Spinal Cord Stimulation (SCS) in Peripheral Ischemic Pain

Between 1982 and 1987,45 patients suffering from painful symptomatology caused by peripheral vascular disease, not curable by medical or surgical therapy, were implanted with epidural neurological stimulators. Measurements used in evaluating the effectiveness of the method were pain control, walking distance, and development of trophic problems. With most patients, we noted a satisfactory and long-lasting degree of pain control. Walking distance increased to a surprising degree. Trophic lesions smaller than 3 sq cm healed, while lesions of greater size required amputation of the limb. Transcutaneous oxygen tension (TcpO₂) was used to study the efects of SCS on peripheral circulation in implanted patients. In addition, TcpO₂ was calculated in 15 patients before and during the percutaneous test to predict the efectiveness of SCS. Regression of painful symptomatology was achieved only in patients whose TcpO_2b improved during the course of the testing. Therefore, this method provides an objective measure for the implantation of a neurostimulator     

Spinal Cord Stimulation in Peripheral Vascular Disease: A Retrospective Analysis of 95 Cases

Abstract: Spinal Cord Stimulation is one of the interventionist treatments used for treating diverse chronic pain syndromes.
This study analyses retrospectively 95 patients diagnosed as suffering from grave peripheral arteriopathy in Fontaine state III (36 patients) and Fontaine state IV (56 patients). Eight patients required a minor amputation and 29 a major amputation. Those patients diagnosed as suffering from diabetes (diabetic arteriopathy) had a higher rate of amputation, above all those diagnosed as Fontaine group III. The most frequent complication was incorrect stimulation (22 cases), which necessitated the repositioning of the electrode.     

Spinal Cord Stimulation (SCS) in Spastic Hemiparesis

Thirteen patients with post-stroke spastic hemiparesis underwent a percutaneous test trial of spinal cord stimulation (SCS) in order to modify their motor disturbances. Clinical evaluation based on Albert's motor scale and neurophysiologcial evaluation consisting of surface EMG during voluntary, involuntary, and reflex motor activity were performed before and during SCS. At the end of the test period, eight patients showed a significant improvement in their motor performance. The EMG analysis confirmed the clinical data. SCS was followed by a reduction or disappearance of synergic coactivation with better agonist-antagonist coordination, a decrease of clonus both in duration and spreading, and better endurance. The effect on motor controi did not increase with time after the first month of SCS, but was long lasting (mean follow-up: 2 years). There was a correlation between sensory deficit and motor outcome suggesting that the enhancement of sensory input put into play by SCS and the consequent development of new sensory-motor integration might be responsible for the improvement in motor performance.     

Spinal Cord Stimulation (SCS) in Deafferentation Pain

Spinal cord stimulation is considered to be ineffective in relieving deafferentation pain. We have retrospectively analyzed the results obtained in a series of 41 patients. Sixteen suffered from pain associated with an incomplete traumatic spinaJ lesion, 15 from a posttherapeutic neuralgia, and 10 from pain due to root and/or nerve damage. At the end of the test period, 43.7% of the patients with paraplegic pain, (40% of those with peripheral deafferentation pain and 66.6% of the ones with postherapeutic neuralgia), reported satisfactory pain relief and were connected to a chronic stimulation system. At mean follow-up (15 months), only 20% of the patients of the first two groups reported sufficient pain relief In the postherapeutic group the figure of responders was unchanged. The mean analgesia achieved was 70%. From this analysis we conclude that the results achieved in the postherapeutic pain patients, although positive in only 66% of them, are remarkably stable with time. Therefore, we recommend a percutaneous test trial of SCS in every case of postherapeutic pain resistant to medical treatment.     

Spinal Cord Stimulation and Motor Disorders

Spinal cord stimulation has been investigated by us during the past 10 years in the treatment of various disorders of the motor system. The effectiveness was studied in 735 cases, including cerebral palsy (212), dystonia (129), torticollis (66), spinal cord injury (169), and degenerative diseases (159). Our resuits indicate that in properly selected patients, stimulating the spinal neural axis is therapeutically effective in the majority of the cases treated. Our data demonstrate that the level stimulated, the pattern and the polarity of the applied field, and the frequency of the stimulation are critical to achieve a satisfactory therapeutic result and must be individualized in each patient.     

Epidural Spinal Electrical Stimulation in Peripheral Vascular Disease

Epidural spinal electrical stimulation (ESES) has been valuable in the control of pain arising from peripheral vascular disease. Thirty-two of 34 patients experience some relief of pain and 12 of 24 patients showed healing of ischemic ulcers. This technique may prove to be useful in preventing or delaying amputation of ischemic limbs. A prospective randomized study has been undertaken to assess whether this form of electrical stimulation can save limbs.     

磁刺激对脊髓损伤后神经再生的影响

目的探讨应用磁刺激(magneticstimulation,MS)对脊髓损伤后脊髓神经再生的影响.方法利用Allen氏WD技术,以10g×2.5cm致伤力造成Wistar大白鼠T8脊髓损伤模型,MS组于术后即刻、1、2、4、8、12、24及48h分别给予磁刺激,以后每周2次磁刺激至术后第8周;对照组在损伤后不做治疗.2组均于术后第8周取损伤区脊髓组织0.5cm作NF200免疫组织化学检查,观察神经纤维再生情况.结果术后第8周,NF200免疫组织化学检查发现MS组神经纤维生长情况明显优于对照组,经统计学分析2组间差异有显著性意义.结论脊髓损伤后应用MS可以保护脊髓神经组织,并且对神经纤维的再生有促进作用.     

New Approach for Spinal Cord Stimulation Trial

Abstract:   Spinal cord stimulation trial phase has remained unchanged for years. The common practice to connect a lead to an external transmitter is not optimal. The operational mode of transmitter is different from implanted system and external bulky device interferes with patient's daily routine. Optimization in the trial period may increase patient's satisfaction and improve outcome of upcoming permanent implantation. The proposed new trial design can be a simple and logical solution of the problem.     

Spinal Cord Stimulation for Severely Ischemic Limbs

Severe atherosclerosis of the lower limbs causes rest pain, skin ulcerations and gangrene. In such situations and when standard surgical treatment had failed or it is impossible to employ, spinal cord stimulation (SCS) seems to be of value. Since April 1985, we have used this technique on 19 patients. The results have been beneficial in 70.6% of the cases and have shown some evidence of increasing cutaneous flow. However, randomized series are required before accepting it as having a special place in the fight against atherosclerotic disease.     

脊髓电刺激治疗神经病理性疼痛的应用进展

脊髓电刺激(SCS)通过电脉冲信号阻断疼痛信号传递,干扰疼痛传导通路,激活阿片通道,刺激蓝斑系统及调节γ-氨基丁酸能系统,从而发挥抑制或减轻疼痛的作用。目前被应用于带状疱疹后神经痛、腰椎术后疼痛综合征、幻肢痛、痛性糖尿病神经病变、头面部神经痛、阴部神经痛等神经病理性疼痛的治疗中。     

Spinal Cord Stimulation for Complex Pain: Initial Experience with a Dual Electrode, Programmable, Internal Pulse Generator

Abstract: The objective of this study was to engage in an 18‐month follow‐up of 20 chronic complex pain patients using a dual electrode, programmable, fully implantable internal pulse generator (IPG) for spinal cord stimulation (SCS). Implant status, stimulation mode, anode‐cathode configuration (array), cathode position, paresthesia overlap, complications, Visual Analog Scores (VAS), and overall satisfaction were prospectively examined in 20 patients implanted with dual 4 contact, staggered, percutaneous electrodes (Pisces 3487A, Medtronic, Minneapolis, Minnesota) internalized to a fully implantable, programmable IPG (Synergy 7466, Medtronic, Minneapolis, Minnesota). All patients had undergone initial implantation for chronic complex axial and extremity pain (eg, Failed Back Surgery Syndrome (FBSS), Complex Regional Pain Syndrome (CRPS)) with dual octapolar, radiofrequency (RF) SCS systems (Advanced Neuromodulation Systems 2098, Plano, Texas). 1 - 3 All patients required conversion to the current dual IPG systems due to RF system receiver sensitivity, preventing further antenna coupling). 1 Dual quadrupolar IPG SCS outcomes were compared to previous long‐term, dual octapolar RF SCS complex pain reports. 1 - 3 Data was collected and analyzed by a disinterested third party. At 18 months, all 20 patients remained implanted. All patients reported using 1 or 2 “best” guarded tripolar or bipolar arrays to maintain favorable paresthesia overlap (77.5%), VAS reduction (9.78 → 4.40), and overall patient satisfaction (80%). Eighty‐five percent of “best” anode‐cathode configurations were activated on both electrode columns about the physiologic midline of the C 3/4 vertebral segments for upper extremity pain, and the T 9/10 vertebral segments for low back and lower extremity pain. Sixty‐seven and one half percent of all electrodes were thoracic and 32.5% were cervical. “Best” arrays were activated as narrow (adjacent contact) guarded cathode tripoles (75%), extended (nonadjacent contact) bipoles/tripoles (15%), or as narrow bipoles (10%). The mean number of active contacts per “best” array was 5.6, with 3.75 anodes and 1.85 cathodes. All patients preferred the current IPG to the prior RF SCS implant, citing RF receiver site sensitivity, difficulty maintaining coupling of the RF antennae, and time intensive RF programming. Conversely, 13 patients (65%) reported IPG site sensitivity that did not affect overall satisfaction. That is, none would convert their current IPG to a smaller IPG to resolve this issue, unless it was of equal longevity. Sixteen patients (80%) were satisfied with the overall level of pain relief, and all (100%) would repeat the IPG SCS implant. This study demonstrates improved overall outcome and patient satisfaction after long‐term, dual octapolar RF SCS conversion to dual quadrupolar IPG SCS systems in the same patient population. It also validates prior dual SCS electrode reports of common array configuration, electrode positioning about the physiologic midline, and patient preference of single or dual programmability in the treatment of chronic complex pain. 1 , 4 , 5 Follow‐up of this initial experience with a multicenter study is warranted.     

Cerebral Hemodynamics During Spinal Cord Stimulation

An increase of cerebral blood flow (CBF) during spinal cord stimulation (SCS) has been shown in man using the 133Xenon inhalation technique. We report the effects of SCS on cerebral hemodynamics studied with transcranial Doppler sonography (TCD). Twenty-six patients with epidural electrodes implanted at the cervical level (11 patients) and at the thoracic level (15 patients) were investigated with recordings of CBF velocity in the middle cerebral arteries before and during SCS. Sixty-three and two-thirds percent of patients with cervical stimulation and 29.4% of patients with thoracic stimulation showed a decrease of cerebral vascular resistance simultaneously with an increase of the velocity of CBF.     

Effects of Epidural Spinal Cord Stimulation and Treadmill Training on Locomotion Function and Ultrastructure of Spinal Cord Anterior Horn after Moderate Spinal Cord Injury in Rats

Objective:To investigate the effects of epidural spinal cord stimulation (ESCS) and treadmill training on the locomotion function and ultrastructure of spinal cord anterior horn after moderate spinal cord injury in rats.Method:Nine adult female Sprague-Dawley rats were randomly distributed into three groups: ①spinal cord injury group (SI, n=3). ②spinal cord injury plus ESCS group (SE, n=3). ③spinal cord injury plus treadmill training group (TT, n=3). All rats received a moderate spinal cord injury surgery. Four weeks after surgery, rats in SE group received an electrode implantation procedure, with the electrode field covering spinal cord segments L2—S1. Four weeks after electrode implantation, rats received subthreshold ESCS for 30 min/d. Rats in TT group received 4cm/s treadmill training for 30min/d. Rats in SI group received no intervention, as a control group. All procedures in these three groups lasted four weeks.The open field Basso,Beattie and Bresnahan(BBB) scale was used before and after intervention to evaluate rats′ hindlimb motor function. Result:After four weeks intervention, rats in TT group improved their open field locomotion scores to 20. In contrast, no significant improvement was observed in groups SI and SE. The morphology of synapses and neurons were similar regardless of whether rats had undergone ESCS, treadmill training or not. Conclusion:ESCS alone was not sufficient to improve the walking ability of spinal cord injured rats. ESCS or treadmill training alone might not contribute to the changes of ultrastructure in anterior horn of spinal cord that underlie the recovery of walking ability. Further research is needed to understand the contributions of combination of ESCS and treadmill training to the rehabilitation of spinal cord injured rats.     

磁刺激对脊髓神经组织损伤的早期保护作用

目的探讨脊髓损伤后应用磁刺激(MagneticStimulation,MS)对损伤脊髓组织早期钙、镁离子的影响。方法实验利用Allen氏WD(Weightdrop,WD)技术,以10g×2.5cm致伤力造成wistar大鼠T     

血管内皮生长因子在脊髓损伤中的应用

血管内皮生长因子在多种疾病的研究中应用越来越多。其中,血管内皮生长因子在脊髓损伤中的应用也受到广泛关注。本文就血管内皮生长因子对脊髓损伤后的作用机制和影响血管内皮生长因子在脊髓损伤中表达的各种因素进行综述。     

Spinal Cord Stimulation for the Treatment of Refractory Angina Pectoris: A Two-Year Follow-Up

Twenty-three patients affected by severe, refractory angina were submitted to permanent spinal cord stimulation (SCS) and then followed in our outpatient clinic for 24 months. During the follow-up period, the number of weekly angina episodes drastically dropped from 9.2 (preimplant) to 1.8 in the 3rd, 2.5 in the 6th, 4.5 in the 12th, and 4.2 in the 24th month, with a statistically significant difference (P < 0.01) between the first and last values. A significant increase in the average exercise time from 320 ± 120 seconds (in baseline condition) to 410 ± 115 seconds (during SCS) was observed at the treadmill stress test (P < 0.01). SCS was well tolerated by all the patients. However, 7 patients died during follow-up (3 myocardial infarctions, 2 noncardiac deaths, and 2 sudden deaths). Three generators were replaced because of battery depletion after 15, 17, and 21 months. No serious complication was observed. In conclusion, in patients with otherwise intractable angina or already submitted to myocardial revascularization, SCS is very effective in reducing the number of angina episodes. The time of the work during exercise stress test is also significantly prolonged.     

Time Dependent Variations of Stimulus Requirements in Spinal Cord Stimulation for Angina Pectoris

The aim of the study was to observe changes over time of the stimulation requirements in spinal cord stimulation (SCS). Of 60 patients treated with SCS, 25 patients were selected because they had neurostimulators capable of measuring impedance noninvasively, and had not experienced electrode displacement. All 25 patients had Medtronic Pisces Quad 3487A (Medtronic, Inc.) neuroelectrodes with the tip positioned in the thoracic epidural space. The accuracy of the neurostimulators impedance measuring circuit was investigated in a test circuit. The error was < 11%. Stimulus requirements and impedance were recorded at the implantation and at follow-ups during a period of 24 months. During the first month after implantation, the stimulus requirements for satisfactory effect varied between +406% and -34%. After that period, only minor deviations were observed in most patients. To optimize the pain reducing effect of the spinal cord stimulation, frequent follow-ups are recommended during the first month; later on, the follow-up intervals can be extended. No tolerance development or pain resistance developed during SCS treatment     

A Severe Case of Complex Regional Pain Syndrome I (Reflex Sympathetic Dystrophy) Managed with Spinal Cord Stimulation

Complex regional pain syndrome is a condition that usually affects the upper or lower extremities. The cause is not clearly understood. We report a case of a severe form of a rapidly progressive complex regional pain syndrome type I developing after a right shoulder injury managed with spinal cord stimulation (SCS). After failed conservative treatments, a rechargeable SCS system was implanted in the cervical spine. Allodynia and dystonia improved but the patient subsequently developed similar symptoms in lower right extremity followed by her lower left extremity. The patient became wheelchair bound. A second rechargeable SCS with a paddle electrode was implanted for the lower extremity coverage. The patient's allodynia and skin lesions improved significantly. However, over time, her initial symptoms reappeared which included skin breakdown. Due to the need for frequent recharging, the system was removed. During explantation of the surgical paddle lead, it was noted by the neurosurgeon that the contacts of the paddle lead were detached from the lead. After successful implantation of another SCS system, the patient was able to reduce her medications and is now able to ambulate with the use of a left elbow crutch.     

Stimulation Characteristics, Complications, and Efficacy of Spinal Cord Stimulation Systems in Patients with Refractory Angina: A Prospective Feasibility Study

Objectives: In a prospective study with a 1-year follow-up we evaluated: (1) the feasibility of a method for the adjustment of spinal cord stimulator (SCS) parameters, (2) complications of SCS, and (3) efficacy of SCS. Methods: In patients receiving an SCS for severe angina unresponsive to standard therapies, SCS characteristics were evaluated within 1 week and at 4, 14, 26, and 52 weeks after SCS treatment. Step-by-step adjustment of pulse output parameters was performed at the electrode configuration at which paresthesias occurred (‘sensory threshold”), covered the anginal area (“adjusted setting”), or provoked pain (“motor threshold”). In addition, the number of anginal attacks and intake of glyceryl trinitrate (GTN) tablets were recorded at regular intervals. Results: Twenty-two patients with either a bipolar (14) or a unipolar (8) system were evaluated. In the 14 patients with bipolar systems, alteration in paresthesias required 26 reprogrammings of the configuration. In the eight patients with bipolar systems who completed the followup without lead dislocation, the mean “sensory threshold” was 3.3 V (1.7–5.6), the mean “adjusted stimulation” output was 4.5 V (2.8–7.6), and the mean “motor threshold” was 4.9 V (2.8–7.7) after 4 weeks SCS. The mean stimulation duration per 24 hours was 14.1% (5%–24%), and the mean standardized impedance was 821 Ω (748–893) after 4 weeks SCS. The unipolar group demonstrated comparable results. After 1-year follow-up the parameters had not changed significantly. During the 1-year follow-up, 6 of 22 patients experienced lead dislocation that required surgery. In all patients, anginal attacks (P < 0.003) and GTN intake (P < 0.005) were reduced significantly with SCS. The effect lasted during the 1 year. Conclusions: During a 1 -year follow-up, the stimulation parameters did not change significantly in the 16 patients without lead dislocations. Our standardized method appears to be feasible for follow-up of SCS. Moreover, SCS seems to be an effective adjuvant therapy for intractable angina, despite a relatively frequent dislocation of the electrode.