Hepatic encephalopathy

Hepatic encephalopathy is diagnosed by looking at the medical history, signs and symptoms, medicine use, and the results of blood tests and other tests. Tests and procedures that may be used to diagnose acute liver failure include:

• Psychological exam. Tests that look for thinking skills may be used when symptoms are hard to detect, such as in covert hepatic encephalopathy. A test that involves naming animals is one such test.
• Neuropsychological tests. Tasks that involve the use of pencil and paper can be used to assess thinking, motor skills, speed and hand coordination. The Psychometric Hepatic Encephalopathy Score is one such test. Tests that check reaction time to sounds, such as the continuous reaction time test, also may be used.
• Blood tests. Blood tests for ammonia, electrolytes, glucose level, C-reactive protein and other markers can help rule out other conditions that have similar symptoms, such as diabetes and stroke. Blood tests also show whether infections or use of alcohol or medicines are a factor.
• Electroencephalogram, also called EEG. An EEG measures electrical activity in the brain. This helps healthcare professionals understand the severity of the condition.
• Imaging tests. A CT scan or MRI that looks at the liver and blood vessels may be done to rule out stroke, seizures or other causes. Scans of the gut area may show issues with liver blood flow.

Stages

The West Haven criteria are used to classify severity of disease. There are five grades, also called stages, of hepatic encephalopathy:

• Grade 0. There are no symptoms, and hepatic encephalopathy is found only by tests.
• Grade 1. Typical symptoms include sleep issues, mild confusion and mood swings.
• Grade 2. Disorientation and unusual behavior are common in grade 2. Daytime drowsiness also may be present.
• Grade 3. Extreme confusion and sleepiness are typical, though the person can still respond to others.
• Grade 4. A type of coma called hepatic coma is present, and the person cannot respond to others.

Grade 0 and grade 1 are known as covert hepatic encephalopathy because in these stages, the condition may not be noticeable. Grades 2 to 4 are called overt hepatic encephalopathy because the symptoms are noticeable.

In the early stages of hepatic encephalopathy, it may be hard to assign a grade. Family members living with someone who is ill may be able to help healthcare professionals by talking about behavior changes that are part of hepatic encephalopathy.

In advanced stages of hepatic encephalopathy, the Glasgow Coma Scale may be used to assess verbal and physical response to sound, touch and other stimuli in people who aren't conscious.