“Mantis Eyes Sign” for Brain Manganese Accumulation

A 59-year-old welder with chronic unprotected manganese exposure presented with isolated lightheadedness. Magnetic resonance imaging of the brain revealed a novel “Mantis Eyes Sign” at the superior colliculus level, which is marked by hyperintense signals of bilateral globus pallidus and seemingly hypointense signals of bilateral corticopontine tracts, resembling the compound eyes and pseudopupils of the mantis, respectively. Partial signal resolution of the patient after chelation therapy and identical imaging pattern in an asymptomatic female co-worker reinforce this sign's use for identifying workers who are exposed to manganese.