What are the causes and prevention strategies for pure menstrual migraines?

Pure Menstrual Migraine: Causes and Prevention Strategies

Pure menstrual migraines are primarily caused by estrogen withdrawal during the menstrual cycle and can be effectively prevented using hormonal therapies, NSAIDs, or triptans started before menses, with transdermal estrogen being particularly effective for maintaining stable hormone levels. 1

Causes of Pure Menstrual Migraine

Pure menstrual migraine (PMM) occurs exclusively around menses and has distinct pathophysiological mechanisms:

• Hormonal Fluctuations: The primary trigger is the natural decline in estrogen levels that occurs just before menstruation 1, 2
• Prostaglandin Release: Increased prostaglandin production during menstruation contributes to migraine pathophysiology 3
• Predictable Pattern: Unlike other migraine types, PMM follows a predictable pattern aligned with regular menstrual cycles 2

Prevention Strategies

Hormonal Interventions

1. Transdermal Estrogen:

   • Highly effective when started just before menstruation
   • Provides sustained low-level estrogen to prevent the sharp decline that triggers migraines 1, 3
   • Apply patches 2-3 days before expected menses and continue through the vulnerable period

2. Progestin-Only Contraceptives:

   • Levonorgestrel IUD (Mirena): Recommended by ACOG as a preferred option for menstrual migraine prevention with >99% effectiveness 1
   • Etonogestrel Implant (Nexplanon): Highly effective (>99%) option that requires no daily compliance 1
   • Depot Medroxyprogesterone Acetate (DMPA): May cause amenorrhea which could benefit migraine control 1

3. Combined Hormonal Contraceptives:

   • Extended or continuous regimens may be considered for better migraine control 1
   • CAUTION: Contraindicated in women with migraine with aura due to significantly increased stroke risk 1
   • Only appropriate for women with migraine without aura 1

Pharmacological Approaches

1. NSAIDs:

   • Start 1-2 days before expected menses
   • Naproxen or naproxen sodium has shown modest but statistically significant effects 4, 5
   • Works by inhibiting prostaglandin synthesis

2. Triptans for Mini-Prophylaxis:

   • Frovatriptan appears to be the triptan of choice based on overall efficacy 6
   • Other effective options include sumatriptan, zolmitriptan, and naratriptan 6
   • Begin 2 days before expected headache and continue through vulnerable period

3. Standard Migraine Preventives (for severe cases):

   • Beta-blockers: Propranolol 120-240 mg daily has consistent evidence for efficacy 4, 1
   • Topiramate: 50-100mg daily, particularly effective for chronic migraine 1
   • Amitriptyline: 10-100mg at night 1

4. Supplements and Herbal Remedies:

   • Magnesium: Has shown benefits over placebo in multiple studies 4
   • Vitamin B2 (Riboflavin): High-dose (400 mg) supplementation showed significant benefits after 3-4 months 4
   • Feverfew: Multiple trials suggest effectiveness with significant reduction in pain intensity and associated symptoms 4

Implementation Algorithm

1. Determine if true PMM: Confirm attacks occur exclusively with menstruation (±2 days before/after onset) for at least 2 out of 3 menstrual cycles

2. First-line approach:

   • For women not requiring contraception: Perimenstrual NSAIDs or triptan mini-prophylaxis
   • For women requiring contraception: Consider progestin-only methods like Levonorgestrel IUD

3. If first-line fails:

   • Try transdermal estrogen therapy during the perimenstrual period
   • Consider combination of NSAID plus triptan mini-prophylaxis

4. For refractory cases:

   • Implement continuous hormonal therapy to eliminate menstrual cycles
   • Add standard migraine preventives (beta-blockers, topiramate, or amitriptyline)

Common Pitfalls and Caveats

• Misdiagnosis: Ensure it's truly PMM rather than menstrually-related migraine (which also occurs at other times)
• Medication overuse: Risk of medication overuse headache if acute treatments are used too frequently 6
• Contraindication awareness: Combined hormonal contraceptives are contraindicated in women with migraine with aura due to stroke risk 1
• Monitoring requirements: Regular follow-up (every 2-3 months initially) is necessary to monitor changes in migraine pattern and treatment effectiveness 1
• Treatment timing: Prevention strategies must be started before the expected onset of menses to be effective

By understanding the hormonal basis of pure menstrual migraine and implementing appropriate preventive strategies, most women can achieve significant reduction in the frequency and severity of these particularly debilitating headaches.