The “Eye of the tiger sign” in Progressive Supranuclear Palsy: Is it a coincidence or not?

Progressive supranuclear palsy (PSP); is a neurodegenerative disorder involved in atypical parkinsonism syndromes. The classical clinical presentation is postural instability, falls, downward paralysis, frontal dementia, and symmetric akinetic-rigid parkinsonism. The atrophy of the mesencephalon in magnetic resonance imaging (MRI) is an important marker in diagnosing the disease. Recently, a few PSP cases reported the “eye of the tiger” sign on MRI. The “eye of the tiger” sign, in globus pallidus, is a sign that bilaterally symmetrically located low signal intensity and central longitudinal hyperintensity are observed. While previously a specific finding for the pantothenate kinase-associated neurodegeneration (PKAN), it is no longer considered specific because of the reported cases of non-PKAN with the “eye of the tiger” sign such as neuropherritinopathy, multi-system atrophy, corticobasal degeneration. In this report, we aimed to contribute to the literature by presenting two PSP cases in which the “eye of the tiger” sign was observed.