Encephalopathy is a condition in which diffuse disease affects brain function and/or structure. Encephalopathy can occur due to numerous causes. The conditions that cause encephalopathy are serious—without treatment, temporary or permanent brain damage, loss of consciousness, and even death can occur.

Here is what you need to know about encephalopathy and its types, causes, symptoms, and more.

Types of Encephalopathy and Causes

Encephalopathy can be acute or chronic. Examples of acute encephalopathy are hepatic, uremic, hypertensive, Hashimoto’s, and Wernicke’s, while chronic traumatic encephalopathy (CTE), hypoxic-ischemic, and spongiform are examples of chronic encephalopathies.

Chronic Traumatic Encephalopathy

Chronic traumatic encephalopathy (CTE) is a progressive (gradually increasing), degenerative (worsening) brain condition linked to repeated blows to the head over a long time period.

While prevalence for CTE isn’t truly known, this type of encephalopathy tends to affect athletes in contact sports (like American football), military personnel who have been exposed to repetitive blunt head trauma, and victims of domestic abuse.

Symptoms of CTE don’t develop right away after head trauma—it will take years of repeated head trauma. Long term effects include depression, memory problems, impulsive behavior, and difficulty making decisions and carrying out tasks.

Hashimoto’s Encephalopathy

Hashimoto’s encephalopathy (HE) is associated with Hashimoto’s thyroiditis, an autoimmune thyroid disease caused by an underactive thyroid. HE has an estimated prevalence of 2.1 per population of 100,000.

HE symptoms include seizures, confusion, and dementia. It is also known to cause psychosis, including visual hallucinations and paranoid delusions.

Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy (HIE)—also known as global hypoxic-ischemic injury—is a type of diffuse brain dysfunction that happens when the brain doesn’t get enough oxygen for a period of time.

This type of injury can result in permanent brain damage. It differs from a stroke in that multiple areas of the brain are affected by low oxygen at once, rather than an area supplied by one blood vessel.

In newborns, HIE can occur prior to birth, during delivery, or shortly after birth. Causes can include pregnancy issues, trauma during delivery, and umbilical knots.

In adults, hypoxic-ischemic injury is usually related to a cardiac arrest, while in older children, the most common causes are drowning and choking.

The range in outcome after HIE varies tremendously. Some babies with HIE will not have noticeable effects, some may suffer permanent brain damage, and others might not survive.

Hypertensive Encephalopathy

Hypertensive encephalopathy is generalized brain dysfunction due to sudden, markedly high blood pressure. Symptoms of hypertensive encephalopathy include headaches, vomiting, balance problems, and confusion. It can lead to seizures or bleeding in the back of the eye.

Hypertensive encephalopathy can occur due to severe kidney failure or from abruptly stopping blood pressure medications.

Infectious Encephalopathies

Infectious encephalopathies are the most serious types of encephalopathies. They result from transmissible spongiform encephalopathies, also known as prion diseases, including chronic wasting disease, fatal familial insomnia, and Creutzfeldt-Jakob disease.

These encephalopathies are characterized by tiny holes that give the brain a spongy-like appearance. Infectious encephalopathies are neurogenerative—after they begin, they continue to cause damage to the brain over time.

Metabolic Encephalopathy

Metabolic encephalopathy occurs when a health condition—like diabetes, kidney failure, heart failure, or liver disease—affects proteins, electrolytes, or nutrients in a way that makes it hard for the brain to work. For example, high blood sugar can lead to confusion or a coma.

Neurological symptoms are common if the underlying cause isn’t optimally treated. Sometimes, brain problems associated with metabolic encephalopathies are reversible.

Wernicke Encephalopathy

Wernicke encephalopathy (WE), which is often caused by alcoholism, is associated with reduced vitamin B levels, especially thiamine (vitamin B1). Symptoms of WE may include confusion, loss of mental acuity, vision changes, and problems with muscle coordination.

Uremic Encephalopathy

Uremic encephalopathy occurs due to kidney failure, which can cause a buildup of uremic toxins in the brain.

Symptoms include lethargy, confusion, seizures, or coma. Uremic encephalopathy is treated with dialysis or a kidney transplant.

Glycine Encephalopathy

Glycine encephalopathy is a genetic or inherited condition in which there are abnormally high levels of glycine (an amino acid) in the brain.

Symptoms of this type of encephalopathy appear in newborn infants and include lack of energy, trouble eating, low muscle tone, abnormal jerking movements, and breathing problems.

Hepatic Encephalopathy

Hepatic encephalopathy can occur with cirrhosis—chronic liver damage, that leads to liver scarring and liver failure.

With hepatic encephalopathy, the liver cannot adequately remove toxins from the blood, and these toxins eventually lead to brain damage.

This type of encephalopathy can be acute (short-term) or chronic (long-term). In some instances, a person with hepatic encephalopathy can become unresponsive and may experience a coma.

Encephalopathy Symptoms

The symptoms of encephalopathy are associated with its cause.

Some of the most common symptoms include:

  • ConfusionForgetfulnessPersonality changesConcentration troubles

Encephalopathy may cause:

  • SeizuresSleep problemsMuscle weaknessUncontrollable muscle twitchesTremorsTrouble speakingTrouble swallowing

If you or a loved one develop any of these symptoms, you should get prompt medical attention.

If you or your loved one have already been diagnosed with encephalopathy, be aware of the following complications:

  • Severe confusionSevere disorientationComa

These are signs of a medical emergency that require immediate care.

Diagnosis

If you are being evaluated for possible encephalopathy, your healthcare provider will ask about your medical history and all medications you are taking. They will also give you a physical examination and neurological examination and may request additional tests.

Tests that may be part of encephalopathy diagnosis include:

  • Blood tests to look for bacteria, viruses, toxins, hormonal or chemical imbalances
  • A spinal tap where your clinician will take a sample of spinal fluid to be examined for bacteria, viruses, toxins, or prions
  • Imaging studies, including computed tomography (CT) or magnetic resonance imaging (MRI)
  • An electroencephalogram (EEG) test to measure electrical activity in the brain

The results of testing can help your healthcare provider determine if you have encephalopathy, the type of encephalopathy, and the cause or causes.

Treatment

Untreated encephalopathy can lead to worsening or permanent brain damage or death. Treatment includes symptom management and relieving the underlying cause. For example, with Hashimoto’s encephalopathy, standard therapy includes glucocorticoids and immunosuppressive medications.

Nutritional supplementation may be recommended to slow down brain damage or to help manage an underlying metabolic condition.

Treatment for chronic traumatic encephalopathy may include behavior therapy, pain management, and cognitive training to improve thinking and problem-solving skills.

Recurrent seizures would be prevented with anticonvulsant drugs.

Prevention

Some types of encephalopathy can be prevented, while others are not preventable. For example, genetic types of encephalopathy, like glycine encephalopathy, aren’t preventable—but hepatic encephalopathy might be.

In rare cases, severe encephalopathy can cause loss of consciousness or coma. If this happens, you will need respiratory support as you are recovering.

Certain lifestyle changes may reduce your risk of developing encephalopathy.

Beneficial lifestyle adjustments can include:

  • Avoiding excess alcohol consumptionReducing exposure to toxinsEating a healthy diet, exercising, and maintaining a healthy weightSeeing your healthcare provider regularlyAvoiding medications that adversely affect the nervous systemReducing your risk of head trauma

A Word From Verywell

Your healthcare provider can provide information about your encephalopathy risk.

If you experience symptoms of encephalopathy, like decreased mental ability, confusion, decreased muscle coordination, and vision or eye changes, it is important to seek immediate medical help. If you have encephalopathy, your healthcare provider can prescribe therapies for treating your symptoms and preventing further brain damage.

The sooner you get medical attention, the sooner you can recover from impaired brain function.