Spinal Myoclonus: Is It An Anesthetic Mystery?

The goal is to present a descriptive study related an unprecedent case of spinal myoclonus (SM) following subarachnoid anesthesia (SA). SM are sudden, brief, involuntary non-generalized spasms that can be an adverse effect of drug administration via neuraxial routes. Female, 67y, ASA II, proposed for hip replacement surgery, with normal preoperative exams. 7min after SA with 10mg of bupivacaine 0,5%, no motor blockade observed, and patient complained of unbearable pain in legs and perineum and bilateral, asymmetrical and arrhythmic myoclonic movements in the lower limbs. The latter solved after 48h of general anesthesia and rocuronium perfusion, amongst other therapeutics. Accordingly, intrathecal bupivacaine appears to be the SM most likely cause, regarding the absence of neurologic and electrolyte disorders, spinal cord direct trauma, drug exchange and normal perioperative examination, imaging and laboratory testing.It is mandatory to always take the patients' anaesthetic histories and recognize, treat and report rare anaesthetic complications.