Patient demographics and MRI-based measurements predict redundant nerve roots in lumbar spinal stenosis: a retrospective database cohort comparison

Background

Up to 40% of patients diagnosed with lumbar spinal stenosis (LSS) show evidence of redundant nerve roots (RNR) of the cauda equina on their magnetic resonance images (MRI). The etiology of RNR is still unclear. Preoperative evidence of RNR is associated with a worse postsurgical outcome. Consequently, potential predictors of RNR could have a prognostic value. The aim was to test whether patient demographics and MRI-based measurements can predict RNR in LSS patients.

Methods

In a retrospective database-based cohort study the preoperative data of 300 patients, 150 with (RNR+) and 150 without (RNR-) evidence of RNR on their MRI were analyzed. Three independent researchers performed the MRI reads. Potential predictors were age, gender, body height (BH), length of lumbar spine (LLS), segmental length of lumbar spine (SLLS), lumbar spine alignment deviation (LSAD), relative LLS (rLLS), relative SLLS (rSLLS), number of stenotic levels (LSS-level), and grade of LSS severity (LLS-grade, increasing from A to D). Binomial logistic regression models were performed.

Results

RNR+ patients were 2.6?years older (p?=?0.01). Weak RNR+ predictors were a two-years age increase (OR 1.06; p?=?0.02), 3?cm BH decrease (OR 1.09; p?=?0.01) and a 5?mm SLLS decrease (OR 1.34; p?<?0.001). Strong RNR+ predictors were a 1% rLLS decrease (OR 2.17; p?<?0.001), LSS-level?≥?2 (OR 2.59; p?=?0.001), LLS-grade C (OR 5.86; p?=?0.02) and LLS-grade D (OR 18.4; p?<?0.001). The mean rSLLS of RNR+ patients was 0.6% shorter (p?<?0.001; 95% C.I. 0.4 to 0.8) indicating a disproportionate shorter lumbar spine.

Conclusions

We identified LSS severity grade and LSS levels as the strongest predictors of RNR. In addition to previous studies, we conclude that a shortened lumbar spine by degeneration is involved in the development of RNR.

     

Antihypertensive efficacy of metoprolol XL/Low dose chlorthalidone (6.25 mg) combination: a randomized,comparative study in Indian patients with mild-to-moderate essential hypertension

Objective

High blood pressure is one of the most important risk factors, directly responsible for increasing the cardiovascular morbidity and mortality. The primary objective was to evaluate the efficacy of metoprolol XL/chlorthalidone against metoprolol XL/hydrochlorothiazide with respect to mean fall in systolic and diastolic blood pressure. The secondary objective was to compare the response rates and to evaluate the tolerability of study medications in patients with mild-tomoderate essential hypertension.

Methods

Total 130 eligible patients (65: metoprolol XL 25 mg/chlorthalidone 6.25 mg; 65: metoprolol XL 25 mg/HCTZ 12.5 mg) were enrolled in this randomized, comparative, multicentric, 12-weeks study. Sixty-two patients from each group completed the study. After 4-weeks of treatment, non-responders from chlorthalidone 6.25 mg combination group were shifted to metoprolol XL 50 mg/chlorthalidone 12.5 mg and non-responders from HCTZ 12.5 mg combination group were escalated to metoprolol XL 50 mg/HCTZ 12.5 mg.

Results

The study treatment groups were comparable with respect to demography and baseline disease characteristics. Both the starting therapies were comparable with respect to mean fall in SBP (p = 0.788) and DBP (p = 0.939), and response rates (p = 1.0) after 4-weeks of therapy. Also both the step-up therapies showed similar mean fall in SBP (p = 0.277) and DBP (p = 0.507) at the end of 12-weeks. However, significantly more number of patients from chlorthalidone 12.5 mg/metoprolol XL 50 mg group responded to therapy as compared to that from HCTZ 12.5 mg/metoprolol XL 50 mg group (p = 0.045). All the reported adverse events were of mild-to-moderate intensity. There were no clinically significant trends in electrolytes (Na⁺, K⁺, Cl^-)and fasting blood sugar, evident across the treatment groups.

Conclusion

Chlorthalidone in combination with metoprolol XL is as effective and well tolerated as widely used combination of metoprolol XL/HCTZ, thus providing an alternative therapeutic option.     

Advanced Trauma Life Support® – ein Versorgungsstandard für Deutschland?

Over the last 30 years the Advanced Trauma Life Support (ATLS) course has become the most successful training program in the world for the early care of severely injured patients. It has shaped trauma care systems in many countries and is now on the verge of being introduced into Germany by the German Society of Trauma Surgery (DGU). However, after publication of the latest edition in 2004 there are rising concerns regarding the lack of multi-disciplinarity, out-dated contents and lack of adaptability to regional needs. This article questions the beneficial effect of ATLS on the advanced German trauma care system and concludes that ATLS is not likely to improve trauma care in Germany.     

Comparison of long-axis and short-axis PROPELLER-EPI for diffusion-weighted Magnetic Resonance Imaging

Echo planar imaging (EPI) in combination with PROPELLER allows high-resolution diffusion-weighted imaging. In this study, the image quality of short-axis and long-axis PROPELLER was compared and optimized using phantom and in vivo data. Furthermore, diffusion-weighted measurements using both sequences were compared with those of a reference sequence. It was found that the long-axis sequence provided better image quality, whereas the results of the diffusion weighted measurements were more accurate with the short-axis variant. and that the results of the diffusion weighted measurements of both sequences agreed well with those of the reference sequence.     

One-stop-shop tumor imaging: buy hypoxia, get lactate free

The ability to noninvasively assess physiological changes in solid tumors is desired for its diagnostic and therapeutic potential. In this issue of JCI, Matsumoto and colleagues reveal their development and use of a novel imaging approach, combining pulsed electron paramagnetic resonance imaging (EPRI) with conventional MRI to image squamous cell carcinoma tumor-bearing mice (See the related article beginning on page 1965). This method provides coregistered images of oxygenation and blood volume/flow with the underlying anatomy and concentrations of metabolites such as lactate and choline. This technique, combining functional and anatomic imaging, shows immediate preclinical applicability in monitoring factors that control tumor hypoxia and metabolism and may have future clinical potential for monitoring tumor response to treatment.     

Model for the response of radiographic films and implications for quality assurance

The present paper describes the development of a model linking the optical density of a radiographic film to the applied dose. This model takes into account the kind of bremsstrahlung used in radiotherapy, and uses fewer parameters compared with the models developed so far. The measurements showed an influence of the field size on the model parameters. Monte Carlo simulations showed that different field sizes and depths in solid water can change the spectral distributions. The spectrum hardens with decreasing field size and increasing depth in phantom material. This has an influence on the model parameters. Nevertheless, the model can still be used to describe the relation between optical density and applied dose for films that are irradiated with fields of different size. A dose-rate dependence was not observed. The size and form of the fields used in calibration and application can therefore cause a systematic error in verification with film.     

Non‐ablative 1550‐nm erbium‐glass and ablative 10 600‐nm carbon dioxide fractional lasers for acne scars: a randomized split‐face study with blinded response evaluation

Background Non‐ablative 1550‐nm erbium‐doped fractional photothermolysis systems (FPS) and 10 600‐nm carbon dioxide fractional laser systems (CO₂ FS) have been effectively used to treat scars. Objective We compared the efficacy and safety of single‐session treatments of FPS and CO₂ FS for acne scars through a randomized, split‐face, evaluator‐blinded study. Methods Eight patients with acne scars were enrolled in this study. Half of each subject’s face was treated with FPS and the other half was treated with CO₂ FS. We used a quartile grading scale for evaluations. Results At 3 months after the treatment, the mean grade of improvement based on clinical assessment was 2.0 ± 0.5 for FPS and 2.5 ± 0.8 for CO₂ FS. On each side treated by FPS and CO₂ FS, the mean duration of post‐therapy crusting and scaling was 2.3 and 7.4 days respectively and that of post‐therapy erythema was 7.5 and 11.5 days respectively. The mean VAS pain score was 3.9 ± 2.0 with the FPS and 7.0 ± 2.0 with the CO₂ FS. Conclusion We demonstrated the efficacy and safety of single‐session acne scar treatment using FPS and CO₂ FS in East Asian patients. We believe that our study could be used as an essential reference when choosing laser modalities for scar treatment.