MRI brain of a 35-year-old woman presenting with relapsing and remitting neurological symptoms shows multiple oval lesions in the periventricular white matter oriented perpendicular to the corpus callosum on a sagittal FLAIR sequence, along with a lesion in the posterior limb of the internal capsule and a juxtacortical lesion. What is this periventricular perpendicular orientation sign called and what diagnosis does it support?

• A Leukoaraiosis pattern; supports cerebral small vessel disease
• B Batwing periventricular oedema; supports hydrocephalus
• C Butterfly glioma pattern; supports glioblastoma
• D Dawson's fingers sign; supports Multiple Sclerosis ✓

Explanation

Dawson's fingers refers to the characteristic periventricular white matter plaques of Multiple Sclerosis that are oriented perpendicular to the long axis of the corpus callosum and ventricles on sagittal FLAIR imaging, following the course of medullary veins along which demyelination occurs. Together with juxtacortical, infratentorial, and spinal cord lesions, they form the basis of the McDonald criteria for MS diagnosis on MRI. Leukoaraiosis appears as confluent, symmetrical periventricular white matter changes without perpendicular orientation. Butterfly glioma crosses the corpus callosum as a single mass.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.