Background Subanesthetics concentrations of lidocaine are able to produce a differential
block of the ectopic discharges, but not propagation of impulses, suppressing differentially
the associated neuropathic pain symptoms. The aim of this study was to investigate the
differences between the analgesic effects of lidocaine 0.5% and a control group of lidocaine
0.1% on several neuroma related pain modalities.
Methods Sixteen patients with neuropathic pain due to painful neuromas caused by nerve injury
participated in this randomized, double-blind experiment. The patterns of sensory changes
were compared before and after injection of 1 ml lidocaine 0.5% and 0.1% close to the
neuroma, the sessions being 1-2 weeks apart. Spontaneous and evoked pains were assessed using
a visual analogue scale (VAS), quantitative and qualitative sensory testing.