Acute vocal fold dystonic reaction to propofol: a case report

Severe Neuroexcitatory Reaction: A Rare and Underrecognized Life-Threatening Complication of Propofol-Induced Anesthesia

“…1 They may present during induction, maintenance or emergence from anaesthesia, or even as delayed reactions. 2 A large spectrum of abnormal movements has been reported in this setting: myoclonus, 3 increase in muscle tone ranging from diffuse rigidity and extensor movements to opisthotonos 4 and dystonic reactions that can be either focal-for example masseteric or laryngeal 5,6 or generalized. 7,8 These abnormal movements are generally accompanied by disorders of consciousness, ranging from intermittent loss of consciousness to marked agitation and even delirium, sometimes referred to as "propofol frenzy."…”

Acute masseter dystonia in a pediatric patient receiving aripiprazole and methylphenidate following induction of general anesthesia

“…Aripiprazole, an atypical antipsychotic approved for treatment of several common psychiatric conditions in pediatric patients, has gained popularity for its favorable risk profile vs typical antipsychotics . It is a partial dopamine agonist with high affinity for the D2 dopamine receptor where partial agonism is thought to limit the risk of extrapyramidal symptoms . However, a 2012 meta‐analysis showed extrapyramidal symptoms as the most common adverse event associated with aripiprazole in children and adolescents .…”

“…The efficacy of antipsychotics is mediated by D2 dopamine receptor antagonism leading to an increase in acetylcholine release . The imbalance between cholinergic‐dopaminergic pathways integrating the cerebral cortex with the basal ganglia may explain dystonic reactions .…”

“…Propofol is associated with a spectrum of abnormal movements from myoclonic seizure‐like activity to dystonic reactions. Such reactions may be attributed to propofol‐induced increase in excitatory cholinergic output . It is possible that the combination of the two agents synergistically increased acetylcholine activity and made the patient more susceptible to dystonic reactions.…”

“…Benztropine, an anticholinergic, is considered first‐line therapy but is neither readily available nor familiar to many anesthesiologists. Therefore, diphenhydramine at 1–2 mg·kg −1 (up to 50 mg) can be administered for its anticholinergic effects .…”