Several months prior to my transplant I began experiencing "brain fog," or hepatic encephalopathy, which the US National Library of Medicine defines as, "... a worsening of brain function that occurs when the liver is no longer able to remove toxic substances in the blood." Among the symptoms are change in sleep patterns, mild confusion, forgetfulness, mental fogginess, personality or mood changes, and poor concentration. Symptoms may become severe and life-threatening.
What is the lasting impact of hepatic encephalopathy on the brain? Doctors in Spain and Italy conducted preliminary research on this topic in a study published in the September 2011 issue of Journal of Hepatology. Researchers used advanced magnetic resonance imaging and Voxed based Morphometry analysis to assess brain tissue density of 51 healthy subjects and 48 patients with cirrhosis.
The researchers reported the following results:
Patients with cirrhosis presented decreased brain density in many areas of the grey and white matter. The extension and size of the affected areas were greater in patients with alcoholic cirrhosis than in those with post-hepatitic cirrhosis and correlated directly with the degree of liver failure and cerebral dysfunction (as estimated by neuropsychological tests and the antecedent of overt hepatic encephalopathy). Twelve additional patients with cirrhosis who underwent liver transplantation were explored after a median time of 11 months (7–50 months) after liver transplant... Compared to healthy subjects, liver transplant patients showed areas of reduced brain density in both grey and white matter.The doctors concluded, "... the loss of brain tissue density is common in cirrhosis, progresses during the course of the disease, is greater in patients with history of hepatic encephalopathy, and persists after liver transplantation."
This study isn't definitive, given the small sample size, yet should lead to further research. Nonetheless, it's troubling information for those of us with cirrhosis. At the same time, it explains a lot. When I become forgetful, I don't just have to use my usual excuses - advancing age, menopause - and can simply blame it on liver disease.
Image courtesy of The New York Public Library. www.nypl.org