[The possible causes of central pontine myelinolysis after liver transplantation].

Objective: To sum up the clinical characteristics of patients with central pontine myelinolysis (CPM) after orthotopic liver transplantation (OLT) and to document the possible causes on CPM.
Methods: 142 patients' data with OLT between January 1999 to May 2003 were analyzed retrospectively. The following risk factors during preoperation were analyzed between patients with and without CPM: primary liver disease, preoperative serum sodium level, magnesium level and plasma osmolality, fluctuation degree of serum sodium concentration, and immunosuppressive drugs level etc.
Results: A total of 13 (9.2%) neurologic symptoms appeared in 142 patients post operation, including 5 cases (3.5%) with CPM and 8 cases (5.6%) with cerebral hemorrhage or infarct. 2 patients who developed CPM after OLT had hyponatremia history before operation (serum sodium <130 mmol/L), and the mean serum sodium level was (130.6 +/- 5.54) mmol/L. The serum sodium level was significantly lower in CPM than that of patients without neurologic complication or with cerebral hemorrhage/infarct (P <0.05). The rises of serum sodium perioperative 48 h after OLT in patients with CPM was significantly greater than that in patients with cerebral hemorrhage/infarct or no neurologic complication (19.5 +/- 6.54) mmol/L, (10.1 +/- 6.43) mmol/L, (4.5 +/- 4.34) mmol/L, respectively, (P < 0.05). Plasma osmolality increased greatly postoperatively in patients with CPM. Hypomagnesemia was noted in all patients perioperatively, but there was not significant difference among groups. The duration of operation in CPM was longer than in others (492 +/- 190.05) min (P <0.05). Cyclosporin A (CsA) levels were normal in all patients, but there was significant difference between patients with and without neurologic complication (P <0.05).
Conclusions: CPM may be more prevalent following liver transplantation. Although the diagnosis of CPM after OLT can be made by complete neurologic evaluation including magnetic resonance imaging (MRI) of the head, the mortality is still very high. The occurrence of CPM may be associated with hyponatremia, rapid rise of serum sodium concentration, postoperative increase of plasma osmolality, the duration of operation and high CsA levels.