreather mask for 15-20 minutes)
• Subcutaneous sumatriptan 6mg (first-line injectable treatment)
• Second-line options: nasal sumatriptan 20mg or zolmitriptan 5mg 1

Bridge Therapy (short-term prevention):

• Corticosteroids: Oral prednisone 60-100mg/day or IV methylprednisolone 250-500mg/day for 5 days with tapering 2, 1

Long-term Prevention:

• Verapamil (at least 240mg/day, often higher doses required) - first-line preventive
• Alternative preventives:
  • Lithium carbonate (800-1600mg/day)
  • Topiramate (100-200mg/day)
  • Methylergonovine (0.4-1.2mg/day) where available 2, 1

Refractory Cases:

• Neurostimulation techniques (occipital nerve stimulation)
• Deep brain stimulation of posterior hypothalamus in specialized centers 2

2. Paroxysmal Hemicrania

• Indomethacin (75-150mg/day) is the definitive treatment and diagnostic test 1, 3
• Complete response to indomethacin is considered pathognomonic

3. SUNCT/SUNA

• Lamotrigine (100-300mg/day) is the preventive drug of choice 1
• Alternative options:
  • Gabapentin (800-2700mg/day)
  • Topiramate (50-300mg/day)
  • Carbamazepine (200-1600mg/day)
• For acute exacerbations: IV lidocaine (1-4mg/kg/hour) under medical supervision 1

4. Hemicrania Continua

• Indomethacin (75-225mg/day) is the definitive treatment 3
• Complete response to indomethacin is diagnostic

Treatment Challenges and Considerations

• MRI brain imaging is recommended to exclude secondary causes 4
• Many TAC patients require preventive treatment due to the frequency and severity of attacks 2
• Medication overuse should be monitored, especially with frequent acute treatments
• Side effect monitoring is crucial:
  • Verapamil: cardiac conduction abnormalities (ECG monitoring recommended)
  • Indomethacin: gastrointestinal effects, renal effects
  • Lamotrigine: skin rash (requires slow titration)

Special Considerations

• For SUNCT/SUNA, there are currently no RCTs or large cohort data, but anticonvulsants such as lamotrigine have shown effectiveness 4
• The British Journal of Anaesthesia notes that early neurosurgical consultation is important when medications fail or side effects become intolerable 4
• For refractory cases, neuromodulation techniques are emerging as alternative options 3

Pitfalls to Avoid

• Misdiagnosis of TACs as trigeminal neuralgia or migraine
• Failure to recognize indomethacin-responsive headaches (paroxysmal hemicrania and hemicrania continua)
• Inadequate dosing of preventive medications (especially verapamil for cluster headache)
• Delayed referral for specialized treatments in refractory cases
• Not considering bridge therapy during initiation of preventive treatment

The treatment approach should be guided by the specific TAC subtype, attack frequency, and patient response to therapy, with regular monitoring for efficacy and side effects.