Menstrual related headaches generally present similarly to nonestrogen-related migraines, which are pulsatile quality, last for about one day, unilateral, associated with nausea, and can be disabling. Many individuals also report photophobia during attacks, which is relieved by lying down in a dark, quiet room. MRHs should align with the late luteal and early follicular stages of the menstrual cycle, which is a headache between two days before the onset of menses to the third day of menstrual bleeding.

Most patients have a normal neurological exam, but some can experience cutaneous allodynia, which is the perception of pain produced by a small stimulus, such as brushing hair, touching the scalp, shaving, or wearing contact lenses resulting in sensitization of central pain pathways in migraine. Additionally, patients can have tenderness or difficulty resting on the allodynic side. Although rare, some studies suggest migraines can be potential risk factors to cause Bell palsy, sensorineural hearing loss, and oculomotor cranial nerve palsies.[4]

In general radiographic images are relatively normal; however, MRI findings can sometimes have white matter hyperintensities, which have been linked to brain hyperperfusion, breakdown of the blood-brain-barrier, and localized cerebral edema, rather than to primary ischemia. Diffuse non-lateralizing brain hyperperfusion generally prevails during migraine attacks for more than 48 hours in the cerebral cortex, thalamus, and basal ganglia.[5] Radiographic imaging is only warranted when the quality, location, and duration are different from previous headaches. Migraines cause vasodilation of intracerebral vessels and sensory sensitization of the trigeminal nerve causing inflammatory changes in the pain-sensitive meninges—the permeability of the blood-brain barrier increases, which releases proinflammatory mediators. Factors to consider when choosing the type of examination depends on the clinical indication, diagnostic performance, availability of CT or MRI, radiologist expertise, and patient contraindications. Any imaging of the vessels requires the use of IV contrast. CTA or MRA examinations image both the arteries and veins. MRH should have normal imaging findings and can sometimes be a diagnosis of exclusion in an emergency medicine setting.

Therapeutic lifestyle measures may be beneficial for controlling migraines, including proper sleep hygiene, healthy nutrition, and routine meal schedules, regular exercise, and managing migraine triggers such as stress, alcohol, weather, and most commonly hormones.

Managing menstrual-related headaches starts with identifying where the headache aligns with the patient’s menstrual cycle. If a patient is already on oral contraceptive pills (OCPs), the headache may be prevented simply by altering her current hormone regimen reducing the estrogen dose to limit the premenstrual decline in estrogen that precipitates the MRH.[6][7]

If women are opposed to starting hormonal therapy, are noncompliant, or contraindications exist, common abortive therapy involves the use of triptans, which target the direct pathophysiologic mechanism of migraines. All triptans are serotonin 1b/1d receptor agonists that prevent pain by blocking trigeminal nerve activation, inhibiting the release of vasoactive peptides, and promoting vasoconstriction.[8][9]

Most nonsteroidal anti-inflammatory drugs (NSAIDs) block COX 1/2 and can be an effective monotherapy in some women. Mefenamic acid has been extensively studied for treating acute MRH and additionally can relieve general dysmenorrhea.[9][10]

Metoclopramide given intravenously has been proven to be as efficacious as triptan therapy when treating acute migraines in an emergency room setting.[11] Akathisia is a potential side effect that can be prevented with the use of diphenhydramine; however, the addition of diphenhydramine does not improve migraine severity.

Dihydroergotamine is an alpha-adrenergic blocker vasoconstrictor and potent serotonin 1b/1d receptor agonist usually reserved in severe cases of chronic intractable migraine headaches or status migrainosus.[12]

Pharmacologic modulation of CGRP activity appears to mediate trigeminovascular pain transmission in migraine. CGRP antagonists are more novel options for acute migraine treatment in patients with either insufficient response or contraindications to first-line medications.[13][14][15]

Other alternative nonpharmacological interventions to consider are nerve blocks. Patients opposed to taking oral or intravenous medications may be strong candidates for the sphenopalatine ganglion block.[16] This technique involves saturating a long cotton-swab in local anesthetic and inserting the swab into the naris of the unilateral side of the patient’s headache while the patient is in the sniffing position. The swab should be inserted until resistance is met at the posterior wall of the nasopharynx and left in place for at least 10 minutes.

Neuromodulation such as transcutaneous electrical nerve stimulation, single-pulse transcranial magnetic stimulation, and in extreme circumstances, surgical deactivation of migraine trigger sites have limited data but are therapies directed at stimulating the nervous system with an electrical current or a magnetic field. These options are generally reserved for patients who have a poor response or contraindications to pharmacological interventions.

The use of opioids in treating MRH is generally avoided due to long term changes in the CNS at the molecular level. Opioids lead to increased descending facilitation from the rostral ventromedial medulla and increased excitatory neurotransmission at the level of the dorsal horn, causing medication overuse headache.[17] Other data suggests that chronic opioid administration increases CGRP expression in primary afferent neurons upregulating pain afferents.

Menstrual related headaches have a broad differential diagnosis, which includes other primary headaches such as tension headache and cluster headaches. Treatment of MRH and other primary headaches do overlap so that diagnosis can be distinguished from features of the history and physical exam of the patient. Some can experience cutaneous allodynia, which is the perception of pain produced by a small stimulus, such as brushing hair, touching the scalp, shaving, or wearing contact lenses resulting in sensitization of central pain pathways in migraine. These episodes typically last seconds to minutes, but when episodes increase in intensity and frequency over time, they are indicative of trigeminal neuralgia, which responds well to a different therapy.

Secondary headaches from trauma, vascular-related injury, metastasis, or infection can also be considered. Cerebral aneurysms, cerebral venous thrombosis, dissection syndromes, encephalitis, meningitis, intracranial hemorrhage, and temporal arteritis will all have different features that can usually be either ruled out or diagnosed with laboratory testing, additional head imaging, or CSF sampling. Since MRH rarely has an association with aura, it is less common to be mistaken for a transient ischemic attack (TIA). Useful features for distinguishing MRH include the duration, timing, quality, comparison to previous headaches, neurological exam, and other associated symptoms during and after the attacks.

Women who suffer from menstrual-related headaches generally have a good prognosis, and headaches usually respond well to conventional first-line pharmacological therapy. However, success is sometimes dependent on the reliability to predict the regularity of a women’s menstrual cycle. Those with irregular cycles are usually not strong candidates for hormone directed therapy.

(Although triptans are relatively safe drugs, some contraindications do exist. Cardiovascular disease should be screened, including hypertension, hypercholesterolemia, smoking history, obesity, diabetes, strong family history of coronary artery disease (CAD), menopause, before initiation of therapy. Prinzmetal angina and CAD are absolute contraindications due to the risk of coronary vasospasm.[18] A full history of other medications should be taken to avoid possible drug-drug interactions. Patients on antidepressants are at higher risk of developing serotonin syndrome. Chronic exposure to triptans could lead to the downregulation of serotonin receptors and changes in central inhibitory pathways that translate to an impairment of antinociceptive activity and a permanent feeling of head pain.

OCPs should not be given to patients who are older than 35 years and smoke cigarettes, have two or more risk factors for CAD or known ischemic heart valve disease, hypertension, history of venous thromboembolism (VTE), thrombogenic mutations such as antiphospholipid disease or systemic lupus erythematosus (SLE), history of stroke, breast cancer, or migraine with aura.[19] These are all risk factors for hypercoagulability and can ultimately lead to an embolism. Studies have shown that the use of combined hormonal contraceptives among women with migraines with aura is at higher risk of ischemic stroke.[19]

NSAIDs are contraindicated in patients with peptic ulcer disease or at risk for gastroduodenal disease due to blocking prostaglandin, which protects the gastric mucosa. Patients at increased risk of cardiovascular disease may be restricted to NSAID use due to reduced prostaglandin I2 production by vascular endothelium with limited inhibition of prothrombotic platelet thromboxane A2 production, making patients at higher risk for embolism. Renal patients should avoid NSAID use due to the blockage of prostaglandins, which promote renal vasodilation and maintain renal perfusion.[20]

Patients who experience frequent or severe headaches may derive some benefit from a headache diary over a one month period where they can record the duration of each headache, the intensity and location, and whether it responded to therapy. Additionally, potential triggers such as food, alcohol, stressors, weather conditions, what day of their menstrual cycle they are on can be logged. This data may provide information for avoidances and may help to determine what triggers their migraine headaches and what makes them better.

Coordinating care between healthcare professionals is an important aspect of patient care, especially when modulating a patient's pharmacological therapy. Whether a woman's menstrual headaches are being managed by a neurologist or in the emergency setting, it is important to coordinate with all physicians. Patients should see the same physician or, at the very least, see a provider in the same health network where other specialists can easily access the electronic medical record. Having old records is an invaluable tool to see if there are any changes in medication regimen, differences in history, or physical exam findings.

Whether it is a neurologist, an emergency physician, or another specialist is currently treating the patient, improving care coordination with the primary care doctor would minimize adverse effects from new interventions given. For example, if a woman with an acute migraine presents, and she does not know that she has an underlying cardiac problem, and she is given triptan therapy, this can lead to fatal coronary vasospasm. 

Monitoring a patient's headache calendar and coordinating the dates with the patient's menstrual cycle is key to targeting treatment. If there are clear differences in the pattern of quality, location, timing in the patient's previous recorded headaches, it can suggest an alternate diagnosis. Collaborating care can ultimately change patient management and can help identify if the patient needs outpatient therapy versus emergent treatment. 

The importance of communication between interprofessional teams cannot be undervalued as patients that are started on combined hormonal contraception can have serious adverse effects. Patients being treated for acute migraines that have worsened may need to change their long-term treatment regimen but not before physicians coordinate therapies.