Central nervous system lesions in adult liver transplant recipients: clinical review with implications for management

Fever in the solid organ transplant patient

Fever is common in the solid organ transplant patient and may be produced by a variety of processes. The approach to the febrile transplant patient must include an extensive search for infection, which may be aided by considering the organ transplanted, time after transplantation, and the patient's immunosuppressed state. In addition, a number of noninfectious causes of fever exist in this population, including allograft rejection, drug fever, and thromboembolic disease. A review of the pathogens commonly noted in posttransplant patients is presented, emphasizing risk factors for disease, typical time of presentation, and particular organ groups affected. In addition, the authors review the noninfectious causes of fever in the solid organ transplant patient.

Central pontine myelinolysis and cyclosporine neurotoxicity following liver transplantation

In a recent series of 44 liver transplants we identified both extrapontine myelinolysis (EPM) - characteristic of cyclosporine neurotoxicity - and central pontine myelinolysis (CPM) in 5 recipients posttransplant. An additional 2 recipients had EPM only posttransplant. MRIs performed in 4 asymptomatic recipients were normal. Large perioperative shifts in serum sodium, hypomagnesemia, and high cyclosporine levels may play a role in the development of these lesions, although the evidence from this study is inconclusive. In addition to supportive care, dilantin was started in patients who had seizures; aggressive magnesium replacement was initiated for hypomagnesemia, and cyclosporine levels were reduced in all patients. All patients demonstrated a slow steady recovery and all but 2 are at home at the time of writing. CPM may be more prevalent than previously appreciated following liver transplantation, although its prognosis may not be as dismal.

Acquired hepatocerebral degeneration in a liver transplant recipient

A 47-year-old-man lapsed into coma 12 h after liver transplantation, and remained comatose until death 38 days later. Prior to transplantation he had repeated episodes of hepatic encephalopathy, but no fixed neurological signs. Autopsy revealed typical features of acquired hepatocerebral degeneration with diffuse but patchy pseudolaminar cortical necrosis, variable amount of neuronal loss in the cerebral cortex, basal ganglia and other areas, and proliferation of Alzheimer type II glia. In addition, there was central pontine and extensive extrapontine myelinolysis involving the lateral and medical geniculate bodies, the thalamus, internal capsule, fornix, mamillothalamic tract, white matter bundles in the caudate and pallidum, the oculomotor nuclei and the foliar white matter of the cerebellum. The distinction between myelinolytic lesions and lesions due to hepatocerebral degeneration was not always clear. Although neurological complications and brain lesions are rather common after liver transplantation, there have been no reports of acquired hepatocerebral degeneration in liver transplant recipients. Our data lend support to the idea that a single prolonged comatose episode, due to hepatic dysfunction, may induce permanent parenchymal brain damage.

Infections in liver transplantation: risk factors and strategies for prevention

Infection affects up to 70% of liver transplant recipients and is the second most common complication after rejection and graft dysfunction. Identified risk factors for infection include: previous transplantation; type of biliary anastomosis; transfusion requirements at surgery; surgical complications; duration of operation; duration of postoperative ventilation; serological status of donor and recipient; steroid use and serotherapy for rejection; and pre- and post-transplant antibiotic usage. The majority of symptomatic infections are bacterial and relate to surgery (intra-abdominal, biliary and wound infections), ventilation and intravenous cannulae. Cytomegalovirus infections occur in 45-100% of recipients but are asymptomatic in the majority. Fungal infections are mostly due to Candida albicans but infections due to Aspergillus spp. occur in approximately 6% and carry a high mortality. There are very few prospective comparative trials of antimicrobial prophylaxis in this patient population. The management of these patients needs to be based on such studies.

Disseminated Nocardia transvalensis infection resembling pulmonary infarction in a liver transplant recipient

Infections due to Nocardia transvalensis are extremely rare: only four disseminated infections with this pathogen have been reported, three of which ended fatally. This is the first report of a liver transplant recipient with Nocardia transvalensis infection. The patient had disseminated infection with pulmonary involvement, which presented as pulmonary infarction. Despite a ten-day delay in the administration of correct therapy, he responded rapidly to trimethoprim-sulfamethoxazole. The pitfalls of differentiating nocardial infection from pulmonary thromboembolism in solid organ transplant recipients and the diagnostic considerations unique to liver transplant recipients are discussed.