Central Pontine Myelinolysis: Clinical and EEG Considerations

ABSTRACT.

Central pontine myelinolysis (CPM) is a severe toxic-metabolic encephalopathy with pronounced involvement of the central portion of the pons, where massive destruction occurs. Involvement of other central nervous system structures (extrapontine, “pontine plus” forms) is found in most severe cases.

This toxic-metabolic encephalopathy was initially ascribed to chronic alcoholism (Adams et al. 1959), but over the past decades it has been found that hyponatremia and its excessively fast correction represent the most common cause of CPM, regardless of existing alcoholism. Liver transplant has been recognized as another important cause of CPM.

Little is known, thus far, about the EEG characteristics of CPM. A personal observation (by A.M.L.) showed mildly excessive slowing in association with general low voltage output. The role of low voltage tracings in lower brainstem (pontine) involvement is the topic of special discussion.

KEY WORDS.:

• Alcoholism
• central pontine myelinolysis
• hyponatremia
• liver transplant
• low voltage EEG