Stability and Effect of Parkinsonian State on Deep Brain Stimulation Cortical Evoked Potentials

ObjectivesTo characterize and compare the stability of cortical potentials evoked by deep brain stimulation (DBS) of the subthalamic nucleus (STN) across the naïve, parkinsonian, and pharmacologically treated parkinsonian states. To advance cortical potentials as possible biomarkers for DBS programming.Materials and MethodsSerial electrocorticographic (ECoG) recordings were made more than nine months from a single non-human primate instrumented with bilateral ECoG grids spanning anterior parietal to prefrontal cortex. Cortical evoked potentials (CEPs) were generated through time-lock averaging of the ECoG recordings to DBS pulses delivered unilaterally in the STN region using a chronically implanted, six-contact, scaled DBS lead. Recordings were made across the naïve followed by mild and moderate parkinsonian conditions achieved by staged injections of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neurotoxin. In addition to characterizing the spatial distribution and stability of the response within each state, changes in the amplitude and latency of CEP components as well as in the frequency content were examined in relation to parkinsonian severity and dopamine replacement.ResultsIn the naïve state, the STN DBS CEP presented as a multiphase response maximal over M1 cortex, with components attributable to physiological activity distinguishable from stimulus artifact as early as 0.45–0.75 msec poststimulation. When delivered using therapeutically effective parameters in the parkinsonian state, the CEP was highly stable across multiple recording sessions within each behavioral state. Across states, significant differences were present with respect to both the latency and amplitude of individual response components, with greater differences present for longer-latency components (all p < 0.05). Power spectral density analysis revealed a high-beta peak within the evoked response, with significant changes in power between disease states across multiple frequency bands.ConclusionsOur findings underscore the spatiotemporal specificity and relative stability of the DBS-CEP associated with different disease states and with therapeutic benefit. DBS-CEP may be a viable biomarker for therapeutic programming.     

Objective predictors of ‘early tolerance’ to ventral intermediate nucleus of thalamus deep brain stimulation in essential tremor patients

Objective

To identify pre-operative clinical and computerized spiral analysis characteristics that may help ascertain which patients with Essential Tremor (ET) will exhibit ‘early tolerance’ to ventral intermediate nucleus of thalamus (Vim) deep brain stimulation (DBS).

Combining robotic exoskeleton and body weight unweighing technology to promote walking activity in tetraplegia following SCI: A case study

Context: To investigate the feasibility of combining the lower-limb exoskeleton and body weight unweighing technology for assisted walking in tetraplegia following spinal cord injury (SCI).

Findings: A 66-year-old participant with a complete SCI at the C7 level, graded on the American Spinal Injury Association Impairment Scale (AIS) as AIS A, participated in nine sessions of overground walking with the assistance from exoskeleton and body weight unweighing system. The participant could tolerate the intensity and ambulate with exoskeleton assistance for a short distance with acceptable and appropriate gait kinematics after training.

Conclusion: This report showed that using technology can assist non-ambulatory individuals following SCI to stand and ambulate with assistance which may promote general physical and psychological health if used in the long term.     

Post-viral atopic airway disease: pathogenesis and potential avenues for intervention

Introduction: In early childhood, wheezing due to lower respiratory tract illness is often associated with infection by commonly known respiratory viruses such as respiratory syncytial virus (RSV) and human rhinovirus (RV). How respiratory viral infections lead to wheeze and/or asthma is an area of active research.

Areas covered: This review provides an updated summary of the published information on the development of post-viral induced atopy and asthma and the mechanisms involved. We focus on the contribution of animal models in identifying pathways that may contribute to atopy and asthma following respiratory virus infection, different polymorphisms that have been associated with asthma development, and current options for disease management and potential future interventions.

Expert commentary: Currently there are no prophylactic therapies that prevent infants infected with respiratory viruses from developing asthma or atopy. Neither are there curative therapies for patients with asthma. Therefore, a better understanding of genetic factors and other associated biomarkers in respiratory viral induced pathogenesis is important for developing effective personalized therapies.     

Not all cemented hips are the same: a register-based (NJR) comparison of taper-slip and composite beam femoral stems

Background and purpose — No difference in outcome has been demonstrated comparing cemented taper-slip and composite beam designs in short-term randomised trials; we assessed outcome differences using a registry analysis.

Patients and methods — All cemented stems with > 100 implantations were identified in the National Joint Registry of England and Wales from April 1, 2003 to September 31, 2013 and categorised as taper-slip or composite beam. Survival analyses using Kaplan–Meier and Cox regression were performed.

Results — We identified 292,987 cemented arthroplasties, of which 16% (47,586) were composite beam stems, with taper-slip stems making up the remainder (n = 245,401). There was a statistically significant increased chance of revision in the composite beam group compared with the taper-slip group (1.7% vs 1.3%, p < 0.001) but statistically no significant differences of survival estimates (p = 0.06). When the 2 groups were segregated to delineate the most implanted model in each category, the differences became more profound with the most implanted taper-slip stem (Exeter V40) showing statistically and clinically significant superior 8-year survival: 97.9% compared with 97.6% for all other taper-slip; 97.5% for the most implanted composite beam (Charnley cemented stem); and 97.7% for all other composite beam.

Interpretation — There was an increased incidence of revision for composite beam stems. The most implanted taper-slip stem demonstrated significant survival advantage vs. all other stems.     

Commonly used agent for acute pain management of sickle cell anemia in Saudi Emergency Department: A narrative review

IntroductionSickle-cell disease (SCD) is one of the most common hematologic inherited disorders in Saudi Arabia. Vaso-occlusive pain crisis in SCD is a major cause for emergency visits and patients’ pain may be undertreated. This study presents a narrative literature review of current agents used to manage acute pain crisis in SCD patients presenting to the emergency department in hospitals of Saudi Arabia.MethodWe conducted a narrative review on relevant published articles about sickle cell disease pain crisis management in Saudi Arabia and included seven relevant studies based on our inclusion criteria.ResultsUsing our search strategy, we included 7 studies Out of 4052. Studies included were conducted in different locations in the country. Four studies were in the Eastern region while only one in Western and One in Central regions. Those studies included around 2441 patients, in total. Morphine was used in 5 studies out of the 7 included. Pethidine was used in 4. One study used Isoxsuprine and another study used tinzaparin.ConclusionWe found that continuous administration of IV morphine accompanied by oral analgesics including NSAIDs and acetaminophen is the most commonly used practice for treating SCD patients presenting with a vaso-occlusive pain crisis. Possible effectiveness of tinzaparin, isoxsuprine, and pethidine as therapeutic options may be considered. However, there was no recommendation for a certain agent to be prescribed. We recommend conducting further clinical randomized-controlled trials.     

Decompression alone versus decompression with fusion in patients with lumbar spinal stenosis with degenerative spondylolisthesis: a systematic review and meta-analysis

Introduction

Surgical decompression is standard care in the treatment of degenerative spondylolisthesis in patients with symptomatic lumbar spinal stenosis, but there remains controversy over the benefits of adding fusion. The persistent lack of consensus on this matter and the availability of new data warrants a contemporary systematic review and meta-analysis of the literature.

Methods

Multiple online databases were systematically searched up to October 2022 for randomized controlled trials (RCTs) and prospective studies comparing outcomes of decompression alone versus decompression with fusion for lumbar spinal stenosis in patients with degenerative spondylolisthesis. Primary outcome was the Oswestry Disability Index. Secondary outcomes included leg and back pain, surgical outcomes, and radiological outcomes. Pooled effect estimates were calculated and presented as mean differences (MD) with their 95% confidence intervals (CI) at two-year follow-up.

Results

Of the identified 2403 studies, eventually five RCTs and two prospective studies were included. Overall, most studies had a low or unclear risk of selection bias and most studies were focused on low grade degenerative spondylolisthesis. All patient-reported outcomes showed low statistical heterogeneity. Overall, there was high-quality evidence suggesting no difference in functionality at two years of follow-up (MD − 0.31, 95% CI − 3.81 to 3.19). Furthermore, there was high-quality evidence of no difference in leg pain (MD − 1.79, 95% CI − 5.08 to 1.50) or back pain (MD − 2.54, 95% CI − 6.76 to 1.67) between patients undergoing decompression vs. decompression with fusion. Pooled surgical outcomes showed less blood loss after decompression only, shorter length of hospital stay, and a similar reoperation rate compared to decompression with fusion.

Conclusion

Based on the current literature, there is high-quality evidence of no difference in functionality after decompression alone compared to decompression with fusion in patients with degenerative lumbar spondylolisthesis at 2 years of follow-up. Further studies should focus on long-term comparative outcomes, health economic evaluations, and identifying those patients that may benefit more from decompression with fusion instead of decompression alone. This review was registered at Prospero (CRD42021291603).

     

International guideline for the delineation of the clinical target volumes (CTV) for nasopharyngeal carcinoma

Purpose

Target delineation in nasopharyngeal carcinoma (NPC) often proves challenging because of the notoriously narrow therapeutic margin. High doses are needed to achieve optimal levels of tumour control, and dosimetric inadequacy remains one of the most important independent factors affecting treatment outcome.

Role of the Functional Polymorphism of Survivin Gene (-31G/C) and Risk of Breast Cancer in a North Indian Population

Introduction

Survivin is an apoptosis inhibitor and plays a primary role in cancer development and progression. One of the most common polymorphism of the survivin promoter -31G/C (rs9904341) influences its expression and is associated with the risk of cancer development. This study was conducted to explore survivin promoter gene -31G/C (rs9904341) polymorphism and the risk of breast cancer.