Can High Blood Pressure Cause Seizures? The Link Between Hypertension and Seizures

Can High Blood Pressure Cause Seizures?

Seizures are sudden and uncontrolled electrical disturbances in the brain that can cause changes in behavior, movements, feelings, and levels of consciousness. About 10% of people will have a seizure at some point in their life. While epilepsy is the most common cause of recurrent seizures, there are many other potential causes as well.

High blood pressure, also known as hypertension, is one of the potential medical conditions that can trigger a seizure even in someone without epilepsy. Let's take a closer look at the link between high blood pressure and seizures.

What is High Blood Pressure?

Blood pressure measures the force of blood pushing against the walls of the arteries as the heart pumps blood around the body. High blood pressure, or hypertension, is when this pressure stays elevated over time.

Blood pressure readings have two numbers. The first (systolic) number represents pressure in the arteries when the heart beats. The second (diastolic) number represents pressure in the arteries when the heart rests between beats.

High blood pressure is defined as:

• Systolic pressure of 130 mmHg or higher
• Diastolic pressure of 80 mmHg or higher

Normal blood pressure is less than 120/80 mmHg. Prehypertension ranges from 120-129/ under 80 mmHg. Stage 1 hypertension is 130-139/80-89 mmHg. Stage 2 is 140/90 mmHg or higher.

What Causes High Blood Pressure?

There are two main types of high blood pressure:

• Primary (Essential) Hypertension - develops gradually over time, usually without an identifiable cause.
• Secondary Hypertension - caused by an underlying medical condition or medication.

Some common causes of secondary hypertension include:

• Kidney disorders
• Adrenal gland tumors
• Congenital defects in blood vessels
• Certain medications, such as birth control pills, decongestants
• Illegal drugs, such as cocaine and amphetamines
• Alcohol abuse or excess alcohol intake
• Obstructive sleep apnea

There are also a number of risk factors that make primary hypertension more likely, such as:

• Older age
• Obesity
• Family history
• Sodium-rich diet
• Excess alcohol consumption
• Smoking
• Stress
• Physical inactivity

How Can Hypertension Lead to a Seizure?

Uncontrolled high blood pressure can begin to damage blood vessels in the brain. This can disrupt normal electrical rhythms and make seizures more likely.

Here are some of the ways hypertension is theorized to trigger seizure activity:

• Cerebral Small Vessel Disease - High pressure damages the small arteries and capillaries in the brain, disrupting oxygen delivery.
• Blood-Brain Barrier Disruption - Hypertension may disrupt the protective barrier between the brain and blood.
• Cerebral Edema - Pressure can force fluid from blood vessels into the brain, leading to swelling.
• Microbleeds - Damaged vessels may leak blood into the brain tissue.
• Ischemic Injury - Reduced blood flow can deprive brain tissue of oxygen.

All of these effects of hypertension on the cerebral vasculature increase the risk of excessive electrical discharge in the brain. The area of the brain affected determines whether it produces sensory, motor, or behavioral symptoms during the seizure.

Hypertensive Crisis and Seizures

A hypertensive crisis occurs when blood pressure rises to dangerously high levels quickly. Systolic pressure is over 180 mmHg and/or diastolic pressure is over 120 mmHg. Without prompt treatment, a hypertensive crisis can lead to organ damage or even become fatal.

A hypertensive crisis may be triggered by:

• Failing to take blood pressure medications correctly
• Interaction between medications
• Sudden withdrawal of blood pressure medications
• Drug abuse
• Major illness or surgery

The rapid and extreme rise in blood pressure increases the risk of cerebral edema, hemorrhage in the brain, and ischemic stroke. All of these effects can irritate brain tissue and make a seizure extremely likely.

Seizures caused by dangerously high blood pressure are considered hypertensive encephalopathy seizures. This is a medical emergency requiring hospitalization to safely lower blood pressure.

Diagnosing Hypertension-Related Seizures

It can sometimes be difficult to determine if high blood pressure is causing seizures, especially if hypertension goes undetected or untreated for a long time.

When a patient without epilepsy experiences an unexplained seizure, doctors will complete a full medical workup looking for potential causes. This includes:

• Physical exam
• Neurological exam
• Medical history review
• Blood tests
• Urine tests
• CT scan of the brain
• MRI of the brain
• EEG
• EKG

If testing uncovers hypertension along with signs of end organ damage consistent with high blood pressure, it increases suspicion of a link. For example, finding left ventricular hypertrophy on EKG suggests chronic hypertension.

However, it is not always clear if seizures are a direct result of hypertension or caused by another underlying condition. Extensive testing may be needed to make an accurate diagnosis.

Can You Have Epilepsy and Hypertension?

Yes, it is possible to have both epilepsy and high blood pressure. In fact, some research shows hypertension may be more common in those with epilepsy compared to the general population.

This link could be related to:

• Certain epilepsy medications raising blood pressure
• Hormonal and nervous system changes from seizures
• Shared risk factors like stress, smoking, and inactivity

In someone with known epilepsy who experiences worsening seizures, a workup for underlying hypertension could be warranted. Controlling high blood pressure may improve seizures by reducing damage to the brain's blood vessels.

Can Hypertension Medications Cause Seizures?

For most people, taking blood pressure lowering medications reduces rather than increases seizure risk. By controlling hypertension, the medications help prevent further vascular damage in the brain.

However, certain high blood pressure medications have been associated with seizures in rare cases, including:

• Beta blockers like propranolol
• Some calcium channel blockers such as verapamil
• Clonidine, a centrally acting alpha-2 agonist

The mechanism behind how these drugs may provoke seizures in certain individuals is not always clear. Possible theories include electrolyte abnormalities or interactions with anti-seizure medications.

If seizures develop after starting a new blood pressure medication, contact your doctor. Switching to a different medication can often control both hypertension and seizures.

Preventing Hypertension-Related Seizures

Careful management of high blood pressure is the best way to avoid seizures caused by chronic hypertension. Key tips include:

• Take any prescribed blood pressure medications exactly as directed.
• Follow your doctors advice for lifestyle changes like diet, exercise, and stress reduction.
• Never stop taking medications abruptly without first consulting your physician.
• Get regular blood pressure monitoring and follow up as recommended.
• Watch for medication side effects and potentially dangerous drug interactions.

Achieving target blood pressure levels minimizes damage to the blood vessels supplying the brain. This reduces the likelihood of electrical dysfunction leading to seizures.

Emergency medical help should be sought immediately for dangerously high blood pressure over 180/120 mmHg to prevent a life-threatening hypertensive crisis.

The Bottom Line

High blood pressure is one potential cause of seizures in adults without epilepsy. Uncontrolled hypertension can damage cerebral blood vessels, disrupt normal electrical signaling, and decrease the seizure threshold.

Rapidly rising blood pressure during a hypertensive emergency is particularly likely to provoke seizures. However, even well-managed chronic hypertension seems to modestly increase overall seizure risk compared to normotensive individuals.

Controlling high blood pressure through medications, lifestyle changes, and prompt treatment of hypertensive crises is key to reducing the likelihood of hypertension-related seizures.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.