Autonomic nervous system education in Europe: EAN/EFAS/INUS survey on curricula and skills in autonomic medicine of European neurology residents and consultants.

BACKGROUND AND PURPOSE: Centers for training in autonomic nervous system (ANS) disorders are not widely available and the recent coronavirus 2019 pandemic temporarily reduced training opportunities in autonomic medicine across European countries. Here we evaluated the current state of education, clinical skills and postgraduate educational preferences on ANS disorders of European neurology residents and consultants. METHODS: A 23-item questionnaire was developed and distributed online amongst European neurology residents and consultants via mailing lists of the European Academy of Neurology. The questions assessed demographics, current training opportunities and learning preferences in ANS disorders. Six multiple-choice questions were used to self-evaluate knowledge of ANS disorders. RESULTS: In all, 285 individuals answered the survey (60% female, mostly 25-34 years of age). All respondents considered clinical autonomic skills necessary for good clinical neurological practice, and 92% would like to increase their ANS knowledge. Female respondents and those who trained in Southern/Eastern/Greater Europe more frequently judged ANS skills important for clinical practice than male respondents (p = 0.012) and respondents from Northern/Western Europe (p = 0.011). Female and younger respondents felt less confident in managing ANS disorders (p = 0.001 and p < 0.001, respectively). Respondents below 45 years of age (p < 0.001) and those with lower confidence in managing ANS disorders (p = 0.004) were more likely to recommend that ANS education is embedded in the residency curriculum. CONCLUSIONS: Most European neurology residents and consultants reported a need for more autonomic education, with additional gender, age and regional differences. These findings underscore the importance of increasing the educational content on autonomic medicine in European medical and postgraduate curricula.

Pre-existing parasympathetic dominance seems to cause persistent heart rate slowing after 6 months of fingolimod treatment in patients with multiple sclerosis.

PURPOSE: Vagomimetic fingolimod effects cause heart rate (HR) slowing upon treatment initiation but wear off with sphingosine-1-phosphate receptor downregulation. Yet, prolonged HR slowing may persist after months of fingolimod treatment. We evaluated whether cardiovascular autonomic modulation differs before and 6 months after fingolimod initiation between patients with RRMS with and without initially prolonged HR slowing upon fingolimod initiation. METHODS: In 34 patients with RRMS, we monitored RR intervals (RRI) and blood pressure (BP), at rest and upon standing up before fingolimod initiation. Six hours and 6 months after fingolimod initiation, we repeated recordings at rest. At the three time points, we calculated autonomic parameters, including RRI standard deviation (RRI-SD), RRI-total-powers, RMSSD, RRI high-frequency [HF] powers, RRI and BP low-frequency (LF) powers, and baroreflex sensitivity (BRS). Between and among patients with and without prolonged HR slowing upon fingolimod initiation, we compared all parameters assessed at the three time points (analysis of variance [ANOVA] with post hoc testing; significance: p < 0.05). RESULTS: Six hours after fingolimod initiation, all patients had decreased HRs but increased RRIs, RRI-SDs, RMSSDs, RRI-HF-powers, RRI-total-powers, and BRS; 11 patients had prolonged HR slowing. Before fingolimod initiation, these 11 patients did not decrease parasympathetic RMSSDs and RRI-HF-powers upon standing up. After 6 months, all parameters had reapproached pretreatment values but the 11 patients with prolonged HR slowing had lower HRs while the other 23 patients had lower parasympathetic RMSSDs and RRI-HF-powers, and BRS than before fingolimod initiation. CONCLUSION: Our patients with prolonged HR slowing upon fingolimod initiation could not downregulate cardiovagal modulation upon standing up even before fingolimod initiation, and 6 months after fingolimod initiation still had more parasympathetic effect on HR while cardiovagal modulation and BRS were attenuated in the other 23 patients. Pre-existing parasympathetic predominance may cause prolonged HR slowing upon fingolimod initiation.

Unveiling the untreated: development of a database algorithm to identify potential Fabry disease patients in Germany.

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder, is caused by mutations in the gene encoding α-galactosidase A, resulting in lysosomal accumulation of globotriaosylceramide and other glycosphingolipids. Early detection of FD is challenging, accounting for delayed diagnosis and treatment initiation. This study aimed to develop an algorithm using a logistic regression model to facilitate early identification of patients based on ICD-10-GM coding using a German Sickness Fund Database. METHODS: The logistic regression model was fitted on a binary outcome variable based on either a treated FD cohort or a control cohort (without FD). Comorbidities specific to the involved organs were used as covariates to identify potential FD patients with ICD-10-GM E75.2 diagnosis but without any FD-specific medication. Specificity and sensitivity of the model were optimized to determine a likely threshold. The cut-point with the largest values for the Youden index and concordance probability method and the lowest value for closest to (0,1) was identified as 0.08 for each respective value. The sensitivity and specificity for this cut-point were 80.4% and 79.8%, respectively. Additionally, a sensitivity analysis of the potential FD patients with at least two codes of E75.2 diagnoses was performed. RESULTS: A total of 284 patients were identified in the potential FD cohort using the logistic regression model. Most potential FD patients were < 30 years old and female. The identification and incidence rates of FD in the potential FD cohort were markedly higher than those of the treated FD cohort. CONCLUSIONS: This model serves as a tool to identify potential FD patients using German insurance claims data.

EFAS/EAN survey on the influence of the COVID-19 pandemic on European clinical autonomic education and research.

PURPOSE: To understand the influence of the coronavirus disease 2019 (COVID-19) pandemic on clinical autonomic education and research in Europe. METHODS: We invited 84 European autonomic centers to complete an online survey, recorded the pre-pandemic-to-pandemic percentage of junior participants in the annual congresses of the European Federation of Autonomic Societies (EFAS) and European Academy of Neurology (EAN) and the pre-pandemic-to-pandemic number of PubMed publications on neurological disorders. RESULTS: Forty-six centers answered the survey (55%). Twenty-nine centers were involved in clinical autonomic education and experienced pandemic-related didactic interruptions for 9 (5; 9) months. Ninety percent (n = 26/29) of autonomic educational centers reported a negative impact of the COVID-19 pandemic on education quality, and 93% (n = 27/29) established e-learning models. Both the 2020 joint EAN-EFAS virtual congress and the 2021 (virtual) and 2022 (hybrid) EFAS and EAN congresses marked higher percentages of junior participants than in 2019. Forty-one respondents (89%) were autonomic researchers, and 29 of them reported pandemic-related trial interruptions for 5 (2; 9) months. Since the pandemic begin, almost half of the respondents had less time for scientific writing. Likewise, the number of PubMed publications on autonomic topics showed the smallest increase compared with other neurological fields in 2020-2021 and the highest drop in 2022. Autonomic research centers that amended their trial protocols for telemedicine (38%, n = 16/41) maintained higher clinical caseloads during the first pandemic year. CONCLUSIONS: The COVID-19 pandemic had a substantial negative impact on European clinical autonomic education and research. At the same time, it promoted digitalization, favoring more equitable access to autonomic education and improved trial design.

Rapid recovery of poststroke cardiac autonomic dysfunction: Causes to be considered.

BACKGROUND AND PURPOSE: Acute stroke frequently causes cardiovascular-autonomic dysfunction (CAD). Studies of CAD recovery are inconclusive, whereas poststroke arrhythmias may wane within 72 h. We evaluated whether poststroke CAD recovers within 72 h upon stroke onset in association with neurological improvement or increased use of cardiovascular medication. METHODS: In 50 ischemic stroke patients (68 ± 13 years old) who-prior to hospital-admission-had no known diseases nor took medication affecting autonomic modulation, we assessed National Institutes of Health Stroke Scale (NIHSS) scores, RR intervals (RRIs), systolic and diastolic blood pressure (BP), respiration rate, parameters reflecting total autonomic modulation (RRI SD, RRI total powers), sympathetic modulation (RRI low-frequency powers, systolic BP low-frequency powers), and parasympathetic modulation (square root of mean squared differences of successive RRIs [RMSSD], RRI high-frequency powers), and baroreflex sensitivity within 24 h (Assessment 1) and 72 h after stroke onset (Assessment 2) and compared data to those of 31 healthy controls (64 ± 10 years). We correlated delta NIHSS values (Assessment 1 - Assessment 2) with delta values of autonomic parameters (Spearman rank correlation tests; significance: p < 0.05). RESULTS: At Assessment 1, patients were not yet on vasoactive medication and had higher systolic BP, respiration rate, and heart rate, that is, lower RRIs, but lower RRI SD, RRI coefficient of variance, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, RMSSDs, and baroreflex sensitivity. At Assessment 2, patients were on antihypertensives, had higher RRI SD, RRI coefficient of variance, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, RMSSDs, and baroreflex sensitivity but lower systolic blood pressure and NIHSS values than at Assessment 1; values no longer differed between patients and controls except for lower RRIs and higher respiration rate in patients. Delta NIHSS scores correlated inversely with delta values of RRI SD, RRI coefficient of variance, RMSSDs, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, and baroreflex sensitivity. CONCLUSIONS: In our patients, CAD recovery was almost complete within 72 h after stroke onset and correlated with neurological improvement. Most likely, early initiation of cardiovascular medication and probably attenuating stress supported rapid CAD recovery.

Incidence, temporal profile and neuroanatomic correlates of poststroke epilepsy.

BACKGROUND AND PURPOSE: The relationship between ischemic stroke site and occurrence of poststroke epilepsy (PSE) is incompletely understood. This study intended to evaluate incidence and temporal profiles of seizures and to correlate ischemic lesion sites with PSE using voxel-based lesion symptom mapping (VLSM). METHODS: Patients with imaging-confirmed first-ever ischemic stroke without prior history of epilepsy were prospectively included. Demographic data, cardiovascular risk factors, and National Institute of Health Stroke Scale (NIHSS) scores were assessed. Data on seizures and modified Rankin scale scores were determined within a 90-day period after stroke onset. Ischemic lesion sites were correlated voxel wise with occurrence of PSE using nonparametric permutation test. Age- and sex-matched patients with first-ever ischemic strokes without PSE after 90 days served as controls for the VLSM analysis. RESULTS: The stroke database contained 809 patients (mean age: 68.4 ± 14.2 years) with first-ever imaging-confirmed ischemic strokes without history of epilep. Incidence of PSE after 90-day follow-up was 2.8%. Five additional patients were admitted to the emergency department with a seizure after 90-day follow-up. Fifty percent of the seizures occurred in the acute phase after stroke. PSE patients had higher NIHSS scores and infarct volumes compared to controls without PSE (p < .05). PSE patients had infarcts predominantly involving the cerebral cortex. The hemisphere-specific VLSM analysis shows associations between PSE and damaged voxels in the left-hemispheric temporo-occipital transition zone. CONCLUSIONS: The data indicate that PSE occurs in a small proportion of patients with rather large ischemic strokes predominantly involving the cerebral cortex. Especially patients with ischemic lesions in the temporo-occipital cortex are vulnerable to develop PSE.

Cardiovascular autonomic regulation correlates with cognitive performance in patients with a history of traumatic brain injury.

BACKGROUND AND OBJECTIVE: Traumatic brain injury (TBI) may afflict brain areas contributing to both cardiovascular autonomic regulation and cognitive performance. To evaluate possible associations between both functions in patients with a history of TBI (post-TBI-patients), we determined correlations between cardiovascular autonomic regulation and cognitive function in post-TBI-patients. METHODS: In 86 post-TBI-patients (33.1 ± 10.8 years old, 22 women, 36.8 ± 28.9 months after injury), we monitored RR intervals (RRI), systolic and diastolic blood pressures (BPsys, BPdia), and respiration (RESP) at rest. We calculated parameters of total cardiovascular autonomic modulation (RRI-standard-deviation (RRI-SD), RRI-coefficient-of-variation (RRI-CV), RRI-total-powers), sympathetic (RRI-low-frequency-powers (RRI-LF), normalized (nu) RRI-LF-powers, BPsys-LF-powers) and parasympathetic modulation (root-mean-square-of-successive-RRI-differences (RMSSD), RRI-high-frequency-powers (RRI-HF), RRI-HFnu-powers), sympathetic-parasympathetic balance (RRI-LF/HF-ratios), and baroreflex sensitivity (BRS). We used the Mini-Mental State Examination and Clock Drawing Test (CDT) to screen the general global and visuospatial cognitive function, and applied the standardized Trail Making Test (TMT)-A assessing visuospatial abilities and TMT-B assessing executive function. We calculated correlations between autonomic and cognitive parameters (Spearman's rank correlation test; significance: P < 0.05). RESULTS: CDT values positively correlated with age (P = 0.013). TMT-A values inversely correlated with RRI-HF-powers (P = 0.033) and BRS (P = 0.043), TMT-B values positively correlated with RRI-LFnu-powers (P = 0.015), RRI-LF/HF-ratios (P = 0.036), and BPsys-LF-powers (P = 0.030), but negatively with RRI-HFnu-powers (P = 0.015). CONCLUSIONS: In patients with a history of TBI, there is an association between decreased visuospatial and executive cognitive performance and reduced parasympathetic cardiac modulation and baroreflex sensitivity with relatively increased sympathetic activity. Altered autonomic control bears an increased cardiovascular risk; cognitive impairment compromises quality of life and living conditions. Thus, both functions should be monitored in post-TBI-patients.

Impact of the COVID-19 pandemic on clinical autonomic practice in Europe A survey of the European Academy of Neurology (EAN) and the European Federation of Autonomic Societies (EFAS).

OBJECTIVE: To investigate the impact of the coronavirus-disease-2019 (COVID-19) pandemic on European clinical autonomic practice. METHODS: Eighty-four neurology-driven or interdisciplinary autonomic centers in 22 European countries were invited to fill in a web-based survey between September and November 2021. RESULTS: Forty-six centers completed the survey (55%). During the first pandemic year, the number of performed tilt-table tests, autonomic outpatient and inpatient visits decreased respectively by 50%, 45% and 53%, and every-third center reported major adverse events due to postponed examinations or visits. The most frequent newly-diagnosed or worsened cardiovascular autonomic disorders after COVID-19 infection included postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension, and recurrent vasovagal syncope, deemed likely related to the infection by ≥50% of the responders. Forty-seven percent of the responders also reported about people with new-onset of orthostatic intolerance, but negative tilt-table findings, and 16% about people with psychogenic pseudosyncope after COVID-19. Most patients were treated non-pharmacologically and symptomatic recovery at follow-up was observed in ≥45% of cases. By contrast, low frequencies of newly-diagnosed cardiovascular autonomic disorders following COVID-19 vaccination were reported, most frequently POTS and recurrent vasovagal syncope, and most of the responders judged a causal association unlikely. Non-pharmacological measures were the preferred treatment choice, with 50-100% recovery rates at follow-up. CONCLUSIONS: Cardiovascular autonomic disorders may develop or worsen following a COVID-19 infection, while the association with COVID-19 vaccines remains controversial. Despite the severe pandemic impact on European clinical autonomic practice, a specialized diagnostic work-up was pivotal to identify non-autonomic disorders in people with post-COVID-19 orthostatic complaints.

Acute right insular ischaemic lesions and poststroke left ventricular dysfunction.

INTRODUCTION: Myocardial injury related to acute ischaemic stroke is common even without primary cardiac disease. We intended to determine associations between values of left ventricular ejection fraction (LVEF) and ischaemic stroke lesion sites. METHODS: Of a local database, patients with acute first-ever ischaemic stroke confirmed by brain imaging but without pre-existing heart disease were included. The cardiac morphology and LVEF were obtained from transthoracic or transesophageal echocardiography, and impaired LVEF was categorised as mild (35%-50%), moderate (34%-25%) and severe (<25%). Patient age, stroke severity, ischaemic lesion volume, prevalence of troponin I increase (>0.1 ng/mL), atrial fibrillation and cardiac wall motion abnormalities were assessed and compared between patients with and without impaired LVEF after stroke (significance: p<0.05). A multivariate voxelwise lesion analysis correlated LVEF after stroke with sites of ischaemic lesions. RESULTS: Of 1209 patients who had a stroke, 231 (mean age 66.3±14.0 years) met the inclusion criteria; 40 patients (17.3%) had an impaired LVEF after stroke. Patients with impaired LVEF had higher infarct volumes (53.8 mL vs 30.0 mL, p=0.042), a higher prevalence of troponin increase (17.5% vs 4.2%, p=0.006), cardiac wall motion abnormalities (42.5% vs 5.2%, p<0.001) and atrial fibrillation (60.0% vs 26.2%, p<0.001) than patients with LVEF of >50%. The multivariate voxelwise lesion analysis yielded associations between decreased LVEF and damaged voxels in the insula, amygdala and operculum of the right hemisphere. CONCLUSION: Our imaging analysis unveils a prominent role of the right hemispheric central autonomic network, especially of the insular cortex, in the brain-heart axis. Our results support preliminary evidence that acute ischaemic stroke in distinct brain regions of the central autonomic network may directly impair cardiac function and thus further supports the concept of a distinct stroke-heart syndrome.

Transcutaneous vagus nerve stimulation - A brief introduction and overview.

Invasive cervical vagus nerve stimulation (VNS) is approved for the treatment of epilepsies, depression, obesity, and for stroke-rehabilitation. The procedure requires surgery, has side-effects, is expensive and not readily available. Consequently, transcutaneous VNS (tVNS) has been developed 20 years ago as non-invasive, less expensive, and easily applicable alternative. Since the vagus nerve reaches the skin at the outer acoustic canal and ear, and reflex-responses such as the ear-cough-reflex or the auriculo-cardiac reflex have been observed upon auricular stimulation, the ear seems well suited for tVNS. However, several sensory nerves with variable fiber-density and significant overlap innervate the outer ear: the auricular branch of the vagus nerve (ABVN), the auriculotemporal nerve, greater auricular nerve, and to some extent the lesser occipital nerve. VNS requires activation of Aß-fibers which are far less present in the ABVN than the cervical vagus nerve. Thus, optimal stimulation sites and parameters, and tVNS-algorithms need to be further explored. Unravelling central pathways and structures that mediate tVNS-effects is another challenge. tVNS impulses reach the nucleus of the solitary tract and activate the locus-coeruleus-norepinephrine system. However, many more brain areas are activated or deactivated upon VNS, including structures of the central autonomic network and the limbic system. Still, the realm of therapeutic tVNS applications grows rapidly and includes medication-refractory epilepsies, depressive mood disorders, headaches including migraine, pain, heart failure, gastrointestinal inflammatory diseases and many more. tVNS might become a standard tool to enhance autonomic balance and function in various autonomic, neurological, psychiatric, rheumatologic, as well as other diseases.

Transcutaneous vagus nerve stimulation and the realm of its therapeutic hopes and physiologic enigmas.

Vagus nerve stimulation (VNS) is an established treatment option for patients with treatment resistant epilepsy and depression. However, the procedure is invasive and has side-effects. Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive alternative. Particularly transcutaneous stimulation at the outer ear is gaining increasing interest. While the scope of therapeutic tVNS applications is expanding, there are still questions regarding the optimal stimulation parameters and site as well as the physiology and pathways of auricular tVNS. This Special Issue of Autonomic Neuroscience: Basic & Clinical provides an introduction and overview on basic aspects as well as special topics of tVNS.

Clinical autonomic nervous system laboratories in Europe: A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies: A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies.

BACKGROUND AND PURPOSE: Disorders of the autonomic nervous system (ANS) are common conditions, but it is unclear whether access to ANS healthcare provision is homogeneous across European countries. The aim of this study was to identify neurology-driven or interdisciplinary clinical ANS laboratories in Europe, describe their characteristics and explore regional differences. METHODS: We contacted the European national ANS and neurological societies, as well as members of our professional network, to identify clinical ANS laboratories in each country and invite them to answer a web-based survey. RESULTS: We identified 84 laboratories in 22 countries and 46 (55%) answered the survey. All laboratories perform cardiovascular autonomic function tests, and 83% also perform sweat tests. Testing for catecholamines and autoantibodies are performed in 63% and 56% of laboratories, and epidermal nerve fiber density analysis in 63%. Each laboratory is staffed by a median of two consultants, one resident, one technician and one nurse. The median (interquartile range [IQR]) number of head-up tilt tests/laboratory/year is 105 (49-251). Reflex syncope and neurogenic orthostatic hypotension are the most frequently diagnosed cardiovascular ANS disorders. Thirty-five centers (76%) have an ANS outpatient clinic, with a median (IQR) of 200 (100-360) outpatient visits/year; 42 centers (91%) also offer inpatient care (median 20 [IQR 4-110] inpatient stays/year). Forty-one laboratories (89%) are involved in research activities. We observed a significant difference in the geographical distribution of ANS services among European regions: 11 out of 12 countries from North/West Europe have at least one ANS laboratory versus 11 out of 21 from South/East/Greater Europe (p = 0.021). CONCLUSIONS: This survey highlights disparities in the availability of healthcare services for people with ANS disorders across European countries, stressing the need for improved access to specialized care in South, East and Greater Europe.

Cardiovascular medication seems to promote recovery of autonomic dysfunction after stroke.

BACKGROUND: Stroke may compromise cardiovascular-autonomic modulation (CAM). The longitudinal post-stroke CAM alterations remain unclear as previous studies excluded patients with cardiovascular medication. This study evaluated whether CAM dysfunction improves after several months in patients under typical clinical conditions, i.e., without excluding patients with cardiovascular medication. METHODS: In 82 ischemic stroke patients [33 women, 64.9 ± 8.9 years, NIHSS-scores 2 (interquartile range 1-5)], we evaluated the applications of cardiovascular medication before stroke, during autonomic tests performed within 1 week, 3 and 6 months after stroke onset. We determined resting RR intervals (RRI), systolic, diastolic blood pressures (BPsys), respiration, parameters reflecting total CAM [RRI-standard deviation (RRI-SD), RRI-total powers], sympathetic [RRI-low-frequency powers (RRI-LF), BPsys-LF powers] and parasympathetic CAM [RMSSD, RRI-high-frequency powers (RRI-HF powers)], and baroreflex sensitivity. ANOVA or Friedman tests with post hoc analyses compared patient data with data of 30 healthy controls, significance was assumed for P < 0.05. RESULTS: More patients had antihypertensive medication after than before stroke. First-week CAM testing showed lower RRIs, RMSSD, RRI-SDs, RRI-total powers, RRI-HF powers, and baroreflex sensitivity, but higher BPsys-LF powers in patients than controls. After 3 and 6 months, patients had significantly higher RRIs, RRI-SDs, RRI-total powers, RMSSDs, RRI-HF powers, and baroreflex sensitivity, but lower BPsys-LF powers than in the 1st week; RMSSDs and RRI-HF powers no longer differed between patients and controls. However, 6-month values of RRIs, RRI-SDs, and baroreflex sensitivity were again lower in patients than controls. CONCLUSIONS: Even mild strokes compromised cardiovagal modulation and baroreflex sensitivity. After 3 months, CAM had almost completely recovered. Recovery might be related to the mild stroke severity. Presumably, CAM recovery was also promoted by the increased application of cardiovascular medication. Yet, slight CAM dysfunction after 6 months suggests continuing autonomic vulnerability.

Posterior circulation ischemic stroke not involving the brainstem is associated with cardiovascular autonomic dysfunction.

BACKGROUND AND PURPOSE: Ischemic stroke may induce cardiovascular autonomic dysfunction, but most previous studies have included patients with anterior circulation ischemic stroke or brainstem stroke. It remains unclear whether posterior circulation ischemic stroke (PCIS) without brainstem involvement also compromises cardiovascular autonomic modulation (CAM). Therefore, we aimed to assess CAM in PCIS patients with and without brainstem involvement. METHODS: In four subgroups of 61 PCIS patients (14 occipital lobe, 16 thalamic, 12 cerebellar, and 19 brainstem strokes) and 30 healthy controls, we recorded RR intervals (RRIs), systolic (SBP) and diastolic blood pressure (DBP), and respiration at supine rest during the first week after stroke onset. We calculated parameters reflecting total CAM (RRI-standard deviation [RRI-SD], RRI-total powers), predominantly sympathetic CAM (RRI-low-frequency [LF] powers and SBP-LF powers] and parasympathetic CAM (root mean square of successive RRI differences [RMSSD], RRI-high-frequency [HF] powers), sympathetic-parasympathetic balance (RRI-LF/HF ratios), and baroreflex sensitivity (BRS). Values were compared among the four PCIS groups and controls using one-way ANOVA Kruskal-Wallis tests, with post-hoc analyses. Significance was assumed for p < 0.05. RESULTS: In each PCIS subgroup, values for RRI, RRI-SD, RMSSD, RRI-HF powers, and BRS were significantly lower, while SBP-LF powers were higher than in the controls. Only in patients with occipital lobe stroke were RRI-LF/HF ratios significantly higher than in controls. Otherwise, autonomic variables did not differ among the four PCIS subgroups. CONCLUSIONS: During the first week after stroke onset, our PCIS patients with occipital lobe, thalamic, cerebellar, or brainstem strokes all had reduced cardiovagal modulation, compromised baroreflex, and increased peripheral sympathetic modulation. The RRI-LF/HF ratios suggest that sympathetic predominance is slightly more prominent after occipital lobe stroke. PCIS may trigger cardiovascular autonomic dysfunction even without brainstem involvement.

Cardiovascular autonomic dysfunction after stroke.

Strokes are the paradigmatic example of the sudden impairment of the cerebral regulation of cardiac autonomic regulation. Although several aspects of dysautonomic cardiovascular regulation post stroke remain unanswered, there has been a wealth of research in this area in the last decade. In this article, we present a state-of-the-art review on the anatomical and functional organization of cardiovascular autonomic regulation, and the pathophysiology, incidence, time course, diagnosis, clinical aspects, prognosis, and management of post-stroke cardiovascular autonomic dysfunction.

Cardiovascular fingolimod effects on rapid baroreceptor unloading are counterbalanced by baroreflex resetting.

BACKGROUND AND PURPOSE: Initial cardiovascular fingolimod effects might compromise baroreflex responses to rapid blood pressure (BP) changes during common Valsalva-like maneuvers. This study evaluated cardiovascular responses to Valsalva maneuver (VM)-induced baroreceptor unloading and loading upon fingolimod initiation. PATIENTS AND METHODS: Twenty-one patients with relapsing-remitting multiple sclerosis performed VMs before and 0.5, 1, 2, 3, 4, 5, and 6 hours after fingolimod initiation. We recorded heart rate (HR) as RR intervals (RRI), systolic and diastolic BP (BPsys, BPdia) during VM phase 1, VM phase 2 early, VM phase 2 late, and VM phase 4. Using linear regression analysis between decreasing BPsys and RRI values during VM phase 2 early, we determined baroreflex gain (BRG) reflecting vagal withdrawal and sympathetic activation upon baroreceptor unloading. To assess cardiovagal activation upon baroreceptor loading, we calculated Valsalva ratios (VR) between maximal and minimal RRIs after strain release. Analysis of variance or Friedman tests with post hoc analysis compared corresponding parameters at the eight time points (significance: p < 0.05). RESULTS: RRIs at VM phase 1, VM phase 2 early, and VM phase 2 late were higher after than before fingolimod initiation, and maximal after 4 hours. Fingolimod did not affect the longest RRIs upon strain release, but after 3, 5, and 6 hours lowered the highest BPsys values during overshoot and all BPdia values, and thus reduced VRs. BRG was slightly higher after 3 and 5 hours, and significantly higher after 4 hours than before fingolimod initiation. CONCLUSIONS: VR-decreases 3-6 hours after fingolimod initiation are physiologic results of fingolimod-associated attenuations of BP and HR increases at the end of strain and do not suggest impaired cardiovagal activation upon baroreceptor loading. Stable and at the time of HR nadir significantly increased BRGs indicate improved responses to baroreceptor unloading. Thus, cardiovascular fingolimod effects do not impair autonomic responses to sudden baroreceptor loading or unloading but seem to be mitigated by baroreflex resetting.

Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology.

Evaluation of disorders of the autonomic nervous system is both an art and a science, calling upon the physician's most astute clinical skills as well as knowledge of autonomic neurology and physiology. Over the last three decades, the development of noninvasive clinical tests that assess the function of autonomic nerves, the validation and standardization of these tests, and the growth of a large body of literature characterizing test results in patients with autonomic disorders have equipped clinical practice further with a valuable set of objective tools to assist diagnosis and prognosis. This review, based on current evidence, outlines an international expert consensus set of recommendations to guide clinical electrodiagnostic autonomic testing. Grading and localization of autonomic deficits incorporates scores from sympathetic cardiovascular adrenergic, parasympathetic cardiovagal, and sudomotor testing, as no single test alone is sufficient to diagnose the degree or distribution of autonomic failure. The composite autonomic severity score (CASS) is a useful score of autonomic failure that is normalized for age and gender. Valid indications for autonomic testing include generalized autonomic failure, regional or selective system syndromes of autonomic impairment, peripheral autonomic neuropathy and ganglionopathy, small fiber neuropathy, orthostatic hypotension, orthostatic intolerance, syncope, neurodegenerative disorders, autonomic hyperactivity, and anhidrosis.