Chronic enteral poisoning caused by potassium permanganate: a case report.

To our knowledge, this is the first case report of a multiple, low dosage ingestion of manganese. A 66-year-old male patient is presented, who ingested 125 ml of a 8% solution of potassium permanganate (10 g) within 4 weeks. As early as 2 weeks after the beginning of poisoning, psychological alterations were noted. Neurological examination revealed disturbances of many subsystems of the CNS. Visually evoked potentials showed prolongation of the P2-latency, not reported in earlier publications. Levels for manganese were elevated in peripheral blood as well as in hair samples. Treatment with calcium trisodium pentetate decreased serum levels and increased urine excretion of manganese. Nine months after poisoning, the first signs of progressive Parkinson disease became evident. The time-course of neurological symptoms seems to depend on a critical dose of manganese.