eye of the tiger sign
A finding seen on T2-weighted MRI, in which there is a very low signal intensity in the globus pallidus due to an excess accumulation of iron, surrounding a central region of high signal intensity attributed to gliosis, increased water content, and neuronal loss with disintegration, vacuolisation, and cavitation of the neuropil, which has been fancifully likened to the eye of a tiger.
First described in Hallervorden-Spatz syndrome (OMIM:234200, this is now known by cognoscenti as neurodegeneration with brain
iron accumulation, given Hallervorden’s link to the Nazi atrocities. The sign has also been reported in other extrapyramidal parkinsonian disorders, to wit, cortical–basal ganglionic degeneration, early-onset levodopa-responsive parkinsonism, and Steele-Richardson-Olszewski syndrome (progressive supranuclear palsy).
References Radiology 2000 217: 895-896