Functional Magnetic Resonance Imaging and Spectroscopy of the Brain in Patients With Chronic Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common neuropsychiatric abnormality, complicating the course of liver disease patients. In the UK, cirrhosis accounts for 4000 deaths per year, and 500,000 people are thought to be infected with chronic hepatitis C, of which up to 20% will develop cirrhosis over 20 years. The condition has been difficult to monitor objectively.

Despite the fact that the syndrome was probably first recognised two thousand years ago, the exact pathogenesis still remains unclear. It is thought to represent a reversible disturbance in brain chemistry and consequent brain swelling, in response to blood containing unfiltered gut-derived toxins entering the cerebral circulation. There is no recognised 'gold standard' test to diagnose and monitor this important, disabling condition. I have developed a novel combination of magnetic resonance imaging (MRI) sequences at 3 Tesla to study the effects of hepatic encephalopathy on the brain in patients with cirrhosis.

We propose to investigate alterations in brain size, function and chemistry before, and then at intervals after 4 weeks anti-encephalopathy treatment with L-ornithine L-aspartate. This will enable the assessment of both the baseline brain alterations of the cohort and the brain's response to therapy and correlation with their clinical response. As such this longitudinal study would allow us to define the sensitivity of the MR techniques.

Each of 50 patients will have blood tests, a 1 hour MRI brain scan and psychometric testing. The psychometric testing will be performed with both a computer-based battery and conventional paer-based tests. They will then be given L-ornithine L-aspartate (LOLA) to take orally for 4 weeks and have repeat blood tests, MRI and psychometric tests.

We will then determine if there is a correlation between the MR data and the results of the psychometric testing.