Objective To assess whether interspinous process device implantation is more effective in the short term than conventional surgical decompression for patients with intermittent neurogenic ...claudication due to lumbar spinal stenosis. Design Randomized controlled trial. Setting Five neurosurgical centers (including one academic and four secondary level care centers) in the Netherlands. Participants 203 participants were referred to the Leiden-The Hague Spine Prognostic Study Group between October 2008 and September 2011; 159 participants with intermittent neurogenic claudication due to lumbar spinal stenosis at one or two levels with an indication for surgery were randomized. Interventions 80 participants received an interspinous process device and 79 participants underwent spinal bony decompression. Main outcome measures The primary outcome at short term (eight weeks) and long term (one year) follow-up was the Zurich Claudication Questionnaire score. Repeated measurements were made to compare outcomes over time. Results At eight weeks, the success rate according to the Zurich Claudication Questionnaire for the interspinous process device group (63%, 95% confidence interval 51% to 73%) was not superior to that for standard bony decompression (72%, 60% to 81%). No differences in disability (Zurich Claudication Questionnaire; P=0.44) or other outcomes were observed between groups during the first year. The repeat surgery rate in the interspinous implant group was substantially higher (n=21; 29%) than that in the conventional group (n=6; 8%) in the early post-surgical period (P<0.001). Conclusions This double blinded study could not confirm the hypothesized short term advantage of interspinous process device over conventional “simple” decompression and even showed a fairly high reoperation rate after interspinous process device implantation. Trial registration Dutch Trial Register NTR1307.
Abstract Background context In patients with sciatica due to a lumbar disc herniation, it is generally recommended to reserve surgical treatment for those who suffer from intolerable pain or those ...who demonstrate persistent symptoms after conservative management. Controversy exists about the necessity of early surgical intervention for those patients that have an additional motor deficit. Purpose The aim of this study was to compare the recovery of motor deficit among patients receiving early surgery to those receiving prolonged conservative treatment. Study design Subgroup analysis of a randomized controlled trial. Patient sample This subgroup analysis focuses on 150 (53%) of 283 patients with sciatica due to a lumbar disc herniation and whose symptoms at baseline (before randomization) were accompanied by a motor deficit. Outcome measures Motor deficit was assessed through manual muscle testing and graded according to the Medical Research Council (MRC) scale. Methods In total, 150 patients with 6 to 12 weeks of sciatica due to a lumbar disc herniation and whose symptoms were accompanied by a moderate (MRC Grade 4) or severe (MRC Grade 3) motor deficit were randomly allocated to early surgery or prolonged conservative treatment. Repeated standardized neurologic examinations were performed at baseline and at 8, 26, and 52 weeks after randomization. This study was supported by a grant from the Netherlands Organization for Health Research and Development (ZonMW) and the Hoelen Foundation The Hague. Results Sciatica recovered among seven (10%) of the 70 patients assigned to early surgery before surgery could be performed, and of the 80 patients assigned to conservative treatment, 32 patients (40%) were treated surgically because of intolerable pain. Baseline severity of motor deficit was graded moderate in 84% of patients and severe in 16% of patients. Motor deficit recovered significantly faster among patients allocated to early surgery (p=.01), but the difference was no longer significant at 26 (p=.21) or 52 weeks (p=.92). At 1 year, complete recovery of motor deficit was found in 81% of patients allocated to early surgery and in 80% of patients allocated to prolonged conservative treatment. Perceived overall recovery of sciatica was directly related to the presence of an accompanying motor deficit. Severe motor deficit at baseline (odds ratio, 5.4; confidence interval, 1.7–17.4) and a lumbar disc herniation encompassing ≥25% of the cross-sectional area of the spinal canal (odds ratio, 6.4; confidence interval, 1.3–31.8) were the most important risk factors for persistent deficit at 1 year. Conclusions Early surgery resulted in a faster recovery of motor deficit accompanying sciatica compared with prolonged conservative treatment but the difference was no longer significant during the final follow-up examination at 1 year.
Abstract
Over the past year, the HCCH, supported by its Permanent Bureau, has continued its work for the progressive unification of the rules of private international law (PIL). This annual ...contribution to the Uniform Law Review provides an overview of the activities of the HCCH from 1 November 2021 to 30 November 2022 and anticipates some upcoming events, encompassing the HCCH’s three main areas of work: international family and child protection law, transnational litigation and apostille, and international commercial, digital, and financial law.
Abstract Background context Patients with sciatica frequently experience disabling back pain. One of the proposed causes for back pain is vertebral end-plate signal changes (VESC) as visualized by ...magnetic resonance imaging (MRI). Purpose To report on VESC findings, changes of VESC findings over time, and the correlation between VESC and disabling back pain in patients with sciatica. Study design/setting A randomized clinical trial with 1 year of follow-up. Patients sample Patients with 6 to 12 weeks of sciatica who participated in a multicenter, randomized clinical trial comparing an early surgery strategy with prolonged conservative care with surgery if needed. Outcome measures Patients were assessed by means of the 100-mm visual analog scale (VAS) for back pain (with 0 representing no pain and 100 the worst pain ever experienced) at baseline and 1 year. Disabling back pain was defined as a VAS score of at least 40 mm. Methods Patients underwent MRI both at baseline and after 1 year follow-up. Presence and change of VESC was correlated with disabling back pain using chi-square tests and logistic regression analysis. Results At baseline, 39% of patients had disabling back pain. Of the patients with VESC at baseline, 40% had disabling back pain compared with 38% of the patients with no VESC (p=.67). The prevalence of type 1 VESC increased from 1% at baseline to 35% 1 year later in the surgical group compared with an increase from 3% to 11% in the conservative group. The prevalence of type 2 VESC decreased from 40% to 29% in the surgical group while remaining almost stable in the conservative group at 41%. The prevalence of disabling back pain at 1 year was 12% in patients with no VESC at 1 year, 16% in patients with type 1 VESC, 11% in patients with type 2 VESC, and 3% in patients with both types 1 and 2 VESC (p=.36). Undergoing surgery was associated with increase in the extent of VESC (odds ratio OR, 8.6; 95% confidence interval CI, 4.7–15.7; p<.001). Patients who showed an increase in the extent of VESC after 1 year did not significantly report more disabling back pain compared with patients who did not show any increase (OR, 1.2; 95% CI, 0.6–2.6; p=.61). Conclusion In this study, undergoing surgery for sciatica was highly associated with the development of VESC after 1 year. However, in contrast with the intuitive feeling of spine specialists, those with and those without VESC reported disabling back pain in nearly the same proportion. Therefore, VESC does not seem to be responsible for disabling back pain in patients with sciatica.
OBJECTIVE This study aimed to determine the prognostic value of MRI variables to predict outcome in patients with herniated disc-related sciatica, and whether MRI could facilitate the decision making ...between early surgery and prolonged conservative care in these patients. METHODS A prospective observational evaluation of patients enrolled in a randomized trial with 1-year follow-up was completed. A total of 283 patients with sciatica who had a radiologically confirmed disc herniation were randomized either to surgery or to prolonged conservative care with surgery if needed. Outcome measures were recovery and leg pain severity. Recovery was registered on a 7-point Likert scale. Complete/near complete recovery was considered a satisfactory outcome. Leg pain severity was measured on a 0- to 100-mm visual analog scale. Multiple MRI characteristics of the degenerated disc herniation were independently scored by 3 spine experts. Cox models were used to study the influence of MRI variables on rate of recovery, and linear mixed models were used to determine the predictive value of MRI variables for leg pain severity during follow-up. The interaction of each MRI predictor with treatment allocation was tested. There were no study-specific conflicts of interest. RESULTS Baseline MRI variables associated with less leg pain severity were the reader's assessment of presence of nerve root compression (p < 0.001), and assessment of extrusion compared with protrusion of the disc herniation (p = 0.006). Both variables tended to be associated, but not significantly, with satisfactory outcome during follow-up (HR 1.45, 95% CI 0.93-2.24, and HR 1.24, 95% CI 0.96-1.61, respectively). The size of disc herniation at baseline was not associated with outcome. There was no significant change in the effects between treatment groups. CONCLUSIONS MRI assessment of the presence of nerve root compression and extrusion of a herniated disc at baseline was associated with less leg pain during 1-year follow-up, irrespective of a surgical or conservative treatment. MRI findings seem not to be helpful in determining which patients might fare better with early surgery compared with a strategy of prolonged conservative care. Clinical trial registration no.: ISRCTN26872154 ( controlled-trials.com ).
Metal ion chelators widely used in experimental protocols and clinical diagnosis are generally assumed to be inert. We previously reported that the ubiquitous chelator EDTA has high levels of ...superoxide suppressing activity. Here, we report that the common chelators calcium chelator EGTA and contrast agent EHPG have significant activities in suppressing superoxide levels depending on the nature of metal ion chelated. The most active species is Mn(II)-EGTA which exhibited an IC
50 value of 0.19
μM for superoxide destruction. In addition, IC
50 values for Mn(II)-EHPG and 2Cu(II)-EGTA were 0.69 and 0.60
μM, respectively. In conclusion, Mn(II) and Cu(II) complexes of the common chelators EGTA and EHPG exhibit considerable superoxide scavenging activities. Caution should be employed in their use in biological systems where superoxide has a key role and they may be useful for the development of catalytic anti-oxidants.
Patients with sciatica frequently complain about associated back pain. It is not known whether there are prognostic relevant differences in Magnetic Resonance Imaging (MRI) findings between sciatica ...patients with and without disabling back pain.
The study population contained patients with sciatica who underwent a baseline MRI to assess eligibility for a randomized trial designed to compare the efficacy of early surgery with prolonged conservative care for sciatica. Two neuroradiologists and one neurosurgeon independently evaluated all MR images. The MRI readers were blinded to symptom status. The MRI findings were compared between sciatica patients with and without disabling back pain. The presence of disabling back pain at baseline was correlated with perceived recovery at one year.
Of 379 included sciatica patients, 158 (42%) had disabling back pain. Of the patients with both sciatica and disabling back pain 68% did reveal a herniated disc with nerve root compression on MRI, compared to 88% of patients with predominantly sciatica (P<0.001). The existence of disabling back pain in sciatica at baseline was negatively associated with perceived recovery at one year (Odds ratio OR 0.32, 95% Confidence Interval 0.18-0.56, P<0.001). Sciatica patients with disabling back pain in absence of nerve root compression on MRI at baseline reported less perceived recovery at one year compared to those with predominantly sciatica and nerve root compression on MRI (50% vs 91%, P<0.001).
Sciatica patients with disabling low back pain reported an unfavorable outcome at one-year follow-up compared to those with predominantly sciatica. If additionally a clear herniated disc with nerve root compression on MRI was absent, the results were even worse.
The big brown bat (Eptesicus fuscus) uses frequency modulated (FM) echolocation calls to accurately estimate range and resolve closely spaced objects in clutter and noise. They resolve glints spaced ...down to 2 μs in time delay which surpasses what traditional signal processing techniques can achieve using the same echolocation call. The Matched Filter (MF) attains 10-12 μs resolution while the Inverse Filter (IF) achieves higher resolution at the cost of significantly degraded detection performance. Recent work by Fontaine and Peremans J. Acoustic. Soc. Am. 125, 3052-3059 (2009) demonstrated that a sparse representation of bat echolocation calls coupled with a decimating sensing method facilitates distinguishing closely spaced objects over realistic SNRs. Their work raises the intriguing question of whether sensing approaches structured more like a mammalian auditory system contains the necessary information for the hyper-resolution observed in behavioral tests. This research estimates sparse echo signatures using a gammatone filterbank decimation sensing method which loosely models the processing of the bat's auditory system. The decimated filterbank outputs are processed with script-l(1) minimization. Simulations demonstrate that this model maintains higher resolution than the MF and significantly better detection performance than the IF for SNRs of 5-45 dB while undersampling the return signal by a factor of six.
The solar atmosphere is a dynamic environment, constantly evolving to form a wide range of magnetically dominated structures (coronal loops, spicules, prominences,
etc
.) which cover a significant ...percentage of the surface at any one time. Oscillations and waves in many of these structures are now widely observed and have led to the new analytic technique of solar magneto-seismology, where inferences of the background conditions of the plasma can be deduced by studying magneto-hydrodynamic (MHD) waves. Here, we generalise a novel magneto-seismological method designed to infer the density distribution of a bounded plasma structure from the relationship of its fundamental and subsequent harmonics. Observations of the solar atmosphere have emphatically shown that stratification, leading to complex density profiles within plasma structures, is common thereby rendering this work instantly accessible to solar physics. We show, in a dynamic waveguide, how the period ratio differs from the idealised harmonic ratios prevalent in homogeneous structures. These ratios show strong agreement with recent observational work. Next, anti-node shifts are also analysed. Using typical scaling parameters for bulk flows within atmospheric waveguides,
e.g.
, coronal loops, it is found that significant anti-node shifts can be predicted, even to the order of 10 Mm. It would be highly encouraged to design specific observations to confirm the predicted anti-node shifts and apply the developed theory of solar magneto-seismology to gain more accurate waveguide diagnostics of the solar atmosphere.
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