Micrograph of Alzheimer type II astrocytes, as may be seen in hepatic encephalopathy Investigations The diagnosis of hepatic encephalopathy can only be made in the presence of confirmed liver disease (types A and C) or a portosystemic shunt (type B), as its symptoms are similar to those encountered in other encephalopathies. To make the distinction, abnormal liver function tests and/or ultrasound suggesting liver disease are required, and ideally a liver biopsy. The symptoms of hepatic encephalopathy may also arise from other conditions, such as bleeding in the brain and seizures (both of which are more common in chronic liver disease). A CT scan of the brain may be required to exclude bleeding in the brain, and if seizure activity is suspected an electroencephalograph (EEG) study may be performed. Rarer mimics of encephalopathy are meningitis, encephalitis, Wernicke's encephalopathy and Wilson's disease; these may be suspected on clinical grounds and confirmed with investigations. The diagnosis of hepatic encephalopathy is a clinical one, once other causes for confusion or coma have been excluded; no test fully diagnoses or excludes it. Serum ammonia levels are elevated in 90% of people, but not all hyperammonaemia (high ammonia levels in the blood) is associated with encephalopathy. A CT scan of the brain usually shows no abnormality except in stage IV encephalopathy, when brain swelling (cerebral oedema) may be visible. Other neuroimaging modalities, such as magnetic resonance imaging (MRI), are not currently regarded as useful, although they may show abnormalities. Electroencephalography shows no clear abnormalities in stage 0, even if minimal HE is present; in stages I, II and III there are triphasic waves over the frontal lobes that oscillate at 5 Hz, and in stage IV there is slow delta wave activity. However, the changes in EEG are not typical enough to be useful in distinguishing hepatic encephalopathy from other conditions. Once the diagnosis of encephalopathy has been made, efforts are made to exclude underlying causes (such as listed above in "causes"). This requires blood tests (urea and electrolytes, full blood count, liver function tests), usually a chest X-ray, and urinalysis. If there is ascites, a diagnostic paracentesis (removal of a fluid sample with a needle) may be required to identify spontaneous bacterial peritonitis (SBP). Classification West Haven criteria The severity of hepatic encephalopathy is graded with the West Haven Criteria; this is based on the level of impairment of autonomy, changes in consciousness, intellectual function, behavior, and dependence on therapy. * Grade 0 - No obvious changes other than a potentially mild decrease in intellectual ability and coordination * Grade 1 - Trivial lack of awareness; euphoria or anxiety; shortened attention span; impaired performance of addition or subtraction * Grade 2 - Lethargy or apathy; minimal disorientation for time or place; subtle personality change; inappropriate behaviour * Grade 3 - Somnolence to semistupor, but responsive to verbal stimuli; confusion; gross disorientation * Grade 4 - Coma Types Micrograph showing liver cirrhosis, a condition that often precedes hepatic encephalopathy. Trichrome stain. A classification of hepatic encephalopathy was introduced at the World Congress of Gastroenterology 1998 in Vienna. According to this classification, hepatic encephalopathy is subdivided in type A, B and C depending on the underlying cause. * Type A (=acute) describes hepatic encephalopathy associated with acute liver failure, typically associated with cerebral oedema * Type B (=bypass) is caused by portal-systemic shunting without associated intrinsic liver disease * Type C (=cirrhosis) occurs in people with cirrhosis - this type is subdivided in episodic, persistent and minimal encephalopathy The term minimal encephalopathy (MHE) is defined as encephalopathy that does not lead to clinically overt cognitive dysfunction, but can be demonstrated with neuropsychological studies. This is still an important finding, as minimal encephalopathy has been demonstrated to impair quality of life and increase the risk of involvement in road traffic accidents. Minimal HE The diagnosis of minimal hepatic encephalopathy requires neuropsychological testing by definition. Older tests include the "numbers connecting test" A and B (measuring the speed at which one could connect randomly dispersed numbers 1–20), the "block design test" and the "digit-symbol test". In 2009 an expert panel concluded that neuropsychological test batteries aimed at measuring multiple domains of cognitive function are generally more reliable than single tests, and tend to be more strongly correlated with functional status. Both the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and PSE-Syndrom-Test may be used for this purpose. The PSE-Syndrom-Test, developed in Germany and validated in several other European countries, incorporates older assessment tools such as the number connection test.
complications of Cirrhosis
complications of Hepatitis
complications of Acute liver failure
complications of Hepatitis B
complications of Hepatitis A
medical cause of Liver cancer
medical cause of Cirrhosis
complications of Hepatitis E