Possible Pathophysiological Hypothesis for Explaining Myoclonus Secondary to Donepezil.

The inhibition of AChE by the AChEI leads to the accumulation of ACh in the synaptic cleft. In predisposed brain regions, this increased cholinergic concentration can lead to twitching. A, choline; B, acetate; C, acetylcholine; D, acetylcholine carrier; E, acetylcholinesterase (AChE); F, choline carrier; Ach, acetylcholine; AChEI, acetylcholine-sterase inhibitor (donepezil, galantamine, and rivastigmine).