Encephalopathy

Encephalopathy is a term that means brain disease, damage, or malfunction.

• Encephalopathy is a broad term used to describe abnormal brain function or brain structure. (Encephalo= brain + pathy= disorder). The abnormality may be transient, recurrent, or permanent. The loss of brain function may be reversible, static and stable, or progressive with increasing loss of brain activity over time.
• 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).
• In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of overall brain dysfunction; this syndrome can have many different organic and inorganic causes.

Encephalopathy vs. encephalitis

• Both affect the brain, but Encephalitis is an inflammation in the brain often from some type of infection.
• Encephalopathy is a permanent or temporary brain damage, disorder or disease, affecting the brain’s function or structure and may be degenerative.

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).

What causes encephalopathy?

The causes of encephalopathy are both numerous and varied. There are over 150 different terms that modify or precede "encephalopathy" in the medical literature and cay be grouped by their cause.

Some examples to show the wide range of causes 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),
• alterations in pressure within the brain (often from bleeding, tumors, or abscesses), or
• brain tumors, trauma or increased pressure in the skull,
  • Trauma often occurs in athletes involved in contact sports known as chronic traumatic encephalopathy (CTE), such as boxing, American football, wrestling, ice hockey, rugby and soccer; other risk factors include being in the military, prior domestic violence, and repeated banging of the head (See: Wikipedia - Chronic traumatic encephalopathy)
  • CTE can only be diagnosed after death, and in a 2017 study of the brains of 111 deceased NFL players, a Boston University researcher found that 110 of them had the disease. (From: People - Jason Hairston had CTE symptoms before death - Here are other football players who had the disease. By Jason Duaine Hahn. 7 Sep 2017)
• prolonged exposure to toxic elements (including solvents, drugs, radiation, paints, industrial chemicals, and certain metals),
• many types of toxic chemicals (mercury, lead, or ammonia), and
• poor nutrition (inadequate vitamin B1 intake or alcohol withdrawal).
• inherited conditions such as Hashimoto’s (autoimmune disease affecting the thyroid) or glycine (high amino acid glycine in the brain)

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).

What are the symptoms of encephalopathy?

Despite the numerous and varied causes of encephalopathy, at least one symptom present in all cases is an altered mental state, which can present as inattentiveness, poor judgment, or poor coordination of movements.

Other serious symptoms that may occur include:

• lethargy,
• dementia,
• seizures,
• tremors,
• muscle twitching and myalgia,
• Cheyne-Stokes respirations (an altered breathing pattern seen with brain damage and coma), and
• coma.

Often the severity and type of symptoms are related to the severity and cause of the brain disease or damage.

Even infants and children can suffer encephalopathy. Similar symptoms can occur in the perinatal period if the neonate had any compromise to brain blood flow during its development. Rasmussen's encephalitis is a rare disease that is seen in children that progresses to intractable seizures if untreated. It may be due to autoantibody development. Another rare form of encephalopathy that usually develops in younger people (about ages 4 to 20 years) is the MELAS syndrome ("Mitochondrial Encephalopathy, Lactic Acidosis, Stroke-like episodes") due to faulty DNA in the patient's mitochondria (a tiny part within the cell that is responsible for energy conversion).

How is encephalopathy diagnosed?

The diagnosis usually involves clinical tests done during the physical examination that includes mental status tests, memory tests and coordination tests as well as different tests that will help diagnose both the primary condition and the possible cause of encephalopathy. Blood tests, spinal fluid examination, brain imaging studies (CT, MRI), electroencephalograms (EEG), and similar diagnostic studies may be used to differentiate the various causes of encephalopathy.

What is the treatment for encephalopathy?

Treatment of encephalopathy varies with the primary cause of the symptoms. Consequently, not all cases of encephalopathy are treated the same.

What are the complications of encephalopathy?

Complications of encephalopathy vary from none to profound mental impairments that lead to death depending on the primary cause. A few complication examples from the wide variety of causes include:

• 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)

What is the prognosis (outlook) for encephalopathy?

The prognosis for a patient with encephalopathy depends on the initial causes and, in general, the length of time it takes to reverse, stop, or inhibit those causes. Consequently, the prognosis varies from patient to patient and ranges from complete recovery to a poor prognosis that often leads to permanent brain damage or death.

A long delay or multiple delays in treatment can lead to a poor prognosis with extensive brain damage, coma, or death. The doctor or team of doctors treating the underlying cause of encephalopathy can offer the best information on the individual's prognosis.

Resources & Additional Reading

• MedicineNet - Encephalopathy. By Charles Patrick Davis, MD, PhD; Medically reviewed 8/13/2018
• NIH - Encephalopathy Information Page
• MedicalNewsToday - What to know about encephalopathy. By: Lana Burgess; Reviewed by Karen Gill, MD; Last reviewed 14 Dec 2018 (IMAGE1)
• Wikipedia - Encephalopathy
• ACP Hospitalist - Encephalopathy, Clinicians often struggle with the distinction between delirium and encephalopathy. By: Richard Pinson, MD,FACP. Jan 2015
• ACP Hospitalist - Encephalopathy, Most patients who are admitted to the hospital with the symptom of mental status alteration, actually have encephalopathy as the cause. By: Richard D Pinson, FACP. Sep 2010
• eMedicineHealth - Encephalopathy. By: Benjamin Wedro, MD, FACEP, FAAEM
• Wikipedia - Chronic traumatic encephalopathy
• Prion Alliance - What are human prion diseases? 2 Dec 2013