Transient global amnesia due to clioquinol

Twelve cases of confusional state after normal or excessive doses of clioquinol are discussed. They resemble transient global amnesia (TGA) of the classic type, but the episodes last longer (1-3 days), they are often accompanied by a variety of mental disturbances, and the onset and end are less well defined than in the classic type. A combination of SMON and acute encephalopathy due to clioquinol was observed in only one case. Apart from amnesia for the acute episode a permanent retrograde amnesia for a few days up to two months was left behind. The pathophysiology of these episodes is not clear, but they resemble the toxic reactions to clioquinol observed in dogs and experimental animals.