Spinal myoclonus anesthesia

A 77-year-old woman undergoing hip replacement surgery received spinal anesthesia with bupivacaine 12 mg. On the first postoperative day she suddenly developed shock-like involuntary jerks, which were diagnosed as spinal myoclonus and confirmed by clinical and elec-trophysiological studies. She was given valproate and clonazepam, and the transient myoclonus disappeared after 4 days. 

Lee JJ, Hwang SM, Lee JS, Jang JS, Lim SY, Hong SJ. Recurrent spinal myoclonus after two episodes of spinal anesthesia at a 1-year interval. Korean J Anesthesiol 2010 59(Suppl) S62-A. 

Spinal anesthesia with intrathecal bupivacaine has been associated with spinal myoclonus [38 ]. 

A 52-year-old woman developed spinal myoclonus 60 minutes after receiving 60 mg of hyperbaric prilocaine 5%. She had involuntary, asymmetrical, brief movements of the legs at a frequency of 10-20/minute. Treatment with intravenous diazepam 5 mg blunted the symptoms but did not abolish them they resolved completely 60 minutes after full recovery from spinal anesthesia. There were no residual signs of neurological impairment. 

Fox EJ, Villanueva R, Schutta HS. Myoclonus following spinal anesthesia. Neurology 1979 29 379-80. 

---