Central pontine myelinolysis and abnormalities in serum sodium

Central pontine myelinolysis (CPM) was found at autopsy in 21 of 220 consecutive patients with chronic liver disease. It showed the same incidence in chronic nonalcoholic as in chronic alcoholic liver disease but did not occur in acute liver disease. No patients had clinical symptoms of CPM, although 15 had encephalopathy. The lesion was active in 13 and inactive in 8. Laboratory data was incomplete in 2 patients with active and 8 with inactive CPM. Of 11 closely monitored patients with active CPM, 6 had a rapid rise in serum sodium of at least 8 meq/l per day, sustained for 5 or more days, and preceding death by 8-21 days; the other 5 showed no rise during 15-64 days prior to death. All patients with a large, rapid, sustained rise in serum sodium showed CPM at autopsy, but half of those with active CPM showed no such sodium changes even though closely monitored.