Facial diplegia, pharyngeal paralysis, and ophthalmoplegia after a timber rattlesnake envenomation.

The timber rattlesnake, also known as Crotalus horridus, is well known to cause significant injury from toxins stored within its venom. During envenomation, toxic systemic effects immediately begin to cause damage to many organ systems including cardiovascular, hematologic, musculoskeletal, respiratory, and neurologic. One defining characteristic of the timber rattlesnake is a specific neurotoxin called crotoxin, or the "canebrake toxin," which is a potent β-neurotoxin affecting presynaptic nerves that can cause paralysis by inhibiting appropriate neuromuscular transmission.