Open-Ring Sign in Tumefactive Demyelination

Abstract

A 20-year old gentleman presented with one-week history of headache and progressive left hemiparesis. There was asymmetric hyperreflexia in all four limbs (left>right), left hemianesthesia and left plantar was extensor. MRI brain showed multiple lesions in bilateral centrum semiovale, bilateral parietal and right paraventricular regions.

The open-ring sign is often present in large, contrast-enhancing demyelinating lesions and helps to differentiate them from neoplasms and infections that usually show complete ring enhancement.