Which physical findings are characteristic of central pontine myelinolysis (CPM)?

Updated: Oct 09, 2017
  • Author: Christopher Luzzio, MD; Chief Editor: Stephen A Berman, MD, PhD, MBA  more...
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Key features of the neurologic exam include confusion, horizontal gaze paralysis, and spastic quadriplegia. Increased limb tone, limb weakness, hyperactive reflexes, and Babinski sign are typical features of spastic quadriplegia or lesions that involve upper motor neurons or the corticospinal tracts. Brain MRI reveals intense symmetric demyelination in the brain stem pons. [10, 11]

The most consistent examination findings are those of pseudobulbar palsy and spastic quadriplegia caused by demyelination of corticospinal and corticobulbar tracts within the pons. The volume of demyelination within the pons is variable. [12] The loss of myelin can occur in adjacent brainstem areas and in more distal supratentorial locations. Thus, a diverse spectrum of examination findings and long-term disabilities are found.

Pseudobulbar palsy is characterized by head and neck weakness, dysphagia, and dysarthria. Lesions within the pons cause horizontal gaze paralysis. Vertical ophthalmoparesis is caused by demyelination extending through the mid brain.

Delirium is extremely common. Coma or delirium results from lesions in the pontine tegmentum and/or thalamus. Abnormalities in sensory modalities usually are not observed.

A large basis pontis lesion may cause a locked-in syndrome, which includes paralysis of lower cranial nerves and limb musculature. Vertical eye movements, blinking, breathing, and alertness may remain intact in these patients.

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