Cluster headaches

Epidemiology & Definition

• Cluster headaches are one of the most painful types of headache.
• More common in men than women, often starting between ages 20 and 40.

Clinical Presentation

• Characterised by recurrent, severe, unilateral (around the eye) headache attacks.
• Episodes typically last between 15 minutes and 3 hours.
• Associated symptoms include:
  • Conjunctival injection (redness).
  • Nasal congestion or rhinorrhoea.
  • Forehead and facial sweating.
  • Miosis (pupil constriction) or ptosis (drooping eyelid).
  • Restlessness or agitation.
• Attack frequency can range from one every other day to up to eight times per day.
• Typically, episodes occur in clusters or bouts lasting several weeks or months, separated by remission periods.

Aetiology & Pathophysiology

• Exact cause is unclear but may be related to abnormalities in the hypothalamus.
• Triggers can include alcohol, strong smells, and changes in sleep pattern.

Investigations

• Diagnosis is largely clinical based on characteristic symptoms.
• Neuroimaging (MRI) may be done to rule out other causes if presentation is atypical.

Management

• Acute attacks: High-flow oxygen and sumatriptan injections or nasal spray.
• Prevention: Verapamil is the mainstay of prophylaxis. Other options include lithium and corticosteroids.

Prognosis

• Condition is chronic with acute episodic bouts. However, pain-free intervals can last months to years.