What is the mechanism behind sexually induced headaches?

The Mechanism Behind Sexually Induced Headaches

Sexually induced headaches are primarily caused by rapid changes in cerebral blood flow, intracranial pressure, and autonomic nervous system activation during sexual activity, particularly at orgasm. 1

Types and Presentation

• Primary headache associated with sexual activity (PHASA) can present in two main forms:

  • Pre-orgasmic: Dull, bilateral headache that gradually intensifies with increasing sexual excitement 1
  • Orgasmic: Sudden, explosive "thunderclap" headache occurring at or around orgasm, primarily occipital, diffuse, and bilateral in location 1

• Sexual activity is comparable to moderate-intensity exercise, requiring 2-3 METs during pre-orgasmic stage and 3-4 METs during orgasmic stage (equivalent to walking at 3-4 mph) 2

Pathophysiological Mechanisms

• Vascular mechanism: Rapid changes in blood pressure and heart rate during sexual arousal and orgasm lead to cerebral vasodilation or vasoconstriction 1

• Mechanical factors: Increased intracranial pressure due to Valsalva maneuver during sexual activity, particularly at orgasm 3

• Autonomic dysregulation: Sudden activation of the sympathetic nervous system during sexual excitement and orgasm 3

• Trigemino-vascular system activation: Both mechanical factors (increased intracranial pressure) and chemical factors (oxidative stress, inflammatory parameters) may trigger the trigemino-vascular system, causing headache 3

Risk Factors and Associations

• Comorbidity with other primary headache disorders, particularly migraine, tension-type headache, and exertional headache 1

• Hypertension is a common comorbidity that may exacerbate the vascular component 1

• History of atopic disease has been identified as a risk factor in some cases 3

Differential Diagnosis

• Critical to rule out secondary causes of headache during sexual activity, including:

  • Subarachnoid hemorrhage 4
  • Reversible cerebral vasoconstriction syndrome (RCVS) 1
  • Cerebral artery dissection (including basilar artery dissection) 4
  • Cerebral venous thrombosis 1
  • Intracranial aneurysm 4

• "Red flags" that warrant immediate neuroimaging include:

  • Abrupt onset of severe headache
  • Marked change in headache pattern
  • Headache that awakens patient from sleep
  • Rapidly increasing frequency of headache
  • Focal neurologic signs or symptoms 3

Diagnostic Approach

• Thorough history to distinguish from other headache types and identify potential secondary causes 1

• Neuroimaging is essential to rule out potentially life-threatening conditions, particularly when presenting as a thunderclap headache 1

• Questions to ask patients should include timing of headache in relation to sexual activity, character and location of pain, associated symptoms, and response to previous treatments 3

Treatment Options

• Preventive approaches:

  • Preemptive treatment 30 minutes before anticipated sexual activity:
    • Indomethacin (most commonly used) 1
    • Triptans have shown efficacy as short-term prophylaxis in some patients 5

• Prophylactic treatment for recurrent cases:

  • Beta-blockers (propranolol) have shown dramatic improvement at doses as low as 40 mg/day 6
  • Calcium channel blockers (diltiazem) have been successful in treating sexual headaches 7
  • Topiramate may be considered for prophylaxis 1

• Acute treatment for prolonged attacks:

  • Triptans may be effective for shortening attacks that last >2 hours (after excluding subarachnoid hemorrhage) 5

Prognosis and Course

• PHASA typically presents as discrete, recurrent events with bouts that may:

  • Self-resolve spontaneously
  • Relapse and remit
  • Continue chronically in some patients 1

• Most cases have a benign course, but patients should be educated about the importance of seeking immediate medical attention if the pattern or severity changes 1

Clinical Pearls and Pitfalls

• Never assume sexual headache is benign without appropriate workup to exclude secondary causes, especially on first presentation 4

• Consider the relationship between exercise capacity and sexual activity - patients with cardiovascular disease should ensure they can achieve 3-5 METs without symptoms before resuming sexual activity 2

• Patients should be advised to report any symptoms experienced during sexual activity (chest pain, shortness of breath) as these may indicate underlying cardiovascular issues 2