Hepatic encephalopathy is a neurological disorder that results from liver dysfunction. The course of the disease varies from coma to personality and cognitive dysfunction. Hepatic encephalopathy is the most dangerous complication of liver disease and in many cases leads to death in a very short time. What are the causes and symptoms of HE?
What is hepatic encephalopathy?
Hepatic encephalopathy is a series of neurological and psychiatric disorders that are caused by the impaired ability of the liver to remove ammonia and other toxins from the blood. Ammonia, phenols, mercaptans, and fatty acids are toxic substances that damage nerve tissue, leading to psychiatric disorders. This failure is often accompanied by esophageal varices and ascites, which are symptoms of cirrhosis. HE is most often a complication of untreated cirrhosis. It is estimated that HE occurs in 30-40% of patients with cirrhosis. Other causes of HE may include both hepatitis and Reye’s syndrome.
Hepatic encephalopathy: types
HE occurs in the form of:
- mild- as a latent form,
- overt – with more complex and complicated symptoms.
The latent form of HE is usually only detectable with clinical tests. Day-to-day symptoms are so minimal as to be almost unnoticeable. Based on duration, overt symptoms of HE are divided into episodic, recurrent (if time to next episode is less than 6 months), and chronic forms. There are several factors that cause an episode of hepatic encephalopathy. These include:
- infections (e.g., pneumonia),
- gastrointestinal bleeding,
- kidney dysfunction,
- alcohol abuse,
- surgery on an organ,
- excessive protein intake,
- use of drugs that depress the nervous system (e.g. benzodiazepines),
- electrolyte disturbances – e.g. hypokalemia, i.e. too low a concentration of potassium in the blood.
Hepatic encephalopathy: symptoms
The symptoms of HE include a number of neurological and psychiatric disorders that determine the intellectual, cognitive and personality zones. The clinical course of hepatic encephalopathy can vary widely. In some patients, the disease will progress slowly, even asymptomatically. In others, symptoms will increase gradually but the course will be much more turbulent. Often, those closest to the patient say that the patient has changed beyond recognition. They may be extremely emotional and their behaviour may be completely unpredictable.
There are 5 degrees of HE in the clinical diagnosis. Grade 0 shows no symptoms, while grade 4 is the most severe, including coma.
Hepatic encephalopathy: diagnosis
Hepatic encephalopathy is diagnosed by:
- medical history,
- laboratory tests (determination of blood ammonia, liver enzymes, potassium and sodium levels)
- electroencephalography (EEG),
- CHESS Scale – the patient answers 9 questions; a score of 0 or 1 indicates no disease, and a score of 9 indicates severe disease,
- exclusion of other diseases – for this purpose additional examinations are performed, e.g. CT, MRI, blood glucose level and others.
Hepatic encephalopathy: treatment
Treatment is based on a diet limiting protein intake to 1-1.5 g/kg body weight per day. Antibiotics and drugs that will accelerate the excretion of toxins from the body, especially ammonia, are also given.
HE is reversible provided specialized treatment is administered early enough and provided the patient does not have other neurological or metabolic diseases. In a few cases, neuropsychiatric changes become permanent. Patients with slow progression of HE have a better prognosis for recovery. Other patients must take special care to eat a proper diet and take appropriate medications to prevent recurrence of hepatic encephalopathy.