encephalopathy
Meaning of encephalopathy: Confusion, drowsiness or a change in personality can all be the visible face of a chemical problem somewhere else in the body.
Definition of encephalopathy
Encephalopathy is any disturbance of brain function severe enough to change how a person thinks, behaves or responds, arising as often from a cause outside the brain as from one inside it. It names a pattern rather than a single disease, so the word is nearly always paired with its cause, as in hepatic, toxic or metabolic encephalopathy.
How encephalopathy is built
- encephal/o Combining form · Greek brain
- -pathy Suffix · Greek disease, disorder
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
What causes it?
| Group | Examples |
|---|---|
| Metabolic | Liver failure, kidney failure, low or high blood sugar, low sodium, thyroid disease, low oxygen |
| Toxic | Alcohol, carbon monoxide, heavy metals, and many medicines including sedatives and opioids |
| Infectious | Viral inflammation of brain tissue, or severe infection elsewhere in the body |
| Structural | Head injury, repeated head impacts, or interrupted blood flow after cardiac arrest |
| Nutritional | Thiamine deficiency, which produces Wernicke encephalopathy |
Hepatic encephalopathy is the most familiar example. When the liver cannot clear substances absorbed from the gut, ammonia and other compounds reach the brain and disturb its function, which is why a liver function test is often part of the assessment when the cause is unclear.
What does it look like?
The first changes are usually quiet ones: reduced attention, a reversed sleep pattern with wakefulness at night, mild disorientation about time or place, or a personality shift that family notice before anyone else does. As it deepens, confusion becomes obvious, speech slows or slurs, and coordination suffers. Liver and kidney causes often produce a coarse flapping tremor when the arms are held out. Severe cases progress to profound drowsiness, seizures and coma. A feature that distinguishes it from most degenerative brain diseases is that it fluctuates, sometimes hour to hour, and it frequently improves when the underlying problem is corrected.
Why is the cause part of the name?
Because on its own the word describes a state, not a diagnosis, and states with identical appearances have entirely different explanations and outcomes. Encephalopathy is also often confused with encephalitis, which is a specific thing: inflammation of brain tissue itself, usually from infection or an immune attack. Encephalitis is one cause of encephalopathy, not a synonym for it. The practical consequence is that the term is only informative once qualified, and identifying which process is at work determines what is looked for next and how quickly the picture is expected to change.
Used in a sentence
The patient's confusion and altered alertness were attributed to hepatic encephalopathy.
Good to know
Encephalopathy describes a pattern of altered brain function rather than a diagnosis in itself, so it is qualified by its suspected cause, as in hepatic or toxic encephalopathy, before it carries clinical meaning.
Word origin
Where “encephalopathy” comes from
Formed from encephalo-, from Greek enkephalos, meaning brain, and -pathy, from Greek pathos, meaning suffering or disease.