Figure 1. Experiment I. The effect of intrathecal administration of 5% lidocaine and 5% lidocaine with 7.5% glucose on sensory impairment. Sensory deficit was assessed using the tail-flick test, with deficit defined as a negative response to the heat stimulus by 8 s (cutoff) 4 days after infusion. The two test solutions produced similar dose-dependent loss of sensory function.