Hemikrani and
TACs

Hemicranias and Trigeminal Autonomic Cephalalgias (TACs) are a group of rare but highly distressing headache conditions characterized by unilateral pain and typical autonomic symptoms such as tearing, redness of the eye and nasal congestion.

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Unilateral headache, often accompanied by tearing, drooping eyelids, and restlessness.

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Crucial to rule out other dangerous causes.

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Correct diagnosis, preferably by a neurologist, is essential to start effective treatment and improve quality of life.

How common are hemicraniums and TACs?

The prevalence of TACs varies, but they are generally rare. Cluster headaches have a prevalence of approximately 0.1%, while paroxysmal hemicrania and SUNCT/SUNA are even rarer.

Different groups

TACs include several subgroups:

  • Cluster headache (Cluster Headache)
  • Paroxysmal hemicrania
  • Hemicrania continua
  • SUNCT (Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing)
  • SUNA (Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic symptoms)
Typical symptoms
  • Cluster headache: Intense, one-sided pain around the eye or temple, accompanied by tearing, nasal congestion and restlessness.
  • Paroxysmal hemicrania: Short-lived, intense bouts of pain often around the eye, with similar autonomic symptoms to cluster headaches.
  • Hemicrania continua: Constant, moderate to severe unilateral headache with periods of exacerbation.
  • SUNCT/SUNA: Very short, intense bouts of pain with frequent episodes per day, accompanied by tearing and redness of the eye.
What is the cause(s) of hemicrania?
  • Cluster headache: Activation of the trigeminal nerve and hypothalamus, genetic factors may play a role.
  • Paroxysmal hemicrania: Similar mechanisms to cluster headache, responds particularly well to indomethacin.
  • Hemicrania continua: Inflammatory component, also responds to indomethacin.
  • SUNCT/SUNA: Activation of the trigeminal nerve and hypothalamus, often triggered by touch or movement.
How long does a seizure last?
  • Cluster headache: Attacks last 15-180 minutes.
  • Paroxysmal hemicrania: Seizures last 2-30 minutes.
  • Hemicrania continua: Constant with exacerbations.
  • SUNCT/SUNA: Seizures last 5-240 seconds.
How often do the seizures occur?
  • Cluster headache: 1-8 attacks per day.
  • Paroxysmal hemicrania: More than 5 seizures per day.
  • Hemicrania continua: Constant with exacerbations.
  • SUNCT/SUNA: 3-200 seizures per day.
What triggers the seizures?
  • Cluster headache: Alcohol, strong odor, stress.
  • Paroxysmal hemicrania: No specific triggers known.
  • Hemicrania continua: No specific triggers known.
  • SUNCT/SUNA: Touching, talking, chewing.
How do you get the diagnoses?

As the symptoms and signs may have more dangerous causes, it is important to get a thorough assessment, preferably by a neurologist. Medical attention should be sought immediately if the symptoms or signs are new. Diagnosis is made through a combination of the patient's symptoms, seizure pattern, and response to specific treatments (such as indomethacin for paroxysmal hemicrania and hemicrania continua).

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Treatment for each group

  • Cluster headache: Sumatriptan, oxygen, verapamil for prevention.
  • Paroxysmal hemicrania: Indomethacin is the first choice.
  • Hemicrania continua: Indomethacin is the first choice.
  • SUNCT/SUNA: Lamotrigine, topiramate, gabapentin.

Prevention for each group

  • Cluster headache: Verapamil, lithium, corticosteroids.
  • Paroxysmal hemicrania: Indomethacin.
  • Hemicrania continua: Indomethacin.
  • SUNCT/SUNA: Preventive treatment with antiepileptic drugs such as lamotrigine.

The points above are taken from the European guidelines for the treatment of hemicrania and TACs.

Diagnostic criteria from ICHD-3 (summarized):

  • Cluster headache: At least five attacks, unilateral pain, accompanied by autonomic symptoms, duration 15-180 minutes.
  • Paroxysmal hemicrania: At least 20 seizures, unilateral pain, duration 2-30 minutes, responds to indomethacin.
  • Hemicrania continua: Constant unilateral headache with exacerbations, responding to indomethacin.
  • SUNCT/SUNA: At least five seizures, very brief, unilateral pain, accompanied by autonomic symptoms, duration 5-240 seconds.

These criteria help clinicians accurately identify and diagnose these complex and painful headaches. Read the criteria in detail here.