Migraine: Putting TIA and Acute Ischemic Stroke in Perspective

RESEARCH UPDATE

People admitted to the hospital for migraine with aura have over two times increased risk for later readmission for transient ischemic attack (TIA).¹ Sometimes called “mini-stroke,” a TIA occurs when blood flow to the brain is briefly interrupted without causing permanent neurological damage. TIAs can increase the risk for later stroke.

The study also found that people admitted with severe migraine that does not respond to medication (status migrainosus) may have almost five times increased risk of later readmission for subarachnoid hemorrhage (SAH), or bleeding into the space around the brain.

A recent meta-analysis has found that about 9% of cerebrovascular events are missed upon initial ED evaluation, and that over 80% of cases initially misdiagnosed as headache were actually SAH.² That study highlighted how misdiagnosis can delay accurate diagnosis of SAH, an often fatal condition.

“Given the high likelihood of misdiagnosis of TIA and SAH, this should raise awareness for physicians evaluating aura-positive patients for TIA symptoms to avoid misclassification. In addition, physicians evaluating patients for status migrainosus may need to consider and evaluate more often for a sentinel bleed of SAH,” wrote first author Lili Velickovic Ostojic, MD,¹ of Mount Sinai Downtown, New York, and colleagues.

To get a better idea of the risk of later cerebrovascular events associated with a hospital admission for migraine, researchers accessed 2013 admissions data housed in the Nationwide Readmissions Database, which includes all payers and uninsured individuals in the US. They used ICD-9 codes to identify 12,448 adult migraine admissions, of which 80.1% were women with a mean age 45.56 years.

About 24% of included individuals had migraine with aura and 14% had status migrainosus. Then they evaluated readmission for acute ischemic stroke, TIA, SAH, and intracerebral hemorrhage 30, 60, and 90 days after the migraine admission. Results were adjusted for age and vascular risk factors.

Key results and take-home points >

Key results

• 30-day readmission rate per 100,000 migraine admissions:

Ischemic stroke: 154

TIA: 86

SAH: 42

Intracranial hemorrhage: 17

• Migraine with aura significantly linked to two times increased risk for readmission for TIA (HR 2.13, p <0.01)

• Status migrainosus significantly linked to almost 5 times increased risk for readmission for SAH (HR 4.83, p=0.04)

The authors mentioned that the study can only reveal associations and cannot prove cause and effect. For example, based on these results it is unclear whether migraine with aura actually causes TIA, or whether migraine with aura is being misdiagnosed as TIA in some cases. They noted that more research is needed to clarify causality.

Take home points

• Nationwide administrative claims-based study found admission for migraine with aura was linked over two times increased risk for later readmission for TIA

• Status migrainosus was linked to almost four times increased risk for SAH

• Results cannot prove causality, but may suggest misdiagnosis in some cases

References:

1. Velickovic Ostojic L, Liang JW, Sheikh HU, Dhamoon MS. Impact of Aura and Status Migrainosus on Readmissions for Vascular Events After Migraine Admission. Headache. 2018; June [Epub ahead of print].

2. Tarnutzer AA, Lee SH, Robinson KA, et al. ED misdiagnosis of cerebrovascular events in the era of modern neuroimaging: A meta-analysis. Neurology. 2017;88:1468-1477.