The neurorehabilitation of post-stroke dysphagia: Physiology and pathophysiology.

Swallowing is a complex process involving the precise contractions of numerous muscles of the head and neck, which act to process and shepherd ingested material from the oral cavity to its eventual destination, the stomach. Over the past five decades, information from animal and human studies has laid bare the complex network of neurones in the brainstem, cortex and cerebellum that are responsible for orchestrating each normal swallow. Amidst this complexity, problems can and often do occur that result in dysphagia, defined as impaired or disordered swallowing. Dysphagia is common, arising from multiple varied disease processes that can affect any of the neuromuscular structures involved in swallowing. Post-stroke dysphagia (PSD) remains the most prevalent and most commonly studied form of dysphagia and, as such, provides an important disease model to assess dysphagia physiology and pathophysiology. In this review, we explore the complex neuroanatomical processes that occur during normal swallowing and PSD. This includes how strokes cause dysphagia, the mechanisms through which natural neuroplastic recovery occurs, current treatments for patients with persistent dysphagia and emerging neuromodulatory treatments.

Characteristics and outcomes of patients with COVID-19 who return to the emergency department: a multicentre observational study by the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN).

OBJECTIVE: Unplanned return emergency department (ED) visits can reflect clinical deterioration or unmet need from the original visit. We determined the characteristics and outcomes of patients with COVID-19 who return to the ED for COVID-19-related revisits. METHODS: This retrospective observational study used data for all adult patients visiting 47 Canadian EDs with COVID-19 between 1 March 2020 and 31 March 2022. Multivariable logistic regression assessed the characteristics associated with having a no return visit (SV=single visit group) versus at least one return visit (MV=return visit group) after being discharged alive at the first ED visit. RESULTS: 39 809 patients with COVID-19 had 44 862 COVID-19-related ED visits: 35 468 patients (89%) had one visit (SV group) and 4341 (11%) returned to the ED (MV group) within 30 days (mean 2.2, SD=0.5 ED visit). 40% of SV patients and 16% of MV patients were admitted at their first visit, and 41% of MV patients not admitted at their first ED visit were admitted on their second visit. In the MV group, the median time to return was 4 days, 49% returned within 72 hours. In multivariable modelling, a repeat visit was associated with a variety of factors including older age (OR=1.25 per 10 years, 95% CI (1.22 to 1.28)), pregnancy (1.86 (1.46 to 2.36)) and presence of comorbidities (eg, 1.72 (1.40 to 2.10) for cancer, 2.01 (1.52 to 2.66) for obesity, 2.18 (1.42 to 3.36) for organ transplant), current/prior substance use, higher temperature or WHO severe disease (1.41 (1.29 to 1.54)). Return was less likely for females (0.82 (0.77 to 0.88)) and those boosted or fully vaccinated (0.48 (0.34 to 0.70)). CONCLUSIONS: Return ED visits by patients with COVID-19 within 30 days were common during the first two pandemic years and were associated with multiple factors, many of which reflect known risk for worse outcomes. Future studies should assess reasons for revisit and opportunities to improve ED care and reduce resource use. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT04702945.

Drivers of Emergency Department Use Among Oncology Patients in the Era of Novel Cancer Therapeutics: A Systematic Review.

BACKGROUND: Patients diagnosed with cancer are frequent users of the emergency department (ED). While many visits are unavoidable, a significant portion may be potentially preventable ED visits (PPEDs). Cancer treatments have greatly advanced, whereby patients may present with unique toxicities from targeted therapies and are often living longer with advanced disease. Prior work focused on patients undergoing cytotoxic chemotherapy, and often excluded those on supportive care alone. Other contributors to ED visits in oncology, such as patient-level variables, are less well-established. Finally, prior studies focused on ED diagnoses to describe trends and did not evaluate PPEDs. An updated systematic review was completed to focus on PPEDs, novel cancer therapies, and patient-level variables, including those on supportive care alone. METHODS: Three online databases were used. Included publications were in English, from 2012-2022, with sample sizes of ≥50, and reported predictors of ED presentation or ED diagnoses in oncology. RESULTS: 45 studies were included. Six studies highlighted PPEDs with variable definitions. Common reasons for ED visits included pain (66%) or chemotherapy toxicities (69.1%). PPEDs were most frequent amongst breast cancer patients (13.4%) or patients receiving cytotoxic chemotherapy (20%). Three manuscripts included immunotherapy agents, and only one focused on end-of-life patients. CONCLUSION: This updated systematic review highlights variability in oncology ED visits during the last decade. There is limited work on the concept of PPEDs, patient-level variables and patients on supportive care alone. Overall, pain and chemotherapy toxicities remain key drivers of ED visits in cancer patients. Further work is needed in this realm.

Feasibility of diffusion-tensor and correlated diffusion imaging for studying white-matter microstructural abnormalities: Application in COVID-19.

There has been growing attention on the effect of COVID-19 on white-matter microstructure, especially among those that self-isolated after being infected. There is also immense scientific interest and potential clinical utility to evaluate the sensitivity of single-shell diffusion magnetic resonance imaging (MRI) methods for detecting such effects. In this work, the performances of three single-shell-compatible diffusion MRI modeling methods are compared for detecting the effect of COVID-19, including diffusion-tensor imaging, diffusion-tensor decomposition of orthogonal moments and correlated diffusion imaging. Imaging was performed on self-isolated patients at the study initiation and 3-month follow-up, along with age- and sex-matched controls. We demonstrate through simulations and experimental data that correlated diffusion imaging is associated with far greater sensitivity, being the only one of the three single-shell methods to demonstrate COVID-19-related brain effects. Results suggest less restricted diffusion in the frontal lobe in COVID-19 patients, but also more restricted diffusion in the cerebellar white matter, in agreement with several existing studies highlighting the vulnerability of the cerebellum to COVID-19 infection. These results, taken together with the simulation results, suggest that a significant proportion of COVID-19 related white-matter microstructural pathology manifests as a change in tissue diffusivity. Interestingly, different b-values also confer different sensitivities to the effects. No significant difference was observed in patients at the 3-month follow-up, likely due to the limited size of the follow-up cohort. To summarize, correlated diffusion imaging is shown to be a viable single-shell diffusion analysis approach that allows us to uncover opposing patterns of diffusion changes in the frontal and cerebellar regions of COVID-19 patients, suggesting the two regions react differently to viral infection.

MRI Assessment of Cerebral Blood Flow in Nonhospitalized Adults Who Self-Isolated Due to COVID-19.

BACKGROUND: Neurological symptoms associated with coronavirus disease 2019 (COVID-19), such as fatigue and smell/taste changes, persist beyond infection. However, little is known of brain physiology in the post-COVID-19 timeframe. PURPOSE: To determine whether adults who experienced flu-like symptoms due to COVID-19 would exhibit cerebral blood flow (CBF) alterations in the weeks/months beyond infection, relative to controls who experienced flu-like symptoms but tested negative for COVID-19. STUDY TYPE: Prospective observational. POPULATION: A total of 39 adults who previously self-isolated at home due to COVID-19 (41.9 ± 12.6 years of age, 59% female, 116.5 ± 62.2 days since positive diagnosis) and 11 controls who experienced flu-like symptoms but had a negative COVID-19 diagnosis (41.5 ± 13.4 years of age, 55% female, 112.1 ± 59.5 since negative diagnosis). FIELD STRENGTH AND SEQUENCES: A 3.0 T; T1-weighted magnetization-prepared rapid gradient and echo-planar turbo gradient-spin echo arterial spin labeling sequences. ASSESSMENT: Arterial spin labeling was used to estimate CBF. A self-reported questionnaire assessed symptoms, including ongoing fatigue. CBF was compared between COVID-19 and control groups and between those with (n = 11) and without self-reported ongoing fatigue (n = 28) within the COVID-19 group. STATISTICAL TESTS: Between-group and within-group comparisons of CBF were performed in a voxel-wise manner, controlling for age and sex, at a family-wise error rate of 0.05. RESULTS: Relative to controls, the COVID-19 group exhibited significantly decreased CBF in subcortical regions including the thalamus, orbitofrontal cortex, and basal ganglia (maximum cluster size = 6012 voxels and maximum t-statistic = 5.21). Within the COVID-19 group, significant CBF differences in occipital and parietal regions were observed between those with and without self-reported on-going fatigue. DATA CONCLUSION: These cross-sectional data revealed regional CBF decreases in the COVID-19 group, suggesting the relevance of brain physiology in the post-COVID-19 timeframe. This research may help elucidate the heterogeneous symptoms of the post-COVID-19 condition. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 3.

Evaluating the Therapeutic Application of Neuromodulation in the Human Swallowing System.

In the last two decades, the focus of neurogenic dysphagia management has moved from passive compensatory strategies to evidence-based rehabilitative approaches. Advances in technology have enabled the development of novel treatment approaches such as neuromodulation techniques, which target the promotion of neurological reorganization for functional recovery of swallowing. Given the rapid pace of development in the field, this review aims to summarize the current findings on the effects of neuromodulation techniques on the human swallowing system and evaluate their therapeutic potential for neurogenic dysphagia. Implications for future clinical research and practical considerations for using neuromodulation in clinical practice will also be discussed.

Future leaders in a Learning Health System: Exploring the Health System Impact Fellowship.

The Canadian health system is reeling following the COVID-19 pandemic. Strains have become growing cracks, with long emergency department wait times, shortage of human health resources, and growing dissatisfaction from both clinicians and patients. To address long needed health system reform in Canada, a modernization of training is required for the next generation health leaders. The Canadian Institutes of Health Research Health System Impact Fellowship is an example of a well-funded and connected training program which prioritizes embedded research and embedding technically trained scholars with health system partners. The program has been successful in the scope and impact of its training outcomes as well as providing health system partners with a pool of connected and capable scholars. Looking forward, integrating aspects of evidence synthesis from both domestic and international sources and adapting a general contractor approach to implementation within the HSIF could help catalyze Learning Health System reform in Canada.

Metaplasticity in the human swallowing system: clinical implications for dysphagia rehabilitation.

Dysphagia is a common and devastating complication following brain damage. Over the last 2 decades, dysphagia treatments have shifted from compensatory to rehabilitative strategies that facilitate neuroplasticity, which is the reorganization of neural networks that is essential for functional recovery. Moreover, there is growing interest in the application of cortical and peripheral neurostimulation to promote such neuroplasticity. Despite some preliminary positive findings, the variability in responsiveness toward these treatments remains substantial. The purpose of this review is to summarize findings on the effects of neurostimulation in promoting neuroplasticity for dysphagia rehabilitation and highlight the need to develop more effective treatment strategies. We then discuss the role of metaplasticity, a homeostatic mechanism of the brain to regulate plasticity changes, in helping to drive neurorehabilitation. Finally, a hypothesis on how metaplasticity could be applied in dysphagia rehabilitation to enhance treatment outcomes is proposed.

Development and pilot testing of a decision aid for navigating breast cancer survivorship care.

BACKGROUND: The predominant oncologist-led model in many countries is unsustainable to meet the needs of a growing cohort of breast cancer survivors (BCS). Despite available alternative models, adoption rates have been poor. To help BCS navigate survivorship care, we aimed to systematically develop a decision aid (DA) to guide their choice of follow-up care model and evaluate its acceptability and usability among BCS and health care providers (HCPs). METHODS: We recruited BCS aged ≥ 21 years who have completed primary treatment and understand English. BCS receiving palliative care or with cognitive impairment were excluded. HCPs who routinely discussed post-treatment care with BCS were purposively sampled based on disciplines. Each participant reviewed the DA during a semi-structured interview using the 'think aloud' approach and completed an acceptability questionnaire. Descriptive statistics and directed content analysis were used. RESULTS: We conducted three rounds of alpha testing with 15 BCS and 8 HCPs. All BCS found the final DA prototype easy to navigate with sufficient interactivity. The information imbalance favouring the shared care option perceived by 60% of BCS in early rounds was rectified. The length of DA was optimized to be 'just right'. Key revisions made included (1) presenting care options side-by-side to improve perceived information balance, (2) creating dedicated sections explaining HCPs' care roles to address gaps in health system contextual knowledge, and (3) employing a multicriteria decision analysis method for preference clarification exercise to reflect the user's openness towards shared care. Most BCS (73%) found the DA useful for decision-making, and 93% were willing to discuss the DA with their HCPs. Most HCPs (88%) agreed that the DA was a reliable tool and would be easily integrated into routine care. CONCLUSIONS: Our experience highlighted the need to provide contextual information on the health care system for decisions related to care delivery. Developers should address potential variability within the care model and clarify inherent biases, such as low confidence levels in primary care. Future work could expand on the developed DA's informational structure to apply to other care models and leverage artificial intelligence to optimize information delivery.

A systematic review and meta-analysis of the effects of intraoral treatments for neurogenic oropharyngeal dysphagia.

BACKGROUND: Rehabilitative treatments for oropharyngeal dysphagia, including oromotor exercises and sensory stimulation, have been widely adopted into clinical practice. However, the effects of these treatments are mainly supported by exploratory studies. As such, their clinical efficacy remains uncertain. OBJECTIVE: Our systematic review and meta-analysis aimed to evaluate the efficacy of intraoral treatments for neurogenic oropharyngeal dysphagia based on evidence from randomised controlled trials (RCTs). METHODS: Six electronic databases were systematically searched between January 1970 and July 2021. Data were extracted and analysed by two independent reviewers. The outcome measure was changes in (any) relevant clinical swallowing-related characteristics. RESULTS: Data from 285 dysphagic patients were collected from 8 RCT studies across a range of intraoral dysphagia treatments. The pooled effect size of all intraoral dysphagia treatments was non-significant compared to control comparators (SMD [95%CI] = 0.23 [-0.22, 0.69], p = .31; I2  = 73%). Subgroup analysis revealed that the pooled effect sizes were also non-significant for oromotor exercises (device-facilitated lip resistance exercises and tongue exercises) (SMD [95%CI] = 0.11 [-0.76, 0.97]; p = .81; I2  = 88%) and sensory stimulation (thermal-tactile, thermo-chemical and electrical stimulation) (SMD [95%CI] = 0.35 [-0.03, 0.72]; p = .07; I2  = 0%). CONCLUSIONS: Our results showed that overall, intraoral dysphagia treatments, including oromotor exercises and sensory stimulation, do not show beneficial effects for neurogenic oropharyngeal dysphagia. The evidence for these treatments remains weak and currently inadequate to support clinical use. Large-scale, multi-centre RCTs are warranted to fully explore their clinical efficacy.

Head Injuries in Rock Climbing: A Scoping Review.

Rock climbing was recognized as a sport at the 2020 Tokyo Olympics. Despite its increasing participation, there is no knowledge synthesis of head injuries (HIs), defined as any injury to the head, associated with climbing, making it challenging for clinicians to provide evidence-based care. Our aim was to synthesize HI literature within rock climbing and identify knowledge gaps. Six databases (Medline, Embase, Sports Medicine & Education Index, SPORTDiscus, CINAHL, and Cochrane) were searched. Two reviewers screened 345 studies and 31 studies were selected for data abstraction. We found the quality of individual studies mainly "fair" to "good." Both HI and traumatic brain injury (TBI) had inconsistent definitions and categorization. The HIs represented between 0 to 36% of reported climbing injuries. Between 11 to 100% of HIs were TBIs, defined as an HI with permanent or temporary neurological sequelae. The most common causes of HIs were outdoor falls and falling objects. Climbing-specific factors associated with the causes were infrequently examined in the literature. Data sources of safety practices were incomplete. Overall, there was a lack of literature examining HIs, mechanisms of injury, and safety practices associated with climbing. To improve the tracking of HIs in climbing, we suggest the use of consistent reporting standards and the creation of a climbing injury surveillance system.

Using Case Costing to Evaluate the Potential Impact of a Reintegration Unit on an Acute-Care Hospital's Capacity and Resources.

The Ontario Ministry of Health funded a reintegration unit to transition hospitalized patients who no longer required acute care to alternate level of care (ALC), such as long-term care. In its first year, 102 (3.5%) patients of the hospital's waiting-for-ALC population were transferred, with 37.3% transferred on the day of ALC readiness. The reintegration unit reduced direct hospital costs by $861,000. Using case costing, we modelled optimized scenarios including all transfers on the day of ALC readiness and increased transfers to the reintegration unit; this helped reduce avoided direct costs by $2.3-$5.4 million. Acute-care bed capacity could have increased by 11%. We outline strategies to optimize future performance of the reintegration unit.

Effects of Neurostimulation on Poststroke Dysphagia: A Synthesis of Current Evidence From Randomized Controlled Trials.

OBJECTIVES: To evaluate the effects of neurostimulation, including repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (tDCS) and pharyngeal electrical stimulation (PES), for poststroke dysphagia based on evidence from randomized controlled trials (RCTs). MATERIALS AND METHODS: Electronic databases were systematically searched between January 1985 and June 2020 and studies were included based on prespecified selection criteria. The quality of studies was evaluated and data were extracted and synthesized by two independent reviewers. The primary outcome measure was change in (any) relevant clinical swallowing-related characteristic. Subgroup analysis were conducted based on follow-up period and stimulation parameters. RESULTS: Data from 852 stroke patients were collected from 26 RCTs studies. Active neurostimulation treatments demonstrated a significant and moderate effect size compared to control treatment (0.69 [95% CI = 0.50, 0.89]; p < 0.001). The effect size of rTMS was the largest (0.73 [95% CI = 0.49, 0.98]; p < 0.001), followed by PES (0.68 [95% CI = 0.22, 1.14]; p = 0.004) and tDCS (0.65 [95% CI = 0.25, 1.04]; p = 0.001). All treatments showed comparable effect sizes within the first two weeks. Between three weeks and two months, tDCS demonstrated the largest effects (1.02 [95% CI = 0.45, 1.59]; p < 0.001) among the three treatments. No significant treatment effects were reported beyond three months. The combined effect size was large when applied in acute (<14 days) stroke (0.8 [95% CI = 0.34, 1.26]; p < 0.001). For noninvasive brain stimulation (NIBS), bihemispheric stimulation demonstrated the strongest effect size (0.93 [95% CI = 0.53, 1.33]; p < 0.001). In contrast, unilateral rTMS using ipsilesional high-frequency stimulation had a combined effect size of 0.83 (95% CI = 0.14, 1.52; p = 0.02). For tDCS, a significant effect size was found only with anodal stimulation applied over the contralesional hemisphere (1.04 [95% CI = 0.54, 1.53]; p < 0.001). CONCLUSIONS: The results show that neurostimulation can benefit patients with poststroke dysphagia. The treatment effects were the strongest in acute stroke patients and within the first two months of application. For NIBS, bihemispheric stimulation appeared to be most effective. The most beneficial hemisphere for unilateral stimulation differed between rTMS and tDCS. These findings provide a platform for future studies and clinical practice.

Preconditioning human pharyngeal motor cortex enhances directional metaplasticity induced by repetitive transcranial magnetic stimulation.

KEY POINTS: Recent studies have proposed therapeutic potential for repetitive transcranial magnetic stimulation (rTMS) in swallowing rehabilitation, yet its outcomes vary across individuals and studies. Such variability may be related to the brain state before stimulation. Metaplasticity is a higher order plasticity which regulates cortical response to plasticity changes. Studies have shown that preconditioning of the hand motor cortex could increase cortical capacity for neuroplastic change and enhance rTMS outcomes. We investigated, for the first time, the directional metaplastic properties in human pharyngeal motor cortex using preconditioned rTMS. We found that preconditioned rTMS with specific time intervals between preconditioning and conditioning rTMS had stronger stimulation effects in both swallowing neurophysiology and behaviour than that without preconditioning. Our results provide evidence for enhanced directional metaplasticity in pharyngeal motor cortex and new insights into its clinical application for dysphagia. ABSTRACT: Despite growing evidence that repetitive transcranial magnetic stimulation (rTMS) can be used as a treatment for dysphagia, its efficacy varies across individuals. Such variability may relate to the pre-stimulation state of neuronal activation. Previous studies found that preconditioning the hand motor cortex before rTMS could enhance stimulation outcomes through metaplasticity. No studies have investigated such mechanisms in human pharyngeal motor cortex. Therefore, we investigated the preconditioning effects of rTMS on swallowing neurophysiology and behaviour. Healthy adults were recruited for swallowing neurophysiological (n = 14) and behavioural (n = 14) experiments. They were first given eight different preconditioned (1 and 5 Hz) rTMS interventions with varying inter-rTMS intervals. Motor evoked potentials (MEPs) were measured before and for 60 min post-rTMS. Based on the changes in pharyngeal MEPs, the optimal preconditioned 1 Hz and 5 Hz rTMS protocols were then applied as interventions while assessing swallowing performance using a reaction time task. We found that 5 Hz rTMS preconditioned with 1 Hz rTMS with 30 min inter-rTMS interval induced the greatest increase on pharyngeal cortical excitability (F1,13  = 21.244; P < 0.001). By comparison, 1 Hz rTMS preconditioned with 5 Hz rTMS with 90 min inter-rTMS interval was most optimal for suppressing pharyngeal motor cortex (F1,13  = 13.547; P = 0.003). Behaviourally, swallowing accuracy was improved after preconditioned 5 Hz rTMS (F1,13  = 10.109, P = 0.007) and reduced after preconditioned 1 Hz rTMS (F1,13  = 14.108, P = 0.009) compared to sham. Thus, two optimal protocols for inducing functional metaplasticity in human pharyngeal motor cortex have been identified. These protocols appear superior to conventional rTMS and may be relevant to future clinical application in neurogenic dysphagia.

A Novel Automated Visual Acuity Test Using a Portable Head-mounted Display.

SIGNIFICANCE: We developed a head-mounted display (HMD) as an automated way of testing visual acuity (VA) to increase workplace efficiency. This study raises its potential utility and advantages, analyzes reasons for its current limitations, and discusses areas of improvement in the development of this device. PURPOSE: Manual VA testing is important but labor-intensive in ophthalmology and optometry clinics. The purpose of this exploratory study is to assess the performance and identify potential limitations of an automated HMD for VA testing. METHODS: Sixty patients from National University Hospital, Singapore, were enrolled in a prospective observational study. The HMD was constructed based on the Snellen chart, with single optotypes displayed at a time. Each subject underwent VA testing of both eyes with the manual Snellen chart tested at 6 m from the subject and the HMD. RESULTS: Fifty-three subjects were included in the final analysis, with an incompletion rate of 11.7% (n = 7). The mean difference in estimated acuity between the HMD and Snellen chart was 0.05 logMAR. However, 95% limits of agreement were large at ±0.33 logMAR. The HMD overestimated vision in patients with poorer visual acuities. In detecting VA worse than 0.30 logMAR (6/12), sensitivity was 63.6% (95% confidence interval, 0.31 to 0.89%), and specificity was 81.0% (95% confidence interval, 0.66 to 0.91%). No significant correlation existed between mean difference and age (r = -0.15, P = .27) or education level (r = 0.04, P = .76). CONCLUSIONS: Advantages of our novel HMD technology include its fully automated nature and its portability. However, the device in its current form is not ready for widespread clinical use primarily because of its low accuracy, which is limited by both technical and user factors. Future studies are needed to improve its accuracy and completion rate and to evaluate for test-retest reliability in a larger population.

Changes in resting motor threshold of the tongue with normal aging and stroke.

AIM OF STUDY: To examine the resting motor threshold of the tongue in healthy adults and stroke survivors. METHODS: Thirty-five healthy adults were classified into three groups: Group 1 (19-38 years; n = 11), Group 2 (50-64 years; n = 12) and Group 3 (66-78 years; n = 12). Six chronic stroke survivors (mean age =59 years, SD = 9.1 years) were recruited (Group 4). The resting motor thresholds (RMTs) of the tongue were measured and compared (i) among the four groups and (ii) between stroke survivors and age-matched healthy adults. RESULTS: Group 3 showed significantly higher RMTs than Group 1 (p = .001) and 2 (p = 0.007). Group 4 showed significantly higher RMTs than Group 1 (p = .003) and 2 (p = .001). The RMTs of Group 3 and 4 were not significantly different (p = .385). The RMT was positively correlated with age (r = 0.534; p = .001). Group 4 showed significantly higher RMTs than the age-matched controls (U = 2.5, p = .009, r = 0.77). CONCLUSIONS: The resting motor threshold of the tongue is significantly increased in adults aged above 65 and in stroke survivors when compared with healthy adults. The findings suggested that the cortical excitability of the tongue deteriorates in the elderly and the stroke population.

Aminoglycoside-associated acute kidney injury in elderly patients with and without shock.

OBJECTIVES: Multiresistant Gram-negative pathogens pose major healthcare concerns with a limited therapeutic armamentarium. Aminoglycosides (AG) are under-utilized due to nephrotoxicity. We aimed to evaluate AG-associated acute kidney injury (AG-AKI) in elderly inpatients, with and without shock. METHODS: We examined the incidence and predictors of AG-AKI by KDIGO criteria and extended renal dysfunction (ERD) in patients aged >60 years. ERD represented a composite of hospital mortality or absence of renal recovery over 6 months following AG-AKI. RESULTS: Two hundred and seventy-eight patients (aged 74 ±â€Š8 years) were studied; 43% and 19% received >7 and >10 days of AG therapy, respectively, and 70% gentamicin (versus amikacin). Thirteen per cent had shock and 17% developed AG-AKI. Comparing all patients with shock versus no shock, AG-AKI developed in 33% versus 14%, respectively (P = 0.005); correspondingly among 47 patients with AG-AKI, more with shock had stage 2/3 AKI (92% versus 43%) and dialysis (50% versus 9%) (P < 0.01), but more had other strong AKI confounders than AG therapy alone (83% versus 40%, P = 0.02). Multivariate analyses identified mechanical ventilation, frusemide administration and AG therapy >10 days as predictors of AG-AKI (P < 0.05), whereas shock, pneumonia and frusemide administration predicted more severe stage 2/3 AG-AKI (P < 0.05). Hospital mortality was 30% versus 7% with AG-AKI versus none (P < 0.001). Twenty-three of 211 (11%) patients with extended analysis had ERD, with 47% experiencing renal recovery following AG-AKI. Mechanical ventilation and contrast administration during index hospitalization predicted ERD (P < 0.05). CONCLUSIONS: AG-AKI is common in the elderly, with a significant risk of ERD, but the cause and severity are greatly influenced by critical illness and shock, more so than AG therapy alone.

Preliminary evidence of the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) on swallowing functions in post-stroke individuals with chronic dysphagia.

BACKGROUND: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. AIMS: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to the tongue region of the motor cortex on swallowing functions and the quality of life of post-stroke individuals with dysphagia. METHODS & PROCEDURES: Two male and two female participants were assigned randomly to active and sham groups. The participants in the active group received 10 sessions of active rTMS for 2 weeks, whereas the sham participants received 10 sessions of sham rTMS for 2 weeks. Each participant received a total of 3000 pulses of 5 Hz active or sham rTMS per day for 10 days. Outcome measures were taken at baseline, 1 week and 1 month post-rTMS. OUTCOMES & RESULTS: Participants who received active rTMS had improved swallowing functions and swallowing-related quality of life at 1 week and 1 month post-stimulation. CONCLUSIONS & IMPLICATIONS: The study showed that excitatory rTMS applied over the tongue motor cortex is a feasible approach in individuals with chronic post-stroke dysphagia. Further investigation with larger sample population is warranted to support the benefit of this stimulation protocol.

Canadian Academy of Sport and Exercise Medicine position statement: athletes at high altitude.

Many sports incorporate training at altitude as a key component of their athlete training plan. Furthermore, many sports are required to compete at high altitude venues. Exercise at high altitude provides unique challenges to the athlete and to the sport medicine clinician working with these athletes. These challenges include altitude illness, alterations in training intensity and performance, nutritional and hydration difficulties, and challenges related to the austerity of the environment. Furthermore, many of the strategies that are typically utilized by visitors to altitude may have implications from an anti-doping point of view.This position statement was commissioned and approved by the Canadian Academy of Sport and Exercise Medicine. The purpose of this statement was to provide an evidence-based, best practices summary to assist clinicians with the preparation and management of athletes and individuals travelling to altitude for both competition and training.

New and Evolving Treatments for Neurologic Dysphagia.

Despite swallowing being a frequently performed daily function, it is highly complex. For a safe swallow to occur, muscles within the head, neck, and thorax need to contract in a concerted pattern, controlled by several swallowing centers at multiple levels of the central nervous system, including the midbrain, cerebral cortex, and cerebellum in addition to five cranial nerves. Dysphagia, or difficulty swallowing, is caused by a long list of pathologic processes and diseases, which can interfere with various stages along the swallowing sensorimotor pathway. When present, dysphagia leads to increased mortality, morbidity, hospital length of stay, and reduced quality of life. Current dysphagia management approaches, such as altering the texture and consistency of foods and fluids and teaching patients rehabilitative exercises, have been broadly unchanged for many years and, in the case of texture modification, are of uncertain effectiveness. However, evidence is emerging in support of new medication-based and neuromodulatory treatment approaches. Regarding medication-based therapies, most research has focused on capsaicinoids, which studies have shown are able to improve swallowing in patients with post-stroke dysphagia. Separately, albeit convergently, in the field of neuromodulation, there is a growing and positive evidential base behind three non-invasive brain stimulation techniques: repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation (TDCS), and pharyngeal electrical stimulation (PES). Should some or all of these emerging therapies fulfill their promise, dysphagia-related patient outcomes may be improved. This paper describes the current state of our understanding regarding new medication and neuromodulation-based neurogenic oropharyngeal dysphagia treatments.