To the Editor We read with interest the article titled “Hemidystonia With One Eye-of-the-Tiger Sign” by Pandey et al.1 The authors published an interesting image depicting a unilateral eye-of-the-tiger sign in a young patient with hemidystonia.
Sethi et al2 described the eye-of-the-tiger sign in 1988 in 2 patients with what was then called Hallervorden-Spatz syndrome (now appropriately named Pantothenate kinase–associated neurodegeneration or neurodegeneration with brain iron accumulation type 1). On 1.5-T magnetic resonance imaging (MRI), it described the typical radiographic appearance on a T2 sequence, showing marked low signal intensity in the globus pallidus completely surrounding a hyperintense central area in the anteromedial region with otherwise normal-appearing MRI.2 The hypointensity was subsequently demonstrated pathologically to correlate with excess iron deposition, and the central hyperintense signal was shown to be due to neuronal loss with gliosis, vacuolization with water accumulation.3
Sethi KD, Mehta SH, Morgan JC. Defining the Eye-of-the-Tiger Sign. JAMA Neurol. 2015;72(5):606. doi:10.1001/jamaneurol.2015.0144