Six migraine patients experienced significant topiramate-related cognitive and language dysfunction that improved with donepezil treatment and allowed uninterrupted topiramate use. These patients represent the first report of topiramate-related cognitive and language dysfunction that improved with a cholinesterase inhibitor. Although, the mechanism responsible for this effect is uncertain, cholinesterase inhibition resulting in cholinergic augmentation and enhanced cognition probably account for some if not most of the improvement.