Preeclampsia is a disorder that affects all the body’s systems, and the brain is no exception. Neurological manifestations of preeclampsia are very common and in fact are some of the “severe features” included in the definition of preeclampsia. These neurological manifestations can include severe headache, blurred vision, confusion, or in very severe cases, stroke, cerebral edema (brain swelling), and seizures (eclampsia).

What Are the Neurological Symptoms of Preeclampsia?

Neurological manifestations of preeclampsia have been recognized for thousands of years. There is a quotation I really like that has been attributed to the ancient Greek physician Hippocrates but is likely even older. This prehistoric physician states: “In pregnancy, drowsiness and headache accompanied by heaviness and convulsions, is generally bad.” This dry comment is just as relevant now as it was 3000 years ago.

Why Is Headache in Pregnancy a Warning Sign?

A pregnant or postpartum woman presenting with severe headache, “drowsiness” (altered mental status), or seizures, represents a neuro-obstetrical emergency and should be treated as such. I personally believe that any woman presenting with eclamptic seizures should have brain imaging as soon as possible after initial stabilization of the airway, breathing, and circulation, and after initiation of treatment for eclampsia (intravenous magnesium sulfate).

Should Women With Eclampsia Receive Brain Imaging?

I have unfortunately seen cases where the next step was not brain imaging, but instead emergent delivery, even though there was no fetal distress. This can lead to delays in diagnosis of potentially catastrophic neurological conditions, including intracerebral hemorrhage, cerebral edema, and cerebral vasospasm.

How Does Preeclampsia Affect the Brain’s Blood Vessels?

As a specialist in vascular neurology, I think of preeclampsia’s impact on the brain as primarily vascular, both short term and long term. In the short term, preeclampsia can cause acute neurovascular conditions like the posterior reversible encephalopathy syndrome (PRES), the reversible cerebral vasoconstriction syndrome (RCVS), and both hemorrhagic and ischemic stroke.

What Are PRES and RCVS in Preeclampsia?

PRES is a syndrome where the blood-brain barrier becomes “leaky” causing swelling in the brain. RCVS causes severe spasms of the arteries in the brain, causing “thunderclap” headaches and in some cases, hemorrhage or ischemia (brain damage due to lack of blood flow). Both PRES and RCVS can be seen outside of pregnancy but we see them frequently in the setting of preeclampsia, especially in the postpartum period. The word “reversible” is a little misleading because while the swelling and spasms can be reversible, the brain damage associated with it is not always reversible.

Can Eclampsia Occur Without Warning Signs?

One very interesting thing is that while untreated preeclampsia can progress to eclampsia, not all cases of eclampsia are preceded by “pre-” eclampsia. Dr. Chris Redman found in a foundational paper about eclampsia that the most common preceding symptom prior to eclamptic seizures is headache, and hypertension is often, but not always present.

Why Do Many Neurological Complications Happen After Delivery?

In addition, traditionally preeclampsia is supposed to be “cured” by delivering the fetus. However, 44% of eclampsia cases in Dr. Redman’s study occurred after delivery. My own research also showed that the majority of severe neurological complications of preeclampsia occur postpartum.

What Is the Long-Term Stroke Risk After Preeclampsia?

In the long term, women who have had preeclampsia have higher risk of stroke later in life. What’s interesting is that it is not necessarily that their risk of stroke throughout their whole life is higher – if people live long enough, pretty much everyone is at risk for stroke. But women with preeclampsia have their strokes earlier in life, even in their 30s, 40s, and 50s which in the world of a stroke neurologist is very young. So preeclampsia seems to be associated with not just increased risk, but accelerated risk of cerebrovascular disease.

How Can Women Reduce Stroke Risk After Preeclampsia?

When I talk about this with my patients, I tell them it’s not that you are doomed to having a stroke. On the contrary, there are so many things that we can do as women to reduce our risk of stroke. Probably number 1, 2, and 3 is to monitor our blood pressure and treat it appropriately. A woman’s risk of stroke begins to increase when her systolic blood pressure is higher than 120, as opposed to 150 in men.

Many women have high blood pressure in the doctor’s office which is attributed to anxiety or “white coat hypertension,” but they actually have chronic hypertension that has not been diagnosed. In addition to blood pressure reduction, there are many other things we can do to reduce our stroke risk – I suggest the American Heart Association’s “Life’s Essential 8” as a starting point.

Does Preeclampsia Affect Long-Term Brain Health?

Many women are also worried about their “brain health,” by which I think most people mean, their cognitive function. There is some evidence to suggest that women who have had preeclampsia are at higher risk of cognitive decline and dementia, especially vascular dementia. Some studies have also shown that women who have had eclampsia have an increased risk of developing new-onset epilepsy and worsening migraines. 

What Can Women Do to Protect Brain Health After Preeclampsia?

The good news is, the same things that reduce the risk of stroke (in particular, blood pressure reduction, and exercise) appear to also reduce the risk of cognitive decline and dementia. Healthy sleep (7-9 hours per night) is also critically important for stroke prevention, brain health, and mental health.

I would recommend that if women are concerned about cognitive symptoms that they speak with their physician about it and inform them about their pregnancy history. If it turns out there is an underlying neurological condition causing cognitive symptoms, it is always best to diagnose it early and if possible, start treatment.

About the Author

Eliza C. Miller, MD, MS is a member of the Preeclampsia Foundation Medical Advisory Board. She is an Associate Professor of Neurology and a vascular neurologist in the Division of Stroke and Cerebrovascular Disease at Columbia University. She completed her medical degree at the Columbia University College of Physicians and Surgeons followed by training in Neurology and Vascular Neurology at New York Presbyterian-Columbia University Irving Medical Center and a Master’s degree in Patient Oriented Research at Columbia’s Mailman School of Public Health. Her research focuses on cerebrovascular complications of preeclampsia and other adverse pregnancy outcomes, using both physiological and epidemiological approaches. She has been continuously funded by the NIH since joining the Columbia faculty in 2017, including grants from the National Institute of Neurological Disorders and Stroke, the Eunice Kennedy Shriver National Institute for Child Health and Development, and the National Institute on Aging. At Columbia, she directs the New York-Presbyterian/Columbia University Irving Medical Center Mothers Center Neurovascular Clinic, a specialized clinic for treatment of individuals with cerebrovascular complications during pregnancy and postpartum.