What are the other Names for this Condition? (Also known as/Synonyms)

• HE (Hypertensive Encephalopathy)
• Malignant Hypertension causing Encephalopathy

What is Hypertensive Encephalopathy? (Definition/Background Information)

• Hypertensive Encephalopathy (HE) occurs as a result of sustained hypertension (high blood pressure) sufficient enough to disrupt proper cerebral blood flow (CBF). Encephalopathy is any damage or disease that affects the brain
• It is caused by a continuous increase in blood pressure (sustained or chronic hypertension) that damages the vessels inside the brain. Hypertension is defined as a blood pressure greater than 140/90mmHg; blood pressure above this threshold is considered potentially dangerous
• The cerebral blood vessels are autoregulated, i.e., they can control their pressure to sustain cerebral blood flow within a given range of systemic blood pressure. When this is absent, it can lead to complications including Hypertensive Encephalopathy
• Hypertensive Encephalopathy can lead to various signs and symptoms, including headaches and nausea. If left untreated, it can lead to severe complications, including seizures and brain stroke, which can be fatal
• Hypertensive Encephalopathy should be diagnosed promptly and treated adequately in order to avoid severe complications. It may be prevented by maintaining a healthy lifestyle and undertaking routine follow-up visits with a primary care physician

Who gets Hypertensive Encephalopathy? (Age and Sex Distribution)

• Hypertensive Encephalopathy is most prevalent in adults; however, hypertension can develop at any age. An estimated 1.13 billion people worldwide have hypertension
• According to medical literature, in 2015, nearly 25% of men and 20% of women had hypertension
• Worldwide, individuals of all racial and ethnic groups may be affected

In the United States, high blood pressure is more common in non-Hispanic black adults (54%) than in non-Hispanic white adults (46%), non-Hispanic Asian adults (39%), or Hispanic adults (36%).

What are the Risk Factors for Hypertensive Encephalopathy? (Predisposing Factors)

The risk factors for Hypertensive Encephalopathy include:

• Sustained or chronic hypertension
• Hypertensive Encephalopathy has been noted to occur with other conditions that include:
  • Congestive heart failure and infarction
  • Pulmonary edema
  • Dissecting aortic aneurism

It is important to note that having a risk factor does not mean one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Hypertensive Encephalopathy? (Etiology)

Hypertensive Encephalopathy is caused by prolonged hypertension. When the blood pressure rises too high, blood vessel injury in the form of damage to blood vessel walls (fibrinoid necrosis) develops, and inadequate blood supply (ischemia) or excess fluids (edema) build up in the brain.

The following factors can cause Hypertensive Encephalopathy:

• Encephalitis (inflammation of the brain) and meningitis (inflammation of the meninges) can cause the blood vessels to rupture when under increased pressure
• Bleeding in the brain caused by head trauma or cerebral infarction (blockage of a vessel)
• Withdrawal from hypertensive medications

What are the Signs and Symptoms of Hypertensive Encephalopathy?

The signs and symptoms of Hypertensive Encephalopathy may be similar to many other neurological conditions. These vary among individuals and may include:

• Headache
• Confusion
• Nausea and vomiting
• Visual disturbances, possibly due to vessel damage to the eyes and optic regions of the brain
• Seizures

This condition is closely related to hypertensive retinopathy (HR), a condition that affects the eyes due to uncontrolled hypertension.

How is Hypertensive Encephalopathy Diagnosed?

A prompt diagnosis of Hypertensive Encephalopathy is critical for early and proper treatment. The diagnosis of Hypertensive Encephalopathy may involve:

• A complete physical examination and medical history evaluation
• Many tests can be done to determine if an individual has hypertension as well as the cause of hypertension, including:
  • Ambulatory monitoring - a test where blood pressure is measured over 24 hours in set time intervals
  • Urine analysis
  • Electrocardiogram (ECG)
  • Blood tests
• A complete neurological and ophthalmoscopic examination (fundoscopic exam of the eye) is essential
• Ultrasound imaging of the kidney and urinary bladder
• Grade IV retinal changes (hypertensive retinopathy) are associated with hypertensive encephalopathy
  • Grade IV is indicated by papilledema - the optic nerve at the back of the eye becomes swollen
  • Lower grades include symptoms such as bleeding, narrowing of blood vessels, retinal fluid buildup, and retinal damage
• An MRI scan of the brain may be performed to detect traces of cerebral edema

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Hypertensive Encephalopathy?

Several complications are associated with Hypertensive Encephalopathy, including:

• Peripheral vascular disease (narrowed blood vessels and less blood flow to limbs)
• Retinopathy (damage to vessels of eyes)
• Nephropathy (damage to vessels of kidneys)
• Kidney failure
• Stroke
• Posterior reversible encephalopathy syndrome (PRES)
  • It is caused by the buildup of cerebral edema in the brain, specifically the posterior occipital and parietal lobes
  • It presents with a rapid onset of symptoms, including headache, seizures, altered consciousness, and visual disturbance
  • If promptly recognized and treated, PRES usually resolves within a week
• Severe cases of Hypertensive Encephalopathy can result in a coma

How is Hypertensive Encephalopathy Treated?

The treatment measures for Hypertensive Encephalopathy include:

• Management of hypertension using various medications: This can include medications such as diuretics, calcium channel blockers, ACE inhibitors, beta-blockers, angiotensin receptor blockers, and other medications
• In some cases of Hypertensive Encephalopathy, observation by a physician for signs of severe hypertension in the hospital may be appropriate
• A brain surgery may be necessary for severe cases of Hypertensive Encephalopathy

How can Hypertensive Encephalopathy be Prevented?

Hypertensive Encephalopathy is most directly influenced by uncontrolled high blood pressure, which can be reduced with a healthy lifestyle. The following measures may be considered:

• Individuals with long-term hypertension are recommended to undertake routine visits to a primary care physician to manage their blood pressure (keep it within a safe range)
• Healthier lifestyle habits, including exercise and avoiding alcohol and tobacco
• Limiting sodium intake and maintaining an overall healthier diet (avoiding foods high in saturated and trans fats)

What is the Prognosis of Hypertensive Encephalopathy? (Outcomes/Resolutions)

Hypertensive Encephalopathy is overall prognosis depends upon its severity and early treatment.

• With prompt treatment, Hypertensive Encephalopathy has a favorable prognosis
• With delayed or absent treatment, there can be a variety of outcomes, including permanent brain damage, with severe cases leading to fatalities

Additional and Relevant Useful Information for Hypertensive Encephalopathy:

It is reported that more than 80% of individuals with hypertension are not known to properly manage their condition adequately, thus leading to various complications.