Abstract Bradykinesia is a cardinal symptom of Parkinson's disease (PD) and describes the slowness of movement revealed in patients. Current PD therapies are based on dopamine replacement, and given ...that bradykinesia is the symptom that best correlates with the dopaminergic deficiency, the knowledge of its fluctuations may be useful in the diagnosis, treatment and better understanding of the disease progression. This paper evaluates a machine learning method that analyses the signals provided by a triaxial accelerometer placed on the waist of PD patients in order to automatically assess bradykinetic gait unobtrusively. This method employs Support Vector Machines to determine those parts of the signals corresponding to gait. The frequency content of strides is then used to determine bradykinetic walking bouts and to estimate bradykinesia severity based on an epsilon-Support Vector Regression model. The method is validated in 12 PD patients, which leads to two main conclusions. Firstly, the frequency content of the strides allows for the dichotomic detection of bradykinesia with an accuracy higher than 90%. This process requires the use of a patient-dependant threshold that is estimated based on a leave-one-patient-out regression model. Secondly, bradykinesia severity measured through UPDRS scores is approximated by means of a regression model with errors below 10%. Although the method has to be further validated in more patients, results obtained suggest that the presented approach can be successfully used to rate bradykinesia in the daily life of PD patients unobtrusively.
Infection and injury are two seemingly unrelated processes that often converge on common innate inflammatory responses mediated by pathogen- or damage-associated molecular patterns (PAMPs or DAMPs). ...If dysregulated, an excessive inflammation manifested by the overproduction and release of proinflammatory mediators (e.g., TNF, IFN-γ, and HMGB1) may adversely lead to many pathogenic consequences. As a counter-regulatory mechanism, the liver strategically re-prioritizes the synthesis and systemic release of acute phase proteins (APP) including the fetuin-A (also termed alpha-2-HS-glycoprotein for the human homologue). Fetuin-A is divergently regulated by different proinflammatory mediators, and functions as a positive or negative APP in injury and infection. It not only facilitates anti-inflammatory actions of cationic polyamines (e.g., spermine), but also directly inhibits PAMP-induced HMGB1 release by innate immune cells. Peripheral administration of fetuin-A promotes a short-term reduction of cerebral ischemic injury, but confers a long-lasting protection against lethal endotoxemia. Furthermore, delayed administration of fetuin-A rescues mice from lethal sepsis even when the first dose is given 24 hours post the onset of disease. Collectively, these findings have reinforced an essential role for fetuin-A in counter-regulating injury- or infection-elicited inflammatory responses.
BACKGROUND:Surgical site infection in the spine is a serious postoperative complication. Factors such as posterior surgical approach, arthrodesis, use of spinal instrumentation, age, obesity, ...diabetes, tobacco use, operating-room environment, and estimated blood loss are well established in the literature to affect the risk of infection. The goal of this study was to analyze and identify independent risk factors for surgical site infection among spine patients undergoing posterior lumbar instrumented arthrodesis.
METHODS:The medical records of 3218 patients who underwent posterior lumbar instrumented arthrodesis from January 2000 to December 2006 were reviewed to identify those who developed a postoperative infection (eighty-four patients; 2.6%). The size of this single-institution patient group allowed construction of a multivariate logistic regression model to evaluate the independent associations of potential risk factors for surgical site infection in the spine.
RESULTS:In the final regression model, obesity, estimated intraoperative blood loss, ten or more people in the operating room, a dural tear, history of diabetes, chronic obstructive pulmonary disease, coronary heart disease, and osteoporosis were critical risk factors for the onset of spinal surgical site infection. Obesity and a history of chronic obstructive pulmonary disease were the strongest risk factors for postoperative spinal infection after adjusting for all other variables. The most common pathogen was methicillin-resistant Staphylococcus aureus with a prevalence of 34.5%. This study established a single institution infection rate for posterior lumbar instrumented arthrodesis at 2.6%.
CONCLUSIONS:This analysis confirms previously demonstrated risk factors for postoperative infection while reporting on new potential independent risk factors of osteoporosis, chronic obstructive pulmonary disease, and dural tears in the setting of posterior lumbar instrumented arthrodesis. Areas of new research can focus on the roles these novel factors may play in the pathogenesis of surgical site infections in the spine.
LEVEL OF EVIDENCE:Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.
Summary
Osteosarcopenia is a common condition among elderly and postmenopausal female patients. Site-specific bone mineral density is more predictive of bone-related complications. Few studies have ...investigated muscle-bone associations. Our results demonstrated that in women, significant positive associations between paraspinal muscles FCSA and vBMD exist at different lumbosacral levels. These regional differences should be considered when interpreting bone-muscle associations in the lumbar spine.
Introduction
There is increasing evidence between bone and muscle volume associations. Previous studies have demonstrated comorbidity between osteoporosis and sarcopenia. Recent studies showed that sarcopenic subjects had a fourfold higher risk of concomitant osteoporosis compared to non-sarcopenic individuals. Although site-specific bone mineral density (BMD) assessments were reported to be more predictive of bone-related complications after spinal fusions than BMD assessments in general, there are few studies that have investigated level-specific bone-muscle interactions. The aim of this study is to investigate the associations between muscle functional cross-sectional area (FCSA) on magnetic resonance imaging (MRI) and site-specific quantitative computed tomography (QCT) volumetric bone mineral density (vBMD) in the lumbosacral region among spine surgery patients.
Methods
We retrospectively reviewed a prospective institutional database of posterior lumbar fusion patients. Patients with available MRI undergoing posterior lumbar fusion were included. Muscle measurements and FCSA were conducted and calculated utilizing a manual segmentation and custom-written program at the superior endplate of the L3–L5 vertebrae level. vBMD measurements were performed and calculated utilizing a QCT pro software at L1–L2 levels and bilateral sacral ala. We stratified by sex for all analyses.
Results
A total of 105 patients (mean age 61.5 years and 52.4% females) were included. We found that female patients had statistically significant lower muscle FCSA than male patients. After adjusting for age and body mass index (BMI), there were statistically significant positive associations between L1–L2 and S1 vBMD with L3 psoas FCSA as well as sacral ala vBMD with L3 posterior paraspinal and L5 psoas FCSA. These associations were not found in males.
Conclusions
Our results demonstrated that in women, significant positive associations between the psoas and posterior paraspinal muscle FCSA and vBMD exist in different lumbosacral levels, which are independent of age and BMI. These regional differences should be considered when interpreting bone and muscle associations in the lumbar spine.
Purpose
We sought to characterize trends in demographics, comorbidities, and postoperative complications among patients undergoing primary and revision cervical disc replacement (pCDR/rCDR) ...procedures.
Methods
In this retrospective database study, the Premier Healthcare database was queried from 2006 to 2019. Annual proportions or medians were calculated for patient and hospital characteristics, comorbidities, and postoperative complications associated with CDR surgery. Trends were assessed using linear regression analyses with year of service as the sole predictor.
Results
A total of 16,178 pCDR and 758 rCDR cases were identified, with a median (IQR) age of 46 (39; 53) and 51 (43; 60) years among patients, respectively. The annual number of both procedures increased between 2006 and 2019, from 135 to 2220 for pCDR (
p
< 0.001), and from 17 to 49 for rCDR procedures (
p
< 0.001), with radiculopathy being the main indication for surgery in both groups. Mechanical failure was identified as a major indication for rCDR procedures with an increase over time (
p
= 0.002). Baseline patient comorbidity burden (
p
= 0.045) and complication rates (
p
< 0.001) showed an increase. For both procedures, an increase in outpatient surgeries and procedures performed in rural hospitals was seen (pCDR:
p
= 0.045;
p
= 0.006; rCDR:
p
= 0.028;
p
= 0.034).
Conclusion
PCDR and rCDR procedures significantly increased from 2006 to 2019. At the same time, comorbidity burden and complication rates increased, while procedures were more often performed in an outpatient and rural setting. The identification of these trends can help guide future practice and lead to further areas of research.
Purpose
Lateral lumbar interbody fusion (LLIF) is a minimally invasive technique that has gained growing interest in recent years. We performed a retrospective review of the medical records and ...operative reports of patients undergoing LLIF between March 2006 and December 2009. We seek to identify the incidence and nature of neurological deficits following LLIF.
Methods
New occurring sensory and motor deficits were recorded at 6 and 12 weeks as well as 6- and 12 months of follow-up. Motor deficits were grouped according to the muscle weakness and severity and sensory deficits to the dermatomal zone. New events were correlated to the patient demographics, pre-operative diagnosis, operative levels, and duration of surgery. At each post-operative time-point patients were queried regarding the presence of leg pain.
Results
A total of 235 patients (139 F; 96 M) with a total of 444 levels fused were included. Average age was 61.5 and mean BMI 28.3. At 12 months’ follow-up, the prevalence of sensory deficits was 1.6%, psoas mechanical deficit was 1.6% and lumbar plexus related deficits 2.9%. Although there was no significant correlation between the surgical level L4–5 and an increased psoas mechanical flexion or lumbar plexus related motor deficit, a trend was observed. Independent risk factors for both psoas mechanical hip flexion deficit and lumbar plexus related motor deficit was duration of surgery.
Conclusion
LLIF is a valuable tool for achieving fusion through a minimally invasive approach with little risk to neurovascular structures.
Population-based database analysis.
To analyze trends in patient- and healthcare-system-related characteristics, utilization and outcomes associated with anterior cervical spine fusions.
Anterior ...cervical decompression and spine fusion (ACDF) is one of the most commonly performed surgical procedures of the spine. However, few data analyzing trends in patient- and healthcare-system-related characteristics, utilization and outcomes exist.
Data from 1990 to 2004 collected in the National Hospital Discharge Survey were accessed. ACDF procedures were identified. Five-year periods of interest (POI) were created for temporal analysis and changes in the prevalence and utilization of this procedure as well as in patient- and healthcare-system-related variables were examined. The changes in the occurrence of procedure-related complications were evaluated.
An estimated total of 771,932 discharges after ACDF were identified. Temporally, an almost 8-fold increase in total prevalence was accompanied by a similar increase in utilization (23/100.000 civilians/POI to 157/100.000/civilians/POI). The highest increase in utilization was observed in those > or =65 years (28-fold). Average age increased from 47.2 years to 50.5 years over time. Length of hospital stay decreased from 5.17 days to 2.38 days. Overall procedure-related complication rates decreased from 4.6% to 3.03%. The prevalence of hypertension, diabetes mellitus, hypercholesterolemia, obesity, pulmonary, and coronary artery increased over time among patients undergoing ACDF.
Despite limitations inherent to secondary analysis of large databases, we identified a number of significant changes in the utilization, demographics, and outcomes associated with ACDF, which can be used to assess the effect of changes in medical care, direct health care resources, and future research. The effect of the increased prevalence of comorbidities on medical practice remains to be evaluated. Further studies are necessary to evaluate causal relationships.
STUDY DESIGN.Longitudinal cohort.
OBJECTIVE.Measure concordance between patients’ and surgeons’ preoperative expectations of lumbar surgery; determine which member of the dyad more closely predicted ...fulfillment of expectations, defined as patient-reported status postoperatively.
SUMMARY OF BACKGROUND DATA.Concordant patient-surgeon expectations reflect effective communication and should foster better outcomes.
METHODS.Preoperatively patients and surgeons completed identical surveys measuring expectations for improvement in symptoms and physical/psychosocial function. Responses ranged from “complete improvement” to “do not have this expectation”; scores for each survey ranged from 0–100 (greatest expectations). Concordance between pairs of patient-surgeon scores was measured with the intraclass correlation coefficient (ICC). Postoperatively fulfillment of expectations was measured from patient-reported amount of improvement received and was calculated as the proportion of patient-reported postoperative score relative to 1) patient-reported preoperative score, and 2) surgeon-reported preoperative score; (range 0 (no expectations fulfilled) to >1 (expectations surpassed)). Clinical measures included patient-reported spine-related disability.
RESULTS.For 402 patient-surgeon pairs, mean survey scores were 73 ± 19 (patients) and 57 ± 16 (surgeons); 84% of patients had higher scores than surgeons, mainly due to expecting complete improvement while surgeons expected a lot/moderate/little improvement. The ICC for the entire sample was .31 (fair agreement); for sub-groups the greatest difference in ICC was for patients with more spine-related disability (ICC = .10, 95%CI .00-.23) versus less disability (ICC = .46, 95%CI .34-.56). 96% of patients were contacted ≥2.0 years postoperatively. Proportions of expectations fulfilled were .79 (0–3.00) (patients) and 1.01 (0–2.29) (surgeons). Thus patients were less likely to anticipate subsequent postoperative status (OR 0.34, 95%CI 0.25–0.45) versus surgeons who were more likely to anticipate patient-reported postoperative status (OR 2.98, 95% CI 2.22–4.00).
CONCLUSIONS.Concordance between patients’ and surgeons’ expectations was fair; due mostly to patients expecting complete improvement while surgeons expected a lot/moderate/little improvement. Compared to patients’ expectations, surgeons’ expectations more closely coincided with patient-reported fulfillment of expectations 2 years postoperatively.Level of Evidence1
Abstract
This work was carried out to find a new and cheap material as source for alternative energy. In the present study a newly recorded bacterial sub-strain (
E. coli
SAY) was used for the ...bio-fermentation of latus leaves. The results show that the bacteria were able to fermenting the sugar presented in the latus leaves and produce ethanol. It was found that the pretreatment increases the amount of sugar available for fermentation and the best results were found with HCL pretreatment. The resulted ethanol concentrations were increased with distillation as well as with dehydration process.
Purpose
The vertebral bone quality (VBQ) score based on magnetic resonance imaging (MRI) was introduced as a bone quality marker in the lumbar spine. Prior studies showed that it could be utilized as ...a predictor of osteoporotic fracture or complications after instrumented spine surgery. The objective of this study was to evaluate the correlation between VBQ scores and bone mineral density (BMD) measured by quantitative computer tomography (QCT) in the cervical spine.
Methods
Preoperative cervical CT and sagittal T1-weighted MRIs from patients undergoing ACDF were retrospectively reviewed and included. The VBQ score in each cervical level was calculated by dividing the signal intensity of the vertebral body by the signal intensity of the cerebrospinal fluid on midsagittal T1-weighted MRI images and correlated with QCT measurements of the C2–T1 vertebral bodies. A total of 102 patients (37.3% female) were included.
Results
VBQ values of C2–T1 vertebrae strongly correlated with each other. C2 showed the highest VBQ value Median (range) 2.33 (1.33, 4.23) and T1 showed the lowest VBQ value Median (range) 1.64 (0.81, 3.88). There was significant weak to moderate negative correlations between and VBQ Scores for all levels C2:
p
< 0.001; C3:
p
< 0.001; C4:
p
< 0.001; C5:
p
< 0.004; C6:
p
< 0.001; C7:
p
< 0.025; T1:
p
< 0.001.
Conclusion
Our results indicate that cervical VBQ scores may be insufficient in the estimation of BMDs, which might limit their clinical application. Additional studies are recommended to determine the utility of VBQ and QCT BMD to evaluate their potential use as bone status markers.
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