[Changes in human evoked spinal potentials (ESP) by epidural lidocaine]

Area of Science:

• Neuroscience
• Anesthesiology
• Spinal Cord Research

Context:

• Debate on epidural anesthesia's mechanism of action.
• Prevailing theory implicates spinal nerve roots.

Purpose:

• To investigate the effects of epidural anesthesia on the spinal cord.
• To correlate changes in evoked spinal potentials (ESP) and tactile sensation with epidural lidocaine administration.

Summary:

• Four patients received epidural anesthesia with lidocaine.
• Measurements showed prolonged ESP latency and decreased amplitude post-injection.
• Sensory changes (hypesthesia, analgesia, anesthesia) correlated with decreased ESP amplitude.

Impact:

• Provides evidence for the spinal cord as a significant site of epidural anesthesia action.
• Challenges the sole reliance on nerve root theories.
• Informs understanding of anesthetic mechanisms and clinical effects.