Overview

Cluster headaches are a type of trigeminal autonomic cephalalgia. It is characterised by a severe unilateral headache and ipsilateral trigeminal autonomic activation, usually happening in episodes or clusters lasting from 15 minutes to 3 hours. It is one of the most painful conditions known to man.

Cluster headaches can be:

  • Episodic (80% of cases) – attacks in periods lasting from 7 days to 1 year separated by pain-free periods of at least a month
  • Chronic (20% of cases) – attacks occurring for >1 year without remission or pain-free periods that last <1 month

Epidemiology

  • More common in men
  • Peak incidence in 20-40 years of age
  • Associated with:

Risk Factors

  • Family history
  • Male sex
  • Smoking
  • Alcohol consumption
  • Head injury

Presentation

Patients usually have severe pain that comes on rapidly, lasting from 15 minutes to 3 hours. Features are:

  • Pain that classically occurs around or behind the eye, temple, or forehead
  • Pain that is described as sharp and stabbing
  • Agitated and restless during attacks
  • Associated autonomic features such as:
    • Eye redness, watering, lid swelling/drooping
    • Nasal congestion/runniness
    • Facial or forehead sweating
    • Miosis/ptosis
  • The clusters may happen at the same time daily

Differential Diagnoses

Migraine

  • Headaches are usually unilateral and pulsatile (throbbing)
  • Attacks usually last at least 4 hours without treatment
  • There may be associated aura/photophobia/phonophobia
  • Autonomic features are usually not seen

Paroxysmal hemicrania

  • Presentation is very similar to cluster headaches
  • Unlike cluster headaches, it is more common in women than men
  • Unlike cluster headaches, it completely responds to indomethacin

Referral

  • Refer/discuss patients with a neurologist or GP with a special interest in headaches
  • Urgently refer to secondary care if patients have features of a secondary headache

Diagnostic Criteria

International Classification of Headache Disorders (ICHD)

Cluster headaches are diagnosed by a specialist. There must be:

  • ≥5 attacks of severe/very severe unilateral pain lasting 15-180 minutes
    • Headache associated with one of:
    • Ipsilateral conjunctival injection and/or lacrimation
    • Nasal congestion and/or rhinorrhoea
    • Fullness in the ear
    • Miosis and/or ptosis
    • Restlessness and/or agitation
  • Attacks occur between one every other day and 8 per day for more than half the time the disorder is active
  • Another diagnosis cannot better explain the symptoms

Management

Acute management

  • 1st-line: 100% O2 and subcutaneous triptan (sumatriptan)

Prophylaxis

  • 1st-line: verapamil

Monitoring and Patient Advice

Monitoring

  • All patients with suspected cluster headaches should be reviewed by a neurologist
  • Patients are generally followed up annually

Patient Advice

  • Patients should avoid triggers – smoking/alcohol consumption and should be helped with these
  • Patients should be educated on the risk of medication overuse headaches
  • Patients should be encouraged to keep a headache diary

Complications and Prognosis

Complications

  • Psychosocial problems e.g. depression
  • Reduced level of functioning and quality of life

Prognosis

  • Periods of remission tend to increase as people get older
  • Chronic cluster headaches can become episodic cluster headaches and vice versa

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