Cluster Headache: Diagnosis and Treatment
The clinical presentation of severe unilateral periorbital or temporal pain with ipsilateral autonomic symptoms (runny nose, watery eyes) lasting 15-180 minutes is diagnostic of cluster headache, and first-line acute treatment consists of subcutaneous sumatriptan 6 mg or 100% oxygen at 12 L/min, with verapamil as the prophylactic agent of choice. 1
Diagnostic Criteria
The diagnosis requires five attacks meeting specific criteria 1:
- Severe unilateral pain in the orbital, supraorbital, or temporal region lasting 15-180 minutes untreated 1, 2, 3
- Attack frequency of 1-8 episodes per day during cluster periods 1, 3
- At least one ipsilateral autonomic symptom: conjunctival injection, tearing (watery eyes), nasal congestion, rhinorrhea (runny nose), eyelid edema, facial sweating, or miosis/ptosis 1, 2, 3
- Restlessness or agitation during attacks (patients pace rather than lie still, distinguishing this from migraine) 1, 3
The attacks often recur at the same time each day, with cluster periods lasting weeks to months, followed by remission periods in episodic cluster headache 2, 3.
Key Distinguishing Features from Other Headache Types
Duration differentiates cluster headache from migraine: cluster attacks last 15-180 minutes versus migraine's 4-72 hours 1. Migraine patients prefer to lie still in dark, quiet rooms with photophobia and phonophobia, while cluster headache patients are agitated and restless 1. The prominent ipsilateral autonomic symptoms are characteristic of cluster headache and typically absent in migraine 1.
Tension-type headache presents bilaterally with pressing/tightening quality and mild-to-moderate intensity, lacking the autonomic features that define cluster headache 1, 4.
Red Flags Requiring Neuroimaging
Before confirming a primary headache diagnosis, exclude secondary causes if any of the following are present 1, 4:
- Focal neurological deficits
- Atypical headache pattern
- Progressive worsening
- New neurological symptoms
- Abnormal neurological examination
- New onset after age 50 (consider giant cell arteritis) 4
MRI brain is the preferred imaging modality when neuroimaging is indicated 1.
Acute Treatment
First-Line Therapies (Level 1 Evidence)
Subcutaneous sumatriptan 6 mg provides relief within 10 minutes in 70% of patients 1. Before prescribing, screen for cardiovascular disease risk factors including hypertension, hypercholesterolemia, smoking, obesity, diabetes, and family history of coronary artery disease 1.
100% oxygen inhalation at 12 L/min demonstrates equal efficacy to sumatriptan 1, 2. This is particularly valuable for patients with cardiovascular contraindications to triptans.
Alternative Acute Therapy
Intranasal zolmitriptan 10 mg serves as an alternative when subcutaneous administration is not feasible 1, 2.
Prophylactic Treatment
First-Line Prophylaxis
Verapamil is the prophylactic drug of choice, starting at 360 mg/day 1, 2. Monitor ECG for PR interval prolongation at higher doses 1. Verapamil can be used for both episodic and chronic cluster headache 2.
Bridging Therapy
While waiting for verapamil to take effect (which may take several weeks), consider 1:
- Oral corticosteroids
- Greater occipital nerve blockade
Additional Prophylactic Options
For episodic cluster headache, galcanezumab is an option 1. However, galcanezumab is not recommended for chronic cluster headache 1.
For chronic cluster headache, consider adding lithium, topiramate, or divalproex sodium to verapamil 1.
Common Pitfalls to Avoid
Do not assume all unilateral headaches are migraines 4. The autonomic symptoms, shorter duration, and restlessness during attacks distinguish cluster headache, which requires different treatment strategies than migraine 4.
Do not miss giant cell arteritis in patients over 50 with new-onset temporal headache, as delayed diagnosis risks permanent vision loss 4.
Screen for medication-overuse headache in patients with frequent headache days, as this perpetuates the headache cycle and requires medication withdrawal 4.