Functional neurologic disorder as a rare complication of dental local anaesthetics: two contrasting cases.

Adverse reactions to dental local anaesthetics are fortunately rare. However, when they occur, they can be severe and debilitating to the patient. Adverse reactions may be either prolonged anaesthesia, with or without dysaesthesia, or systemic reactions. Although these systemic reactions are commonly thought to be allergies, this is rarely the case. Much more commonly, these adverse systemic reactions are either cardiovascular or from the central nervous system. This paper describes two contrasting cases of functional neurologic disorder which illustrates the consequences and appropriate management. The responsibilities of the dentist who injected the local anaesthetic are outlined.