Given his normal liver function tests and abdominal ultrasound studies, we considered this possibility unlikely. Basal ganglia hyperintensities on T1-weighted sequences are also observed in patients on parenteral nutrition, and in patients with manganese toxicity. Given his history, we felt that manganese toxicity was the most likely cause for his presentation. This diagnosis was supported by demonstrating high manganese levels in serum and urine. It was first discovered in 1771 by the Swedish chemist Scheele.
Manganese dioxide is the most commonly encountered form of Mn.
Improvement in industrial hygiene has limited manganese toxicity among mining workers. However, manganese toxicity continues to be reported due to industrial and agricultural exposures. Manganese toxicity typically results from pulmonary absorption. Mn dust and fumes are responsible for most of industrially associated manganese toxicity. Other causes for Mn toxicity include potassium permanganate ingestion.