554 TRANSSACRAL STEROID INJECTION IN THE MANAGEMENT OF NEUROPATHIC PAIN DUE TO ACCIDENTAL INTRANEURAL INJECTION OF SCIATIC NERVE

Poster Sessions / European Journal of Pain 13 (2009) S55–S285 S163 symptoms and analgesic requirements were recorded. Diagnostic block was performed with nerve stimulator using 0.5% lidocaine at the proximal of nerve injury. Therapeutic block with 80mg methylprednisolone was performed after a week and repeated with 40mg methylprednisolone after a month. VAS scores following diagnostic block (VAS1), before 2nd block (VAS2), after 1 month (VAS3) and 3 months (VAS4) were noted. Symptoms and analgesic requirements were re-evaluated in each visit. Results: VAS0 was significantly higher than subsequent assessments (p < 0.001). VAS3 was higher than VAS4 in Group II (p = 0.025). Symptoms and analgesic requirements significantly decreased in both groups (p = 0.001). Discussion: We suggest that peripheral nerve block with steroids provide efficient management in the treatment of acute and chronic neuropathic pain and repeating the intervention increases the efficacy in chronic processes. 554 TRANSSACRAL STEROID INJECTION IN THE MANAGEMENT OF NEUROPATHIC PAIN DUE TO ACCIDENTAL INTRANEURAL INJECTION OF SCIATIC NERVE H.E. Eker*, O. Yalcin Cok, P. Ergenoglu, H. Ulger, P. Poyraz, A. Aribogan. Baskent University, Department of Anaesthesiology and Reanimation, Adana, Turkey Background and Aims: Intraneural injection is a common injury mechanism of sciatic nerve. The sciatic nerve injection generates neuropathic pain with inflammatory neuritis. The steroids inhibit the production of inflammatory mediators and reduce ectopic discharges on damaged neural membranes. Here, we present the results of transsacral steroid injection on neuropathic pain in 3 patients with accidental sciatic nerve injury due to intraneural injection. Cases: Three patients, 32, 45 and 70 years-old, respectively, complaining of severe neuropathic pain, paresthesia and progressive weakness of the lower extremity with difficulty in walking secondary to gluteal injection were admitted to the clinic. The symptoms were resistant to drug therapy with amitriptyline and gabapentin. Electromyography disclosed axonal damage of sciatic nerve. The initial examination of the patients revealed a visual analog pain score (VAS) as 10, 10 and 9, respectively. Diagnostic block was performed through the unilateral S1-S2-S3 sacral foramina with 22-G spinal needle by 5mL 1% lidocaine into each foramen. VAS scores decreased to 1, 2 and 1, respectively. One week later, the patients were administered 80mg methylprednisolone with 1% lidocaine in 15mL solution shared equally into each foramen. The block was repeated with 40mg methylprednisolone after one month and a full recovery was achieved in all patients. The patients were checked after 3 months and no motor and sensory deficit existed. Conclusion: The neuropathic pain due to accidental intraneural injection of sciatic nerve that is resistant to standard drug therapy may be treated successfully with transsacral steroid injections. 555 ABNORMALITIES OF SENSORY FUNCTION IN DIFFERENT TYPES OF TRIGEMINAL PAIN W. El Ghoul*, T. Nurmikko. Unit of Neuroscience Research, School of Clinical Sciences, University of Liverpool, Pain Research Institute, Clinical Sciences Centre, Lower Lane, Liverpool, Merseyside, United Kingdom Background and Aims: Trigeminal neuralgia (TN), trigeminal neuropathy (TNP) and non-neuropathic facial pain (NNFP) are usually diagnosed through history. We investigated whether quantitative sensory testing (QST) can be used to differentiate between these conditions. Methods: Patients with unilateral symptoms with one of the three conditions and healthy volunteers underwent QST to determine detection thresholds for thermal, tactile and punctate stimuli. Additionally, all subjects were tested for dynamic allodynia and temporal summation to mechanical stimuli. Within group (affected vs. unaffected sides, affected versus unaffected branches) and between-group results were analysed using ANOVA, unpaired t-tests and z-scores. Z-scores were used to standardise results obtained from each modality into a single unit. This simplified the interpretation and comparison between patient groups. Results: 53 subjects were recruited (18 TN, 15 TNP, 9 NNFP, 11 controls). Results showed increase of detection threshold for thermal stimuli in TNP group compared to the healthy volunteers group. Increase in threshold for tactile stimuli was detected in the TN and TNP group. The same trends were demonstrated by the z-scores. Detection thresholds for tactile stimuli were decreased in TNP patients within the affected division when compared to the unaffected divisions. Conclusions: QST can be used to differentiate between TN, TNP and to an extent NNFP patients. Method of z-scores suited the clinical setting since it simplified the interpretation of multiple sensory modalities. 556 THERMAL SENSORY TESTING PREDICTS NEUROPATHIC PAIN IN GUILLAIN BARRE SYNDROME D. Fletcher1,4, V. Martinez1,4, F. Martin1, D. Orlikowski2, T. Sharshar2, M. Chauvin3,4, D. Bouhassira4,5, N. Attal4,5. 1Universite´ Versailles Saint-Quentin, APHP, Hoˆpital Raymond Poincare´, Service d’Anesthe´sie Re´animation Chirurgicale, Garches, France; 2Universite´ Versailles Saint Quentin, APHP, Hoˆpital Raymond Poincare´, Re´animation Me´dico-Chirurgicale, Garches, France; 3Hoˆpital Ambroise Pare´, APHP, Service d’Anesthe´sie Re´animation Chirurgicale, Boulogne, France; 4INSERM U 792, Hoˆpital Ambroise Pare´, Centre d’Evaluation et de Traitement de la Douleur, Boulogne-Billancourt, France; 5Universite´ Versailles Saint Quentin, Versailles, France Background and Aims: Neuropathic pain in frequent and often severe in Guillain Barre (GB) syndrome but its mechanisms remain unknown. This study aimed to prospectively investigate the sensory and pain characteristics of patients with GB syndrome. Methods: Thirty-one patients with GB syndrome (19 men, 12 women, mean age 50.1±17 years) were included and compared to 10 paired healthy volunteers. Evaluation was performed in the intensive care unit, at 1 and 6 months and included screening for neuropathic pain (DN4), pain intensity and quality (VAS, Neuropathic Pain Symptom Inventory, SF-McGill), quantitative sensory testing (brush, mechanical/thermal detection and pain thresholds, responses to suprathreshold stimuli) and electromyography (in 23 patients). Results: Patients with GB syndrome exhibited significant impairment of all QST values compared to controls. Among GB patients, 14 had neuropathic pain, 8 had non-neuropathic pain and 9 were painfree. Patients with or without neuropathic pain were indistiguishable as regards mechanical and thermal detection, pain thresholds and eletrophysiological data. However, allodynia to brush and hyperalgesia to mechanical punctate stimuli were present only in the neuropathic pain group. Furthermore patients with neuropathic pain had more severe impairment of responses to suprathreshold heat – but not cold – stimuli at the foot compared to the other groups (p = 0.001) suggesting a selective impairment of C nociceptor function. The latter was correlated to VAS pain ratings. Concusions: Intensity of pain in painful GB syndrome seems to depend on C nerve fiber damage and deafferentation.