Red Flags in Pregnant Women With Headache

Pauline Anderson

August 31, 2015

About 35% of pregnant women with acute headache who came to the hospital emergency department and received a neurologic consultation had a secondary disorder, in many cases preeclampsia, a new study shows.

The study uncovered "red flags" that might prompt further investigation, said author Mathew Robbins, MD, associate professor of clinical neurology, Albert Einstein College of Medicine, and chief of neurology, Jack D. Weiler Hospital, Montefiore Medical Center, New York.

"The biggest red flag was if someone had an elevated blood pressure at the time of their acute headache presentation; this increased the risk of diagnosing secondary headache about 17-fold."

Another red flag, he said, was a lack of previous headache history. In the study, this was associated with a five-fold increased likelihood that the headache was secondary to another condition. Other warning signs included fever, seizures, and psychiatric problems.

Dr Mathew Robbins

"A severe headache in pregnancy should be taken seriously and should prompt consideration for diagnoses other than migraine," said Dr Robbins. "It could mean that such patients will need some type of diagnostic workup, which could include brain MRI or monitoring with serial blood pressure for preeclampsia."

Their findings were published online August 19 in Neurology.

Researchers reviewed charts of 140 pregnant women presenting with acute headache at the emergency department, labor and delivery triage, or antepartum units at the Jack D. Weiler Hospital in the Bronx, New York, from July 1, 2009, to June 30, 2014, for whom a neurology consultation was requested.

They looked at details related to headache history and acute headache symptoms, including pain location; laterality; duration; attack frequency; and the presence of nausea, aura, high blood pressure, and other symptoms.

The mean age of the study participants was 29.4 years, and most participants were African American (39.3%) or Hispanic (36.4%). About 78% had a history of headache, although in most cases they reported that the acute attack differed from their previous pattern in features such as duration, severity, or frequency. Just over half the sample sought care for the acute headache during the third trimester of pregnancy.

Migraine was the most common diagnosis for the acute attack, making up 59.3% of the sample overall and 91.2% of those with primary headache.

Within this primary headache group, 57.1% had migraine without aura, 37.4% migraine with aura, 8.8% chronic migraine, and 33.0% status migrainous.

Those with primary headache did not differ from those with secondary headache in terms of age, race, or number of prior pregnancies.

In the secondary headache group, hypertensive disorders of pregnancy were the most common diagnosis (51.0%), which was mostly preeclampsia (38.8%).

Medical Comorbidities

Asthma was the most common medical comorbidity overall. The authors noted that psychiatric diagnoses most often featured depression (7.9%), anxiety (4.3%), and bipolar disorder (3.6%) and were more common among patients with primary compared with those who had secondary headache (24.2% vs 4.1%; P = .002).

The women with primary headache were more likely than those with secondary headache to have phonophobia (59.3% vs 34.7%; P = .005) but had similar rates of nausea, vomiting, and photophobia.

Visual disturbance was the most common associated neurologic symptom (56.4%), followed by somatosensory disturbance and vertigo or dizziness. Seizures were present in 12.2% of patients with secondary headache but none with primary headache (P = .0015).

Aura was present in 39.6% of the primary headache group; of these patients, 69.4% had no history of aura.

Patients with secondary headache more often had high blood pressure (55.1% vs 8.8%) and fever (8.2% vs 0.0%) than did patients with primary headache.

Almost 88% of the entire sample had some form of neuroimaging, including brain MRI, magnetic resonance venography (MRV) of the head, magnetic resonance angiography (MRA) of the head, head computed tomography, MRA of the neck, and cervical spine MRI. Of these, 17.8% had abnormal findings that led to the secondary headache diagnosis.

The most common incidental findings were hypoplastic transverse venous sinus (n = 13) and small subcortical white matter hyperintensities (n = 8).

Headaches among pregnant women in the clinical setting have not been extensively studied before, according to Dr Robbins "Hospital-based neurologists are always seeing pregnant women with acute severe headache and grappling with what's the diagnosis to help them treat it," he said. "We were sort of surprised that there wasn't much in the literature that addressed this really basic clinical question."

While the current study focused on headache diagnosis rather than treatment, Dr Robbins commented that some accepted advice surrounding headache treatment during pregnancy has recently been questioned. For example, many experts believe that triptans interrupt blood flow to the fetus, but safety data from a registry kept by GlaxoSmithKline (makers of sumatriptan) show that this drug doesn't appear to lead to a major elevation in adverse pregnancy outcomes, said Dr Robbins.

On the other hand, the idea that barbiturates are harmless to the developing baby has been challenged. New evidence indicates an increase in fetal cardiac defects in those exposed during pregnancy.

The large number of African American and Hispanic women in the current study could reflect the urban, largely underserviced population the hospital serves, said Dr Robbins. "It could be that the diagnostic rates are influenced by poor access to, or poor continuity, of prenatal care."

He also pointed out that being African American is in itself a risk factor for preeclampsia, which might have influenced headache diagnoses in the study.

Dr Robbins also recognized the "two layers of bias" in the study: It included only patients with a headache severe enough to send them to the hospital and only those with a headache severe enough to prompt a neurologic consultation.

"Diagnostic Minefield"

Asked by Medscape Medical News to comment, Randolph Evans, MD, clinical professor of neurology, Baylor College of Medicine, Houston, Texas, who is on the Medscape Neurology editorial advisory board, said two earlier studies support the finding that a significant percentage of pregnant women presenting with acute headaches had secondary disorders.

He doesn't find this surprising. "I have personally seen most of these secondary causes of headaches during pregnancy as well as viral meningitis without fever, sphenoid sinusitis, intracranial neoplasm, and cervical carotid dissection." 

Many patients, and even some obstetricians, think it's normal to have headaches during pregnancy, said Dr Evans.

"The neurologist should be aware that pregnancy is a potential diagnostic minefield and to diagnose primary headaches with care as some of these missed diagnoses can result in poor outcomes for the patient and malpractice suits. Thoughtful use of MRI of the brain, MRA/MRV of the brain, and MRA of the neck and occasional lumbar puncture will lead to the correct diagnosis."

Dr Robbins serves on the editorial board for Headache and is a section editor for Current Pain and Headache Reports. He has received royalties for educational activities with the American Headache Society, American College of Physicians, Prova Education, SUNY Downstate, and North Shore-LIJ Hofstra School of Medicine, and book royalties for Headache (Neurology in Practice series) from Wiley.

Neurology. Published online August 19, 2015. Abstract


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