This issue of Metabolic Brain Disease contains papers based on part of the lectures given at the 5th International Hannover Conference on Hepatic Encephalopathy, which was held from May 23–May 26, 2009, in Mainz, Germany.

In line with the tradition of these conferences scientists from various disciplines came together to discuss the pathophysiological basis, the clinical features, and therapeutical access to neuropsychiatric syndromes associated with liver disease. Main topics of the conference besides the pathophysiology of hepatic encephalopathy were the reversibility of hepatic encephalopathy after liver transplantation, neurological complications after liver transplantation, and the role of hyponatremia for the development, the prognosis and the diagnosis of hepatic encephalopathy. These topics are covered in this issue by representative papers.

The organizers wish to express their gratitude to the participants of the meeting and the authors of the papers within this issue of Metabolic Brain Disease. But, although people were in high spirits due to fruitful scientific discussions and pleasant surroundings, everybody felt a painful loss: Dr. Andres Blei, who died in October 2008, had regularly participated in the Hannover Conferences on Hepatic Encephalopathy. His presence at the former conferences was fondly remembered and his spirit was clearly missed in Mainz.

Dr. Blei was one of the leaders in hepatology and an outstanding expert in hepatic encephalopathy. He was a role model as clinician and as scientist and he was also a wonderful person. One of Dr. Blei’s most admirable and amiable personal attributes was his continuous friendly and open-minded encouragement of young people. He liked to discuss with them, and they felt respected and encouraged by his mentorship.

In memory of his exceptional personality and excellent scientific work we decided to honor Dr. Andy Blei’s memory by the establishment of the “Andy-Blei-Travel-Awards”. These awards shall be granted to young scientists working in the field of hepatic encephalopathy to enable them to take part in the International Hannover Conferences on Hepatic Encephalopathy now and in the future.

The awardees of the conference in 2009 were Dr. Chantal Bemeur, Neuroscience Research Unit, Hopital Saint-Luc, University of Montreal; Dr. A.R. Jayakumar, Dept of Neuropathology, VA Medical Center, University of Miami; Dr. Mark McPhail, Imperial College School of Medicine, London; Dr. Carmina Montoliu, Laboratory of Neurobiology, Centro de Investigacion Principe Felipe, Valencia; Dr. Chris Rose, Neuroscience Research Unit, Hopital Saint-Luc, University of Montreal and Dr. Hannah Wilson, Univ. Dept. of Medicine, Royal Free Hospital, London.

The awards were granted thanks to the generous support of several sponsors. We would like to thank the Deutsche Forschungsgemeinschaft, the Federal Ministry of Education and Research, the Integrated Research and Treatment Center Transplantation at Hannover Medical School, Solvay Pharmaceuticals, Merz Pharmaceuticals GmbH, the Falk Foundation, the B.Braun-Foundation, Novartis Pharmaceuticals, Ocera Pharmaceuticals, Fresenius Kabi and B. Braun Melsungen AG.