This sign is observed upon magnetic resonance tomography (MRI). It can be seen in several diseases including Hallervorden-Spatz syndrome, where the pathophysiology has been hypothesized to be related to iron deposition in the globus pallidus (associated with low signal intensity on T2-weighted images) accompanied by other pathological processes such as gliosis and water accumulation that are responsible for the high signal intensity at the central globus pallidus.