Propriospinal myoclonus following intrathecal bupivacaine in hip surgery: a case report

Abstract

Propriospinal myoclonus is a rare disorder characterized by sudden, shock-like, involuntary jerks that arise from the axial muscles and spread both rostrally and caudally to other myotomes through slow polysynaptic pathways. It can be idiopathic or secondary to intrinsic and extrinsic spinal cord lesions; additionally, it can develop as an adverse effect to the administration of several drugs, including neuraxial local anesthetics. This article describes a case of transient propriospinal myoclonus in a 77-year-old woman undergoing surgery for hip replacement who received 12 mg of 0.5% normobaric bupivacaine administered by a 25-G spinal needle. On postoperative day 1, the patient presented with spinal myoclonus, defined by clinical and electrophysiologic studies. Valproate and clonazepam controlled the symptoms, and on day 4 the myoclonus completely disappeared. Few cases of myoclonus induced by intrathecal bupivacaine administration have been reported in the literature, but systematic reviews written to clarify the global incidence and the physiopathology of this complication are still lacking.