Butyrylcholinesterase and cognitive function.

Butyrylcholinesterase (BuChE) is expressed in brain structures involved in cognition, but the effect of selective BuChE inhibitors on human cognitive function is unknown. We report a patient whose cognitive function deteriorated following a reduction and improved following reinstitution of ethopropazine, a selective BuChE inhibitor. We suggest that, because neurons expressing BuChE may be involved in cognition, there is merit to further evaluation of selective BuChE inhibitors in treating cognitive dysfunction.