Risk Factors for Central Pontine and Extrapontine Myelinolysis After Liver Transplantation

BACKGROUND: Central pontine and extrapontine myelinolysis (CPM/EPM) are severe neurologic complications after liver transplantation. METHODS: The present work retrospectively evaluated single-center prevalence of CPM/EPM and associated risk factors: cause of liver disease, hepatic encephalopathy, preoperative, intraoperative, and perioperative blood components use, serum levels, and variation of Na, Cl, and K and immunosuppression were compared between CPM/EPM patients and control group of transplanted patients without neurologic complications. RESULTS: Among 997 transplants, CPM/EPM were diagnosed in 11 patients (1.1%), of whom four were CPM, one was EPM, and six were associated CPM and EPM. Control group consisted of 44 transplanted patients. Central pontine and extrapontine myelinolysis patients experienced higher intraoperative and perioperative serum Na/24 hr variations compared to controls (16.69 ± 5.17 vs. 9.8 ± 3.4 mEq/L, P = 0.001). Maximum peak of intraoperative or perioperative serum Na was significantly higher in patients compared to controls (151.5 ± 3.3 vs. 140.8 ± 6.2 mEq/L, P ≤ 0.001), but no difference in preoperative serum Na was detected. Three patients presented hypernatremia as isolated risk factor. CONCLUSION: Extrapontine myelinolysis can be found isolated or associated with CPM in up to two of three liver transplanted patients with myelinolysis. A marked variation of perioperative serum Na remains the main risk factor even in patients without preexisting hyponatremia; however, isolated hypernatremia may be solely responsible in some cases.