Fact-sheet: Central pontine myelinolysis
Updated on 09/26/2017 at 2:15 PM
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Definition
Central pontine demyelination, the etiologies of which include:
- osmotic (hyponatremia corrected too rapidly -> osmotic demyelination)
- malnutrition
- chronic alcoholism
- diabetes
- cancer
- chemotherapy
- renal failure
May be associated with extrapontine myelinolysis (50%).
Clinical features
Occurs in 75% of cases in chronic alcoholic patients. Rapid correction of severe hyponatremia ++ Pseudobulbar syndrome: Impaired consciousness Tetraparesis Seizure Dysarthria, dysphagia Oculomotor palsy
CT
Centropontine hypodensity (more advanced forms).
MRI
DELAYED signs: Initial MRI often negative, should be repeated in cases with a suggestive clinical picture.
Central pontine myelinolysis:
-T1 hypointense, T2 hyperintense centropontine lesion, triangular with posterior base in early forms, rounded in more chronic forms.
-Restricted diffusion (ADC increased in the late residual phase).
-Possible contrast enhancement in the early phase.
-Diffusion tensor imaging: edematous corticospinal tract with pontine fibers displaced posteriorly.
-No hemorrhage.
Extrapontine myelinolysis:
- Symmetric T2 hyperintensities of the basal ganglia (particularly the thalami), cerebral peduncles, internal and external capsules, hemispheric white matter, cerebellum, and spinal cord.
In children: Intense bilateral hippocampal hyperintensity may be associated.
Course: Possible clinical and radiologic regression.
Differential diagnosis
Faced with pontine T2 hyperintensities:
-Vascular (asymmetric involvement, clinical context): acute ischemia, leukoaraiosis (increased ADC)
-Inflammatory demyelinating lesion.
-Neoplastic: glioma, metastasis
-Metabolic: Wilson disease, low blood glucose Hypoglycemia, hypertensive encephalopathy