High Blood Pressure and Seizures

There are many causes for epilepsy, ranging from head trauma and injury, to strokes and infections. Whilst late onset epilepsy has increased over the last decades, there are still between 32% and 48% of cases where the cause remains uncertain or completely unknown. There is still much to learn about epilepsy and its causes and studies that must be conducted. 

One more recent concern has been whether high blood pressure could be an underlying cause for epilepsy. Research conducted in 2021 found that high blood pressure can increase the risk of epilepsy by 2.5 times. The same study also found that taking antihypertensive medications can then reduce this risk.  

Vascular conditions have been shown to be a factor in late onset epilepsy by increasing or decreasing blood flow to the brain, thus triggering seizures. 

Why does high blood pressure increase risk of seizures? 

Although studies have shown the link between high blood pressure and the risk of seizures and epilepsy, there is still a lack of clarity on the underlying mechanism that makes it so. 

Dr Jason Haputman, a neurosurgeon at Seattles Children’s Hospital commented: “These results are particularly interesting because whether or not high blood pressure (hypertension) in and of itself is an independent risk factor for stroke has been a topic of controversy. The thought is that independent of the presence of stroke, hypertension may lead to disease of small arteries throughout the brain that can cause injuries on the microscopic level.”

“These injuries could potentially lead to epilepsy with or without the presence of a visible or symptomatic stroke. This research is important because hypertension is not only common, but it is modifiable – that is, we may have ways of assessing and treating it. This would need to be pursued in larger, more diverse patient populations to fully assess exactly how much this is a risk factor and to test the potential interventions,”

One theory (of several), is that the link comes from the renin-angiotensin system (RAS) within the brain. This is the area of the brain that regulates blood pressure. In a study conducted with mice, after repetitive seizures the mice were shown to have between 2.6 and 8.2 times the components of RAS than those who had no seizures. 

However, as stated, this is just one theory out of many, none of which have been definitively proven beyond doubt as of yet. More research is simply needed to help understand why it is so.  

Treatment 

Although the reason for the link is unclear, the prescribed treatment is not. Reducing blood pressure in cases where a person has been diagnosed with hypertension is the key to decreasing risk of epilepsy and seizures. 

Thankfully, high blood pressure is treatable using a combination of antihypertensive medication, diet and lifestyle changes. Managing high blood pressure can help to reduce the risk of late onset epilepsy.