Treatment of Central Pontine Myelinolysis
The treatment of central pontine myelinolysis (CPM) focuses primarily on prevention through careful correction of sodium imbalances, as there is no specific curative therapy once demyelination has occurred. 1
Prevention
- Prevent CPM by limiting sodium correction to no more than 8 mmol/L in 24 hours in patients with hyponatremia 1, 2
- For patients with advanced liver disease, alcoholism, malnutrition, or prior encephalopathy, use even more cautious correction rates (4-6 mmol/L per day) due to higher risk of osmotic demyelination syndrome 1
- For severe symptoms (seizures, coma), initial correction by 6 mmol/L over 6 hours or until symptoms improve is recommended, but still maintain the 24-hour limit 1
- CPM can occur even when sodium correction is kept within recommended guidelines, suggesting that the condition may sometimes be a complication of hyponatremia itself rather than just its treatment 3
Management of Established CPM
- There is no specific curative treatment for CPM once it has developed 2
- Supportive care is the mainstay of management, focusing on preventing complications and optimizing recovery 1
- For patients with hypernatremia who developed CPM, reduce sodium at a rate of 10-15 mmol/L per 24 hours using D5W as the primary fluid for free water replacement 1
- In cases with neurological impairment, some clinicians have used steroids and intravenous immunoglobulins, though evidence for their efficacy is limited 4
Clinical Presentation and Diagnosis
- Clinical features typically reflect damage to descending motor tracts and include spastic tetraparesis, pseudobulbar paralysis, and locked-in syndrome 2
- Atypical presentations may include cerebellar syndromes without pyramidal tract involvement 2 or neuropsychiatric manifestations such as acute psychosis, paranoia, or hallucinations 5
- MRI is the imaging procedure of choice, showing an area of prolonged T1 and T2 relaxation in the central pons 2
- Initial MRI may be unremarkable, with changes becoming apparent only on repeat imaging after 1-2 weeks 5
Special Considerations
- CPM can occur in patients with minimal hyponatremia, particularly in those with AIDS, suggesting other contributing factors such as hypoalbuminemia 6
- CPM can also occur following rapid correction of hypernatremia, not just hyponatremia 4
- Recovery from CPM varies widely, ranging from no improvement to substantial neurological recovery 2
- Mortality risk is significantly higher in patients with AIDS who develop eunatremic CPM compared to those with hyponatremia-associated CPM 6
Monitoring During Treatment
- For patients with hyponatremia requiring correction, monitor serum sodium levels every 2-4 hours during initial treatment 1
- If overcorrection occurs, consider relowering with electrolyte-free water or desmopressin 1
- Watch for early signs of osmotic demyelination syndrome, which typically occurs 2-7 days after rapid correction 1