Hyper-acute effects of sub-concussive soccer headers on brain function and hemodynamics.

Introduction: Sub-concussive head impacts in soccer are drawing increasing research attention regarding their acute and long-term effects as players may experience thousands of headers in a single season. During these impacts, the head experiences rapid acceleration similar to what occurs during a concussion, but without the clinical implications. The physical mechanism and response to repetitive impacts are not completely understood. The objective of this work was to examine the immediate functional outcomes of sub-concussive level impacts from soccer heading in a natural, non-laboratory environment. Methods: Twenty university level soccer athletes were instrumented with sensor-mounted bite bars to record impacts from 10 consecutive soccer headers. Pre- and post-header measurements were collected to determine hyper-acute changes, i.e., within minutes after exposure. This included measuring blood flow velocity using transcranial Doppler (TCD) ultrasound, oxyhemoglobin concentration using functional near infrared spectroscopy imaging (fNIRS), and upper extremity dual-task (UEF) neurocognitive testing. Results: On average, the athletes experienced 30.7 ± 8.9 g peak linear acceleration and 7.2 ± 3.1 rad/s peak angular velocity, respectively. Results from fNIRS measurements showed an increase in the brain oxygenation for the left prefrontal cortex (PC) (p = 0.002), and the left motor cortex (MC) (p = 0.007) following the soccer headers. Additional analysis of the fNIRS time series demonstrates increased sample entropy of the signal after the headers in the right PC (p = 0.02), right MC (p = 0.004), and left MC (p = 0.04). Discussion: These combined results reveal some variations in brain oxygenation immediately detected after repetitive headers. Significant changes in balance and neurocognitive function were not observed in this study, indicating a mild level of head impacts. This is the first study to observe hemodynamic changes immediately after sub-concussive impacts using non-invasive portable imaging technology. In combination with head kinematic measurements, this information can give new insights and a framework for immediate monitoring of sub-concussive impacts on the head.

Effect of Baduanjin exercise on cerebral blood flow and cognitive frailty in the community older adults with cognitive frailty: A randomized controlled trial.

Objectives: Regular Baduanjin exercise training has been shown to be beneficial to the physical and cognitive health of older adults, but the underlying mechanisms remain to be investigated. This study examined the influence of Baduanjin on cerebral hemodynamics in community-dwelling older adults with cognitive frailty. Design: Randomized controlled trial. Methods: A total of 102 eligible participants were randomly allocated into the Baduanjin exercise intervention group (BEG) or usual physical activity control group (CG) for 24 weeks. Cerebral hemodynamic parameters of bilateral middle/anterior cerebral artery and basilar artery, cognitive ability and physical frailty were assessed using Transcranial Doppler (TCD), Montreal Cognitive Assessment (MoCA) and Edmonton Frailty Scale (EFS) at baseline and 24 weeks post-intervention. Results: After 24 weeks intervention, the changes in peak systolic velocity (PSV), mean blood flow velocity (MBFV), and end diastolic velocity (EDV) in the right middle cerebral artery and basilar artery were better in the BEG than in the CG; the increase in MoCA scores and the decrease in EFS scores were significantly higher in the BEG than in the CG. Moreover, the interaction of exercise and time on those variables showed obvious significance. Conclusions: The 24 weeks Baduanjin exercise training had a positive beneficial effect on cerebral blood flow in community-dwelling older adults with cognitive frailty. This may be a potential mechanism by which Baduanjin exercise improves the cognitive frailty in older adults. Trial registration: Chinese Clinical Trial Registry, ChiCTR1800020341. Date of registration: December 25, 2018, http://www.chictr.org.cn/showproj.aspx?proj=29846.

Dataset of middle cerebral artery blood flow stability in response to high-definition transcranial electrical stimulation.

This supplementary dataset is supportive of the randomized sham-controlled, double-blind, crossover clinical trial investigating polarity- and intensity-dependent effects of high-definition transcranial electrical stimulation (HD-tDCS) applied over the right temporo-parietal junction on mean middle cerebral artery blood flow velocity (MCA-BFv) bilaterally. Data of eleven healthy right-handed adults (6 women, 5 men; mean age 31 ± 5.6 years old) were analyzed for MCA-BFv, assessed using transcranial doppler ultrasound on the stimulated and the contralateral hemisphere concomitantly, during and after 3 blocks of 2 min HD-tDCS at 1, 2, and 3 mA. Participants received three electrical stimulation conditions (anode center, cathode center, and sham) randomly ordered across different days. The collected data is publicly available at Mendeley Data. This article and the data will inform future related investigations and safety analysis of transcranial non-invasive brain stimulation.

Transcranial Doppler microemboli and acute brain injury in extracorporeal membrane oxygenation: A prospective observational study.

Objective: Extracorporeal membrane oxygenation (ECMO) carries a high morbidity of acute brain injury (ABI) with resultant mortality increase. Transcranial Doppler (TCD) allows real-time characterization of regional cerebral hemodynamics, but limited data exist on the interpretation of microembolic signals (MES) in ECMO. Methods: This prospective cohort study was conducted at a single tertiary care center, November 2017 through February 2022, and included all adult patients receiving venoarterial (VA) and venovenous (VV) ECMO undergoing TCD examinations, which all included MES monitoring. Results: Of 145 patients on ECMO who underwent at least 1 TCD examination, 100 (68.9%) patients on VA-ECMO received 187 examinations whereas 45 (31.1%) patients on VV-ECMO received 65 examinations (P = .81). MES were observed in 35 (35.0%) patients on VA-ECMO and 2 (4.7%) patients on VV-ECMO (P < .001), corresponding to 46 (24.6%) and 2 (3.1%) TCD examinations, respectively. MES were present in 29.4% of patients on VA-ECMO without additional cardiac support, compared with 38.1% with intra-aortic balloon pump and 57.1% with left ventricular assist device, but these differences were not statistically significant (P = .39; P = .20, respectively). Presence or number of MES was not associated with VA-ECMO cannulation mode (23.4% MES presence in peripheral cannulation vs 25.8% in central cannulation, P = .80). In both VA- and VV-ECMO, MES presence or number was not associated with presence of clot or fibrin in the ECMO circuit or with any studied hemodynamic, laboratory, or ECMO parameters at the time of TCD. ABI occurred in 38% and 31.1% of patients on VA- and VV-ECMO, respectively. In multivariable logistic regression analyses, neither ABI nor a composite outcome of arterial thromboembolic events was associated with presence or number of MES in VA- ECMO. Conclusions: TCD analysis in a large cohort of patients on ECMO demonstrates a significant number of MES, especially in patients on VA-ECMO with intra-aortic balloon pump, and/or left ventricular assist device. However, clinical associations and significance of TCD MES remain unresolved and warrant further correlation with systematic imaging and long-term neurologic follow-up.

Subarachnoid hemorrhage due to middle cerebral artery dissection mimicking aneurysm - Case report.

We report a case of subarachnoid hemorrhage due to a dissecting middle cerebral artery that was misdiagnosed as saccular aneurysm. A 74-years old female patient presented with headache and neck pain for 4 days. Brain magnetic resonance imaging revealed subarachnoid hemorrhage in both Sylvian fissures. A ruptured left middle cerebral artery bifurcation saccular aneurysm and unruptured basilar tip aneurysm were diagnosed. The patient was treated surgically using the transsylvian approach. However, no saccular aneurysm was found during the surgery, and the diagnosis was corrected for middle cerebral artery dissection. We treated the dissected segment of the middle cerebral artery and performed clip reinforcement. We experienced a case of middle cerebral artery dissection with no neurological deficit, which was misdiagnosed as a saccular aneurysm. If the stump of the occlusion is conical, dissection should be suspected. High-resolution magnetic resonance imaging and angiography should be performed for a differential diagnosis if dissection is suspected.

The role of diffuse correlation spectroscopy and frequency-domain near-infrared spectroscopy in monitoring cerebral hemodynamics during hypothermic circulatory arrests.

OBJECTIVES: Real-time noninvasive monitoring of cerebral blood flow (CBF) during surgery is key to reducing mortality rates associated with adult cardiac surgeries requiring hypothermic circulatory arrest (HCA). We explored a method to monitor cerebral blood flow during different brain protection techniques using diffuse correlation spectroscopy (DCS), a noninvasive optical technique which, combined with frequency-domain near-infrared spectroscopy (FDNIRS), also provides a measure of oxygen metabolism. METHODS: We used DCS in combination with FDNIRS to simultaneously measure hemoglobin oxygen saturation (SO2), an index of cerebral blood flow (CBFi), and an index of cerebral metabolic rate of oxygen (CMRO2i) in 12 patients undergoing cardiac surgery with HCA. RESULTS: Our measurements revealed that a negligible amount of blood is delivered to the cerebral cortex during HCA with retrograde cerebral perfusion, indistinguishable from HCA-only cases (median CBFi drops of 93% and 95%, respectively) with consequent similar decreases in SO2 (mean decrease of 0.6 ± 0.1% and 0.9 ± 0.2% per minute, respectively); CBFi and SO2 are mostly maintained with antegrade cerebral perfusion; the relationship of CMRO2i to temperature is given by CMRO2i = 0.052e0.079T. CONCLUSIONS: FDNIRS-DCS is able to detect changes in CBFi, SO2, and CMRO2i with intervention and can become a valuable tool for optimizing cerebral protection during HCA.

Delayed cerebral ischemia causing cortical blindness due to repeat cocaine use weeks subsequent to aneurysmal subarachnoid hemorrhage.

Cocaine is a known vasoactive drug associated with poor clinical outcomes and high in-hospital mortality related to aneurysmal subarachnoid hemorrhage; however, the association of prior cocaine use with the incidence of vasospasm and delayed cerebral ischemia remains controversial. We report a case of a 42-year-old male with a history of active cocaine use who presented with a severe headache. Imaging demonstrated diffuse cisternal subarachnoid hemorrhage due to a ruptured basilar apex aneurysm, which was successfully treated with endovascular coil embolization. Despite expedited endovascular treatment and an initially benign clinical course, he suffered from delayed cerebral ischemia resulting in cortical blindness due to bilateral posterior cerebral artery vasospasm secondary to repeat cocaine use weeks after his initial ictus. To our knowledge, the present case is the first to describe delayed cerebral ischemia resulting in a severe neurologic deficit due to repeat cocaine use weeks subsequent to aneurysm rupture. We review the current literature on the association of cocaine use with the incidence of vasospasm and delayed cerebral ischemia as well as the effects of cocaine on the cerebrovasculature.

Indian National Association for the Study of the Liver Consensus Statement on Acute Liver Failure (Part 1): Epidemiology, Pathogenesis, Presentation and Prognosis.

Acute liver failure (ALF) is an infrequent, unpredictable, potentially fatal complication of acute liver injury (ALI) consequent to varied etiologies. Etiologies of ALF as reported in the literature have regional differences, which affects the clinical presentation and natural course. In this part of the consensus article designed to reflect the clinical practices in India, disease burden, epidemiology, clinical presentation, monitoring, and prognostication have been discussed. In India, viral hepatitis is the most frequent cause of ALF, with drug-induced hepatitis due to antituberculosis drugs being the second most frequent cause. The clinical presentation of ALF is characterized by jaundice, coagulopathy, and encephalopathy. It is important to differentiate ALF from other causes of liver failure, including acute on chronic liver failure, subacute liver failure, as well as certain tropical infections which can mimic this presentation. The disease often has a fulminant clinical course with high short-term mortality. Death is usually attributable to cerebral complications, infections, and resultant multiorgan failure. Timely liver transplantation (LT) can change the outcome, and hence, it is vital to provide intensive care to patients until LT can be arranged. It is equally important to assess prognosis to select patients who are suitable for LT. Several prognostic scores have been proposed, and their comparisons show that indigenously developed dynamic scores have an edge over scores described from the Western world. Management of ALF will be described in part 2 of this document.

Subarachnoid Hemorrhage "Fast Track": A Health Economics and Health Care Redesign Approach for Early Selected Hospital Discharge.

OBJECTIVE: To determine whether earlier hospital discharge is feasible and safe in selected patients with subarachnoid hemorrhage (SAH) using an outpatient "fast-track" protocol. PATIENTS AND METHODS: We conducted a prospective quality improvement cohort study with the primary feasibility end point of patients with SAH deemed safe for discharge by treating team consensus. All patients received detailed education and outpatient transcranial Doppler monitoring; caregivers could contact the on-call team 24-7. Primary safety end points were adverse events after discharge and hospital readmission. RESULTS: From January 1, 2010, to January 1, 2015, our center had 377 SAH diagnoses, of which 200 were included in the final cohort, 36 qualifying for fast-track early discharge. The 30-day readmission rate for fast-track patients was 11.0% (4 of 36) compared with 11.4% (18 of 164) for non-fast-track patients. The rate of delayed cerebral ischemia and stroke was 3% (1 of 36) in the fast-track group vs 25.0% (41 of 164) for the non-fast-track group. Adverse events occurred in 11.0% (4 of 36) of the fast-track group compared with 26.0% (43 of 164) in the non-fast-track group. The mean length of stay was reduced 60% from 15 days to 6.6 days in the fast-track group. CONCLUSION: Although our fast-track group was relatively small, data suggested early feasibility and safety in a carefully selected group of patients with SAH. Direct and indirect financial benefits of early discharge over a 5-year period were an estimated savings at least $864,000 in overall costs. A comparative effectiveness study is planned to replicate and validate these results using a larger multicenter design.

In vivo evaluation of urokinase-loaded hollow nanogels for sonothrombolysis on suture embolization-induced acute ischemic stroke rat model.

The urokinase-type plasminogen activator (uPA) loaded hollow nanogels (nUK) were synthesized by a one-step reaction of glycol chitosan and aldehyde capped poly (ethylene oxide). The resultant formulation is sensitive to diagnostic ultrasound (US) of 2 MHz. Herein, we evaluated the in vivo sonothrombolysis performance of the nUK on acute ischemic stroke rat model which was established by suture embolization of middle cerebral artery (MCA). Via intravenous (i.v.) administration, the experimental data prove a controlled release of the therapeutic protein around the clots under ultrasound stimulation, leading to enhanced thrombolysis efficiency of the nUK, evidenced from smaller infarct volume and better clinical scores when compared to the i.v. dose of free uPA no matter with or without US intervention. Meanwhile, the preservation ability of the nanogels not only prolonged the circulation duration of the protein, but also resulted in the better blood-brain barrier protection of the nUK formulation, showing no increased risk on the hemorrhagic transformation than the controls. This work suggests that the nUK is a safe sonothrombolytic formulation for the treatment of acute ischemic stroke.

The effects of chronic trans-resveratrol supplementation on aspects of cognitive function, mood, sleep, health and cerebral blood flow in healthy, young humans.

Single doses of resveratrol have previously been shown to increase cerebral blood flow (CBF) with no clear effect on cognitive function or mood in healthy adults. Chronic resveratrol consumption may increase the poor bioavailability of resveratrol or otherwise potentiate its psychological effects. In this randomised, double-blind, placebo-controlled, parallel-groups study, a total of sixty adults aged between 18 and 30 years received either placebo or resveratrol for 28 d. On the 1st and 28th day of treatment, the performance of cognitively demanding tasks (serial subtractions, rapid visual information processing and 3-Back) (n 41 complete data sets) was assessed, alongside blood pressure (n 26) and acute (near-IR spectroscopy (NIRS)) and chronic (transcranial Doppler) measures of CBF (n 46). Subjective mood, sleep quality and health questionnaires were completed at weekly intervals (n 53/54). The results showed that the cognitive effects of resveratrol on day 1 were restricted to more accurate but slower serial subtraction task performance. The only cognitive finding on day 28 was a beneficial effect of resveratrol on the accuracy of the 3-Back task before treatment consumption. Subjective ratings of 'fatigue' were significantly lower across the entire 28 d in the resveratrol condition. Resveratrol also resulted in modulation of CBF parameters on day 1, as assessed by NIRS, and significantly increased diastolic blood pressure on day 28. Levels of resveratrol metabolites were significantly higher both before and after the day's treatment on day 28, in comparison with day 1. These results confirm the acute CBF effects of resveratrol and the lack of interpretable cognitive effects.

Perioperative monitoring in liver transplant patients.

Liver transplant (LT) is a major surgical undertaking involving major fluid shifts, hemodynamic instability and metabolic derangements in a patient with preexisting liver failure and multisystemic derangements. Monitoring and organ support initiated in the preoperative phase is continued intraoperatively and into the postoperative phase to ensure an optimal outcome. As cardiovascular events are the leading cause of non-graft related death among LT recipients, major emphasis is placed on cardiovascular monitoring. The other essential monitoring are the continuous assessment of coagulapathy, extent of metabolic derangements, dyselectrolytemis and intracranial pressure monitoring in patients with fulminant hepatic failure. The type and extent of monitoring differs with need according to preexisting child status of the patient and the extent of systemic derangements. It also varies among transplant centers and is mainly determined by individual or institutional practices.