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Background: Occipital nerve stimulation (ONS) has shown promising results in small uncontrolled trials in patients with medically intractable chronic cluster headache (MICCH). We aimed to establish whether ONS could serve as an effective treatment for patients with MICCH., Methods: The ONS in MICCH (ICON) study is an investigator-initiated, international, multicentre, randomised, double-blind, phase 3, electrical dose-controlled clinical trial. The study took place at four hospitals in the Netherlands, one hospital in Belgium, one in Germany, and one in Hungary. After 12 weeks' baseline observation, patients with MICCH, at least four attacks per week, and history of being non-responsive to at least three standard preventive drugs, were randomly allocated (at a 1:1 ratio using a computer-generated permuted block) to 24 weeks of occipital nerve stimulation at either 100% or 30% of the individually determined range between paraesthesia threshold and near-discomfort (double-blind study phase). Because ONS causes paraesthesia, preventing masked comparison versus placebo, we compared high-intensity versus low-intensity ONS, which are hypothesised to cause similar paraesthesia, but with different efficacy. In weeks 25-48, participants received individually optimised open-label ONS. The primary outcome was the weekly mean attack frequency in weeks 21-24 compared with baseline across all patients and, if a decrease was shown, to show a group-wise difference. The trial is closed to recruitment (ClinicalTrials.gov NCT01151631)., Findings: Patients were enrolled between Oct 12, 2010, and Dec 3, 2017. We enrolled 150 patients and randomly assigned 131 (87%) to treatment; 65 (50%) patients to 100% ONS and 66 (50%) to 30% ONS. One of the 66 patients assigned to 30% ONS was not implanted and was therefore excluded from the intention-to-treat analysis. Because the weekly mean attack frequencies at baseline were skewed (median 15·75; IQR 9·44 to 24·75) we used log transformation to analyse the data and medians to present the results. Median weekly mean attack frequencies in the total population decreased from baseline to 7·38 (2·50 to 18·50; p<0·0001) in weeks 21-24, a median change of -5·21 (-11·18 to -0·19; p<0·0001) attacks per week. In the 100% ONS stimulation group, mean attack frequency decreased from 17·58 (9·83 to 29·33) at baseline to 9·50 (3·00 to 21·25) at 21-24 weeks (median change from baseline -4·08, -11·92 to -0·25), and for the 30% ONS stimulation group, mean attack frequency decreased from 15·00 (9·25 to 22·33) to 6·75 (1·50 to 16·50; -6·50, -10·83 to -0·08). The difference in median weekly mean attack frequency between groups at the end of the masked phase in weeks 21-24 was -2·42 (95% CI -5·17 to 3·33). In the masked study phase, 129 adverse events occurred with 100% ONS and 95 occurred with 30% ONS. None of the adverse events was unexpected but 17 with 100% ONS and eight with 30% ONS were labelled as serious, given they required brief hospital admission for minor hardware-related issues. The most common adverse events were local pain, impaired wound healing, neck stiffness, and hardware damage., Interpretation: In patients with MICCH, both 100% ONS intensity and 30% ONS intensity substantially reduced attack frequency and were safe and well tolerated. Future research should focus on optimising stimulation protocols and disentangling the underlying mechanism of action., Funding: The Netherlands Organisation for Scientific Research, the Dutch Ministry of Health, the NutsOhra Foundation from the Dutch Health Insurance Companies, and Medtronic., Competing Interests: Declaration of interests MDF reports grants and consultancy or industry support from Electrocore, Medtronic, Eli Lilly, Amgen, Novartis, and TEVA, and independent support from The Netherlands Organisation for Scientific Research, The Netherlands Organisation for Health Research and Development, The Dutch Brain and Heart Foundations, The Dutch Ministry of Health, and The NutsOhra Foundation from the Dutch Insurance Companies. FJPMH reports grants and consultancy fees from Abbott, Saluda, and Pfizer, and independent support from The Netherlands Organisation for Health Research and Development. IFdC reports travel grants from Electrocore. All other authors report no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: About 10% of cluster headache patients have the chronic form. At least 10% of this chronic group is intractable to or cannot tolerate medical treatment. Open pilot studies suggest that occipital nerve stimulation (ONS) might offer effective prevention in these patients. Controlled neuromodulation studies in treatments inducing paraesthesias have a general problem in blinding. We have introduced a new design in pain neuromodulation by which we think we can overcome this problem., Methods/design: We propose a prospective, randomised, double-blind, parallel-group international clinical study in medically intractable, chronic cluster headache patients of high- versus low-amplitude ONS. Primary outcome measure is the mean number of attacks over the last four weeks. After a study period of six months there is an open extension phase of six months. Alongside the randomised trial an economic evaluation study is performed., Discussion: The ICON study will show if ONS is an effective preventive therapy for patients suffering medically intractable chronic cluster headache and if there is a difference between high- and low-amplitude stimulation. The innovative design of the study will, for the first time, assess efficacy of ONS in a blinded way.

Background: Intractable spasticity can be treated effectively with continuous infusion of intrathecal baclofen. Because evidence for its use in the treatment of children with spastic cerebral palsy is lacking, we conducted a randomised controlled trial., Aims: To test whether continuous infusion of intrathecal baclofen is effective in comparison with standard treatment only., Methods: Seventeen children, aged 13.2 (SD 2.8) years, with intractable spastic cerebral palsy were randomised to receive a Synchromed pump for continuous infusion of intrathecal baclofen after either 1 month (CITB group) or 6 months (Control group). Primary outcomes were the 6-month-change scores on the 0-10 visual analogue scale for individually formulated problems and the caregiver assistance scale of the Pediatric Evaluation of Disability Inventory self-care domain. One of the secondary outcome measures was health related quality of life as measured with the Child Health Questionnaire-PF50., Results: Nine children were randomly assigned to the CITB group and eight to the Control group. The visual analogue scale for individual problems improved with 4.0 (SD 1.7) in the CITB group and changed with -0.2 (SD 1.3) in the Control group (p=0.001). Pediatric Evaluation of Disability Inventory scores did not change significantly. The Child Health Questionnaire-PF50 6-month-change score significantly differed in favour of the CITB group for the domains of bodily pain/discomfort (p=0.014), mental health (p=0.045), psychosocial status (p=0.027) and parents' personal time limitation (p=0.043)., Conclusion: The results of this randomised controlled trial establish continuous infusion of intrathecal baclofen to be effective in carefully selected children with problems caused by intractable spastic cerebral palsy.

Background: Prospective studies that address both efficacy and safety of continuous infusion of intrathecal baclofen (CITB) in children with spastic cerebral palsy (CP), and that use outcome measures beyond muscle tone are lacking., Aims: To study the efficacy at 12 months and safety up to 24 months after start of CITB in children with intractable spastic CP., Methods: Nine girls and eight boys, aged 13.7 years (SD 2.9), received a SynchroMed pump for CITB. We prospectively recorded effects and adverse events at regular follow-up visits up to 24 months. Outcome measures included the 0-10 visual analogue scale (VAS) for individual problems, Gross Motor Function Measure (GMFM) and health related quality of life as measured with the Child Health Questionnaire-PF50., Results: CITB for 12 months significantly improved the VAS for individual problems with 4.7 (SD 2.0; p=0.000), VAS for ease of care with 5.2 (SD 2.1; p=0.000), VAS for pain with 5.4 (SD 2.7; p=0.002); GMFM sitting dimension with 3.3 (range -4.0 to 22.0; p=0.022), GMFM goal dimension with 4.0 (range 0.0-26.0; p=0.007); and Child Health Questionnaire-PF50 domains of bodily pain/discomfort with 25.6 (SD 35.9; p=0.016) and mental health with 9.8 (SD 11.3; p=0.007). During a mean follow-up of 18.4 months (range 12-24), we recorded 80 adverse events. Eight adverse events were serious, but not life-threatening., Conclusions: CITB was effective at 12 months and safe up to 24 months for carefully selected children with intractable spastic CP. CITB relieved pain, facilitated ease of care and improved mental health. The majority of children could extend their activities and participation.

The authors present the case of a 49-year-old female patient with complex regional pain syndrome-Type I (CRPSI) who was suffering from nonhealing wounds and giant bullae, which dramatically improved after spinal cord stimulation (SCS). The scientific literature concerning severe cutaneous manifestations of CRPS-I and their treatment is reviewed. Nonhealing wounds and bullae are rare manifestations of CRPS-I that are extremely difficult to treat. Immediate improvement of both wounds and bullae after SCS, such as in this case, has not been reported previously in literature. Considering the rapidly progressive nature of these severe skin manifestations, immediate treatment, possibly with SCS, is mandatory.

Sciatic nerve ligation in rats (chronic constriction injury (CCI)) induces signs and symptoms that mimic human conditions of neuropathy. The central mechanisms that have been implicated in the pathogenesis of neuropathic pain include increased neuronal excitability, possibly a consequence of decreased availability of spinal GABA. GABA availability is regulated by the presence of the GABA-transporters (GATs). This study investigates the dorsal horn expression of the transporter GAT-1 and its functional involvement towards pain behaviour in the CCI model. Male Lewis rats (total n=37) were subjected to CCI or to a sham procedure. A sub-group of animals was treated with the GAT-1 antagonist NO-711. Behavioural testing was performed pre-surgery and at 7 days post-surgery. Testing included evaluation of mechanical allodynia using Von Frey filaments, thermal allodynia with a hot-plate test and observational testing of spontaneous pain behaviour. Subsequently, spinal protein expression of GAT-1 was assessed by Western blotting. Animals were sacrificed 7 days following surgery. CCI markedly increased mechanical and thermal allodynia and spontaneous pain behaviour after 7 days, while the sham procedure did not. GAT-1 was increased in spinal cord homogenates compared contralateral to the ligation side after 7 days. NO-711 treatment significantly reduced all tested pain behaviour. These data provide evidence for possible functional involvement of GAT-1 in the development of experimental neuropathic pain. The latter can be derived from observed analgesic effects of early treatment with NO-711, a selective GAT-1 inhibitor. The obtained insights support the clinical employment of GAT-1 inhibitors to treat neuropathic pain.

Neuronavigation is a frequently used method in the planning of intracranial neurosurgical procedures. During surgery however, due to anatomical changes such as loss of cerebrospinal fluid, tumour resection and oedema, preoperative data become inaccurate. Updated data acquisition during the procedure using intraoperative MRI (iMRI) overcomes this problem, as it enables maximum tumour resection or accurate tumour biopsy, whilst minimizing the risk of damaging healthy brain tissue. The choice between low field and high field strength systems depends on the desired image quality and integration into the regular workflow. In spite of its high costs, iMRI surgery seems to be cost-effective, due to reduced length of hospital stay, reduced repeat resection, and reduced hospital charges. In the future, intraoperative imaging combined with virtual planning stations, is expected to play an important role in implementing robotization into neurosurgery.

Intrathecal baclofen (ITB) therapy can be very effective in the treatment of intractable spasticity, but its effectiveness and safety have not yet been thoroughly studied in children with cerebral palsy (CP). The aims of this double-blind, randomized, placebo-controlled, dose-finding study were to select children eligible for continuous ITB infusion, to assess the effective ITB bolus dose, and to evaluate the effects, side effects, and complications. Outcome measures included the original Ashworth scale and the Visual Analogue Scale for individually formulated problems. We studied nine females and eight males, aged between 7 and 16 years (mean age 13y 2mo [SD 2y 9mo]). Twelve children had spastic CP and five had spastic-dyskinetic CP. One child was classified on the Gross Motor Function Classification System at Level III, two at Level I V, and 14 at Level V. The test treatment worked successfully for all 17 children with an effective ITB bolus dose of 12.5 microg in one, 20 microg in another, 25 microg in 10, and 50 microg in five children. ITB significantly reduced muscle tone, diminished pain, and facilitated ease of care. The placebo did not have these effects. Nine side effects of ITB were registered, including slight lethargy in seven children. Fourteen children had symptoms of lowered cerebrospinal fluid pressure. We conclude that ITB bolus administration is effective and safe for carefully selected children with intractable spastic CP.

Objective: To evaluate feasibility and utility of the soleus H-reflex and tibialis anterior flexor reflex (FR) in identifying spinal cord neuronal response to intrathecal baclofen (ITB) in children with severe spastic cerebral palsy., Methods: During a randomized, double-blind, placebo-controlled dose-escalation test treatment, maximum H amplitude/maximum M amplitude (H/M ratio) and FR parameters were bilaterally recorded at baseline and 2-3 h after intrathecal bolus administration of placebo and increasing doses of baclofen until both an improvement in the individual treatment goal(s) and a one-point reduction on the Ashworth scale were observed., Results: Electrophysiological data of 14 children were studied. The H-reflex was feasible in 13 children, the FR threshold area in 9 and the FR, elicited with supramaximal stimulation, in only one child. After ITB, the H/M ratio significantly decreased (left: 0.67+/-0.47 to 0.15+/-0.18, P=0.005; right: 0.55+/-0.32 to 0.14+/-0.19, P=0.002) without placebo effect. FR threshold area after ITB, only decreased significantly in children not taking oral baclofen (left: 146+/-53 to 41+/-54 mV ms, P=0.000; right: 156+/-80 to 66+/-48 mV ms, P=0.002)., Conclusions: This is the first randomized, double-blind, placebo-controlled dose-escalation study in spastic children demonstrating the soleus H-reflex to be a feasible and objective measure to quantify the decreasing motoneuron excitability in response to ITB bolus administration. Only in children not taking oral baclofen, FR threshold area can also be used as an objective outcome measure, yet feasibility is limited., Significance: We suggest introducing the H-reflex as the electrophysiological gold standard for the evaluation of the effect of ITB in spastic children.

Objective: The aim of this study was to introduce a useful diagnostic method to evaluate baclofen pump system-related complications without disturbing the continuous delivery of intrathecal baclofen., Methods: We present a case report on the use of an indium (111) diethylenetriaminepentaacetic acid (DTPA) flow study in the evaluation of a lumbar swelling in a 16-year-old girl with spastic cerebral palsy, treated with continuous intrathecal baclofen (CITB)., Results: Disconnection or damage of the catheter leading to leakage of baclofen into the lumbar swelling could be ruled out by the use of an indium (111) DTPA flow study. This is the first report to illustrate the implementation of an lndium (111) DTPA flow study without interrupting the infusion of CITB., Conclusion: An indium (111) DTPA flow study is a non-invasive, safe and patient friendly diagnostic method which can be of great help in the evaluation of pump- or catheter-related complications and does not need to interfere with the delivery of CITB.

The aim of the present study was to assess the effect of bilateral subthalamic nucleus (STN) stimulation and dopaminergic medication on speed of mental processing and motor function. Thirty-nine patients suffering from advanced Parkinson disease (PD) were operated on. Motor function and reaction time (RT) performance [simple RT (SRT) and complex RT (CRT)] were evaluated under four experimental conditions with stimulation (stim) and medication (med) on and off: stim-on/med-on, stim-on/med-off, stim-off/med-off and stim-off/med-on. In the last condition, the patients received either low medication (usual dose) or high medication (suprathreshold dose). STN stimulation improved the motor performance in the SRT and CRT tasks. Furthermore, STN deep brain stimulation (DBS) also improved response preparation as shown by the significant improvement of the RT performance in the SRT task. This effect of STN DBS on the RT performance in the SRT task was greater as compared with the CRT task. This is due to the more complex information processing that is required in the CRT task as compared to the SRT task. These data suggest that treatment of STN hyperactivity by DBS improves motor function, confirming earlier reports, but has a differential effect on cognitive functions. The STN seems to be an important modulator of cognitive processing and STN DBS can differentially affect motor and associative circuits.

We present here a descriptive article on the development of a national quality system for neuromodulatory techniques in the Netherlands. In 1994, due to reimbursement difficulties in the Netherlands, a Neuromodulation Working Group (WGN) undertook an initiative to develop a national quality system for neuromodulation. It was believed that with official recognition of neuromodulation as a therapy by the health authorities in the Netherlands, a quality system for monitoring would then follow. To that purpose an observational study was performed. Integration of this entire primary process (from intake to control phase) was based upon an inventory of the practices of the most experienced medical specialists practicing neuromodulation in the Netherlands. Based on the study data, nine quality indicators were identified that would allow monitoring of the quality of care to patients in the Netherlands. The study resulted in a positive feedback to the National Health Insurance Board and the Ministry of Health in the Netherlands. Neuromodulation for chronic pain and disabling spasticity is now recognized and fully reimbursed within the limits of the newly developed quality system. We therefore conclude that developed quality systems can provide a basis for medical specialists to cooperate around groups of patients or diseases. These quality systems can facilitate implementation and innovation within the health care system. The role of medical specialists and their will to cooperate is essential.

The aim of the present study was to determine the effects of monopolar and bipolar high frequency stimulation (HFS) on histological damage and current flow using a commonly applied stimulus amplitude (300 microA). Bipolar HFS resulted in a large amount of histological damage whereas with monopolar HFS no damage was observed except for the electrode trajectory. Oscilloscopic readings confirmed that this was due to the application of twice as much current to the target with bipolar HFS. Our results demonstrate that there are differences in tissue damage dependent of polarity. In order to create a better comparison to the clinical condition, we suggest that the present rodent models for studying the effect of chronic HFS require further adjustment. This can be achieved by decreasing the present current densities to a level comparable to the human situation.

Background: Spinal cord stimulation (SCS) may have a place in the treatment of patients with inoperable chronic critical leg ischaemia., Methods: A systematic review and meta-analysis was performed of all controlled studies comparing SCS in addition to any form of conservative treatment for inoperable chronic critical leg ischaemia. Main endpoints were limb salvage, pain relief and clinical situation. Systematic methodological appraisal and data extraction were performed by independent reviewers., Results: Of the 18 reports found, nine trials, comprising 444 patients, matched the selection criteria. After pooling, limb salvage at 12 months appeared significantly greater in the SCS group (risk difference (RD) -0.13 (95 per cent confidence interval (c.i.) -0.04 to -0.22)). Significant pain relief occurred in both treatment groups, but patients who received SCS required significantly less analgesia and reached Fontaine stage 2 more often than those who did not have SCS (RD 0.33 (95 per cent c.i. 0.19 to 0.47)). Complications of SCS were problems of implantation (8.2 per cent), changes in stimulation requiring reintervention (14.8 per cent) and infection (2.9 per cent)., Conclusion: The addition of SCS to standard conservative treatment improves limb salvage, ischaemic pain and the general clinical situation in patients with inoperable chronic critical leg ischaemia. These benefits should be weighed against the cost and the (minor) complications associated with the technique., (Copyright 2004 British Journal of Surgery Society Ltd.)

Baseline and 12-month follow-up data from a prospective controlled study on patients treated with SCS for neuropathic limb pain (NLP) are analyzed critically. The outcome on pain, use of medication, and quality of life are reported and compared with the literature. Patients enrolled from April 1999 to December 2001 were part of a quality system study by the Dutch Working Group on Neuromodulation. In two years, more than 400 patients were admitted for several indications of chronic neuropathic pain. Failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) were the largest cohorts. FBSS was defined as persistent limb pain with/or without concomitant minor back pain after prior surgery for a slipped lumbar disc or spinal instability. SCS was a last resort therapy. Two criteria were used for eligibility: a SCL-90 score below 225 and a mean visual analog score (VAS) of four days according to Jensen of ≥ 5. One hundred sixty nine patients were registered for FBSS. Thirty four did not fulfill the eligibility criteria, and 135 received several questionnaires for baseline evaluation. Thirty patients did not have successful trial stimulation (< 50% pain relief), leaving 105 patients for implantation. The mean scores of the baseline evaluation were: SCL 137 (SD 28.3) and VAS 7.3 (SD 1.2), McGill pain questionnaire (MPQ) total PRI: 22.4 (9.4), Sickness Impact Profile (SIP) total score: 19.4 (SD10.1), ROLAND disability (RD) 16.9 (SD 3.5) and EUROQOL (EQ-5D) 55.2 (SD 14.5) (simple linear index). Medication quantification scale at intake was 11.5 (SD 7.9). 56.2% of the patients used one or more narcotic drugs at intake. 82% of the patients did not have a paid job at the time of inclusion. 61% of the patients lost their job due to their medical problems. Scores at 12-m follow-up were VAS 3.0 (SD 2.4), MPQ 10.8 (SD 8), SIP 11.7 (SD 9.4), EQ-5D 38.2 (SD 19.2) and RD 12.4 (SD 4.8). The difference between baseline and 12-m follow-up is statistically significant for all measures. We conclude that the outcome measures indicate that SCS significantly reduces pain and enhances quality of life in patients having NLP not responding to other adjuvant therapy. Recommendations are proposed to make studies more comparable.

Background: Because neuromodulation was not included in the national health insurance system, the Dutch Neuromodulation Group (DNG) developed national standards and a continuous quality improvement (CQI) system for consistency in application of neuromodulation techniques and in the quality of outcomes., Developing the National Quality Improvement System: A stepwise approach was used in which the following ten steps were taken: (1) selected participating medical specialists and their centers, (2) described the treatment protocol, (3) collected data in a national database, (4) organized feedback sessions for the DNG, (5) formulated quality indicators, (6) adjusted the process of treatment, (7) formalized the structure of the DNG, (8) defined responsibilities, (9) established procedures for future development, and (10) made agreements with payers., Discussion: Making reimbursement for expensive health care interventions contingent on a national CQI system created a powerful financial incentive to continuously provide effective care in an efficient manner.

Objective: To report our experience on hardware-related infections following deep brain stimulation (DBS)., Methods: The present article presents the retrospective clinical notes review of gained in a two-centre, single-surgeon study experience of 108 consecutive DBS cases between 1996 and 2002. In all patients the minimum follow-up was six months. One hundred and eight patients received an intracerebral electrode implantation and 106 underwent internalization., Results: In total 178 electrodes were implanted with a mean follow-up of 42.6 months and a cumulative follow-up of 367.7 patient-years. Four patients (3.8%) developed an infection related to the DBS-hardware and all were initially treated with antibiotics. Two patients eventually required additional surgical treatment., Conclusion: Infections due to DBS-hardware can result in considerable levels of morbidity. In certain cases antibiotic therapy may be adequate. In others, surgical intervention to externalise the electrodes may be necessary. In our experience, there was never a need to remove the electrodes.

Objectives: to determine which patients with unreconstructible critical limb ischaemia (CLI) might benefit from spinal cord stimulation (SCS)., Methods: literature review., Results: limb salvage in patients with an intermediate transcutaneous oxygen pressure (TcpO2) was not significantly higher with SCS (76%) than with conservative therapy (p=0.08). However, a limb salvage of 88% was achieved with SCS if the difference between the supine and sitting TcpO2 baseline values (DeltaTcpO2) was > or =15 mmHg. A rise in TcpO2 after trial stimulation of at least 15% resulted in a limb salvage of 77% at 18 months (p<0.01)., Conclusion: randomised studies show no benefit of SCS over conservative therapy in patients with non-reconstructible CLI. However, data from experimental and non-randomised studies suggest this may be due to sub-optimal patient selection for SCS. Further trials are needed to identify subgroups who may benefit from SCS.

A questionnaire was sent to Dutch neurosurgeons and neurologists in order to assess current management strategies for cerebellar hematoma. Seven patients were presented, using as determinants: size of hematoma, coma score, interval to clinical deterioration, hydrocephalus, comorbidity, anticoagulant treatment and age. Neurological management options were: no treatment, monitoring or referral for neurosurgery. Neurosurgical options were: no treatment, monitoring, hematoma evacuation, and/or external ventricular drainage. Ninety-seven of 161 (60%) neurologists, and 58 of 85 neurosurgeons (68%) responded. Only 20 respondents (13%) made use of a local guideline. Overall agreement was perfect in 1 case and moderate to high in the others, but chance-adjusted agreement (kappa) between pairs of neurologists and neurosurgeons who were matched for referral center was not statistically significant except in 1 case, a deeply comatose patient with a 4-cm hematoma. In an alert, slightly ataxic patient with a large (4.5-cm) hematoma, 84 neurologists (88%) decided not to refer the patient. The estimated time for transfer between centers was of no influence on this decision. We conclude that the management of cerebrellar hematoma can be improved upon by encouraging the use of local guidelines, and by promoting early referral to a center with neurosurgical facilities., (Copyright 2001 S. Karger AG, Basel)

We carried out an assessment of pain and quality of life of patients with critical limb ischaemia during the follow-up of a multicentre randomized trial in more detail than previously reported. In a multicentre clinical trial 120 patients were randomized between medical treatment and medical treatment plus spinal cord stimulation. Patients were selected on the basis of clinical symptoms and macrocirculatory data as described in the European consensus document on critical limb ischaemia. Data were collected at intake and then 1, 3, 6, 12 and 18 months later. Primary outcome measures were limb salvage, pain relief and quality of life. Patient and limb survival was estimated with the Kaplan-Meier method. Pain was evaluated using the visual analogue scale (VAS), the McGill pain questionnaire, the pain score of the Nottingham Health Profile (NHP) and the use of analgesics. Quality of life was evaluated using the NHP, the EuroQol and mobility subscore of the Sickness Impact Profile. The 2-year limb survival was 52% for SCS treatment and 46% for standard treatment (p =0.47). Pain relief was considerable in both treatment strategies (p<0.005) with no significant differences between the strategies. The improvement occurred within the first few months and remained stable during further follow-up. Patients with SCS used fewer non-narcotic and narcotic drugs (p<0.001 at t=1 and t=3, p<0.002 at t=6). The overall scores of quality of life improved significantly (p<0.05), with no difference in score between treatments. The subscores of mobility and energy of the NHP in non-amputated patients was significantly better in the SCS group (p<0.005). Amputation had a negative effect on mobility, resulting in a difficult rehabilitation but relieved pain substantially (p<0. 05). In contrast to the existing literature, the randomized trial revealed no major difference in overall pain and quality of life assessment between treatment groups. The effect on energy and mobility was significantly better in patients treated with SCS, who also used substantially fewer analgesics., (Copyright 2000 European Federation of Chapters of the International Association for the Study of Pain.)

This study was done to evaluate the effect of spinal cord stimulation (SCS) on critical limb ischemia and to report technical problems and complications. One hundred and twenty patients with critical limb ischemia were eligible for randomization between medical treatment and medical treatment plus SCS. Sixty received a spinal cord stimulator (Itrel II; Medtronic, Minneapolis, Minn., USA). Primary outcome measures were limb salvage and pain relief. The mean pain reduction in both treatment groups was 50% (from 5 to 2.5 on the visual analog scale). The 2-year limb survival was 52% (SCS) versus 46% (standard treatment; p = 0.47). The number of patients undergoing major amputations in the SCS group with intermediate TcpO2 values was half of that in the standard group (14 vs. 28; 24 vs. 48%; p = 0.17). Implantation was successful in 51 patients. Technical problems such as loss of stimulation due to lead displacement occurred in 13 patients (22%), local infection at the site of implantation occurred in 3 patients (5%), resulting in a total complication rate of 27%. Premature depletion of the battery occurred within 2 years in 3 patients (5%). There were no lead fractures, epidural infections, hematoma or cerebrospinal fluid leakage. Training of physicians and better reliability of the hardware should reduce the frequency of technical problems. Lead displacement remains the major technical problem. The search for prognostic factors of limb salvage is important. One microcirculatory measurement (TcpO2) seems to have a prognostic value, which remains to be described more precisely.

Purpose: Patients with non-reconstructable critical limb ischemia generally undergo medical treatment only to prevent or postpone amputation. There is some evidence that spinal cord stimulation (SCS) stimulates ischemic wound healing. Thus, this could benefit limb survival through improved skin perfusion. We investigated the effect of SCS versus conservative treatment on skin microcirculation in relation to treatment outcome in patients with non-reconstructable critical limb ischemia., Methods: Standard medical treatment plus SCS was compared with only standard medical treatment in a multicenter randomized controlled trial comprised of 120 patients with surgically non-reconstructable chronic rest pain or ulceration. We investigated skin microcirculation by means of capillary microscopy, laser Doppler perfusion, and transcutaneous oxygen measurements in the foot. The microcirculatory status just before treatment was classified in three categories (poor, intermediate, and good) and was related to limb survival after a minimum follow-up period of 18 months., Results: Clinical parameters, peripheral blood pressures, and limb survival rates showed no significant differences between the SCS and standard groups during the follow-up period. In both treatment groups, amputation frequency after 18 months was high in patients with an initially poor microcirculatory skin perfusion (SCS 80% vs standard treatment 71%; NS) and low in those with a good skin perfusion (29% vs 11 %, respectively; NS). In patients with an intermediate skin microcirculation amputation, frequency was twice as low in patients additionally treated with SCS as in the standard treatment group (48% vs 24%; P =.08). In these patients, microcirculatory reactive hyperemia during the follow-up period reduced in the standard group but not in the SCS group (P <.01)., Conclusion: Selection on the basis of the initial microcirculatory skin perfusion identifies patients in whom SCS can improve local skin perfusion and limb survival.

Purpose: We investigated the usefulness of skin microcirculatory investigations to predict imminent major amputation in patients with non-reconstructible critical limb ischemia., Methods: One hundred eleven patients with non-reconstructible chronic rest pain or small ulcers and an ankle blood pressure of 50 mm Hg or less or an ankle-to-brachial pressure index of 0.35 or less were included. Nailfold capillary microscopy (CM; big toe, sitting), transcutaneous oxygen pressure (TcpO2; forefoot, supine; 44 degrees C), and laser Doppler perfusion measurements (LD; pulp of big toe, supine) were performed at rest and during reactive hyperemia. Patients were classified according to their skin microcirculatory status just before the start of the treatment in three groups: those with a "good," "intermediate," or "poor" microcirculation, according to a combination of predefined cutoff values (Poor: capillary density less than 20/mm2, absent reactive hyperemia in CM and LD, TcpO2 less than 10 mm Hg; good: capillary density of 20/mm2 or more, present reactive hyperemia in CM and LD, TcpO 2 of 30 mm Hg or more). Subsequently, patients received maximum conservative therapy from the surgeon, who was unaware of the microcirculatory results. After a follow-up period of as long as 36 months, limb survival and disposing factors were analyzed and compared with the initial microcirculatory status., Results: Cox regression analysis showed a significant prognostic value of the microcirculatory classification (hazard ratio = 0.28, P <.0001), but not of the Fontaine stage, ankle blood pressure, or the presence of diabetes mellitus for the occurrence of an amputation. Positive and negative predictive values were 73% and 67%, respectively. The cumulative limb survival at 6 and 12 months was 42% and 17% in the poor microcirculatory group, 80% and 63% in the intermediate microcirculatory group, and 88% and 88% in the good microcirculatory group ( P <.0001, log-rank)., Conclusion: Microcirculatory screening and classification is useful in detecting non-reconstructible critical ischemia that requires amputation, which is not detectable by means of the clinical stage or blood pressure parameters. Most of the poor patient group will require amputation. In the intermediate and good groups, nonsurgical treatment appears sufficient for limb salvage.

Background: For patients with critical limb ischaemia, spinal-cord stimulation has been advocated for the treatment of ischaemic pain and the prevention of amputation. We compared the efficacy of the addition of spinal-cord stimulation to best medical treatment in a randomised controlled trial., Methods: 120 patients with critical limb ischaemia not suitable for vascular reconstruction were randomly assigned either spinal-cord stimulation in addition to best medical treatment or best medical treatment alone. Primary outcomes were mortality and amputation. The primary endpoint was limb survival at 2 years., Findings: The mean (SD) age of the patients was 72.6 years (10.3). Median (IQR) follow-up was 605 days (244-1171). 40 (67%) of 60 patients in the spinal-cord-stimulator group and 41 (68%) of 60 patients in the standard group were alive at the end of the study, (p=0.96). There were 25 major amputations in the spinal-cord-stimulator group and 29 in the standard group, (p=0.47). The hazard ratio for survival at 2 years without major amputation in the spinal-cord stimulation group compared with the standard group was 0.96 (95% CI 0.61-1.51)., Interpretation: Spinal-cord-stimulation in addition to best medical care does not prevent amputation in patients with critical limb ischaemia.

A new type of spinal cord stimulation electrode, providing contact combinations with a transverse orientation, is presented. Electrodes were implanted in the cervical area (C4-C5) of two chronic pain patients and the stimulation results were subsequently simulated with a computer model consisting of a volume conductor model and active nerve fiber models. For various contact combinations a good match was obtained between the modeling results and the measurement data with respect to load resistance (less than 20% difference), perception thresholds (16% difference), asymmetry of paresthesia (significant correlation) and paresthesia distributions (weak correlation). The transversally oriented combinations provided the possibility to select either a preferential dorsal column stimulation, a preferential dorsal root stimulation or a mixed stimulation. The (a)symmetry of paresthesia could largely be affected in a predictable way by the selection of contact combinations as well. The transverse tripolar combination was shown to give a higher selectivity of paresthesia than monopolar and longitudinal dipolar combinations, at the cost of an increased current (more than twice).

The available data in the literature (177 cases), two current clinical patients, and cases which occurred in The Netherlands (13) were reviewed concerning the clinical presentation, pathological features, radiological data, and treatment options of chondrosarcoma of the cranial base. The mean age of patients was 37 years, the male/female ratio 1:1.1. The most frequent complaints were diplopia with oculomotor disorders (51%), headache (31%), and decreased hearing, dizziness, and tinnitus with statoacusticus dysfunction (21%). The mean duration of symptoms before diagnosis was 27 months. The chondrosarcomas were located in the petrosal bone in 37% (47 cases), in the occipital bone and clivus in 23% (30 cases), in the sphenoid bone in 20% (25 cases) and to a lesser extent in frontal, ethmoidal, and parietal bones (14%). In 6% (eight cases) the primary location was in dural tissue. Radiological examinations showed bone destruction and variable calcification (CT), involvement of neuronal and vascular structures (MRI), and mostly hypovascularity on angiography. On histological examination 51% of tumours were classified as grade I, 11% grade II, 30% mesenchymal, and 8% myxoid. The mesenchymal type was the most malignant as illustrated by a strong tendency to intradural and cerebral growth and possibly occurrence in younger age groups. The treatment of choice until recently was surgery because of the critical location and local aggressive nature. Regrowth of tumour after surgery occurred in 53% of the patients (average after 32 months). Charged particle irradiation gave a five year survival of 83-94% and a local control rate of 78%-91%. Both in surgery and radiotherapy there is treatment related morbidity and mortality that should be considered when offering these therapies. Recent promising results imply that charged particle radiotherapy, in combination with surgery, may be the therapeutical choice of the future.

Objectives: Review of the design of a clinical study to evaluate of the efficacy of epidural spinal cord electrical stimulation (ESES) as compared to best medical treatment in patients with nonreconstructible critical limb ischaemia., Design: Randomised controlled clinical trial of pragmatic type, which will be analysed according to the intention-to-treat principle. The treatment strategies are ESES, in addition to best medical treatment, and best medical treatment alone. Patients are followed-up for at least 18 months., Setting: The ESES-trial is an ongoing multicentre trial in 17 hospitals in The Netherlands., Patients: Patients with critical limb ischaemia, nonsuitable for either primary intervention or reintervention after failing reconstructions., Chief Outcome Measures: Limb survival, patient survival, quality of life and cost-effectiveness., Main Results: From November 1991 until May 1994 120 patients had been enrolled. Using life-table analysis, at one year 76% of these randomised patients were alive: 41% without amputation and 35% with amputation. Quality of life of the trial patients was low, even compared to other severely ill patient groups, such as liver and heart transplant candidates., Conclusions: Considering the high incidence of death and amputation, 18 months of follow-up seems adequate to detect a clinically relevant outcome improvement from ESES-treatment, if present. We hope to present the results of this study at the end of 1995.

Marking of the skull prior to craniotomy on the basis of CT images can prove to be a difficult problem. The method reported here essentially consists of a procedure which involves tilting and manoeuvreing the head within the scanner so that the surface marker is perpendicular to the skull at the site of the lesion. This is easy, useful and not time consuming.

The advantages of computed tomography-guided preoperative localization of brain lesions are illustrated in four cases of solitary tuberculoma and in one case of tuberculous abscess of both the cerebrum and the cerebellum. The role of stereotactic diagnostic techniques is emphasized. The clinical presentation and the computed tomography findings in these patients were equivalent to those from glial or metastatic tumors. Synchronous pulmonary tuberculosis was not present in these patients, but in three patients there was metachronous tuberculosis. Tuberculous meningitis had not developed in any of the patients.

A patient with a completely thrombosed giant aneurysm arising from the trunk of the basilar artery is described. Although it is difficult to differentiate this anomaly from a posterior fossa tumor, negative angiographic findings combined with certain computed tomographic (CT) signs may point to the correct diagnosis. Our case demonstrates that one of these CT signs (viz. ringlike contrast enhancement) can be explained by the presence of vasa vasorum in the aneurysm wall.

Fifty-three patients with trigeminal neuralgia were treated with percutaneous radiofrequency Gasserian ganglion coagulation. An individually adjusted degree of coagulation was applied. The procedure was successful in 45 patients (85%). The median follow-up was two years; only two of the remaining 45 patients had relapse of symptoms. Four patients experienced side effects consisting of troublesome facial dysaesthesia. Our data indicate that percutaneous radiofrequency coagulation of the Gasserian ganglion is a safe and reliable procedure in the treatment of medication resistant trigeminal neuralgia.