What could be causing headaches during intercourse in an adult with a possible history of headaches or other medical conditions?

Headache During Intercourse

Immediate Evaluation Required

Any headache during sexual activity requires urgent neuroimaging with non-contrast head CT to rule out subarachnoid hemorrhage (SAH), as thunderclap headache during intercourse is a red flag requiring emergency evaluation. 1

Critical Red Flags Requiring Emergency Workup

• First or worst headache of life during sexual activity mandates immediate CT scan, as basilar artery dissection and SAH can present identically to benign primary headache associated with sexual activity (PHASA) 1, 2
• Thunderclap onset (sudden, severe headache reaching maximum intensity within seconds to minutes) requires CT within 6 hours if possible, followed by lumbar puncture with spectrophotometric analysis for xanthochromia if CT is negative 1
• Headache persisting beyond 24 hours, any neurological deficits, neck stiffness, fever, or first occurrence in patients over 40 years old all warrant immediate imaging 1
• Do not assume benign primary headache without imaging, as approximately 10-43% of SAH patients experience sentinel headaches before catastrophic rupture 1

Essential Clinical Documentation

Document the following specific features 3, 1:

• Timing: Pre-orgasmic (dull, progressive with sexual excitement) versus orgasmic (explosive, sudden at climax) 4, 5
• Location: Typically bilateral occipital or diffuse in PHASA 6, 5
• Duration: PHASA typically lasts minutes to hours (mean ~21 minutes in case series) 5
• Character: Explosive/thunderclap versus gradual build-up 4
• Associated symptoms: Nausea, vomiting, photophobia, neck stiffness, focal neurological signs 1
• History of migraine: PHASA is commonly comorbid with migraine 4

Differential Diagnosis

Life-Threatening Causes (Must Rule Out First)

• Subarachnoid hemorrhage from ruptured aneurysm 1, 2
• Basilar artery dissection (can present identically to benign PHASA) 2
• Reversible cerebral vasoconstriction syndrome (RCVS) 4
• Cerebral vasospasm 4

Benign Primary Headache Associated with Sexual Activity (PHASA)

• Lifetime prevalence 1-1.6% in general population 6
• More common in males, typically onset in third decade 5
• Two subtypes: pre-orgasmic (dull, builds with excitement) and orgasmic (explosive at climax) 4
• Self-limited episodes that may relapse and remit 4

Diagnostic Workup Algorithm

If Presenting <6 Hours from Onset

1. Non-contrast head CT immediately on high-quality scanner 1
2. If CT negative: Proceed to lumbar puncture with spectrophotometric analysis for xanthochromia 1
3. If CT and LP negative but high suspicion remains: Consider digital subtraction angiography (DSA) to diagnose or exclude cerebral aneurysm, dissection, or RCVS 1

If Presenting >6 Hours from Onset OR with Neurological Deficit

1. Non-contrast head CT immediately 1
2. Lumbar puncture mandatory if CT negative, as CT sensitivity decreases after 6 hours 1
3. CT angiography has ~97% sensitivity for ruptured aneurysms but does not directly evaluate for SAH 1

Focused Neurological Examination

Document 1:

• Focal neurological signs
• Neck stiffness and limited neck flexion
• Mental status and memory assessment
• Coordination testing
• Fundoscopic examination if available

Treatment of Confirmed PHASA (After Excluding Secondary Causes)

Acute/Preemptive Treatment

Indomethacin or triptans administered 30-60 minutes prior to sexual activity are first-line preemptive therapies 4

• NSAIDs (ibuprofen or naproxen) as early as possible during attack for mild-to-moderate headaches 7
• Triptans for moderate-to-severe attacks 7
• Add antiemetic (metoclopramide or prochlorperazine) if nausea present 7

Prophylactic Treatment

Propranolol 40 mg daily is highly effective for preventing recurrent PHASA, with dramatic improvement typically seen within 2 weeks 6

Initiate prophylactic therapy if 7:

• More than two headaches per week
• Frequent acute medication use risking medication-overuse headache

Evidence-based prophylactic options 4:

• Beta-blockers (propranolol or metoprolol) - first-line 7, 6
• Topiramate - strong evidence from randomized controlled trials 7
• Calcium channel blockers 4
• CGRP-targeted therapies may provide relief based on case reports, though no randomized controlled trials exist 4

Treatment Duration

• Maintain prophylactic treatment for 6 months, then reassess 6
• Many patients experience self-limited episodes that resolve spontaneously 4

Critical Pitfalls to Avoid

• Never discharge without imaging on first presentation of sexual activity-related headache 1, 8
• Do not rely on patient reassurance or prior similar episodes, as sentinel headaches precede catastrophic SAH 1
• Avoid opiates as routine therapy - they cause medication-overuse headaches and rebound phenomena 7
• Limit NSAID use to no more than 2 days per week to prevent medication-overuse headache 7
• Avoid ergotamine overuse - frequent use leads to medication-overuse headache 7

Discharge Instructions (After Negative Workup)

Patients must return immediately for 1:

• Worsening headache
• New neurological symptoms
• Persistent headache beyond 24 hours