- Email: [email protected]
578 A STRONG OPIOID IN NEUROPATHIC PAIN: HYDROMORPHONE
Poster Sessions / European Journal of Pain 13 (2009) S55–S285
Results: At the last follow-up control (t45) both groups reported a good pain relief (VAS≤ 3). More specific: in group A at t30 VAS 4±0.98 at t45 VAS 2±1.17; while in group B at t30 VAS 4 ± 0.75 at t45 VAS 2±1.21. Our study failed to show a statistic significative difference (p < 0.05). 3 subjects of group A with DN related sleep difficulties reported the greatest pain relief with improved sleep quality. 2 subjects of group B reported urinary retention and decrease of libido after the treatment. Discussion: According to our data Duloxetin may be considered an effective treatment for neuropatic pain with better tolerability than usual antidepressants. 576 EFFECTS OF RESVERATROL AND a-LIPOIC ACID TREATMENTS ON DIABETIC NEUROPATHY SIGNS: A STUDY WITH STREPTOZOTOCIN-DIABETIC RATS P. Pereira-Terra *, C. Morgado, I. Tavares. Institute of Histology and Embryology, Faculty of Medicine of Porto and IBMC, Porto, Portugal Background and Aims: Oxidative stress has been considered an ethiological mechanism of diabetic neuropathy. In the present study, we aimed to evaluate the effects of antioxidant treatments, using resveratrol and a-lipoic acid, on the behaviour signs of diabetic neuropathy. Methods: Male Wistar rats were rendered diabetic by STZ intaperitoneal injection (60 mg/Kg, STZ rats). At 4 weeks postinjection the animals received a daily intraperitoneal injection of resveratrol (20 mg/Kg), a-lipoic acid (100 mg/Kg), during 2 weeks. Prior and after treatments, the animals were behaviourally evaluated for thermal and mechanical nociception, using paw pressure test and Hargreaves test, respectively. Results: Prior to treatment, STZ rats presented increased paw thermal latency and decreased mechanical thresholds. Resveratrol treatment ameliorated thermal sensitivity but a-lipoic acid had no effect. a-lipoic acid ameliorated mechanical sensitivity, whereas resveratrol had no effects. Conclusion: Antioxidant treatments with resveratrol and a-lipoic acid present opposite effects on behavioural signs of diabetic neuropathy which demands a future study of the mechanisms of their protective action. A time-course study of the effects of antioxidant treatments in reversion of diabetic neuropathy along with an evaluation of their value in the prevention of diabetic neuropathy will be performed in a near future. It will be also important to assess if higher doses or treatments for longer periods will revert the responses to levels of non-diabetic animals. Support by FCT project PTDC/SAU/64643/2006. 577 PARTIAL SENSORY RHIZOTOMY IN TREATMENT OF TRIGEMINAL NEURALGIA WITHOUT NEUROVASCULAR CONFLICT P. Peric *, B. Antic. Dept. of Neurosurgery, Military Medical Academy, Belgrade, Serbia We retrospectively analyzed the outcome of partial sensory rhizotomy (PSR) of the trigeminal sensory root in 26 patients who underwent posterior fossa exploration (PFE) due to surgical treatment of medically intractable idiopathic (18) and recurrent (5) trigeminal neuralgia (TN) as well as TN complicating multiple sclerosis (3). PSR was performed in cases without neurovascular conflict during PFE or recurrent TN after microvascular decompression. Immediate complete postoperative pain relief (BNI-score I) was achieved in all the patients. Eight years after surgery, 22 patients (84.6%) were free of pain (BNI-score I), in 3 patients (11.5%) there was some residual pain controlled with medication (BNI-score IIIb) whereas in 1 case (3.8%) no pain relief (BNI-score V) was archived. There was no immediate postoperative mortality as well as serious complications. Corneal hypoesthesia and facial numbness were not present in our patients. Four patients (15.4%) experienced mild facial dysesthesia without
S169
the need for additional treatment. Postoperative cerebrospinal fluid rhinorrhea in 3 patients (11.3%) was resolved with spinal drainage. In our experience, PSR is safe and effective surgical procedure in the management of TN without neurovascular conflict during PFE or recurrent TN after microvascular decompression. The 84.6% of complete pain-free patients after a mean follow-up of 8 years in our series, seems to confirming this opinion. 578 A STRONG OPIOID IN NEUROPATHIC PAIN: HYDROMORPHONE A. Piroli, C. Guetti, C. Angeletti, A. Paladini, A. Ciccozzi, F. Marinangeli *, E. Petrucci, G. Varrassi. Department of Anaesthesiology and Pain Medicine, University of L’Aquila, Italy, L’Aquila, Italy Background and Aims: Use of opioid analgesics for neuropathic pain (NP) is becoming more widely accepted and long-acting formulations are an important option. To assess efficacy and safety of extended-release hydromorphone use in reducing moderate-tosevere peripheral NP. Methods: In this study, patients were dissatisfied with their previous therapy before being switched to hydromorphone and the current analgesia was imposed in 3–6 days. Maintenance treatment was carried on for 28 days. Thereafter patients received then treatment with oral hydromorphone starting at 8 mg/die, with the option to increase dosage until adequate analgesia was achieved. Results: Hydromorphone was given to 10 patients; 80% completed all study. Stabilization of treatment was obtained by 90% of patients, the majority in two titration steps (4.2±1.1 days). Mean pain intensity scores, reported by Visual Analogical Scale (VAS = 0–10), decreased during treatment (p ≤ 0.001). The most frequently used dose was 8 mg. The number of patients with adequate pain control increased from 4% to 40% during the first period. During maintenance treatment, it increased to 90% on day 28. The interference of pain with mental or physical activities and the effects on sleep and quality of life improved from baseline to end point (p ≤ 0.001). The most common adverse events affected gastrointestinal tract and CNS (20% and 10% respectively). Conclusions: Hydromorphone significantly increased NP control and improved functioning and quality of life. It was well tolerated. This study shows that 4 weeks is a rational test to allow hydromorphone to improve NP control. 579 ADMINISTRATION OF LOW DOSES OF INSULIN AND IGF-1 IMPROVES PAINFUL DIABETIC NEUROPATHY IN STREPTOZOTOCIN-DIABETIC RATS L. Silva *, C. Morgado, P. Pereira-Terra, I. Tavares. Institute of Histology and Embryology, Faculty of Medicine of Porto and IBMC, University of Porto, Porto, Portugal Insulin and insulin-like growth factor (IGF-1) elicit neuroprotective effects on diabetic neuropathy but their direct repercussions on pain, independent of hyperglycemia correction, remain unclear. In the present study, we evaluated the effects in the pain behavioral responses of streptozotocin-induced diabetic rats (STZ rats) of administrating low doses of insulin and IGF-1 that maintain the hyperglycemic condition of the rats. Diabetes was induced by an intraperitoneal (i.p) injection of STZ (60 mg/kg) using male Wistar rats. One week after injection, STZ rats were subcutaneously injected 3 times per week during 3 weeks with insulin (2 IU), IGF-1 (2.5 mg/Kg) or saline. During the treatment period, the animals were weekly tested for the evaluation of mechanical and thermal nociception using the paw pressure test and tail-flick test, respectively. Saline-injected STZ rats presented mechanical hyperalgesia beginning at 1 week post-injection and loss of thermal sensation at 2 weeks, both of which aggravate with diabetes progression. Insulin and IGF-1 treatments prevented the aggravation of mechanical
Results: At the last follow-up control (t45) both groups reported a good pain relief (VAS≤ 3). More specific: in group A at t30 VAS 4±0.98 at t45 VAS 2±1.17; while in group B at t30 VAS 4 ± 0.75 at t45 VAS 2±1.21. Our study failed to show a statistic significative difference (p < 0.05). 3 subjects of group A with DN related sleep difficulties reported the greatest pain relief with improved sleep quality. 2 subjects of group B reported urinary retention and decrease of libido after the treatment. Discussion: According to our data Duloxetin may be considered an effective treatment for neuropatic pain with better tolerability than usual antidepressants. 576 EFFECTS OF RESVERATROL AND a-LIPOIC ACID TREATMENTS ON DIABETIC NEUROPATHY SIGNS: A STUDY WITH STREPTOZOTOCIN-DIABETIC RATS P. Pereira-Terra *, C. Morgado, I. Tavares. Institute of Histology and Embryology, Faculty of Medicine of Porto and IBMC, Porto, Portugal Background and Aims: Oxidative stress has been considered an ethiological mechanism of diabetic neuropathy. In the present study, we aimed to evaluate the effects of antioxidant treatments, using resveratrol and a-lipoic acid, on the behaviour signs of diabetic neuropathy. Methods: Male Wistar rats were rendered diabetic by STZ intaperitoneal injection (60 mg/Kg, STZ rats). At 4 weeks postinjection the animals received a daily intraperitoneal injection of resveratrol (20 mg/Kg), a-lipoic acid (100 mg/Kg), during 2 weeks. Prior and after treatments, the animals were behaviourally evaluated for thermal and mechanical nociception, using paw pressure test and Hargreaves test, respectively. Results: Prior to treatment, STZ rats presented increased paw thermal latency and decreased mechanical thresholds. Resveratrol treatment ameliorated thermal sensitivity but a-lipoic acid had no effect. a-lipoic acid ameliorated mechanical sensitivity, whereas resveratrol had no effects. Conclusion: Antioxidant treatments with resveratrol and a-lipoic acid present opposite effects on behavioural signs of diabetic neuropathy which demands a future study of the mechanisms of their protective action. A time-course study of the effects of antioxidant treatments in reversion of diabetic neuropathy along with an evaluation of their value in the prevention of diabetic neuropathy will be performed in a near future. It will be also important to assess if higher doses or treatments for longer periods will revert the responses to levels of non-diabetic animals. Support by FCT project PTDC/SAU/64643/2006. 577 PARTIAL SENSORY RHIZOTOMY IN TREATMENT OF TRIGEMINAL NEURALGIA WITHOUT NEUROVASCULAR CONFLICT P. Peric *, B. Antic. Dept. of Neurosurgery, Military Medical Academy, Belgrade, Serbia We retrospectively analyzed the outcome of partial sensory rhizotomy (PSR) of the trigeminal sensory root in 26 patients who underwent posterior fossa exploration (PFE) due to surgical treatment of medically intractable idiopathic (18) and recurrent (5) trigeminal neuralgia (TN) as well as TN complicating multiple sclerosis (3). PSR was performed in cases without neurovascular conflict during PFE or recurrent TN after microvascular decompression. Immediate complete postoperative pain relief (BNI-score I) was achieved in all the patients. Eight years after surgery, 22 patients (84.6%) were free of pain (BNI-score I), in 3 patients (11.5%) there was some residual pain controlled with medication (BNI-score IIIb) whereas in 1 case (3.8%) no pain relief (BNI-score V) was archived. There was no immediate postoperative mortality as well as serious complications. Corneal hypoesthesia and facial numbness were not present in our patients. Four patients (15.4%) experienced mild facial dysesthesia without
S169
the need for additional treatment. Postoperative cerebrospinal fluid rhinorrhea in 3 patients (11.3%) was resolved with spinal drainage. In our experience, PSR is safe and effective surgical procedure in the management of TN without neurovascular conflict during PFE or recurrent TN after microvascular decompression. The 84.6% of complete pain-free patients after a mean follow-up of 8 years in our series, seems to confirming this opinion. 578 A STRONG OPIOID IN NEUROPATHIC PAIN: HYDROMORPHONE A. Piroli, C. Guetti, C. Angeletti, A. Paladini, A. Ciccozzi, F. Marinangeli *, E. Petrucci, G. Varrassi. Department of Anaesthesiology and Pain Medicine, University of L’Aquila, Italy, L’Aquila, Italy Background and Aims: Use of opioid analgesics for neuropathic pain (NP) is becoming more widely accepted and long-acting formulations are an important option. To assess efficacy and safety of extended-release hydromorphone use in reducing moderate-tosevere peripheral NP. Methods: In this study, patients were dissatisfied with their previous therapy before being switched to hydromorphone and the current analgesia was imposed in 3–6 days. Maintenance treatment was carried on for 28 days. Thereafter patients received then treatment with oral hydromorphone starting at 8 mg/die, with the option to increase dosage until adequate analgesia was achieved. Results: Hydromorphone was given to 10 patients; 80% completed all study. Stabilization of treatment was obtained by 90% of patients, the majority in two titration steps (4.2±1.1 days). Mean pain intensity scores, reported by Visual Analogical Scale (VAS = 0–10), decreased during treatment (p ≤ 0.001). The most frequently used dose was 8 mg. The number of patients with adequate pain control increased from 4% to 40% during the first period. During maintenance treatment, it increased to 90% on day 28. The interference of pain with mental or physical activities and the effects on sleep and quality of life improved from baseline to end point (p ≤ 0.001). The most common adverse events affected gastrointestinal tract and CNS (20% and 10% respectively). Conclusions: Hydromorphone significantly increased NP control and improved functioning and quality of life. It was well tolerated. This study shows that 4 weeks is a rational test to allow hydromorphone to improve NP control. 579 ADMINISTRATION OF LOW DOSES OF INSULIN AND IGF-1 IMPROVES PAINFUL DIABETIC NEUROPATHY IN STREPTOZOTOCIN-DIABETIC RATS L. Silva *, C. Morgado, P. Pereira-Terra, I. Tavares. Institute of Histology and Embryology, Faculty of Medicine of Porto and IBMC, University of Porto, Porto, Portugal Insulin and insulin-like growth factor (IGF-1) elicit neuroprotective effects on diabetic neuropathy but their direct repercussions on pain, independent of hyperglycemia correction, remain unclear. In the present study, we evaluated the effects in the pain behavioral responses of streptozotocin-induced diabetic rats (STZ rats) of administrating low doses of insulin and IGF-1 that maintain the hyperglycemic condition of the rats. Diabetes was induced by an intraperitoneal (i.p) injection of STZ (60 mg/kg) using male Wistar rats. One week after injection, STZ rats were subcutaneously injected 3 times per week during 3 weeks with insulin (2 IU), IGF-1 (2.5 mg/Kg) or saline. During the treatment period, the animals were weekly tested for the evaluation of mechanical and thermal nociception using the paw pressure test and tail-flick test, respectively. Saline-injected STZ rats presented mechanical hyperalgesia beginning at 1 week post-injection and loss of thermal sensation at 2 weeks, both of which aggravate with diabetes progression. Insulin and IGF-1 treatments prevented the aggravation of mechanical