Pathological Substrate Research Articles

Mechanistic Intimate Insights into the Role of Hydrogen Sulfide in Alzheimer's Disease: A Recent Systematic Review.

In the rapidly evolving field of Alzheimer's Disease (AD) research, the intricate role of Hydrogen Sulfide (H2S) has garnered critical attention for its diverse involvement in both pathological substrates and prospective therapeutic paradigms. While conventional pathophysiological models of AD have primarily emphasized the significance of amyloid-beta (Aβ) deposition and tau protein hyperphosphorylation, this targeted systematic review meticulously aggregates and rigorously appraises seminal contributions from the past year elucidating the complex mechanisms of H2S in AD pathogenesis. Current scholarly literature accentuates H2S's dual role, delineating its regulatory functions in critical cellular processes-such as neurotransmission, inflammation, and oxidative stress homeostasis-while concurrently highlighting its disruptive impact on quintessential AD biomarkers. Moreover, this review illuminates the nuanced mechanistic intimate interactions of H2S in cerebrovascular and cardiovascular pathology associated with AD, thereby exploring avant-garde therapeutic modalities, including sulfurous mineral water inhalations and mud therapy. By emphasizing the potential for therapeutic modulation of H2S via both donors and inhibitors, this review accentuates the imperative for future research endeavors to deepen our understanding, thereby potentially advancing novel diagnostic and therapeutic strategies in AD.

Association of MRI leptomeningeal enhancement with disability worsening in progressive multiple sclerosis: A clinical and post-mortem study

Background: Leptomeningeal enhancement (LME) has been described as a biomarker of meningeal inflammation in multiple sclerosis (MS). Objective: The aim of this study was to (1) assess if LME is predictive of disability worsening in progressive MS (pMS) patients and (2) investigate the pathological substrates of LME in an independent post-mortem MS series. Methods: In total, 115 pMS patients were imaged yearly with 1.5T MRI, using post-contrast CUBE 3D FLAIR for LME detection. Endpoint: to identify the baseline variables predictive of confirmed disability worsening (CDW) at 24 months follow-up. Post-mortem, inflammation, and structural changes of the leptomeninges were assessed in 12 MS/8 control brains. Results: LME (27% of patients at baseline) was associated with higher EDSS and lower brain volume (nBV). LME was unchanged in most patients over follow-up. LME at baseline MRI was independently associated with higher risk of 24 months CDW (HR 3.05, 95% CI 1.36–6.84, p = 0.007) in a Cox regression, including age, nBV, T2 lesion volume, high-efficacy treatments, and MRI disease activity. Post-mortem, focal structural changes (fibrosis) of the leptomeninges were observed in MS, usually associated with inflammation (Kendall’s Tau 0.315, p < 0.0001). Conclusions: LME is frequently detected in pMS patients using 1.5T MRI and is independently predictive of disability progression. LME could result from both focal leptomeningeal post-inflammatory fibrosis and inflammation.

MRI features of neuronal intranuclear inclusion disease, combining visual and quantitative imaging investigations

ObjectiveTo observe the radiological characteristics of Neuronal Intranuclear Inclusion Disease (NIID) on lesion locations and diffusion property using quantitative imaging analysis. MethodsVisual inspection and quantitative analyses were performed on MRI data from 31 retrospectively included patients with NIID. Frequency heatmaps of lesion locations on T2WI and DWI were generated using voxel-wise analysis. Gray matter volume (GMV), white matter volume (WMV) and diffusion property of apparent diffusion coefficient (ADC) values of patients were voxel-wisely compared with healthy controls. Moreover, the ADC values within the DWI-detected lesion were compared with those within the adjacent cortical gray matter and white matter. Voxel-based lesion symptom mapping (VLSM) techniques, were used to determine the relationship between DWI lesion location and disease durations. ResultsBy visual inspection on the imaging findings, we proposed an “cockscomb flower sign” for describing the radiological feature of DWI hyperintensity within the corticomedullary junction. A “T2WI-DWI mismatch of spatial distribution” pattern was also revealed with visual inspection and frequency heatmaps, for describing the feature of a wider lesion distribution covering white matter shown on T2WI than that on DWI. Voxel-based morphometry comparison revealed that wildly reduced GMV and WMV, both the lesion areas detected by DWI and T2WI demonstrated ADC increase in patients. Furthermore, the ADC values within the DWI-detected lesion were intermediate between the adjacent cortex and the deep white matter with highest ADC. VLSM analysis revealed that frontal lobe, parietal lobe and internal capsule damage were associated with higher NIID durations. ConclusionNIID features with “cockscomb flower-like” DWI hyperintensity in area of corticomedullary junction, based on a “T2WI-DWI mismatch of spatial distribution” of lesion locations. The pathological substrate of corticomedullary junction hyperintensity on DWI, can not be explained as diffusion restriction. These typical radiological features of brain MRI would be helpful for diagnosis of NIID.

Basis of movement control in dystonia and why botulinum toxin should influence it?

Dystonia is a network disorder involving multiple brain regions, such as the motor cortex, sensory cortex, basal ganglia, and cerebellum. Botulinum toxin (BoNT) is the first-line therapy for treating focal dystonia and is a potent molecule that blocks the release of acetylcholine at the peripheral neuromuscular junction. However, the clinical benefits of BoNT are not solely related to peripheral muscle relaxation or modulation of afferent input from the muscle spindle. An increasing body of evidence, albeit in smaller cohorts, has shown that BoNT leads to distant modulation of the pathological brain substrates implicated in dystonia. A single treatment session of BoNT has been observed to reduce excessive motor excitability and improve sensory processing. Furthermore, owing to plasticity effects that are induced by botulinum, neural reorganization of pathological networks occurs, presumably leading to defective motor programs of dystonia replaced with normal movement patterns. However, longitudinal studies investigating the effects of multiple treatment sessions in large, well-characterized homogenous cohorts of dystonia will provide further compelling evidence supporting central botulinum mechanisms.

Differences in atrial substrate localization using late gadolinium enhancement-magnetic resonance imaging, electrogram voltage, and conduction velocity: a cohort study using a consistent anatomical reference frame in patients with persistent atrial fibrillation.

Electro-anatomical voltage, conduction velocity (CV) mapping, and late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) have been correlated with atrial cardiomyopathy (ACM). However, the comparability between these modalities remains unclear. This study aims to (i) compare pathological substrate extent and location between current modalities, (ii) establish spatial histograms in a cohort, (iii) develop a new estimated optimized image intensity threshold (EOIIT) for LGE-MRI identifying patients with ACM, (iv) predict rhythm outcome after pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF). Thirty-six ablation-naive persistent AF patients underwent LGE-MRI and high-definition electro-anatomical mapping in sinus rhythm. Late gadolinium enhancement areas were classified using the UTAH, image intensity ratio (IIR >1.20), and new EOIIT method for comparison to low-voltage substrate (LVS) and slow conduction areas <0.2 m/s. Receiver operating characteristic analysis was used to determine LGE thresholds optimally matching LVS. Atrial cardiomyopathy was defined as LVS extent ≥5% of the left atrium (LA) surface at <0.5 mV. The degree and distribution of detected pathological substrate (percentage of individual LA surface are) varied significantly (P < 0.001) across the mapping modalities: 10% (interquartile range 0-14%) of the LA displayed LVS <0.5 mV vs. 7% (0-12%) slow conduction areas <0.2 m/s vs. 15% (8-23%) LGE with the UTAH method vs. 13% (2-23%) using IIR >1.20, with most discrepancies on the posterior LA. Optimized image intensity thresholds and each patient's mean blood pool intensity correlated linearly (R2 = 0.89, P < 0.001). Concordance between LGE-MRI-based and LVS-based ACM diagnosis improved with the novel EOIIT applied at the anterior LA [83% sensitivity, 79% specificity, area under the curve (AUC): 0.89] in comparison to the UTAH method (67% sensitivity, 75% specificity, AUC: 0.81) and IIR >1.20 (75% sensitivity, 62% specificity, AUC: 0.67). Discordances in detected pathological substrate exist between LVS, CV, and LGE-MRI in the LA, irrespective of the LGE detection method. The new EOIIT method improves concordance of LGE-MRI-based ACM diagnosis with LVS in ablation-naive AF patients but discrepancy remains particularly on the posterior wall. All methods may enable the prediction of rhythm outcomes after PVI in patients with persistent AF.

Reciprocal regulation between the molecular clock and kidney injury.

Tubulointerstitial fibrosis is the common pathological substrate for many etiologies leading to chronic kidney disease. Although perturbations in the circadian rhythm have been associated with renal disease, the role of the molecular clock in the pathogenesis of fibrosis remains incompletely understood. We investigated the relationship between the molecular clock and renal damage in experimental models of injury and fibrosis (unilateral ureteral obstruction, folic acid, and adenine nephrotoxicity), using genetically modified mice with selective deficiencies of the clock components Bmal1, Clock, and Cry We found that the molecular clock pathway was enriched in damaged tubular epithelial cells with marked metabolic alterations. In human tubular epithelial cells, TGFβ significantly altered the expression of clock components. Although Clock played a role in the macrophage-mediated inflammatory response, the combined absence of Cry1 and Cry2 was critical for the recruitment of neutrophils, correlating with a worsening of fibrosis and with a major shift in the expression of metabolism-related genes. These results support that renal damage disrupts the kidney peripheral molecular clock, which in turn promotes metabolic derangement linked to inflammatory and fibrotic responses.

Comprehensive pathological and genetic investigation of three young adult myotonic dystrophy type 1 patients with sudden unexpected death.

The mechanism and pathological substrate of arrhythmogenic events in dystrophic myopathy type 1 (DM1) have not been fully established, especially for patients without progression of motor and/or cardiac disability. Therefore, we aimed to clarify the pathological appearance and genetic factors, other than CTG repeats in DMPK, associated with sudden cardiac death in patients with DM1. A pathological investigation including the cardiac conduction system in the heart and whole-exome sequencing was conducted for three young adults (Patient 1; 25-year-old female, Patient 2; 35-year-old female, Patient 3; 18-year-old male) with DM1 who suffered sudden death. Only Patient 1 showed abnormal electrocardiogram findings before death. The pathological investigation showed severe fibrosis of the atrioventricular conduction system in Patient 1 and severe fatty infiltration in the right ventricle in Patient 2. Several minimal necrotic/inflammatory foci were found in both patients. Patient 3 showed no significant pathological findings. A genetic investigation showed CORIN_p.W813* and MYH2_p. R793* in Patient 1, KCNH2_p. V794D and PLEC_p. A4147T in Patient 2, and SCN5A_p.E428K and SCN3B_ p.V145L in Patient 3 as highly possible pathogenic variants. The present study showed varied heart morphology in young adults with DM1 and sudden death. Synergistic effects of various genetic factors other than CTG repeats may increase the risk of sudden cardiac death in DM1 patients, even if signs of cardiac and skeletal muscle involvement are mild. Comprehensive genetic investigations, other than CTG repeat assessment, may be useful to estimate the risk of sudden cardiac death in DM1 patients.

Charting the Next Road Map for CSF Biomarkers in Alzheimer's Disease and Related Dementias.

Clinical prediction of underlying pathologic substrates in people with Alzheimer's disease (AD) dementia or related dementia syndromes (ADRD) has limited accuracy. Etiologic biomarkers - including cerebrospinal fluid (CSF) levels of AD proteins and cerebral amyloid PET imaging - have greatly modernized disease-modifying clinical trials in AD, but their integration into medical practice has been slow. Beyond core CSF AD biomarkers (including beta-amyloid 1-42, total tau, and tau phosphorylated at threonine 181), novel biomarkers have been interrogated in single- and multi-centered studies with uneven rigor. Here, we review early expectations for ideal AD/ADRD biomarkers, assess these goals' future applicability, and propose study designs and performance thresholds for meeting these ideals with a focus on CSF biomarkers. We further propose three new characteristics: equity (oversampling of diverse populations in the design and testing of biomarkers), access (reasonable availability to 80% of people at risk for disease, along with pre- and post-biomarker processes), and reliability (thorough evaluation of pre-analytical and analytical factors influencing measurements and performance). Finally, we urge biomarker scientists to balance the desire and evidence for a biomarker to reflect its namesake function, indulge data- as well as theory-driven associations, re-visit the subset of rigorously measured CSF biomarkers in large datasets (such as Alzheimer's disease neuroimaging initiative), and resist the temptation to favor ease over fail-safe in the development phase. This shift from discovery to application, and from suspended disbelief to cogent ingenuity, should allow the AD/ADRD biomarker field to live up to its billing during the next phase of neurodegenerative disease research.

Nigral Pathology Contributes to Microstructural Integrity of Striatal and Frontal Tracts in Parkinson's Disease.

Motor and cognitive impairment in Parkinson's disease (PD) is associated with dopaminergic dysfunction that stems from substantia nigra (SN) degeneration and concomitant α-synuclein accumulation. Diffusion magnetic resonance imaging (MRI) can detect microstructural alterations of the SN and its tracts to (sub)cortical regions, but their pathological sensitivity is still poorly understood. To unravel the pathological substrate(s) underlying microstructural alterations of SN, and its tracts to the dorsal striatum and dorsolateral prefrontal cortex (DLPFC) in PD. Combining post-mortem in situ MRI and histopathology, T1-weighted and diffusion MRI, and neuropathological samples of nine PD, six PD with dementia (PDD), five dementia with Lewy bodies (DLB), and 10 control donors were collected. From diffusion MRI, mean diffusivity (MD) and fractional anisotropy (FA) were derived from the SN, and tracts between the SN and caudate nucleus, putamen, and DLPFC. Phosphorylated-Ser129-α-synuclein and tyrosine hydroxylase immunohistochemistry was included to quantify nigral Lewy pathology and dopaminergic degeneration, respectively. Compared to controls, PD and PDD/DLB showed increased MD of the SN and SN-DLPFC tract, as well as increased FA of the SN-caudate nucleus tract. Both PD and PDD/DLB showed nigral Lewy pathology and dopaminergic loss compared to controls. Increased MD of the SN and FA of SN-caudate nucleus tract were associated with SN dopaminergic loss. Whereas increased MD of the SN-DLPFC tract was associated with increased SN Lewy neurite load. In PD and PDD/DLB, diffusion MRI captures microstructural alterations of the SN and tracts to the dorsal striatum and DLPFC, which differentially associates with SN dopaminergic degeneration and Lewy neurite pathology. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Assessing neuroinflammatory differences in FTLD‐Tau vs FTLD‐TDP using free water diffusion

AbstractBackgroundFrontotemporal lobar degeneration (FTLD) is associated with two pathological substrates: Tau and TAR‐DNA‐binding protein 43 (TDP‐43). In‐vivo detection of the pathological substrate is still not possible in FTLD‐related syndromes but progressive supranuclear palsy (PSP) is consistently associated with FTLD‐Tau while semantic‐variant primary progressive aphasia (svPPA) and FTD‐MND (FTD‐ALS) are associated with FTLD‐TDP. In the absence of disease‐specific markers in FTLD, it is necessary to identify biomarkers that can help distinguish FTLD‐Tau and FTLD‐TDP. Recent research has implicated neuroinflammation as a common feature across FTLD subtypes (Bright et al., 2019), however further research is required to investigate neuroinflammatory differences between FTLD‐Tau and FTLD‐TDP, given that microglial burden and activation may differ in FTLD subtypes (Woollacott et al., 2020). The free water fraction (FW), a metric generated from diffusion MRI (dMRI) (Pasternak et al., 2009), is a non‐specific marker of neuroinflammation (Bergamino, Walsh and Stokes, 2021). We will investigate differences in FW diffusion between patients with presumed FTLD‐Tau versus FTLD‐TDP. We hypothesize that differences in neuroinflammation between FTLD‐Tau and FTLD‐TDP can be identified using the free water measure, which may infer neuroinflammatory differences.MethodFree‐water maps were generated from dMRI datasets obtained from 43 subjects: 19 with presumed FTLD‐Tau (PSP, mean age = 70), 6 with presumed FTLD‐TDP (mean age = 67, 4 svPPA, 2 FTD‐ALS), and 19 healthy controls (mean age 63). Grey matter (GM) was segmented from T1‐weighted MRIs using FSL’s ‘fast’, projected onto the diffusion MRI space, where free‐water maps were averaged across the GM. The average free water estimates from FTLD‐Tau, FTLD‐TDP and control datasets were tested for group differences using student’s t‐tests and analysis of covariance (ANCOVA), with age as a covariate.ResultsANCOVA revealed significant differences between the groups (F = 6.47, p &lt; 0.01). Post‐hoc tests showed significantly higher free‐water in FTLD‐Tau (p&lt;0.01) and FTLD‐TDP (p&lt;0.01) compared to controls. There was also higher free water in FTLD‐TDP in comparison to FTLD‐Tau, approaching significance (p = 0.0503)ConclusionOur preliminary data shows significant differences between healthy controls and patients with FTLD‐Tau and FTLD‐TDP and a trend for increased free water in FTLD‐TDP patients vs FTLD‐Tau, which may be indicative of neuroinflammatory differences.

New insight in epicardial ablations: 3D-printed additive manufacturing as intra-procedural diagnostic and operative tool

Abstract Funding Acknowledgements Type of funding sources: None. Background The feasibility of additive manufacturings (AMs) as peri-procedural tools has already been established. In order to extend their use to intra-procedural tools for surgical, interventional, or electrophysiology procedures, AMs must be able to convey specific data from cardiac imaging and to come into contact with both biological tissue and energy sources. Methods A resin (MED625FLX) and a urethane thermoplastic elastomer (TPU) were chosen as materials for AMs, printed in a variety of thicknesses and configurations. Geometry test was conducted to compare the properties of materials before and after sterilization. In-vitro test was carried out in a wet lab to validate the safety related to propagation of energy underneath the material during application of power sources; three different sources (cryothermal, bipolar radiofrequency, unipolar radiofrequency) were tested. The release of debris derived from the AM on the biological tissue was verified both with electron microscopy and Raman spectroscopy. Results Geometries below 1 mm and above 2.5 mm did not pass the test after sterilization for both materials. A total of 100 energy applications were delivered during in-vitro testing. Temperature was kept constant. The type of material used for the AM, the energy-type delivered and the factorial combination of distance/material and distance/energy-type had a significant p-value for temperature changes on the tissue underneath the AM (Temperature*Material p=0,003; Temperature*Energy p&amp;lt;0,001; Temperature*Material*Position p=0,02; Temperature*Position*Energy p&amp;lt;0,001). Post-hoc test using Dunn's procedure showed significant p-values for distance (Temperature*Position p&amp;lt;.001) and energy-type erogated (Temperature*Energy*Cryo-biRF p&amp;lt;.001; Temperature*Energy*Cryo-uniRF p&amp;lt;.001; Temperature*Energy*biRF-uniRF p&amp;lt;.001), while there were no significant differences of temperature in relation to AM thickness and material. Raman spectroscopy on biological tissues revealed that no AM particles &amp;gt;1μm were released. Conclusions The use of AMs in intra-operative cardiac procedures may be feasible and safe, and it can be employed as a reliable integration of cardiological imaging into tangible localisation of certain specific structures or pathological substrates.

Electroanatomic mapping in athletes: Why and when. An expert opinion paper from the Italian Society of Sports Cardiology

Three-dimensional electroanatomical mapping (EAM) has the potential to identify the pathological substrate underlying ventricular arrhythmias (VAs) in different clinical settings by detecting myocardial areas with abnormally low voltages, which reflect the presence of different cardiomyopathic substrates. In athletes, the added value of EAM may be to enhance the efficacy of third-level diagnostic tests and cardiac magnetic resonance (CMR) in detecting concealed arrhythmogenic cardiomyopathies. Additional benefits of EAM in the athlete include the potential impact on disease risk stratification and the consequent implications for eligibility to competitive sports. This opinion paper of the Italian Society of Sports Cardiology aims to guide general sports medicine physicians and cardiologists on the clinical decision when to eventually perform an EAM study in the athlete, highlighting strengths and weaknesses for each cardiovascular disease at risk of sudden cardiac death during sport. The importance of early (preclinical) diagnosis to prevent the negative effects of exercise on phenotypic expression, disease progression, and worsening of the arrhythmogenic substrate is also addressed.

Pathomorphology of cutaneous mastocytosis

Introduction. Mastocytosis as a result of mast cell infiltration of the skin and other organs develops at any age. The relevance of this work is determined by the lack of systematic data on the pathomorphological features of the clinical forms and types of cutaneous mastocytosis, defined by the Consensus European-American Mastocytosis Group and the WHO classification in 2016. The variability of dermatological clinical manifestations in children and adults, the difficulties in interpreting laboratory tests create a problem for verifying the diagnosis and further treatment. The aim. To determine the main pathohistological features of clinical forms and types of cutaneous mastocytosis. Material and methods. The article includes data from patients who were treated and monitored at the Moscow Scientific and Practical Center of Dermatovenereology and Cosmetology in 2019–2022. Results. The literature and own data on the characteristic pathomorphological patterns that are important for the diagnosis of mastocytosis with skin lesions in children and adults are systematized. The pathological substrate of lesions in diffuse cutaneous mastocytosis and mastocytoma was a massive infiltrate of mast cells in the papillary and reticular layers of the dermis. The histological picture in the monomorphic type of maculopapular cutaneous mastocytosis (MPCM) in children was characterized by a relatively lower density of mast cell infiltration of the papillary dermis compared to other clinical forms of mastocytosis. Also, in children, the density of mast cells in the affected skin was significantly higher compared to adults. In addition, in adults with PPCM, the papillary dermis was less infiltrated with mast cells. This confirms the opinion that the monomorphic type of MPCM in children is phenotypically similar to MPCM in adults. Conclusions. Further prospective follow-up of patients may allow conclusions to be drawn about the prognostic value of pathological examination in mastocytosis in adults and children.

Uric acid significantly correlates with the presence of low-voltage areas at the endocardial mapping in patients with non-valvular atrial fibrillation

Background and aimsInterest in the role of atrial substrate in maintaining Atrial Fibrillation (AF) is growing. Fibrosis is the culprit in the electrical derangement of the myocytes. Many cardiovascular risk factors are known to be linked to atrial scarring; among them Uric Acid (UA) is emerging. The purpose of our study is to find whether UA is associated with Left Atrium (LA) with pathological substrate. Methods and results81 patients who underwent radiofrequency transcatheter ablation for nonvalvular AF at the cardiological department of the Niguarda Hospital were enrolled in an observational, cross-sectional, single-center study. UA levels were analysed before the procedure. High density electroanatomic mapping of the LA was performed and patients were divided according to the presence or not of areas of pathological substrate (bipolar voltage <0.5 mV in sinus rhythm). 19 patients showed a LA with pathological substrate. These subjects showed a significant higher prevalence of persistent phenotype of AF (84.2 vs. 25.8%, p < 0.001). UA levels were significantly higher in the group of patients with LA with pathological substrate (6.8 ± 1.9 vs 5.3 ± 1.4 mg/dL, p < 0.001) as well as the prevalence of hyperuricemia (26.5 vs. 6.5%, p = 0.021). The association between uric acid LA with pathological substrate remains significant even after correction for confounding factors (age, left ventricular dysfunction, valvular disease, arrythmia phenotype and furosemide use) and also when the ratio UA/creatinine was evaluated. ConclusionsIn a population of patients who underwent AF ablation, higher UA levels were significantly associated with pathological LA substrate at electro-anatomical mapping.

MR guided cardiac ablation: how to build an interventional magnetic resonance suite and what's the role of the imaging.

Magnetic resonance (MR) represents a new interesting imaging approach for guiding electrophysiology (EP)-based ablation procedures of atrial flutter and typical atrial fibrillation. This new approach permits to reach good results if compared with conventional EP ablation. Tissue characterization by MR permits to detect cardiac anatomy and pathological substrate like myocardial scars well visualized with late gadolinium enhancement (LGE) sequences. Intra-procedural imaging is useful to real-time follow the catheter during the ablation procedure and at the same time to visualize cardiac anatomy in addition to understanding if the ablation is correctly performed using oedema sequences. Performing cardiac ablations inside an MR room permits to reduce radiation exposure and occupational illnesses.

Spontaneous coronary artery dissection: an unpredictable event.

Spontaneous coronary artery dissection (SCAD) is an under-recognized cause of acute coronary syndrome that predominantly affects women in adulthood and is the leading cause of acute myocardial infarction in pregnancy. The most common clinical presentation is ST-segment elevation myocardial infarction (STEMI) or non-STEMI, followed by cardiogenic shock (∼2%), sudden cardiac death (0.8% in autopsy series), cardiac arrest, ventricular arrhythmias (∼5%), and Takotsubo syndrome. The prevalence of SCAD in the general population is largely uncertain due to underdiagnosis. Oral contraceptives, post-menopausal therapy, and infertility treatments are recognized associated factors. The pathological substrates (fibromuscular dysplasia) and triggers (especially emotional stress) are commonly present in affected women. The few cases with a precise genetic aetiology occur in the context of syndromic and non-syndromic connective tissue diseases. The only true certainty in SCAD is the overwhelming prevalence in women. The first event as well as the recurrence (up to 30%, which varies depending on the definition) is largely unpredictable. The treatment strategy is highly individualized and requires extensive additional study in order to optimize outcomes and prevent major adverse cardiovascular events in affected individuals. We have known about SCAD for nearly a century, but we still do not know how best to prevent, diagnose, and treat it, making SCAD a highly important and unmet clinical need.

Ablation of ventricular arrhythmias in cardiogenetic diseases.

Sudden cardiac death is a leading cause of mortality, claiming millions of lives every year. Recent advances in cardiac arrhythmia mapping have demonstrated that the ventricular epicardial region has a critical arrhythmogenic role in some inherited cardiogenetic diseases. Historically, electroanatomic abnormalities have been identified in the ventricular epicardium of patients with arrhythmogenic right ventricular cardiomyopathy. More recently, epicardial pathological substrates have been identified also in electrical disease (Brugada syndrome, early repolarization syndrome) and currently in long QT syndrome. In light of these findings, the epicardial area has emerged as an important determinant in sudden cardiac death-related cardiomyopathies.

Reversible Apical Hypertrophy in a Young Competitive Athlete with Familiar Hypertrophic Cardiomyopathy.

BACKGROUND Differential diagnosis between athlete's heart and hypertrophic cardiomyopathy is sometimes challenging in sport cardiology since endurance training can cause a distinct pattern of functional and structural changes of the cardiovascular system. It is of crucial importance to accurately diagnose it and stratify the arrhythmic risk since hypertrophic cardiomyopathy is one of the leading causes of sudden cardiac death in young athletes. Apical hypertrophic cardiomyopathy is a relatively rare form of hypertrophic cardiomyopathy that predominantly affects the apex of the left ventricle and usually has a nonobstructive physiology. Few data and studies are available on influence of aerobic training (and detraining) on morphological changes in athletes with apical hypertrophic cardiomyopathy. CASE REPORT We present the case of a 19-year-old male soccer athlete with family history for obstructive hypertrophic cardiomyopathy, with electrocardiographic and morphological left ventricular remodeling in association with sports activity. Intensive aerobic training led to marked T-wave inversion on 12-lead ECG and left ventricular hypertrophy compatible with apical hypertrophic cardiomyopathy. Genetic testing confirmed the presence of familial variant c853C>T, p.(Arg 285Cys) on TNNT2 gene. After 18 months detraining, we observed a complete regression of ECG abnormalities and a reverse remodeling of the left ventricular hypertrophy. No pharmacological therapy was indicated; periodic cardiological evaluations were advised. Monitoring devices or implantable cardioverter defibrillator were not recommended. CONCLUSIONS This case suggests that intensive aerobic training can affect the pathological hypertrophic cardiomyopathy substrate, facilitating the development of left ventricular hypertrophy and, more interesting, regression of structural changes after detraining.

Therapeutic potential of blocking GAPDH nitrosylation with CGP3466b in experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is a neuroinflammatory disease of the central nervous system (CNS). Although classically considered a demyelinating disease, neuroaxonal injury occurs in both the acute and chronic phases and represents a pathologic substrate of disability not targeted by current therapies. Nitric oxide (NO) generated by CNS macrophages and microglia contributes to neuroaxonal injury in all phases of MS, but candidate therapies that prevent NO-mediated injury have not been identified. Here, we demonstrate that the multifunctional protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is robustly nitrosylated in the CNS in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. GAPDH nitrosylation is blocked in vivo with daily administration of CGP3466b, a CNS-penetrant compound with an established safety profile in humans. Consistent with the known role of nitrosylated GAPDH (SNO-GAPDH) in neuronal cell death, blockade of SNO-GAPDH with CGP3466b attenuates neurologic disability and reduces axonal injury in EAE independent of effects on the immune system. Our findings suggest that SNO-GAPDH contributes to neuroaxonal injury during neuroinflammation and identify CGP3466b as a candidate neuroprotective therapy in MS.

Early suppression of excitability in subcortical band heterotopia modifies epileptogenesis in rats

Malformations of cortical development represent a major cause of epilepsy in childhood. However, the pathological substrate and dynamic changes leading to the development and progression of epilepsy remain unclear. Here, we characterized an etiology-relevant rat model of subcortical band heterotopia (SBH), a diffuse type of cortical malformation associated with drug-resistant seizures in humans. We used longitudinal electrographic recordings to monitor the age-dependent evolution of epileptiform discharges during the course of epileptogenesis in this model. We found both quantitative and qualitative age-related changes in seizures properties and patterns, accompanying a gradual progression towards a fully developed seizure pattern seen in adulthood. We also dissected the relative contribution of the band heterotopia and the overlying cortex to the development and age-dependent progression of epilepsy using timed and spatially targeted manipulation of neuronal excitability. We found that an early suppression of neuronal excitability in SBH slows down epileptogenesis in juvenile rats, whereas epileptogenesis is paradoxically exacerbated when excitability is suppressed in the overlying cortex. However, in rats with active epilepsy, similar manipulations of excitability have no effect on chronic spontaneous seizures. Together, our data support the notion that complex developmental alterations occurring in both the SBH and the overlying cortex concur to creating pathogenic circuits prone to generate seizures. Our study also suggests that early and targeted interventions could potentially influence the course of these altered developmental trajectories, and favorably modify epileptogenesis in malformations of cortical development.