Update on headshaking

Idiopathic head-shaking (also termed trigeminal neuralgia, trigeminally mediated head-shaking) is a facial pain syndrome. As such, local anaesthesia of the maxillary and caudal nasal branches of the trigeminal nerve can be a useful diagnostic adjunct (in the absence of maxillary pathology). Previously within the veterinary literature, the caudal nasal nerve has been referred to as the ‘posterior ethmoidal nerve’ but the latter term is less frequently adopted now to avoid confusion with the ethmoidal nerve, which arises from the ophthalmic branch of the trigeminal nerve (local anaesthesia of this nerve is performed using a completely different technique). Local anaesthesia of the maxillary and caudal nasal nerves using the methodology described below is the currently accepted diagnostic technique for horses with idiopathic head-shaking/trigeminal neuralgia. Horses must be consistently head-shaking prior to diagnostic anaesthesia and be re-evaluated in the same environment to assess response ...