Table 1.

Comparative diagnostic nerve block response categories. Adapted from The utility of comparative local anesthetic blocks versus placebo- controlled blocks for the diagnosis of cervical zygapophysial joint pain. [22].

Response Group	Definition
Concordant	Longer pain relief with bupivacaine <7 h of pain relief with lignocaine <24 h with bupivacaine
Concordant prolonged	Longer pain relief with bupivacaine >7 h of pain relief with lignocaine >24 h of pain relief with bupivacaine
Discordant	Longer pain relief with lignocaine, <7 h of pain relief with lignocaine <24 h of pain relief with bupivacaine
Discordant prolonged	Longer pain relief with lignocaine >7 h of pain relief with lignocaine >24 h of pain relief with bupivacaine
Discrepant	Pain relief with only one of the local anesthetics
Negative	No relief at any cervical level from either local anesthetic