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Patients with degenerative disc disease may suffer from chronic lumbar discogenic (DP) or radicular leg (RLP) pain. Minimally invasive DiscoGel therapy involves the percutaneous injection of an ethanol gel into the degenerated disk’s nucleus pulposus. This paper compares the 1-year outcome of such treatment in DP and RLP patients. We operated on 67 patients (49 men and 18 women) aged 20–68 years (mean age 46 ± 11 years) with DP (n = 45) and RLP (n = 22), of at least 6–8 weeks duration, with no adverse effects. We evaluated the treatment outcome with Core Outcome Measures Index (COMI) and Visual Analog Scale (VAS). A year after the ethanol gel injection, in the DP cohort, COMI and VAS dropped by 66% (6.40 vs. 2.20) and 53% (6.33 vs. 2.97), respectively. For the RLP patients, the corresponding values dropped 48% (7.05 vs. 3.68) and 54% (6.77 vs. 3.13). There were no differences between the cohorts in COMI and VAS at the follow-up end. Six months into the study, 74% of DP and 81% of RLP patients did not use any analgesics. Ethanol gel therapy can be effective for many patients. Moreover, its potential failure does not exclude surgical treatment options.

BackgroundLong-range persistent correlations in stride time (ST) and length (SL) are the fundamental traits of treadmill gait. Our recent work showed that the ST and SL time series’ statistical properties originated from the superposition of large-scale trends and small-scale fluctuations (residuals). Trends served as the control manifolds about which ST and SL fluctuated. The scaling exponents of the residuals were slightly smaller than 0.5.Research questionDo random changes in treadmill belt speed affect the trend properties and scaling exponents of ST/SL residuals?MethodsWe used Multivariate Adaptive Regression Splines (MARS) to determine gait trends during a walk on a treadmill whose belt speed was perturbed by a strong random noise. Then, we calculated the scaling exponents of MARS residuals with the madogram estimator.ResultsExcept for the ST at the lowest treadmill speed v = 0.8 m/s, the normalized trend duration was at least three times greater than that for the unperturbed walk. The Cauchy distribution scale parameter, which served as a measure of the width of SL and ST trend slope distributions, was at v = 1.2 m/s, almost 50% and 25% smaller than the unperturbed values. The differences were even greater at v = 1.6 m/s: 73% and 83%. For all speeds, the ST and SL MARS residuals were strongly anti-persistent. At v = 1.2 m/s, the corresponding scaling exponents were equal to 0.37±0.10 and 0.25±0.09. Apart from ST at v = 0.8 m/s, the ST/SL scaling indices were close to 0.5.SignificancePersistence of gait parameters is closely related to the properties of their trends. Longer trends with a gentle slope and strong anti-persistence of ST/SL residuals are the manifestations or tight control required during the perturbed treadmill walk.

During treadmill walking, the subject’s stride length (SL) and duration (ST) yield a stride speed (SS) which fluctuates over a narrow range centered on the treadmill belt’s speed. We recently demonstrated that ST and SL trends are strongly correlated and serve as control manifolds about which the corresponding gait parameters fluctuate. The fundamental problem, which has not yet been investigated, concerns the contribution of SL and ST fluctuations to SS variability. To investigate this relation, we approximate SS variance by the linear combination of SL variance and ST variance, as well as their covariance. The combination coefficients are nonlinear functions of ST and SL mean values and, consequently, depend on treadmill speed. The approximation applies to constant speed treadmill walking and walking on a treadmill whose belt speed is perturbed by strong, high-frequency noise. In the first case, up to 80% of stride speed variance comes from SL fluctuations. In the presence of perturbations, the SL contribution decreases with increasing speed, but its lowest value is still twice as large as that of either ST variance or SL-ST covariance. The presented evidence supports the hypothesis that stride length adjustments are primarily responsible for speed maintenance during walking. Such a control strategy is evolutionarily advantageous due to the weak speed dependence of the SL contribution to SS variance. The ability to maintain speed close to that of a moving cohort did increase the chance of an individual’s survival throughout most of human evolution.

Introduction The purpose of this study was to provide a translation, cross-cultural adaptation, and validation of the Polish language version of the pain sensitivity questionnaire (PSQ). The process followed widely accepted guidelines. Methods The translated questionnaire underwent thorough psychometric testing. In total, the data of 144 subjects (mean age 52.53±13 years), who underwent evaluation for lower back pain, were included. Results The exploratory factor analysis revealed a two-factor structure, PSQ-moderate and PSQ-minor. The internal consistency was good (Cronbach's α was 0.96). There was a fair and significant correlation between the results of the PSQ and the coping strategy questionnaire (CSQ; Spearman's rho was 0.27). The test-retest reliability was favorable, and the intraclass correlation coefficient (ICC) for the CSQ total was 0.93 with a mean interval of 9.04 days between administrations. Conclusion Our results show that the Polish version of the PSQ is valid and can be recommended for Polish-speaking patients.

Objectives: Cervical disc arthroplasty (CDA) has become an alternative treatment for cervical radiculopathy and myelopathy. This technique preserves appropriate motion at both the index and adjacent disc levels and consequently may prevent adjacent segment degeneration (ASD). The authors performed a meta-analysis to compare the safety and efficacy of CDA to those of the gold standard, anterior cervical discectomy and fusion (ACDF). Both surgical and clinical parameters were employed to verify the hypothesis that CDA can reduce the risk of ASD. Methods: The meta-analysis comprised high-quality randomized controlled trials that compared CDA and ACDF treatments of cervical degenerative disc disease. Included papers reported data for at least one of the following outcomes: 1) surgical parameters, 2) questionnaire clinical indices (pre- and postoperative values), and 3) complication rates at 24 months; in addition, for ASD we analyzed 60 month or longer follow-ups. We used mean differences (MDs) or ORs to compare treatment effects between CDA and ACDF. Results: Twenty studies with 3,656 patients (2,140 with CDA and 1,516 with ACDF) met the inclusion criteria. CDA surgery, with mean duration longer than that of ACDF, was associated with higher blood loss. Visual analog scale neck pain score was significantly smaller for CDA (mean difference =-2.30, 95% CI [-3.72; -0.87], P=0.002). The frequency of dysphagia/ dysphonia (OR =0.69, 95% CI [0.49; 0.98], P=0.04) as well as the long-term ASD rate for CDA was significantly smaller (OR =0.33, 95% CI [0.21; 0.50], P,0.0001). Conclusion: A significantly lower probability of ASD reoperations in the CDA cohort after a 60-month or longer follow-up was the most important finding of this study. Despite the moderate quality of this evidence, the pooled data corroborated for the very first time that CDA was efficacious in preventing ASD.

Introduction The purpose of this study was to provide a translation, cross-cultural adaptation, and validation of the Polish language version of the pain sensitivity questionnaire (PSQ). The process followed widely accepted guidelines. Methods The translated questionnaire underwent thorough psychometric testing. In total, the data of 144 subjects (mean age 52.53±13 years), who underwent evaluation for lower back pain, were included. Results The exploratory factor analysis revealed a two-factor structure, PSQ-moderate and PSQ-minor. The internal consistency was good (Cronbach’s α was 0.96). There was a fair and significant correlation between the results of the PSQ and the coping strategy questionnaire (CSQ; Spearman’s rho was 0.27). The test-retest reliability was favorable, and the intraclass correlation coefficient (ICC) for the CSQ total was 0.93 with a mean interval of 9.04 days between administrations. Conclusion Our results show that the Polish version of the PSQ is valid and can be recommended for Polish-speaking patients.

There is mounting evidence of a link between the properties of electroencephalograms (EEGs) of depressive patients and the outcome of pharmacotherapy. The goal of this study was to develop an EEG biomarker of antidepressant treatment response which would require only a single EEG measurement. We recorded resting 21-channel EEG in 17 in-patients suffering from bipolar depression in eyes-closed and eyes-open conditions. The EEG measurement was performed at the end of a short washout period which followed previous unsuccessful pharmacotherapy. We calculated the normalized wavelet power of alpha rhythm using two referential montages and an average reference montage. The difference in the normalized alpha wavelet power between 10 responders and 7 non-responders was most strongly pronounced in link mastoid montage in the eyes-closed condition. In particular, in the occipital (O1, O2, Oz) channels the wavelet power of responders was up to 84 % higher than that of non-responders. Using a novel classification algorithm we were able to correctly predict the outcome of treatment with 90 % sensitivity and 100 % specificity. The proposed biomarker requires only a single EEG measurement and consequently is intrinsically different from biomarkers which exploit the changes in prefrontal EEG induced by pharmacotherapy over a given time.

Optimization of energy cost determines average values of spatio-temporal gait parameters such as step duration, step length or step speed. However, during walking, humans need to adapt these parameters at every step to respond to exogenous and/or endogenic perturbations. While some neurological mechanisms that trigger these responses are known, our understanding of the fundamental principles governing step-by-step adaptation remains elusive. We determined the gait parameters of 20 healthy subjects with right-foot preference during treadmill walking at speeds of 1.1, 1.4 and 1.7 m/s. We found that when the value of the gait parameter was conspicuously greater (smaller) than the mean value, it was either followed immediately by a smaller (greater) value of the contralateral leg (interleg control), or the deviation from the mean value decreased during the next movement of ipsilateral leg (intraleg control). The selection of step duration and the selection of step length during such transient control events were performed in unique ways. We quantified the symmetry of short-term control of gait parameters and observed the significant dominance of the right leg in short-term control of all three parameters at higher speeds (1.4 and 1.7 m/s)., Comment: 11 pages, 4 figures

There is mounting evidence of a link between the properties of electroencephalograms (EEGs) of depressive patients and the outcome of pharmacotherapy. The goal of this study was to develop an EEG biomarker of antidepressant treatment response which would require only a single EEG measurement. We recorded resting 21-channel EEG in 17 in-patients suffering from bipolar depression in eyes-closed and eyes-open conditions. The EEG measurement was performed at the end of a short washout period which followed previous unsuccessful pharmacotherapy. We calculated the normalized wavelet power of alpha rhythm using two referential montages and an average reference montage. The difference in the normalized alpha wavelet power between 10 responders and 7 non-responders was most strongly pronounced in link mastoid montage in the eyes-closed condition. In particular, in the occipital (O1, O2, Oz) channels the wavelet power of responders was up to 84 % higher than that of non-responders. Using a novel classification algorithm we were able to correctly predict the outcome of treatment with 90 % sensitivity and 100 % specificity. The proposed biomarker requires only a single EEG measurement and consequently is intrinsically different from biomarkers which exploit the changes in prefrontal EEG induced by pharmacotherapy over a given time.