There is no specific test used to diagnose HE. A Hepatic Encephalopathy diagnosis is based on a combination of three things:
- Your medical history;
- Your symptoms;
- A thorough clinical exam by your healthcare provider.
Blood tests can identify abnormalities associated with liver and kidney dysfunction, infections, bleeding and other conditions that may contribute to HE. However, these tests are not specific to HE and simply aid in making the Hepatic Encephalopathy diagnosis which is based on your history and symptoms. Ammonia levels are sometimes used, but these values alone cannot diagnose HE.
Because many of the symptoms of HE also occur in people with other types of brain disease or damage – such as stroke, brain tumor, or bleeding inside the skull – your healthcare provider may order specialized pictures of your brain to rule these out.
These imaging tests, as they’re called, are obtained by using various types of equipment and will likely include MRI (magnetic resonance imaging) and CT (computerized tomography) scans. In addition, your doctor may order an EEG (electroencephalogram), a test that measures the electrical activity of your brain, to look for brain wave changes associated with HE.
Since there is no specific “HE test” the diagnosis of HE is often referred to as a diagnosis of exclusion. This means that it’s important for your doctor to exclude – or rule out – other possible causes for your symptoms in order to correctly diagnose you with HE.