Spreading depolarizations (SD) are waves of abrupt, near-complete breakdown of neuronal transmembrane ion gradients, are the largest possible pathophysiologic disruption of viable cerebral gray matter, and are a crucial mechanism of lesion development. Spreading depolarizations are increasingly recorded during multimodal neuromonitoring in neurocritical care as a causal biomarker providing a diagnostic summary measure of metabolic failure and excitotoxic injury. Focal ischemia causes spreading depolarization within minutes. Further spreading depolarizations arise for hours to days due to energy supply-demand mismatch in viable tissue. Spreading depolarizations exacerbate neuronal injury through prolonged ionic breakdown and spreading depolarization-related hypoperfusion (spreading ischemia). Local duration of the depolarization indicates local tissue energy status and risk of injury. Regional electrocorticographic monitoring affords even remote detection of injury because spreading depolarizations propagate widely from ischemic or metabolically stressed zones; characteristic patterns, including temporal clusters of spreading depolarizations and persistent depression of spontaneous cortical activity, can be recognized and quantified. Here, we describe the experimental basis for interpreting these patterns and illustrate their translation to human disease. We further provide consensus recommendations for electrocorticographic methods to record, classify, and score spreading depolarizations and associated spreading depressions. These methods offer distinct advantages over other neuromonitoring modalities and allow for future refinement through less invasive and more automated approaches.

Background: We aimed to assess whether distinct lifestyle strategies can differentially affect specific body adipose depots. Methods: We performed an 18-month randomized controlled trial among 278 sedentary adults with abdominal obesity (75%) or dyslipidemia in an isolated workplace with a monitored provided lunch. Participants were randomized to isocaloric low-fat or Mediterranean/low-carbohydrate (MED/LC) diet+28 g walnuts/day with/without added moderate physical activity (PA; 80% aerobic; supervised/free gym membership). Overall primary outcome was body fat redistribution, and the main specific end point was visceral adipose tissue (VAT). We further followed the dynamics of different fat depots (deep and superficial subcutaneous, liver, pericardial, muscle, pancreas, and renal sinus) by magnetic resonance imaging. Results: Of 278 participants (age, 48 years, 89% men, body mass index, 30.8 kg/m ² ), 86% completed the trial with good adherence. The low-fat group preferentially decreased reported fat intake (−21.0% versus −11.5% for the MED/LC; P <0.001), and the MED/LC group decreased reported carbohydrates intake (−39.5% versus −21.3% for the low-fat group; P <0.001). The PA ⁺ groups significantly increased the metabolic equivalents per week versus the PA ⁻ groups (19.0 versus 2.1; P =0.009). Whereas final moderate weight loss was indifferent, exercise attenuated the waist circumference rebound with the greatest effect in the MED/LC ^PA+ group ( P <0.05). VAT (−22%), intrahepatic (−29%), and intrapericardial (−11%) fats declines were higher than pancreatic and femur intermuscular fats (1% to 2%) loss. Independent of weight loss, PA ⁺ with either diet had a significantly greater effect on decreasing VAT (mean of difference, −6.67cm ² ; 95% confidence interval, −14.8 to −0.45) compared with PA ⁻ . The MED/LC diet was superior to the low-fat diet in decreasing intrahepatic, intrapericardial, and pancreatic fats ( P <0.05 for all). In contrast, renal sinus and femoral intermuscular fats were not differentially altered by lifestyle interventions but by weight loss per se. In multivariate models further adjusted for weight loss, losing VAT or intrahepatic fat was independently associated with improved lipid profile, losing deep subcutaneous adipose tissue with improved insulin sensitivity, and losing superficial subcutaneous adipose tissue remained neutral except for an association with decreased leptin. Conclusions: Moderate weight loss alone inadequately reflects the significant lifestyle effects on atherogenic and diabetogenic fat depots. The MED/LC diet mobilizes specific ectopic fat depots, and exercise has an independent contribution to VAT loss. Fat depots exhibit diverse responsiveness and are differentially related to cardiometabolic markers. Distinct lifestyle protocols may uniquely induce fat mobilization from specific anatomic sites. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01530724.

Background: Traumatic brain injury (TBI) is an important cause of focal epilepsy. Animal experiments indicate that disruption of the blood–brain barrier (BBB) plays a critical role in the pathogenesis of post-traumatic epilepsy (PTE). Objective: To investigate the frequency, extent and functional correlates of increased BBB permeability in patient with PTE. Methods: 32 head trauma patients were included in the study, with 17 suffering from PTE. Patients underwent brain MRI (bMRI) and were evaluated for BBB disruption, using a novel semi-quantitative technique. Cortical dysfunction was measured using electroencephalography (EEG), and localised using standardised low-resolution brain electromagnetic tomography (sLORETA). Results: Spectral EEG analyses revealed significant slowing in patients with TBI, with no significant differences between patients with epilepsy and those without. Although bMRI revealed that patients with PTE were more likely to present with intracortical lesions (p = 0.02), no differences in the size of the lesion were found between the groups (p = 0.19). Increased BBB permeability was found in 76.9% of patients with PTE compared with 33.3% of patients without epilepsy (p = 0.047), and could be observed years following the trauma. Cerebral cortex volume with BBB disruption was larger in patients with PTE (p = 0.001). In 70% of patients, slow (delta band) activity was co-localised, by sLORETA, with regions showing BBB disruption. Conclusions: Lasting BBB pathology is common in patients with mild TBI, with increased frequency and extent being observed in patients with PTE. A correlation between disrupted BBB and abnormal neuronal activity is suggested.

Recent animal experiments indicate a critical role for opening of the blood-brain barrier (BBB) in the pathogenesis of post-traumatic epilepsy (PTE). This study aimed to investigate the frequency, extent, and functional correlates of BBB disruption in epileptic patients following mild traumatic brain injury (TBI). Thirty-seven TBI patients were included in this study, 19 of whom suffered from PTE. All underwent electroencephalographic (EEG) recordings and brain magnetic resonance imaging (bMRI). bMRIs were evaluated for BBB disruption using novel quantitative techniques. Cortical dysfunction was localized using standardized low-resolution brain electromagnetic tomography (sLORETA). TBI patients displayed significant EEG slowing compared to controls with no significant differences between PTE and nonepileptic patients. BBB disruption was found in 82.4% of PTE compared to 25% of non-epileptic patients (P=.001) and could be observed even years following the trauma. The volume of cerebral cortex with BBB disruption was significantly larger in PTE patients (P=.001). Slow wave EEG activity was localized to the same region of BBB disruption in 70% of patients and correlated to the volume of BBB disrupted cortex. We finally present a patient suffering from early cortical dysfunction and BBB breakdown with a gradual and parallel resolution of both pathologies. Our findings demonstrate that BBB pathology is frequently found following mild TBI. Lasting BBB breakdown is found with increased frequency and extent in PTE patients. Based on recent animal studies and the colocalization found between the region of disrupted BBB and abnormal EEG activity, we suggest a role for a vascular lesion in the pathogenesis of PTE.