What are the clinical features and treatment options for cluster headaches?

Clinical Features of Cluster Headache

Cluster headache is characterized by severe unilateral orbital, supraorbital, or temporal pain lasting 15-180 minutes with ipsilateral autonomic symptoms, occurring 1-8 times daily in episodic clusters. The hallmark presentation includes excruciating unilateral pain with at least one ipsilateral autonomic feature (lacrimation, conjunctival injection, nasal congestion/rhinorrhea, ptosis, eyelid edema, facial sweating, or miosis) plus a distinctive sense of restlessness or agitation. 1

Pain Characteristics

• Severity and Location: The pain is severe to very severe in intensity, strictly unilateral, and localized to the orbital, supraorbital, and/or temporal regions 2, 1
• Duration: Individual attacks last 15-180 minutes if untreated 1, 2
• Frequency: Attacks occur with remarkable frequency of 1-8 times per day, and may occur as frequently as every other day 2, 1

Autonomic Features (Ipsilateral to Pain)

• Most common symptoms include lacrimation, conjunctival injection, nasal congestion or rhinorrhea, ptosis, eyelid edema, forehead/facial sweating, and miosis 2, 1
• At least one ipsilateral autonomic symptom must be present for diagnosis 1
• These autonomic features are robust and distinctive, helping differentiate cluster headache from other primary headache disorders 3

Behavioral Features

• Restlessness and agitation are pathognomonic features that distinguish cluster headache from migraine 2, 4
• Patients typically pace, rock, or exhibit motor restlessness during attacks, in stark contrast to migraine patients who prefer to lie still in a dark, quiet room 1

Temporal Patterns

• Episodic cluster headache (ECH): Attacks occur in clusters (bouts) lasting weeks to months, separated by remission periods 4, 2
• Chronic cluster headache (CCH): Attacks occur for more than 1 year without remissions or with remissions lasting less than 3 months 4
• Circadian and circannual periodicity: Attacks often occur at the same time of day and during the same season annually, reflecting distinctive temporal patterns 3

Common Triggers

• Alcohol is the most common trigger during active cluster periods 2
• Nitroglycerin and foods containing nitrates can precipitate attacks 2
• Strong odors may trigger attacks 2

Distinguishing from Other Headache Types

• Versus Migraine: Cluster headache has shorter duration (15-180 minutes vs. 4-72 hours), lacks photophobia/phonophobia/nausea as primary features, and patients are restless rather than still 1
• Versus Tension-type headache: Cluster headache is strictly unilateral with severe intensity and autonomic features, whereas tension headache is bilateral, pressing/tightening, mild-to-moderate, and lacks autonomic symptoms 1, 5

Epidemiology

• Prevalence: Affects less than 1% of the population (approximately 0.1%) 2, 6
• Gender: Two to three times more common in males 2
• Age of onset: Mean age of onset is 30 years 2

Diagnostic Criteria

• Five attacks meeting the pain, duration, frequency, and autonomic symptom criteria are required for diagnosis 1
• Neuroimaging (preferably MRI brain) is warranted to exclude structural mimics in patients presenting with cluster headache symptoms 3, 1

Common Pitfall

The average diagnostic delay is 7 years, with cluster headache frequently misdiagnosed as migraine or sinusitis 4. The relatively short-lasting attack of severe pain in one eye with typical autonomic symptoms should immediately raise suspicion for cluster headache and prompt referral to neurology 4, 7.