Brief overview
- Cause: Severe dysfunction of the liver; usually triggered by chronic liver disease such as cirrhosis of the liver
- Symptoms: Neuro-psychiatric disorders of varying severity depending on the degree; reduced cognitive performance and concentration problems, confusion, inappropriate behavior, hand tremors, slurred speech, drowsiness, disorientation; in the worst case, coma
- Course of the disease and prognosis: Depends on the degree of the disease (pre-stage and grade 1-4); the higher the grade, the worse the prognosis; recurrence possible after treatment if the cause has not been treated
- Treatment: Mainly elimination of triggering factors, e.g. discontinuation of certain medications such as dehydrating agents or narrowing of an existing liver stent
What is hepatic encephalopathy?
Hepatic encephalopathy (HE) is a common and serious complication of chronic liver disease and acute liver failure. The symptoms are caused by disorders of the brain and range from mild concentration problems, confusion and slurred speech to unconsciousness, the so-called hepatic coma.
How does hepatic encephalopathy develop?
Rising concentrations of harmful substances in the blood
If the liver is no longer able to break down toxins into harmless components, the concentration of harmful substances in the blood increases. This has severe effects on the whole body, especially on the central nervous system (CNS), in particular the brain cells. Various substances are involved – above all ammonia, a breakdown product of various amino acids (building blocks of proteins).
Normally, the liver processes ammonia into non-toxic urea, which is excreted. If this mechanism is disrupted, more and more ammonia enters the brain and causes certain brain cells – the so-called astrocytes – to swell. The intracranial pressure rises. Ultimately, liver failure leads to an accumulation of fluid in the brain (cerebral edema).
Hepatic encephalopathy: triggers
Acute liver failure as a result of a viral infection or poisoning is a possible trigger for acute hepatic encephalopathy. In this case, liver function is impaired within a few days.
In most cases, however, the cause is a chronic liver disease to which other factors are suddenly added. In such cases, it does not develop suddenly, but slowly and insidiously. The factors include
- Bleeding in the gastrointestinal tract
- Protein-rich food
- Diarrhea, vomiting or laxatives
- Certain medications (e.g. sedatives)
Sometimes doctors treat liver cirrhosis with a so-called portosystemic shunt, an artificial connection in the vascular system that ensures that the blood from the intestines, stomach and spleen is no longer collected and passed through the damaged liver. This is sometimes useful before a liver transplant. However, a possible side effect of this procedure is hepatic encephalopathy, as the blood is no longer filtered.
What are the symptoms?
The swollen cells in the brain change the concentration of various messenger substances. This impairs communication between the nerve cells. As a result, hepatic encephalopathy causes various neurological symptoms, which are divided into four stages and a preliminary stage depending on their severity.
Neuropsychological and neurophysiological tests as well as imaging procedures such as magnetic resonance imaging are used for diagnosis based on the neuropsychological symptoms.
Pre-stage (minimal hepatic encephalopathy)
- Concentration
- Short-term memory
- Visual-spatial perception
- Processing of information
- Fine motor skills
Nothing can be determined neurologically at this stage. However, this stage can be detected with various psychometric tests such as number or drawing tasks.
Caution: There is already an increased risk of road traffic accidents!
Hepatic encephalopathy: stage 1
In the first stage, the symptoms are still comparatively mild and, like the preliminary stage, are often only recognizable to close relatives or friends:
- sleep disturbances
- Mood swings
- Euphoria
- Mild confusion
- Difficulty concentrating
- Eye fluttering
Hepatic encephalopathy: stage 2
With the help of electroencephalography (EEG), changes in brain waves can be recorded from the second stage onwards, which indicate hepatic encephalopathy. Otherwise, the symptoms from stage 1 intensify and are supplemented by others:
- personality changes
- disorientation
- fatigue
- Memory disorders
- Altered facial expressions (grimacing)
- Rough trembling of the hands (“flapping tremor”)
Hepatic encephalopathy: stage 3
The intoxication is far advanced and the symptoms are severe.
- Patient sleeps most of the time.
- Severe disorientation
- “Flapping tremor”
- Indistinct speech
Hepatic encephalopathy: stage 4
- Liver coma (“hepatic coma”)
- Patient can no longer be woken up, but still reacts to stimuli.
In acute liver failure, the affected person usually progresses through the individual stages very quickly and there is a risk of falling into a coma within days. However, hepatic encephalopathy only progresses slowly and gradually in people with chronic liver failure. In most cases, there is no pronounced cerebral edema during the course of the disease.
Chronic progression is particularly common in older people. They usually only show mild neuropsychiatric symptoms in their “basic condition”. In between, acute phases with more pronounced symptoms occur.
What is the life expectancy?
Hepatic encephalopathy can be treated. However, if the actual cause is not eliminated, HE very often recurs after some time and entails the same risks as before. Accordingly, drug prophylaxis with lactulose is recommended.
Life expectancy is greatly reduced by hepatic encephalopathy. However, an exact life expectancy cannot be predicted, as the prognosis depends on the severity of the HE, the underlying disease and the available treatment options.
Hepatic encephalopathy: treatment
Elimination of triggering factors
- Stopping gastrointestinal bleeding
- Discontinuation of dehydrating agents (diuretics)
- Discontinuing benzodiazepines and/or taking antagonists
- Narrowing of a liver shunt
- Treatment of certain infections
Reduction of the ammonia load
- Lactulose and Lacitol increase the acidity in the intestine, which reduces the absorption of ammonia from the intestine
- Taking an antibiotic that weakens bacteria that produce ammonia
- A temporary low-protein diet. Reduce meat and eggs in particular, as ammonia is produced during their digestion
Further measures
The following substances are sometimes additionally administered, as they sometimes further improve the patient’s condition:
- Zinc (to prevent cell damage in the liver and help regenerate it)
- Intravenous ornithine aspartate (to accelerate the urea cycle, thereby reducing ammonia levels and improving brain function)
- Branched-chain amino acids (to prevent the body from breaking down its own protein to compensate for a deficiency, as this would produce ammonia)
