Mielinolisis central pontina en trasplante hepático / Central pontine myelinolysis after liver transplantation. Report of five cases

ABSTRACT

Background: Central Pontine Myelinolysis (CPM) is the most severe neurological complication after liver transplantation and apparently is not related to changes in osmolarity. Aim: To report five transplanted patients with CPM. Patients and Methods: In a series of 27 patients subjected to liver transplantation between 2005 and 2008, we found five patients who developed CPM. Results: All patients presented a severe hepatic encephalopathy. In the absence of alterations in osmolality, they developed, between the second to seventh day after transplantation, a central quadriplegia, hyperreflexia and Babinski sign, with preservation of sensorium. Magnetic resonance imaging showed demyelination of the motor pathway only in the protuberance. Motor recovery first began in the fingers and hands, followed by forearms, toes, feet, arms and finally the legs, defining a somatotopic recovery of the cortico-spinal pathway. Conclusions: This form of regaining motility shows that the selective involvement of the pyramidal tract in CPM, is according to its location in the pons and suggests a local entrapment. It is due to the structural rigidity of the protuberance that limits the expansive requirements of cytotoxic and vasogenic edema, and only affects the long fibers of cortico-spinal tracts, sensitized by encephalopathy. The entrapment syndromes generally preserve the axons, injure myelin and have no inflammatory reactions.