PEDBASE.org - The Pediatric Database - Detailed information of CENTRAL PONTINE MYELINOLYSIS

CENTRAL PONTINE MYELINOLYSIS

DEFINITION:

A neurodegenerative disorder characterized by degeneration of the CNS white matter that primarily affects the pons.

EPIDEMIOLOGY:

incidence: ?
age of onset:
- mostly in adults but has been seen in children as young as 3 years
risk factors:

1. Major

iatrogenic - rapid correction of hyponatremia
other electrolyte disturbances, alcoholism, liver disease

2. Minor

adrenal insufficiency, brain tumor, carcinoma, cerebral edema, chemotherapy, congestive heart failure, cranio-pharyngioma, Hodgkin's Disease, hyperglycemic coma, leukemia, malnutrition, renal disease, sepsis, sickle cell disease, Wilson's Disease

PATHOGENESIS:

1. Background

rapid rise in serum sodium -> osmotic injury to the endothelial cells -> increased capillary permeability -> altered blood-brain barrier and/or release of myelinotoxic factors -> edema and demyelination
affected areas tend to be those with extensive grey-white matter apposition: base of pons, striatum, thalamus, geniculate bodies

PATHOLOGY:

1. In Affected Areas

destruction of myelin shealth, i.e., basis pontis (base of pons)
absent or decreased oligodendroglia
foamy macrophages

CLINICAL FEATURES:

1. Neurological Manifestations

reflect dysfunction of various areas of the pons
degree of severity related to size of lesion
- dysarthria
- dysphasia
- extraocular muscle palsies
- pupillary abnormalities
- quadraparesis or quadraplegia
- changes in the corticospinal reflexes
- tremor
- incontinence
- seizures
- "locked-in" syndrome

INVESTIGATIONS:

1. Serum

hyponatremia (<120 mmol/l)
other electrolyte disturbances

2. Imaging Studies

1. CT/MRI

demyelinated pontine lesions
- usually symmetrical and involving the midline basis pontis but can be asymmetric
demyelination of other regions
- thalamus, internal capsule, cerebrum, cerebellum

3. Others

brainstem auditory evoked potentials may reveal delayed con-duction velocity through the pons

MANAGEMENT:

1. Treat Underlying Disorder

correct hyponatremia slowly
no treatment for CPM once occurs

2. Neuroresuscitation Protocol for Cerebral Edema

head of bed elevation with head in midline
hyperventilation
mannitol and/or diuretics

Pediatric Database - CENTRAL PONTINE MYELINOLYSIS

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