Transient neurologic syndrome (TNS)

Transient neurologic syndrome (TNS)

TNS, formerly called transient radicular irritation (TRI), occurs most commonly after spinal anesthesia with lidocaine (Xylocaine). Symptoms include back pain that develops after the block resolves and radiates to the buttocks and legs.

The pain is not associated with motor or sensory loss or electromyographic changes. It can be severe, requiring hospital admission of outpatients, and typically resolves within 1 to 4 days. It appears to occur more commonly when outpatients are operated on in the lithotomy position and appears to be less likely when patients are pregnant