Neurological Complications of Local Anaesthetics in Dentistry

Abstract

Neurological complications following the administration of a local anaesthetic can be alarming. By reading reports of such incidents, dentists who find themselves in similar situations will be able to reassure their patients and act accordingly. The authors have reviewed the literature for those neurological complications that have been reported and offer an explanation of their aetiology. Examples of complications covered are facial nerve palsy, transient amaurosis, post-injection paraesthesia, Horner's syndrome, transient paralysis of combined cranial nerves III, IV and VI, sudden unilateral deafness and abducens nerve palsy. A thorough knowledge of the relevant anatomy pertinent to the various injections used in dental surgery is essential and is highlighted in the text.

Occular complications following dental local anesthesia

“…�n the e�ent that such a co��lication does occur, the �ost i��ortant ste� is to cal� the �atient. �n cases of di�lo�ia, it is reco��ended to co�er the �a-tient�s affected e�e in order to �re�ent the un�leasant sensation of double �ision (21).…”

Temporary pupillary dilatation and ptosis: complications of PSA nerve block: a case report and review of literature

“…There exists constant anastomosis between orbital branch of middle meningial artery and recurrent meningial division of lacrimal artery. This lacrimal artery supplies the lateral rectus muscle, lacrimal gland and outer half of the eye lids, which, due to these anatomical considerations, may explain all the above symptoms [8]. Temporary blindness has been reported following PSA nerve block due to a large quantity of LA under great pressure diffusing through the inferior orbital fissure and coming into contact with optic nerve.…”

Superficial skin necrosis and neurological complications following administration of local anaesthetic: a case report

“…An intra-arterial injection may circulate in a retrograde fashion reaching the carotid bifurcation where it may be distributed to the central nervous system via the internal carotid artery; this is the proposed mechanism for visual and auditory disturbances following inferior dental blocks. 4 This phenomenon of reverse carotid flow was proposed and demonstrated in animal studies by Aldrete et al 11 Malamed 12 considered retrograde flow is only possible with injections administered faster than one cartridge in 30 seconds. This would help account for the systemic neurological symptoms observed in our patient.…”

“…1 Complications include postoperative trismus, palpitations and diaphoresis; however, transient amaurosis, sudden unilateral deafness and cranial nerve palsies have also been reported. [1][2][3][4] A previously unreported case of cutaneous and neurological complications following suspected intra-arterial injection of local anaesthetic solution is presented and the possible mechanisms of this unusual presentation are discussed.…”