Midazolam-induced athetoid movements of the lower extremities during epidural anesthesia reversed by physostigmine

Midazolam is a short-acting, water-soluble benzodiazepine used for induction and maintenance of general anesthesia and as an adjunct to regional anesthesia. This substance produces several types of untoward reactions, including agitated excitement, mental confusion, and uncooperativeness, as well as dystonic extrapyramidal reactions, such as tonic clonic movements, muscle tremor, and athetoid movements. We describe two patients who developed akinesthesia with athetoid movements of the lower extremities after receiving midazolam as a premedication and as an adjunct to epidural anesthesia. These movements occurred with a sensory level of T₄ as assessed by pinprick, even though the patients were unable to move their lower extremities.