Encephalopathy is a term that means brain disease, damage, or malfunction. Encephalopathy can present a very broad spectrum of symptoms that range from mild, such as some memory loss or subtle personality changes, to severe, such as dementia, seizures, coma, or death.
In general, encephalopathy is manifested by an altered mental state that is sometimes accompanied by physical manifestations (for example, poor coordination of limb movements).
The term encephalopathy, in most cases, is preceded by various terms that describe the reason, cause, or special conditions of the patient that leads to brain malfunction.
For example, anoxic encephalopathy means brain damage due to lack of oxygen, and hepatic encephalopathy means brain malfunction due to liver disease.
Additionally, some other terms either describe body conditions or syndromes that lead to a specific set of brain malfunctions. Examples of these are metabolic encephalopathy and Wernicke’s encephalopathy (Wernicke’s syndrome).
There are over 150 different terms that modify or precede “encephalopathy” in the medical literature; the purpose of this article is to introduce the reader to the main categories of conditions that fall under the broad term of encephalopathy.
What causes encephalopathy?
The causes of encephalopathy are both numerous and varied.
Some examples of causes of encephalopathy include:
- infectious (bacteria, viruses, parasites, or prions),
- anoxic (lack of oxygen to the brain, including traumatic causes),
- alcoholic (alcohol toxicity),
- hepatic (for example, liver failure or liver cancer),
- uremic (renal or kidney failure),
- metabolic diseases (hyper- or hypocalcemia, hypo- or hypernatremia, or hypo- or hyperglycemic),
- many types of toxic chemicals (mercury, lead, or ammonia),
- alterations in pressure within the brain (often from bleeding, tumors, or abscesses), and
- poor nutrition (inadequate vitamin B1 intake or alcohol withdrawal).
These examples do not cover all of the potential causes of encephalopathy but are listed to demonstrate the wide range of causes.
Although numerous causes of encephalopathy are known, the majority of cases arise from several major categories (some examples in parentheses):
- infection (HIV, Neisseria meningitides, herpes, and hepatitis B and hepatitis C),
- liver damage (alcohol and toxins),
- brain anoxia or brain cell destruction (including trauma), and
- kidney failure (uremic).
Some drugs may cause encephalopathy; for example, posterior reversible encephalopathy syndrome (PRES) may occur due to the use of drugs like tacrolimus and cyclosporine.
This syndrome manifests with symptoms of headache, confusion, and seizures.
What Are the Symptoms of Encephalopathy?
Your symptoms will depend on the cause and severity of your encephalopathy.
You may have difficulty focusing or suffer from memory loss. Also, you may have trouble with problem-solving skills.
Other people may notice symptoms in you before you do. A changing personality is one such symptom. For example, you may be more outgoing than you were before the encephalopathy.
You may be more or less calm than you were before the disease.
You could also be lethargic and drowsy.
Possible neurological symptoms include:muscle weakness in one area, poor decision-making or concentration
- involuntary twitching
- difficulty speaking or swallowing
When Should I Seek Medical Help?
You should see a doctor promptly if you experience symptoms of encephalopathy. If you are already receiving treatment for brain disease, be aware of the following signs:
- severe confusion
- severe disorientation
These can be signs of a medical urgency, and may mean that your condition is getting worse.
How Is Encephalopathy Diagnosed?
To diagnose encephalopathy, your doctor will ask you questions about your medical history and your symptoms. He or she will also perform a medical exam to check for mental and neurological symptoms.
If your doctor suspects that you have brain disease, he or she may conduct tests to determine the causes and severity of your disease. Tests may include:
- blood tests to detect diseases, bacteria, viruses, toxins, or prion
- spinal tap (taking a sample of your spinal fluid to look for diseases, bacteria, viruses, toxins, or prion)
- computed tomography (CT) or magnetic resonance imaging (MRI) scan of your brain to detect abnormalities or damage
- electroencephalogram (EEG) test to measure the electrical activity in your brain
How Is Encephalopathy Treated?
The treatment for encephalopathy varies according to the cause. Treatment may consist of medications to treat your symptoms and medications or surgery to treat the underlying cause.
Your doctor may recommend nutritional supplements to slow the damage to your brain, and/or a special diet to treat underlying causes.
In some cases of the disease, such as when the brain does not receive enough oxygen, you may slip into a coma. In severe cases like this, your doctor may put you on life support to keep you alive.
What are the complications of encephalopathy?
Complications of encephalopathy vary from none to profound mental impairments that lead to death. The complications can be similar in some cases. Also, many investigators consider encephalopathy itself to be a complication that arises from a primary health problem or primary diagnosis.
Complications depend on the primary cause of encephalopathy and can be illustrated by citing a few examples from the wide variety of causes:
- Hepatic (liver) encephalopathy (brain swelling with herniation, coma, death)
- Metabolic encephalopathy (irritability, lethargy, depression, tremors; occasionally, coma or death)
- Anoxic encephalopathy (wide range of complications, from none in short-term anoxia to personality changes, severe brain damage to death in long-term anoxic events)
- Uremic encephalopathy (lethargy, hallucinations, stupor, muscle twitching, seizures, death)
- Hashimoto’s encephalopathy (confusion, heat intolerance, dementia)
- Wernicke’s encephalopathy (mental confusion, memory loss, decreased ability to move eyes)
- Bovine spongiform encephalopathy (BSE) or “mad cow disease” (ataxia, dementia, and myoclonus or muscle twitching without any rhythm or pattern)
- Shigella encephalopathy (headache, stiff neck, delirium, seizures, coma)
- Infectious causes of pediatric encephalopathy (irritability, poor feeding, hypotonia or floppy baby syndrome, seizures, death)
The best way to understand potential complications is to discuss these with the diagnosing doctor who can discuss the possible problems associated with the specific cause(s) of the type of encephalopathy.
Is Encephalopathy Preventable?
Some types of encephalopathy—like hereditary types—are not preventable. However, some types are preventable.
In general, living a healthy lifestyle can reduce your risk factors for brain disease. Making the following changes can lessen the risk of many underlying causes of encephalopathy:
- avoiding excess alcohol
- reducing exposure to toxic substances like drugs
- eating a healthy diet
- seeing your doctor regularly
Your long-term outlook depends on the cause and severity of your encephalopathy. All types can be fatal if severe enough. Some types are always fatal.
According to the National Institute of Neurological Disorders and Stroke, transmissible spongiform encephalopathy results in death within three months to a few years from the onset of the disease (NINDS).
Treatment for the cause of your brain disease may improve your symptoms or may get rid of the encephalopathy. Depending on the type of encephalopathy, you may or may not have permanent damage to your brain.