Mario Habek, Alessandra Fanciulli, Magdalena Krbot Skorić, Roland D Thijs
{"title":"Rome was not built in a day, nor is a resilient clinical autonomic care unit.","authors":"Mario Habek, Alessandra Fanciulli, Magdalena Krbot Skorić, Roland D Thijs","doi":"10.1007/s10286-026-01208-1","DOIUrl":"10.1007/s10286-026-01208-1","url":null,"abstract":"","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"401-403"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147590351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taylor B Crouch, Maggie Nguyen, Mary Wells, Tammy Redman, Yoni Ashar, Howard Schubiner, Grace Westcott, Patricia Kinser, Madison Maxwell, Gisela Chelimsky, Thomas Chelimsky
{"title":"An alternative \"Port\"? Rationale and development process for POts Reprocessing Therapy (PORT), a brain-body therapy for postural tachycardic syndrome (POTS).","authors":"Taylor B Crouch, Maggie Nguyen, Mary Wells, Tammy Redman, Yoni Ashar, Howard Schubiner, Grace Westcott, Patricia Kinser, Madison Maxwell, Gisela Chelimsky, Thomas Chelimsky","doi":"10.1007/s10286-026-01189-1","DOIUrl":"10.1007/s10286-026-01189-1","url":null,"abstract":"<p><strong>Purpose: </strong>Postural tachycardia syndrome (POTS) is a chronic disorder marked by excessive orthostatic tachycardia, without clear structural/organic (e.g., cardiovascular) etiology. Recent evidence suggests that persistent autonomic symptoms may be driven by threat-induced and central nervous system-maintained dysregulation, similar to centralized chronic pain disorders. This study describes the rationale and development process of a brain-body intervention-POts Reprocessing Therapy (PORT)-aimed at reducing orthostatic symptomatology by taking advantage of the brain's plasticity.</p><p><strong>Methods: </strong>PORT was adapted from pain reprocessing therapy (PRT), an evidence-based mind-body approach for treating centralized chronic pain. The initial protocol was developed through consultations with multidisciplinary experts, including the developers of PRT. To refine the protocol, a focus group was conducted with five women participants with POTS who underwent an early version of PORT. Rapid qualitative analysis was conducted to identify themes and inform intervention improvements.</p><p><strong>Results: </strong>The intervention consists of a medical evaluation followed by eight weekly treatment sessions. Intervention components include psychoeducation, safety learning-based exposure to symptoms, somatic inquiry, and emotional processing. Focus group participants identified reduced fear about symptoms, greater understanding of their condition, and improved functioning. Participants provided suggestions around language and content, and some shared emotional challenges of the treatment, underscoring the need for sensitive provider communication and implementation.</p><p><strong>Conclusion: </strong>This study introduces a novel therapeutic treatment for POTS that targets centrally mediated processes hypothesized to underlie persistent autonomic dysregulation. Trials are underway to formally assess feasibility, acceptability, and efficacy.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"373-385"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13265598/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147303023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Symptoms are an optimal target for orthostatic hypotension screening and management: an argument in favor.","authors":"Jose Ricardo Lopez Castellanos","doi":"10.1007/s10286-026-01213-4","DOIUrl":"10.1007/s10286-026-01213-4","url":null,"abstract":"<p><p>Orthostatic hypotension (OH), defined as a sustained reduction of ≥ 20 mmHg in systolic or ≥ 10 mmHg in diastolic blood pressure within 3 minutes of standing, represents one of the most clinically significant manifestations of autonomic failure. Beyond its hemodynamic definition, OH is associated with disabling symptoms, falls, syncope, reduced quality of life, increased healthcare utilization, and excess mortality. In clinical practice, management often requires balancing objective blood pressure measurements with the patient's lived experience of orthostatic intolerance. This viewpoint argues that symptoms represent an appropriate and clinically meaningful target for screening and management of OH. Three central assumptions support this perspective. First, patients are reliable reporters of orthostatic symptoms and clinicians are capable interpreters of these reports. Validated patient-reported outcome measures, such as the Orthostatic Hypotension Questionnaire (OHQ), demonstrate that symptom burden and functional impairment can be reproducibly quantified and that clinically meaningful changes can be detected. Second, although the relationship between orthostatic blood pressure changes and symptoms is not absolute, evidence supports a clinically relevant association, with symptomatic individuals often experiencing greater cerebral hypoperfusion when upright. Third, symptoms serve as a practical proxy for meaningful OH-related outcomes, including functional independence, fall risk, and quality of life, and have been accepted as primary endpoints in pivotal clinical trials. A symptom-centered framework complements objective hemodynamic assessment by contextualizing physiological findings within patients' functional experience. Integrating symptom reporting with orthostatic measurements provides a pragmatic, patient-centered approach to screening, treatment decisions, and evaluation of therapeutic response in OH.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"321-324"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13265585/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147728826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paulo Bastos, Marc Kermorgant, Margherita Fabbri, Frederic Roche, Vincent Pichot, Fabienne Ory-Magne, Clémence Leung, Olivier Rascol, Wassilios G Meissner, Alexandra Foubert-Samier, David Bendetowicz, Cécile Proust Lima, Anne Pavy-le-Traon
{"title":"Heart rate variability provides prognostic value in multiple system atrophy.","authors":"Paulo Bastos, Marc Kermorgant, Margherita Fabbri, Frederic Roche, Vincent Pichot, Fabienne Ory-Magne, Clémence Leung, Olivier Rascol, Wassilios G Meissner, Alexandra Foubert-Samier, David Bendetowicz, Cécile Proust Lima, Anne Pavy-le-Traon","doi":"10.1007/s10286-026-01190-8","DOIUrl":"10.1007/s10286-026-01190-8","url":null,"abstract":"<p><strong>Purpose: </strong>Multiple system atrophy (MSA) is a progressive neurodegenerative disorder characterized by autonomic dysfunction, parkinsonism, and cerebellar impairment. Understanding the physiological correlates of disease severity and survival remains challenging due to heterogeneity in disease progression. Heart rate variability (HRV) is a noninvasive measure of autonomic nervous system function. However, the role of nonlinear HRV in MSA remains incompletely understood.</p><p><strong>Methods: </strong>This study investigated the association between HRV features, clinical severity, and survival in MSA (n = 214). Regression models were used to examine relationships between HRV and disease severity assessed by the Unified MSA Rating Scale (UMSARS), as well as time to death. Survival analyses evaluated the contribution of HRV features to risk stratification, and mediation analysis explored the relationships among HRV, UMSARS, and survival.</p><p><strong>Results: </strong>HRV features were negatively associated with disease severity, consistent with progressive autonomic dysfunction. While individual HRV features showed limited associations with UMSARS, their combination demonstrated a stronger relationship. Models incorporating HRV features showed associations with time to death comparable to those based on UMSARS, and the combined inclusion of HRV and UMSARS was associated with improved accuracy. Mediation analyses suggested that HRV captures physiological information related to survival that is not fully reflected by clinical severity scores.</p><p><strong>Conclusions: </strong>HRV features are associated with disease severity and survival in MSA and provide complementary physiological information beyond established clinical scales. These findings support the relevance of HRV as an exploratory modeling tool for autonomic dysfunction in MSA and highlight candidate features for future longitudinal and validation studies, rather than establishing a validated prognostic model.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"347-365"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147275776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"From \"evidence is scarce\" to trial-ready care pathways in POTS: an audit-ready roadmap prompted by Schiweck et al.","authors":"M Vijayasimha, M Srikanth","doi":"10.1007/s10286-026-01204-5","DOIUrl":"10.1007/s10286-026-01204-5","url":null,"abstract":"<p><p>Postural orthostatic tachycardia syndrome (POTS) represents a growing clinical and public health challenge, particularly in the context of post-infectious and post-COVID-19 syndromes. Recent systematic synthesis highlights that, despite widespread clinical use of pharmacologic and non-pharmacologic interventions, high-certainty randomized evidence remains scarce and heterogeneous. In this correspondence, prompted by contemporary treatment reviews, we argue that the primary limitation is no longer the absence of therapies but the absence of decision-grade trial architecture. We propose an audit-ready, globally scalable framework that integrates phenotype-stratified pragmatic trials, platform-based comparative effectiveness designs, and a minimum core outcome set anchored to minimally clinically important differences. Emphasis is placed on patient-relevant functional recovery, interpretability across health systems, and equitable implementation beyond tertiary autonomic centers.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"423-424"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147572820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mario Habek, Alessandra Fanciulli, Anne Pavy-Le Traon, Walter Struhal, Magdalena Krbot Skorić, Luka Crnošija, Ivan Adamec, Marco Bozzali, Cristian Falup-Pecurariu, Jens Jordan, Evert Kaal, Gregor K Wenning, Giovanna Calandra Buonaura, Giacomo Chiaro, Pietro Cortelli, Pietro Guaraldi, Max J Hilz, Valeria Iodice, Astrid Juhl Terkelsen, Anita Kamondi, Marc Stefan Dawid Milner, Diogo Reis Carneiro, Camilla Rocchi, Isabel Rocha, Łukasz Rzepiński, Iva Stanković, Beatriz Tijero, Roland D Thijs
{"title":"Setting up an autonomic unit within the neurological department: a position statement of the European Federation of Autonomic Societies.","authors":"Mario Habek, Alessandra Fanciulli, Anne Pavy-Le Traon, Walter Struhal, Magdalena Krbot Skorić, Luka Crnošija, Ivan Adamec, Marco Bozzali, Cristian Falup-Pecurariu, Jens Jordan, Evert Kaal, Gregor K Wenning, Giovanna Calandra Buonaura, Giacomo Chiaro, Pietro Cortelli, Pietro Guaraldi, Max J Hilz, Valeria Iodice, Astrid Juhl Terkelsen, Anita Kamondi, Marc Stefan Dawid Milner, Diogo Reis Carneiro, Camilla Rocchi, Isabel Rocha, Łukasz Rzepiński, Iva Stanković, Beatriz Tijero, Roland D Thijs","doi":"10.1007/s10286-026-01187-3","DOIUrl":"10.1007/s10286-026-01187-3","url":null,"abstract":"<p><strong>Purpose: </strong>The growing recognition of autonomic nervous system (ANS) dysfunction across a broad spectrum of neurological and systemic diseases calls for structured, multidisciplinary care. This position statement by the European Federation of Autonomic Societies aims to provide guidance on establishing an autonomic unit within a neurology department.</p><p><strong>Methods: </strong>A Task Force appointed by the European Federation of Autonomic Societies board in October 2022 proposed staffing and equipment requirements for autonomic units, based on a literature review, survey data from ANS laboratories, and existing diagnostic guidelines. These propositions were integrated into the initial 25 questions and refined using a modified Delphi method to achieve expert consensus. Consensus was predefined as ≥ 80% agreement. Statements that did not reach consensus were revised and reassessed in subsequent rounds.</p><p><strong>Results: </strong>After three rounds of Delphi surveys, expert consensus was achieved on the minimal and optimal requirements for autonomic unit personnel, technical equipment, and the availability of multidisciplinary care.</p><p><strong>Conclusion: </strong>This European Federation of Autonomic Societies position statement presents practical, expert-based recommendations to promote the development of autonomic units across various healthcare systems. By establishing minimum and optimal standards for staffing, equipment, and interdisciplinary collaboration, the document offers a clear framework for standardizing clinical care and supporting collaborative research. This statement serves as a foundational resource for clinicians, administrators, and policymakers committed to strengthening the ANS care infrastructure.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"325-340"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13265601/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146149286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rubens Paulo Salomão, Marcelo Rodrigues Masruha, José Luiz Pedroso, Orlando G P Barsottini
{"title":"Adult-onset spontaneous periodic hypothermia with hyperhidrosis: three cases of a Shapiro syndrome variant.","authors":"Rubens Paulo Salomão, Marcelo Rodrigues Masruha, José Luiz Pedroso, Orlando G P Barsottini","doi":"10.1007/s10286-026-01202-7","DOIUrl":"10.1007/s10286-026-01202-7","url":null,"abstract":"","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"413-415"},"PeriodicalIF":4.6,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147764147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bridget R Mueller, Maya C Campbell, Michael Kaplan, Jihan Grant, Jasmin Jean, Marianna Vinokur, Daniel Clauw, Jessica Robinson-Papp
{"title":"Beyond the headache: autonomic reflex dysfunction and heightened sensory sensitivity contribute to orthostatic intolerance in migraine.","authors":"Bridget R Mueller, Maya C Campbell, Michael Kaplan, Jihan Grant, Jasmin Jean, Marianna Vinokur, Daniel Clauw, Jessica Robinson-Papp","doi":"10.1007/s10286-025-01176-y","DOIUrl":"10.1007/s10286-025-01176-y","url":null,"abstract":"<p><strong>Objective: </strong>Our overarching objective was to determine whether autonomic reflex dysfunction and heightened sensory sensitivity contribute to orthostatic intolerance (OI) in patients with migraine.</p><p><strong>Methods: </strong>Adults with migraine (N = 30) underwent autonomic function tests summarized as the Composite Autonomic Severity Score (CASS) and vagal/adrenergic baroreflex sensitivity (BRS-V/A). Postural orthostatic tachycardia syndrome (POTS) and orthostatic hypotension/hypertension were diagnosed during tilt table testing. A cold pressor test (CPT) evaluated sympathetic vasomotor function. Participants completed the Migraine Disability Assessment (MIDAS), the 2011 Fibromyalgia (FM) Survey Criteria, and chronic overlapping pain condition (COPC) screening.</p><p><strong>Results: </strong>The number of headache days per month correlated with CASS (p = 0.001), BRS-V (p < 0.001), and the CPT (p = 0.003) in the expected direction, with increasing autonomic nervous system (ANS) reflex dysfunction correlating with increasing number of headache days. During tilt testing, OI was prevalent (25/30; 83%) and was reported by all patients with chronic migraine. An abnormal cardiovascular response to tilt was present in 63%; POTS was the most common etiology (56.2%). Patients reporting OI during tilt table testing despite a normal cardiovascular response (33%) had higher FM scores (15.8 ± 3.6 vs. 7.5 ± 4.6; p < 0.01) and a greater prevalence of non-headache COPCs (88.8% vs. 20.0%, p = 0.02) than asymptomatic patients.</p><p><strong>Conclusions: </strong>Increased headache frequency correlates with increasing ANS reflex dysfunction. The high prevalence of OI in patients with migraine may be due to both autonomic reflex dysfunction and an abnormal cardiovascular response to tilt (i.e., concordant OI) and heightened sensory sensitivity (i.e., discordant OI).</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"191-203"},"PeriodicalIF":4.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13158859/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145793656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Horacio Kaufmann, Jose-Alberto Palma, Patricio Millar Vernetti, Mechteld Kuijpers, Grace Nkrumah, Un Jung Kang, Thong Ma, Rebecca A Betensky, Daniel O Claassen, Prashanthi Vemuri, Paula Trujillo, Andrew Siderowf, Claudio Soto, Andrew S Feigin, Glenn T Stebbins, Joe Lindahl, Irfan Qureshi, Anna-Karin Berger, Marla Husnik, Alessandra Fanciulli, Werner Poewe, Florian Krismer, Italo Biaggioni, Wolfgang Singer
{"title":"Multiple System Atrophy Combined Outcome Assessment (MuSyCA): process, format, and validation plan.","authors":"Horacio Kaufmann, Jose-Alberto Palma, Patricio Millar Vernetti, Mechteld Kuijpers, Grace Nkrumah, Un Jung Kang, Thong Ma, Rebecca A Betensky, Daniel O Claassen, Prashanthi Vemuri, Paula Trujillo, Andrew Siderowf, Claudio Soto, Andrew S Feigin, Glenn T Stebbins, Joe Lindahl, Irfan Qureshi, Anna-Karin Berger, Marla Husnik, Alessandra Fanciulli, Werner Poewe, Florian Krismer, Italo Biaggioni, Wolfgang Singer","doi":"10.1007/s10286-026-01192-6","DOIUrl":"10.1007/s10286-026-01192-6","url":null,"abstract":"<p><strong>Purpose: </strong>The Unified Multiple System Atrophy Rating Scale (UMSARS) is widely used as an outcome measure in MSA trials, but it has limitations for clinical trial use. To address these, we developed the Multiple System Atrophy Combined Outcome Assessment (MuSyCA), a comprehensive multimodal tool for disease-modifying MSA trials. The purpose of this manuscript is to describe the development and validation plan for MuSyCA, with emphasis on its structure, intended use, and assessment of reliability, validity, and sensitivity in tracking disease progression.</p><p><strong>Methods: </strong>The development of MuSyCA followed a multistep process. Candidate outcome assessments were identified through systematic literature review and analysis of longitudinal data from large MSA cohorts. Content was refined through multiple Delphi-like consensus rounds involving MSA experts, patient advocacy groups representatives, and industry stakeholders. Cognitive interviews conducted in 20 patients with MSA evaluated the clarity and clinical relevance of patient- and clinician-reported outcomes; feedback was incorporated into a subsequent version of the MuSyCA. Validation is ongoing and includes assessment of construct validity, internal consistency, test-retest reliability, and responsiveness. Longitudinal analyses to determine sensitivity to change over time are ongoing.</p><p><strong>Results: </strong>MuSyCA combines patient- and clinician-reported outcomes, biomarkers (neurofilament light chain, neuroimaging), and performance-based measures to capture subjective and objective aspects of MSA progression, enhancing its utility to detect treatment effects in clinical trials. MuSyCa is not intended to be used in clinical practice.</p><p><strong>Conclusions: </strong>MuSyCA offers a multidimensional approach to MSA assessment, supporting precise, disease-relevant evaluations in trials of putative disease-modifying therapies. Its validation will provide a standardized multimodal outcome measure, advancing MSA therapeutic development.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"233-243"},"PeriodicalIF":4.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13055879/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147316614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Francesco Riganello, Maria D Cortese, Martina Vatrano, Lucia F Lucca, Maria E Pugliese, Maria Ursino, Elio Leto, Antonio Cerasa, Nicholas Schiff, Andrea Soddu
{"title":"New insights and predictability from in vivo recordings of paroxysmal sympathetic hyperactivity in disorders of consciousness.","authors":"Francesco Riganello, Maria D Cortese, Martina Vatrano, Lucia F Lucca, Maria E Pugliese, Maria Ursino, Elio Leto, Antonio Cerasa, Nicholas Schiff, Andrea Soddu","doi":"10.1007/s10286-025-01175-z","DOIUrl":"10.1007/s10286-025-01175-z","url":null,"abstract":"<p><strong>Purpose: </strong>Paroxysmal sympathetic hyperactivity (PSH) is a severe complication of acquired brain injuries (ABIs), characterized by sudden autonomic surges that exacerbate clinical outcomes. Its pathophysiology remains debated, and early biomarkers are lacking. This study aims to investigate autonomic changes preceding PSH and assess the feasibility of predictive modeling using heart rate variability (HRV).</p><p><strong>Methods: </strong>Continuous electrocardiogram (ECG) recordings were obtained from six male patients with disorders of consciousness (DoC), including unresponsive wakefulness syndrome and minimally conscious state. A total of 24 PSH episodes and 24 matched control (noPSH) events were analyzed. HRV metrics, including entropy measures and power spectral density (PSD), were evaluated. A support vector machine (SVM) classifier was implemented to differentiate PSH from control events and to predict PSH onset.</p><p><strong>Results: </strong>PSH events were associated with significant heart rate increases, reduced entropy-based complexity, and decreased PSD in both low-frequency (LF) and high-frequency (HF) bands. An increased very-low-frequency (VLF)/(LF + HF) ratio suggested potential involvement of the renin-angiotensin-aldosterone system (RAAS) in PSH pathogenesis. The SVM classifier achieved perfect classification during the event. In addition, 10 min prior to onset, the model reached 67% sensitivity, 100% specificity, and 83% balanced accuracy.</p><p><strong>Conclusions: </strong>HRV analysis reveals distinct autonomic signatures preceding PSH and suggests, as a working hypothesis, that dysregulation of the RAAS may play a role. However, VLF power is influenced by multiple mechanisms and cannot be considered a specific or exclusive marker of RAAS activity. SVM-based predictive modeling offers a promising tool for PSH detection, providing a basis for investigating autonomic/neuroendocrine regulation, including RAAS.</p>","PeriodicalId":10168,"journal":{"name":"Clinical Autonomic Research","volume":" ","pages":"175-190"},"PeriodicalIF":4.6,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13068689/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145818418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}