[A case of unexpected involuntary movement of lower extremities during epidural anesthesia]

A 79-year-old man was scheduled for transurethral resection of the bladder tumor. Preoperative clinical and laboratory examinations revealed no abnormalities. An epidural catheter was inserted into the L3-4 interspace and 1.5% lidocaine 10 ml was injected smoothly with no abnormal signs. Thirty minutes after the injection, involuntary movement of lower extremities was noticed. When the catheter was removed after the operation, there was neither hemorrhage nor pain at the puncture site. Neither sensory disorder nor paralysis occurred while the movement continued for 150 minutes. No abnormal findings which might cause the involuntary movement were detected by clinical examinations including the cerebral CT and lumbar MRI. The detailed mechanism of the involuntary movement was not clarified, but exclusion of several complications including epidural hematoma by CT and MRI examination is essential for further diagnosis and treatment.