Contralateral treatment with lidocaine reduces spinal neuronal activity inmononeuropathic rats

In anaesthetised and paralysed rats with chronic constriction of the sciati c nerve, the effects of subcutaneous contralateral lidocaine (100 mul) on t he activity of lumbar (L-4-L-5) wide dynamic range neurons ipsilateral to t he constriction have been investigated. The results show reduction of the s pontaneous hyperactivity for 60 min; suppression or reduction of the respon ses to contralateral noxious stimulation for 60 min; lack of effect on the responses to ipsilateral noxious stimulation, except for the afterdischarge duration, reduced for 60 min. The finding that the altered neuronal activi ty following peripheral nerve injury associated to behavioural signs of neu ropathic pain, can be reduced by contralateral treatment, may provide furth er suggestions to neuropathic pain mechanisms and management. (C) 2001 Publ ished by Elsevier Science Ireland Ltd.