Unexpected neurologic deficit following spinal anesthesia

A case of unexpected neurologic deficit of the left lower extremity following a successful spinal block is reported.

A spinal block was performed in a 45-year-old woman with a 25-gauge Whitaker needle at the L3-L4 interspace. After establishing flow of clear cerebrospinal fluid, 1.6 mL of 0.75% bupivacaine was injected into the subarachnoid space. The patient had a good motor and sensory block (level T4), and she underwent uneventful extracorporeal shock wave lithotripsy of a right kidney stone. After satisfactory recovery in the postanesthesia care unit, she was transferred to the ambulatory surgical center for further recovery and discharge home.

About 11 hours after administration of the spinal anesthetic and recovery from the spinal block, the patient complained of not being able to move her left leg. Neurologic examination revealed motor loss and hyperesthesia to touch, vibration, pressure, and temperature from her groin to toes in the left leg only. The remainder of the neurologic examination was normal. A nuclear magnetic resonance scan of the spine revealed no abnormality. Neurologic and psychiatric consultations were sought, and the patient was diagnosed to have a conversion disorder. She responded to psychological intervention and returned to her previous state of health in 2 weeks.

Neurologic deficit following spinal or epidural block should be investigated completely and appropriate consultations sought. Psychiatric disorder may be a rare cause of neurologic deficit after successful regional anesthesia and should be made part of a complete workup.