[Central pontine myelinolysis after hepatic transplantation]

We report two cases of central pontine myelinolysis (CPM) following liver transplantation. The incidence may well be underestimated as in the past the diagnosis of CPM was based on postmortem findings. Malnutrition, poor clinical condition, encephalopathy are common features of transplanted patients developing CPM. The clinical course is characterized by a biphasic pattern; after normal recovery from anesthesia, there is a subsequent and gradual deterioration in the neurological state. The complex syndrome associates loss of consciousness, flaccid quadriplegia and pseudobulbar palsy. Among the many factors suspected of inducing CPM, a rapid correction of natremia (> 12 mmole/l/day) seems most probable. With regards to liver transplantation, CPM presents rather specific problems. Delaying transplantation to correct hyponatremia carries a risk of severe hepatic encephalopathy. On the other hand, the intraoperative compensation of blood losses with high sodium content blood products tends to induce an abrupt rise in sodium serum concentration. Moreover, renal capacity to excrete sodium is often impaired, due to hepatic insufficiency and surgical procedure. Transplantation should not be delayed, but as infusion of large amounts of sodium cannot be avoided (fresh frozen plasma, human albumin, red blood cells), natremia may be controlled by continuous veno-venous hemofiltration with low sodium content substitution fluids.