脊髓电刺激术治疗内脏痛的研究进展

背景 脊髓电刺激术(spinal cord stimulation,SCS)可以缓解多种原因导致的疼痛,改善器官功能,尤其对于神经病理性疼痛和周围血管病变引起的缺血性疼痛的治疗作用明显.最近研究发现,其对内脏痛性疾病也有艮好的缓解作用.目的 通过综述SCS在内脏痛中的应用及其作用机制,为内脏痛的治疗提供参考. 内容 SCS的发展及其对内脏痛的镇痛机制,对各种内脏痛相关疾病的治疗效应和进展. 趋向 SCS可以治疗药物治疗效果欠佳的内脏痛疾病,为内脏痛的治疗提供新的工具.     

Huge epidural hematoma after surgery for spinal cord stimulation

Summary Objective and importance. Spinal epidural haematoma (SEH) following implantation of an epidural spinal cord electrode is a very rare complication but one that must not be overlooked. This case is unusual because of the almost holocord extension of the haematoma and the excellent recovery obtained by prompt surgical treatment.Clinical presentation. A 69 years old man with normal serum coagulation parameters was submitted to spinal cord stimulation (SCS) for chronic pain syndrome. After a minimal L1 laminotomy the patient developed paraplegia due to a large haematoma at D4-L2.Intervention. Surgical removal of the entire clot by a D4-L2 laminectomy was performed immediately.Conclusion. Large epidural haematoma can result from SCS and this complication may be cured by appropriate and prompt surgery.     

Spinal cord stimulation and limb ischemia: Neurophysiological mechanisms involved in pain relief

Summary   Background: Spinal cord stimulation is a spin-off of the well-known “Gate Control Theory of Pain” presented byMelzack undWall in 1965. However, up to now very little is known about the mechanisms behind the beneficial effects. Methods: Several different mechanisms are activated by spinal cord stimulation. The present state of knowledge is reviewed. Results: The “Gate Control Theory of Pain” comprehends a model in which the nociceptive unmyelated afferents are inhibited by stimulation of non-nociceptive myelinated afferents. Although the concept of this theory is not longer tenable in all its aspects, the idea remains unchanged. At present, several hypotheses are discussed: a simple blocking of pain transmission by a direct effect on the spinothalamic tracts, activation of descending inhibitory pathways, segmental inhibition via coarse fibre activation and brain stem loops to thalamocortical mechanisms, long-term suppression of the sympathic activity and antidromic effects on peripheral reflex circuits and the release of neurotransmitters. Conclusions: Several different mechanisms are activated by spinal cord stimulation. Further research is necessary to increase knowledge of the neurophysiological and neurochemical changes activated by stimulation.      

Sacral spinal cord and root potentials evoked by the stimulation of the dorsal nerve of penis and cord conduction delay for the bulbocavernosus reflex

Segmental spinal cord and root potentials in response to stimulations of the dorsal nerve of penis, tibial nerve, and the sural nerve were epidurally recorded in normal subjects. EMG responses from the bulbocavernosus (BC) and the various leg muscles were also recorded in response to bipolar stimulations by the same epidural needle electrodes of the sacral cord and lumbosacral roots. The afferent conduction velocity from the penis to Th₁₂-L₁ intervertebral level was about 40 m/sec on the average, which is significantly slower than those obtained by the stimulation of the mixed and cutaneous nerves at the lower limb. The latency of the motor responses of the BC muscle from Th₁₂-L₁ spine levels were found comparatively longer than those of thigh muscles on maximal epidural stimulation in spite of the shorter distances to the BC muscle. The central conduction delay within the sacral cord of the bulbocavernosus reflex was calculated and found to be about 8.2 msec, while the central conduction time was about 1.1 msec for the Soleus-H-Reflex. These findings may suggest that there may be about 5–6 synapsis necessary for the first component of the bulbocavernosus reflex, though some faster oligosynaptic cord linkage may also exist.     

Spinal cord stimulation for relief of abdominal pain in two patients with familial Mediterranean fever

Familial Mediterranean fever is a hereditary disease characterizedby recurrent attacks of fever and serosal inflammation thatcommonly presents as severe abdominal pain. Though colchicineremains the mainstay of treatment, a significant proportionof patients are partially responsive, unresponsive or intolerantto it. We present two such cases where spinal cord stimulation(SCS) was used to manage the paroxysmal abdominal pain associatedwith this disease. Abdominal visceral pain pathways and theapplication of SCS techniques in its management are discussed.     

Tramadol for pain relief in children undergoing herniotomy: a comparison with ilioinguinal and iliohypogastric blocks

BACKGROUND: Prevention of postoperative pain in children is one of the most important objectives of the anesthesiologist. Preoperative ilioinguinal and iliohypogastric nerve blocks have been widely used to provide analgesia in children undergoing herniorrhaphy. Tramadol is an analgesic with micro-opioid and nonopioid activity. In this study we compared the usage of intravenous tramadol with ilioinguinal and iliohypogastric nerve blocks for control of post-herniorrhaphy pain in children aged 2-7 years. METHODS: Sixty patients were randomly allocated to two groups of thirty. One group received tramadol 1.5 mg.kg(-1) i.v. before induction of general anesthesia and the other had an ilioinguinal and iliohypogastric nerve block with 0.5% bupivacaine (0.25 ml.kg(-1)) before skin incision. We assessed pain using the Children's Hospital of Eastern Ontario Pain Scale and the Categorical Pain Scale. RESULTS: At 1, 4 and 24 h after surgery the two groups had identical pain scores. At 2 and 3 h after surgery the tramadol group experienced significantly less pain (P < 0.05). The rescue drug for residual pain, was used equally in the two groups. None of the 60 patients had respiratory depression but the tramadol group patients were found to have more episodes of nausea and vomiting (P < 0.05). CONCLUSIONS: We concluded that tramadol can have at least the same analgesic effect as that of ilioinguinal and iliohypogastric nerve blocks for post-herniorrhaphy pain in children, with even a superior effect at the time of maximal analgesia. We also highlight the troublesome side-effect of nausea and vomiting which brings into question the benefits of using this opioid that seems to lack respiratory depression.     

Percutaneous peripheral nerve stimulation for treatment of shoulder pain after spinal cord injury: A case report

Context: This describes the first person with spinal cord injury (SCI) treated with percutaneous peripheral nerve stimulation for chronic shoulder pain.

Findings: From baseline to one-week after treatment, the subject's worst pain in the last week, rated on a 0–10 numerical rating scale (BPI-SF3), decreased by 44%. Pain interference decreased and remained below baseline 12 weeks after the end of treatment. There was an associated improvement in the mental component of quality of life.

Conclusion: This case demonstrates the feasibility of treating shoulder pain in patients with SCI with percutaneous PNS. To demonstrate efficacy further studies are required.     

Transcutaneous electrical nerve stimulation: an effective treatment for pain caused by renal colic in emergency care

PURPOSE: Acute renal colic is one of the most anguishing forms of pain in humans. We hypothesized that TENS is an effective pain treatment in patients with acute renal colic. MATERIALS AND METHODS: A total of 100 patients with acute flank pain and suspected renal colic consented to participate in our study. Paramedic 1 recorded baseline parameters at the emergency site and at the end of transportation. Paramedic 2 performed TENS in patients randomly assigned to G1 with actual TENS or to G2 with sham TENS. Pain and anxiety were measured using paper based visual analog scales on a scale of 0 to 100 mm. RESULTS: Of 100 screened patients 73 had renal colic, including 39 in G1 and 34 in G2. There was no significant difference with regard to potentially influencing factors, such as patient age, sex, weight, height, blood pressure and heart rate, pain, nausea and anxiety between the groups before treatment. G1 showed a significant mean pain decrease +/- SD of more than 50% (85.7 +/- 10.5 to 33.3 +/- 16.0 mm, p <0.01). G2 showed no variation in mean pain scores (85.8 +/- 18.0 to 82.6 +/- 14.3 mm). G1 showed changes in the mean anxiety score (69.0 +/- 8.4 to 37.7 +/- 15.1 mm, p <0.01), nausea score (90.7 +/- 9.2 to 44.9 +/- 22.0 mm) and heart rate (92 +/- 10 to 64 +/- 8 bpm), while G2 showed nonsignificant changes. CONCLUSIONS: This trial shows that local TENS is a rapid and effective treatment for renal colic pain. We found TENS to be a good nondrug therapy under the difficult circumstances of out of hospital rescue.     

Gastric tube volume after duodenal switch and its correlation to short-term weight loss

Background Bariatric operations may have a restrictive and a malabsorptive component. The restrictive component is considered key for short-term weight loss. However, there are important volume discrepancies between gastric reservoirs in different bariatric surgical techniques, which questions the real meaning of the restrictive part of the operation. We have investigated the relationship between residual gastric volume after sleeve gastrectomy in duodenal switch (DS) and weight loss over the first postoperative year. Methods 14 patients submitted to a modified DS and one patient submitted to a sleeve gastrectomy were studied. All patients had an abdominal CT performed between the third and the ninth postoperative month to measure residual gastric volume. Gastric tube volume was correlated to early postoperative weight loss. Results Mean excess BMI loss was 75% at 12 months. Mean gastric tube volume was 208 cc. Gastric volume was not related to preoperative weight or BMI; instead, it was directly related to patient’s height. There was no statistical relation between gastric volume and weight loss at 3, 6, 9 or 12 months after the operation. Conclusion After DS, gastric tube volume is not directly related to weight changes. Other factors could have influence on intake restriction, such as gastric tube compliance or different mechanisms of satiety induction, because no differences in weight loss were observed between narrow tubes and wider ones, despite important variations in volume.     

Implantable devices for pain control: spinal cord stimulation and intrathecal therapies

Untreated chronic pain is costly to society and to the individual suffering from it. The treatment of chronic pain, a multidimensional disease, should rely on the expertise of varying health care providers and should focus not only on the neurobiological mechanisms of the process but also on the psychosocial aspects of the disease. Implantable devices are costly and invasive, and such efficacious therapies should be used only when more conservative and less costly therapies have failed to provide relief of pain and suffering. Spinal cord stimulation provides neuromodulation of neuropathic, but not nociceptive, pain signals and when used for appropriate indications in the right individuals provides approximately 60–80% long-term pain relief in 60–80% of patients trialled for efficacy. Intrathecal therapies with opioids such as morphine, fentanyl, sufentanil or meperidine – or non-opioids such as clonidine or bupivacaine – provide analgesia in patients with nociceptive or neuropathic pain syndromes. Baclofen, intrathecally, provides profound relief of muscle spasticity due to multiple sclerosis, spinal cord injuries, brain injuries or cerebral palsy.     

Complex regional pain syndrome: the case for spinal cord stimulation (a brief review)

Complex regional pain syndrome is a disabling disorder with an unknown mechanism which is extremely resistant to conventional pharmaceutical and therapeutic therapies. In this paper we present the underlying theories of this disorder. We present spinal cord stimulation as an alternative to conventional interventions in the management of this disabling condition spinal cord stimulation significantly improves pain, reduces narcotic intake and improves activity levels and overall quality of life. There is now a significant body of evidence to support the utilization of spinal cord stimulation in the management of complex regional pain syndrome.     

Invasive and non-invasive brain stimulation for treatment of neuropathic pain in patients with spinal cord injury: A review

Context

Past evidence has shown that invasive and non-invasive brain stimulation may be effective for relieving central pain.

Objective

To perform a topical review of the literature on brain neurostimulation techniques in patients with chronic neuropathic pain due to traumatic spinal cord injury (SCI) and to assess the current evidence for their therapeutic efficacy.

Methods

A MEDLINE search was performed using following terms: “Spinal cord injury”, “Neuropathic pain”, “Brain stimulation”, “Deep brain stimulation” (DBS), “Motor cortex stimulation” (MCS), “Transcranial magnetic stimulation” (TMS), “Transcranial direct current stimulation” (tDCS), “Cranial electrotherapy stimulation” (CES).

Results

Invasive neurostimulation therapies, in particular DBS and epidural MCS, have shown promise as treatments for neuropathic and phantom limb pain. However, the long-term efficacy of DBS is low, while MCS has a relatively higher potential with lesser complications that DBS. Among the non-invasive techniques, there is accumulating evidence that repetitive TMS can produce analgesic effects in healthy subjects undergoing laboratory-induced pain and in chronic pain conditions of various etiologies, at least partially and transiently. Another very safe technique of non-invasive brain stimulation – tDCS – applied over the sensory-motor cortex has been reported to decrease pain sensation and increase pain threshold in healthy subjects. CES has also proved to be effective in managing some types of pain, including neuropathic pain in subjects with SCI.

Conclusion

A number of studies have begun to use non-invasive neuromodulatory techniques therapeutically to relieve neuropathic pain and phantom phenomena in patients with SCI. However, further studies are warranted to corroborate the early findings and confirm different targets and stimulation paradigms. The utility of these protocols in combination with pharmacological approaches should also be explored.     

Comparison of transcutaneous electrical nerve stimulation (TENS) and functional electrical stimulation (FES) for spasticity in spinal cord injury - A pilot randomized cross-over trial

Objective: Spasticity following spinal cord injury (SCI) can impair function and affect quality of life. This study compared the effects of transcutaneous electrical nerve stimulation (TENS) and functional electrical stimulation (FES) on lower limb spasticity in patients with SCI.

Design: Double blind randomized crossover design.

Setting: Neuro-rehabilitation unit, Manipal University, India.

Participants: Ten participants (age: 39 ± 13.6 years, C1–T11, 1–26 months post SCI) with lower limb spasticity were enrolled in this study.

Interventions: Participants were administered electrical stimulation with TENS and FES (duration - 30 minutes) in a cross over manner separated by 24 hours.

Outcome Measures: Spasticity was measured using modified Ashworth scale (MAS) [for hip abductors, knee extensors and ankle plantar flexors] and spinal cord assessment tool for spastic reflexes (SCATS). Assessments were performed at baseline, immediately, 1 hour, 4 hours, and 24 hours post intervention.

Results: A between group analysis did not show statistically significant differences between FES and TENS (P > 0.05). In the within group analyses, TENS and FES significantly reduced spasticity up to 4 hours in hip adductors and knee extensors (P < 0.01). SCATS values showed significant reductions at 1 hour (P?=?0.01) following TENS and 4 hours following FES (P?=?0.01).

Conclusion: A single session of electrical stimulation with FES and TENS appears to have similar anti-spasticity effects that last for 4 hours. The findings of this preliminary study suggest that both TENS and FES have the potential to be used as therapeutic adjuncts to relieve spasticity in the clinic. In addition, FES may have better effects on patients presenting with spastic reflexes.     

Pharmacokinetics and clinical effect during continuous epidural infusion with ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief

Background: Ropivacaine has shown less systemic toxicity than bupivacaine, and comparatively low muscle-blocking properties could constitute another advantage when used epidurally for obstetric pain relief. We aimed primarily to compare maternal and foetal drug disposition following continuous epidural infusion of ropivacaine or bupivacaine.
Methods: Twenty-four full-term, nulliparous women were randomized to continuous epidural infusion (10 ml/h) of ropivacaine 2.5 mg/ml or bupivacaine 2.5 mg/ml for labour pain relief in a double-blind, parallel-group design. Maternal blood samples were collected up to 24 h after the end of infusion as well as taken from the umbilical cord at the time of delivery. Sensory and motor block as well as analgesia were assessed. All the women were monitored by cardiotocography and neonatal assessment was performed.
Results: The sensory block was adequate for both drugs. Higher plasma levels (total and free) were seen with ropivacaine, although the infusion with bupivacaine continued on average for about 2 hours longer. However, the ratios between maternal and umbilical blood concentrations were similar for both drugs. Normal neonatal Apgar and neonatal adaptive capacity scores (NACS) were found in both groups.
Conclusion: A continuous epidural infusion of 25 mg/h ropivacaine or bupivacaine both produced good labour pain relief. Higher total and free plasma concentrations were seen for ropivacaine. The ratios between maternal and umbilical plasma levels were similar for both drugs.