Central pontine myelinolysis

Clinc

• CPM is a neurological condition involving severe damage to the myelin sheath of nerve cells in the Pons
• It is characterized by Acute paralysis, Dysphagia, Dysarthria, Pseudobulbar palsy, and locked-in syndrome (loss of all muscle movement except for eye movements).
• Since this original description, demyelination in other areas of CNS associated with osmotic stress has been described outside the pons (extrapontine).
• Osmotic demyelination syndrome is the term used for both central pontine myelinolysis and extrapontine myelinolysis.
• Its most common cause is the rapid correction of low blood sodium levels (Hyponatremia). If the sodium levels are corrected too quickly, water gets driven out of the brain cells which causes widespread damage throughout the entire brain. Once CPM has begun, it cannot be corrected. Therefore, the best treatment of CPM is prevention by correcting hyponatremia at a consistent rate.[13]

Signs and symptoms

• Prior to its onset, patients may present with the neurological signs and symptoms of hyponatraemic encephalopathy such as nausea and vomiting, confusion, headache and seizures. These symptoms may resolve with normalisation of the serum sodium concentration.
• 3 to 5 days later, a second phase of neurological manifestations occurs correlating with the onset of myelinolysis.
• Observable immediate precursors may include
  • Seizures
  • Disturbed consciousness
  • Gait changes
  • Decrease / Cessation of respiratory function
• Classical clinical presentation is the progressive development of
  • Spastic quadriparesis
  • Pseudobulbar palsy
  • Emotional lability (pseudobulbar affect)
  • Other more variable neurological features associated with brainstem damage.
  • These result from a rapid myelinolysis of the corticobulbar and corticospinal tracts in the brainstem.

10% of people with central pontine myelinolysis, extrapontine myelinolysis is also found. In these cases symptoms of Parkinson's disease may be generated.

Related disease

Central pontine myelinolysis may also occur in patients prone to hyponatremia affected by:

• Severe liver disease (e.g., cirrhosis) / Liver transplant / Alcoholism / Hypokalemia
• Severe electrolyte disorders: Hypothermia / Severe burns / Malnutrition / Anorexia nervosa / Hyperemesis gravidarum
• HIV/AIDS
• Wernicke encephalopathy

Central pontine myelinolysis Entities / Miasms

	PLV	TBE
Paralysis, Spastic or Spasm	+++
Dysarthria or Mouth speech difficult	+++
Dysphagia	+++	+++
Consciousness altered	+++	+++
Seizure	+++	+++
Ataxia or Gait abnormality or in coordination		+++
Qauderi paresis	+++	+++
Emotional lability		+++