Dawson's fingers
Characteristic ovoid lesions perpendicular to ventricles on MRI, pathognomonic for multiple sclerosis.
Full Definition
Dawson's fingers are characteristic ovoid or flame-shaped white matter lesions that extend perpendicularly from the lateral ventricles, best visualized on FLAIR MRI sequences. These lesions represent demyelinating plaques that follow the perivenular distribution of inflammatory infiltrates along medullary veins. Named after Scottish pathologist James Walker Dawson, who first described these perivenular lesions in multiple sclerosis pathology specimens, Dawson's fingers are considered pathognomonic (characteristic) of MS and help distinguish it from other white matter diseases. The perpendicular orientation to the ventricles, resembling fingers pointing away from the ventricular surface, is a key diagnostic criterion in the 2017 McDonald criteria for MS diagnosis.
Usage
Usage note: Always possessive (Dawson's) and capitalized as an eponym.
In Context
- "The FLAIR images clearly demonstrated Dawson's fingers extending from the lateral ventricles." — Radiology report
- "The presence of Dawson's fingers strongly supported the diagnosis of multiple sclerosis over other demyelinating conditions." — Neurological consultation