What are the symptoms and treatment options for cluster headaches?

Cluster Headache: Clinical Presentation and Management

Diagnostic Criteria

Cluster headache requires five attacks with severe unilateral orbital, supraorbital, or temporal pain lasting 15-180 minutes, occurring 1-8 times daily, accompanied by at least one ipsilateral autonomic symptom. 1, 2

Pain Characteristics

• Severe to very severe intensity with strictly unilateral location 1, 2
• Duration: 15-180 minutes (untreated) 1
• Frequency: 1-8 attacks per day during active periods 1
• Patients exhibit restlessness and agitation during attacks, often pacing rather than lying still (unlike migraine) 3, 4

Ipsilateral Autonomic Features (at least one required)

• Lacrimation (tearing) 1
• Conjunctival injection 1, 2
• Nasal congestion or rhinorrhea 1
• Forehead and facial sweating 1
• Ptosis (eyelid drooping) 1
• Miosis (pupil constriction) 1
• Eyelid edema 1

Pattern Recognition

• Episodic cluster headache: Attacks occur in clusters (bouts) lasting weeks to months, followed by remission periods 3, 4
• Chronic cluster headache: Attacks persist for >1 year without remission 4, 5
• Circadian and circannual periodicity: Attacks often occur at fixed times of day or night 5, 6

Key Distinguishing Features from Other Headaches

Versus Migraine

• Shorter duration: 15-180 minutes (cluster) vs. 4-72 hours (migraine) 2
• Patient behavior: Restless/pacing (cluster) vs. lying still in dark room (migraine) 2
• Autonomic symptoms: Prominent ipsilateral features (cluster) vs. photophobia/phonophobia/nausea (migraine) 2
• Pain quality: Not typically throbbing or pulsating like migraine 1

Versus Tension-Type Headache

• Location: Strictly unilateral (cluster) vs. bilateral (tension) 1
• Intensity: Severe/very severe (cluster) vs. mild-moderate (tension) 1
• Quality: Not pressing/tightening like tension headache 1
• Autonomic features: Present (cluster) vs. absent (tension) 2

Common Triggers

• Alcohol consumption during active cluster periods 3
• Nitroglycerin and nitrate-containing foods 3
• Strong odors 3

Acute Attack Treatment

First-line therapy consists of subcutaneous sumatriptan 6 mg OR 100% oxygen inhalation at 12 L/min, both achieving relief in approximately 70% of patients within 10-15 minutes. 2, 7

Subcutaneous Sumatriptan

• Dose: 6 mg subcutaneously 1, 2, 7
• Efficacy: 49% pain-free at 10 minutes, 74-75% relief at 15 minutes 7
• Onset: <10 minutes 7
• Cardiovascular screening required: Assess for CAD risk factors (hypertension, hypercholesterolemia, smoking, obesity, diabetes, family history) before prescribing 2
• Can be self-administered via autoinjector 7

High-Flow Oxygen

• Dose: 100% oxygen at 12 L/min 2, 8, 4
• Efficacy: Equal to sumatriptan 2
• Duration: Inhale for 15 minutes 4

Alternative Acute Therapies

• Intranasal zolmitriptan 10 mg: Effective alternative when subcutaneous route not feasible 1, 2
• Intranasal sumatriptan: Less effective than subcutaneous but available option 8

Prophylactic Treatment

First-Line Prophylaxis

Verapamil is the prophylactic drug of choice, starting at 360 mg/day, with clinical practice often requiring 480-720 mg/day. 2, 8, 4

• Starting dose: 360 mg/day 2, 4
• Typical effective dose: 480-720 mg/day (double the cardiology dose) 4
• ECG monitoring required: Check PR interval at higher doses for heart block 2, 4
• Insufficient evidence for or against verapamil per recent systematic review, but remains standard of care based on clinical experience 1

Episodic Cluster Headache Prophylaxis

• Galcanezumab: Recommended for episodic cluster headache prevention 1, 2
• NOT recommended for chronic cluster headache 1

Bridging/Transitional Therapy

Use oral corticosteroids OR greater occipital nerve blockade while waiting for verapamil to take effect. 2, 4, 5

• Oral prednisolone: Short-term use at cluster onset 8, 4
• Greater occipital nerve block: Pharmacological blockade as alternative 2, 8, 4

Add-On Prophylactic Options for Refractory Cases

• Lithium: Particularly for chronic cluster headache 8, 4, 5
• Topiramate: Possibly effective 8, 4, 5
• Divalproex sodium: Add-on option 2, 8, 4
• Melatonin: Possibly effective 8, 3
• Gabapentin: May be useful 8, 5

Non-Pharmacologic Treatment

Neuromodulation

• Noninvasive vagus nerve stimulation: Suggested for acute treatment of episodic cluster headache 1
• Occipital nerve stimulation: Option for drug-refractory chronic cluster headache 4, 5, 6
• Deep brain stimulation of hypothalamus: Reserved for medically refractory chronic cases 4, 5, 6
• Sphenopalatine ganglion stimulator: NOT recommended (suggested against) 1

Critical Clinical Pitfalls

Diagnostic Delay

• Average diagnostic delay: 7 years due to misdiagnosis as migraine or sinusitis 4
• The combination of very severe unilateral orbital pain lasting <3 hours with ipsilateral autonomic symptoms should immediately trigger consideration of cluster headache 4, 5

Red Flags Requiring Neuroimaging

• MRI brain is mandatory at initial presentation to exclude structural mimics 5
• Neuroimaging indicated for: focal neurological deficits, atypical headache pattern, progressive worsening, new neurological symptoms, abnormal neurological examination 2

Treatment Timing

• Acute treatments must be administered immediately due to rapid onset and short duration of attacks 6
• Oral medications are generally too slow for acute cluster headache attacks 6