Osmotic demyelination syndrome improving after immune-modulating treatment: Case report and literature review

Osmotic demyelination syndrome (ODS), which embraces central pontine and extrapontine myelinolysis, is an uncommon neurological disorder that occurs due to plasma osmotic changes.

We present the case of a 55-year-old man, who presented with severe hyponatremia due to repeated vomiting, antidepressant treatment and consumption of large amounts of water. Fifteen days after sodium correction, the patient showed fluctuation of vigilance, dysarthria and dysphagia, tremor, cogwheel rigidity, bilateral facial palsy, ophthalmoplegia and tetraparesis. A brain MRI scan revealed extrapontine and later on pontine myelinolysis. He received intravenous steroids and subsequently immunoglobulin. His status began to improve gradually after completion of immunoglobulin and at three month-follow-up had no neurological deficit.

A comprehensive literature search of all reported ODS cases that received immunoglobulin, steroids or plasmapheresis was conducted in the electronic databases PubMed and Web of science.

Improvement was seen in most cases that received immunoglobulin either during treatment or in the first days after treatment. With regard to steroids, although most cases reported improvement in the following months their effect on the outcome is unclear. Most cases treated with plasmapheresis reported favorable outcome at variable follow-up time. Immunoglobulin and steroids have immunomodulatory effects, which could contribute to promotion of myelin repair in ODS. Plasmapheresis has effects on the immune system beyond removing myelinotoxins from the circulation. More evidence is required to support their use in ODS. However, in view of the disease severity, these therapeutic choices should be considered in the clinical management of ODS.