What is the appropriate work-up and treatment for a patient presenting with cluster headaches?

Cluster Headache Work-Up

All patients presenting with suspected cluster headache require brain MRI to exclude structural mimics before initiating treatment. 1, 2

Diagnostic Criteria

The diagnosis is clinical and based on the International Headache Society criteria 3:

• Five or more attacks with frequency of 1-8 attacks per day 3
• Severe unilateral orbital, supraorbital, or temporal pain lasting 15-180 minutes untreated 3, 4
• At least one ipsilateral autonomic feature on the same side as the pain 3:
  • Lacrimation (most common) 4
  • Conjunctival injection 4
  • Nasal congestion or rhinorrhea 4
  • Forehead/facial sweating 3
  • Miosis 3
  • Ptosis 3, 4
  • Eyelid edema 3, 4
• Sense of restlessness or agitation (patients typically pace during attacks, unlike migraine where patients prefer to lie still) 5, 2

Key Clinical Features to Elicit

Temporal pattern 1, 5:

• Attacks occur in clusters (bouts) lasting weeks to months in episodic form 1
• Chronic cluster headache: attacks occur for >1 year without remission 5
• Distinctive circadian periodicity—attacks frequently occur at night, awakening patients from sleep 1, 2
• Circannual periodicity in episodic forms 1, 2

Common triggers to identify 4:

• Alcohol consumption 4
• Nitroglycerin 4
• Foods containing nitrates 4
• Strong odors 4

Demographics 4:

• Mean age of onset: 30 years 4
• Male predominance (2-3 times more common) 4

Essential Work-Up

Neuroimaging is mandatory 1:

• Brain MRI is required to exclude structural mimics (tumors, vascular malformations, pituitary lesions) 1
• This distinguishes cluster headache from secondary causes presenting with similar symptoms 1

Baseline ECG 5:

• Required before initiating verapamil therapy 5
• Monitor PR interval with higher doses (480-720 mg/day may be needed, which is double the cardiology dose) 5

Common Pitfalls

Diagnostic delay averages 7 years 5:

• Cluster headache is frequently misdiagnosed as migraine or sinusitis 5
• The relatively short-lasting attack of severe pain in one eye with typical autonomic symptoms should immediately raise suspicion 5

Red flags requiring urgent evaluation 6, 7:

• New headache after age 50 (consider temporal arteritis, mass lesions) 7
• Abnormal neurological examination 7
• Progressive worsening pattern 7
• Fever or signs of infection 7

Referral to neurology is recommended for all cluster headache cases 7 given the complexity of management and need for specialized treatment strategies including potential neuromodulation for refractory cases 5, 8.