Central pontine myelinolysis: clinical and MRI correlates.

Central pontine myelinolysis (CPM) is a rare condition characterised by spastic tetraparesis, pseudobulbar palsy and the 'locked-in syndrome'. It is frequently fatal. We report a patient who developed CPM secondary to profound hyponatraemia and who recovered with no disability. Serial magnetic resonance imaging (MRI) demonstrated characteristic abnormalities within the pons at the onset of the disease, whereas computerised tomography was normal. Clinical improvement was followed six months later by progressive resolution of the MRI changes, with almost complete resolution after 18 months. Clinical and MRI findings correlate early in the course of CPM but clinical recovery predates MRI improvement by several months.