title: Lidocaine test in neuralgia.
abstract: Ten patients with organic nerve injury causing chronic neuropathic pain were tested for the effects of intravenous lidocaine versus saline upon psychophysical somatosensory variables. The variables assessed were the subjective magnitude of pain, area of mechanical hyperalgesia and presence and magnitude of thermal heat/cold hyperalgesia. The study methods applied to evaluate these conditions were the conventional testing of somatosensory submodalities with area mapping and the subjective magnitude estimation of spontaneous pain. It was found that spontaneous pain and mechanical hyperalgesia were consistently improved, transiently, by intravenous administration of lidocaine in all 10 patients; areas of hyperalgesia which extended beyond the territory of the nerve also improved transiently. Spontaneous pain and mechanical hyperalgesia, but not hypoesthesia, were transiently improved by injection of saline in only 1 of the 10 patients. This outcome is probably due to a placebo effect. This improvement is in keeping with the inhibition of anomalous neural impulses which can be generated anywhere along the sensory channels responsible for generating spontaneous pain and hyperalgesia. Thus, intravenous lidocaine is proposed as a diagnostic aid in the examination of patients complaining of complex sensory disorders associated with nerve injury. The transient pain relief may allow a fuller identification of the area of sensory loss.
authors.affiliation: Clinica Neurologica VI Università di Milano and Centro di Neuroalgologia Istituto Scientifico H San Raffaele, MilanItaly Istituto Fisiologia Centri Nervosi (CNR), MilanItaly.
authors.forename: Paolo
authors.initials: P
authors.lastname: Marchettini
authors.forename: Marco
authors.initials: M
authors.lastname: Lacerenza
authors.forename: Claudio
authors.initials: C
authors.lastname: Marangoni
authors.forename: Giulio
authors.initials: G
authors.lastname: Pellegata
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Sotgiu
authors.forename: Salvatore
authors.initials: S
authors.lastname: Smirne
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002908:Chronic Disease; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000503:physiopathology; D010147:Pain Measurement; D011674:Pulse / Q000187:drug effects; D012677:Sensation / Q000502:physiology
chemical_list: D008012:Lidocaine