What is the workup for cluster headaches?

Workup for Cluster Headaches

The diagnostic workup for cluster headaches should include a thorough clinical assessment based on the International Headache Society criteria, with neuroimaging reserved for patients with abnormal neurological examination findings or atypical headache features. 1

Clinical Diagnostic Criteria

• Cluster headaches are characterized by severe unilateral pain in the orbital, supraorbital, and/or temporal region lasting 15-180 minutes untreated 1
• Attacks occur with a frequency of one to eight attacks per day 1
• Pain must be accompanied by at least one ipsilateral autonomic symptom:
  • Lacrimation (tearing) 1
  • Conjunctival injection (red eye) 1
  • Nasal congestion or rhinorrhea 1
  • Ptosis (drooping eyelid) 1
  • Eyelid edema 1
  • Forehead/facial sweating 1
  • Miosis (pupil constriction) 1
• Restlessness or agitation during attacks is present in approximately 68% of patients and is a distinguishing feature from migraine 2

History Elements to Assess

• Pattern of attacks: episodic (periods of headaches followed by remission) or chronic (attacks occurring for >1 year without remission or with remissions <1 month) 3
• Timing of attacks: cluster headaches often have circadian periodicity, occurring at the same time each day 4
• Potential triggers: alcohol (particularly red wine), nitrates, strong odors 2, 3
• Smoking history: 66% of cluster headache patients are current smokers 2
• Presence of migrainous features: approximately 23% report aura-like symptoms 2

Physical Examination

• Complete neurological examination to identify any abnormalities that might suggest secondary causes 1
• Assessment for autonomic features during an attack (if possible) 1
• Evaluation for signs of increased intracranial pressure 1

Neuroimaging

• Brain MRI is warranted in all patients presenting with symptoms suggestive of cluster headache to exclude structural mimics 4
• CT or MRI should be considered if any of the following are present:
  • Abnormal neurological examination 1
  • Atypical headache features not fulfilling cluster headache criteria 1
  • Headache worsened by Valsalva maneuver 1
  • Headache awakening patient from sleep 1
  • New-onset headache in older patients 1
  • Progressively worsening headache 1

Differential Diagnosis

• Migraine: typically longer duration (4-72 hours), less severe, with nausea/vomiting and photo/phonophobia 1, 5
• Tension headache: bilateral, pressing/tightening quality, mild to moderate intensity 5
• Secondary headaches: intracranial pathology, temporal arteritis, trigeminal neuralgia 5
• Other trigeminal autonomic cephalalgias: paroxysmal hemicrania, SUNCT (short-lasting unilateral neuralgiform headache with conjunctival injection and tearing) 3

Treatment Confirmation

• Response to specific treatments can help confirm diagnosis:
  • Rapid response to subcutaneous sumatriptan (effective in 81% of cluster headache patients) 6, 2
  • Response to high-flow oxygen inhalation 7
  • Response to verapamil or corticosteroids for prevention 2, 7

Common Pitfalls to Avoid

• Misdiagnosing as migraine or sinusitis due to the location and autonomic features 2
• Failing to recognize the circadian and seasonal periodicity characteristic of cluster headaches 4
• Overlooking the need for neuroimaging in patients with first presentation or atypical features 4
• Delaying effective treatment, as cluster headaches cause extreme pain and significant disability 3

Following this systematic approach to the workup of cluster headaches will help ensure accurate diagnosis and appropriate management of this severely painful condition.