What is Central Pontine Myelinosis?

Central pontine myelinosis is a rare neurological disorder that results from acute damage to a part of the brainstem called the pons. Problems occur when the protective myelin linings of nerve cells in the pons start to disintegrate. The exact causes of central pontine myelinosis are not clear, but people who receive aggressive treatment for very low sodium levels are at the highest risk of developing symptoms. Patients may experience slurred speech, mental slowness and confusion, motor movement difficulties, and other serious complications. There is no cure for the disorder, but medications and guided therapy can help many people regain some of their cognitive and physical abilities.

Myelin sheaths are composed of specialized cells that protect delicate structures in the nervous system and facilitate rapid electrical signaling. In the pons, myelin sheaths are vital to normal cognitive functioning and control over muscle movements throughout the body. Central pontine myelinosis is the degeneration of these important sheaths. In some cases, myelin destruction extends beyond the pons to impair other areas of the brain and central nervous system.

Receiving hospital treatment for hyponatremia, or blood sodium deficiency, is the leading risk factor for developing central pontine myelinosis. Intravenous fluids and medications that are meant to restore normal sodium levels can have major, immediate impacts on the brainstem and quickly lead to myelin degeneration. Patients who suffer from long-term alcoholism, malnutrition, anorexia, or chronic liver failure are at an increased risk of brainstem complications from hyponatremia treatment.

The symptoms of central pontine myelinosis can vary, but most patients first experience a phenomenon called spastic quadriplegia. Muscles in the arms and legs become stiff, weak, and prone to sudden spasms. In addition, many people with the condition develop speech difficulties, changes in vision, difficulties swallowing, and poor balance. The disorder may also lead to deficits in concentration, memory, and information processing. It is also possible to suffer from delirium or slip into a coma shortly after the first symptoms arise.

A neurologist can diagnose central pontine myelinosis by evaluating physical symptoms, reviewing a patient's medical history, and looking at imaging scans of the brain. Magnetic resonance imaging often reveals subtle swelling or tissue damage on the pons. Treatment for the condition is supportive in nature and typically involves the use of antipsychotics, antidepressants, muscle relaxers, and other medications to help with acute symptoms. Patients who are mentally stable are usually enrolled in physical therapy programs to help them rebuild muscle strength and improve coordination.