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

Cluster Headache Clinical Features and Treatment

Cluster headache is characterized by severe unilateral headache attacks lasting 15-180 minutes with ipsilateral autonomic symptoms including lacrimation, nasal congestion, ptosis, miosis, eyelid edema, and facial sweating, occurring in cyclical patterns with periods of remission. 1, 2

Clinical Features

Diagnostic Criteria

• Attack pattern: Five attacks with frequency of 1-8 attacks daily 1
• Pain characteristics:
  • Severe unilateral pain in orbital, supraorbital, or temporal region
  • Duration: 15-180 minutes untreated
  • Intensity: Extremely severe (often described as one of the most painful human experiences) 3

Autonomic Symptoms (ipsilateral to pain)

• Lacrimation (tearing)
• Nasal congestion or rhinorrhea
• Ptosis (drooping eyelid)
• Miosis (pupillary constriction)
• Eyelid edema
• Forehead and facial sweating 1, 4

Behavioral Features

• Restlessness or agitation during attacks (in contrast to migraine where patients prefer to lie still) 5
• Patients may pace, rock, or bang their head against the wall due to pain intensity 4

Temporal Patterns

• Circadian rhythmicity: Attacks often occur at the same time each day, particularly at night 4
• Circannual periodicity: Attacks cluster in bouts during specific months of the year 4
• Classification:
  • Episodic: Cluster periods lasting 6-12 weeks followed by remission periods
  • Chronic: Attacks continuing for ≥1 year without remission periods lasting ≥3 months 3

Triggers

• Alcohol (most consistent dietary trigger)
• Strong odors (solvents, cigarette smoke)
• Nitroglycerin and foods containing nitrates
• Napping or changes in sleep patterns 4, 5

Epidemiology

• Prevalence: 0.5-1.0 per 1,000 people 4
• Gender distribution: 2-3 times more common in males 5
• Mean age of onset: 30 years 5
• Family history present in approximately 10% of cases 4

Treatment Options

Acute Treatment

1. High-flow oxygen therapy:

   • 100% oxygen at 12-15 L/min via non-rebreathable mask
   • Weak recommendation but highly effective and safe 1, 6

2. Triptans:

   • Subcutaneous sumatriptan 6 mg (weak recommendation) 1, 7
   • Intranasal zolmitriptan 10 mg (weak recommendation) 1
   • FDA-approved specifically for cluster headache 7
   • Efficacy demonstrated in controlled trials with pain relief in 74-75% of patients at 15 minutes 7

Preventive Treatment

1. For episodic cluster headache:

   • Galcanezumab (weak recommendation) 1, 3
   • Noninvasive vagus nerve stimulation (weak recommendation) 1

2. Other preventive options (insufficient evidence but commonly used):

   • Verapamil (most widely used preventive agent) 8, 6
   • Lithium 8, 6
   • Melatonin 5, 6
   • Topiramate 5, 6
   • Corticosteroids (short-term use for transitional therapy) 5

Refractory Cases

• Greater occipital nerve blocks 5
• Neuromodulation techniques (in experimental settings):
  • Deep brain stimulation of the hypothalamus
  • Occipital nerve stimulation 4, 8

Clinical Pearls and Pitfalls

Diagnostic Pitfalls

• Often misdiagnosed as migraine or trigeminal neuralgia, leading to years of diagnostic delay 3
• Cluster headache differs from migraine in:
  • Shorter duration (hours vs. days)
  • Presence of autonomic features
  • Restlessness during attacks (vs. preference for stillness in migraine)
  • Strict unilaterality (usually same side in each bout)

Treatment Considerations

• Acute treatments must be rapidly accessible as attacks reach full intensity quickly 8
• Oxygen therapy is underutilized despite being highly effective and having minimal side effects 3
• Alcohol should be completely avoided during cluster periods as it reliably triggers attacks 4
• Prophylactic treatment should begin at the onset of a cluster period in episodic cluster headache

Prognosis

• Disease course is unpredictable over a lifetime
• Some patients experience only one bout, while others progress from episodic to chronic form 4
• High rate of suicidal ideation due to extreme pain intensity 3

The management of cluster headache requires prompt diagnosis and aggressive treatment due to the excruciating nature of the pain. Both acute and preventive strategies should be implemented based on the frequency and pattern of attacks.