Blunted tachycardia and cardiac sympathetic denervation in isolated rapid eye movement sleep behavior disorder.

BACKGROUND: Isolated rapid eye movement sleep behavior disorder (iRBD) serves as a prodromal phase of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Blunted tachycardia (BT) during postural changes indicates neurogenic orthostatic hypotension, a marker of autonomic dysfunction. We aimed to investigate whether BT is associated with cardiac sympathetic neurogenic denervation. Additionally, we conducted a preliminary short-term follow-up to examine the potential prognostic significance of BT regarding phenoconversion and mortality. METHODS: Forty-three patients with iRBD at Shiga University of Medical Science Hospital underwent active standing tests to identify BT, defined by a specific ratio of decrease in systolic blood pressure to inadequate increase in heart rate after standing, and orthostatic hypotension. 123I-metaiodobenzylguanidine myocardial scintigraphy (123I-MIBG) and dopamine transporter single-photon emission computed tomography (DAT-SPECT) were performed. Participants were followed up for 3.4 ± 2.4 years for phenoconversion and 4.0 ± 2.3 years for mortality assessment, and the risk of events was analyzed using log-rank tests. RESULTS: Among the 43 participants (mean age, 72.3 ± 7.9 years; 8 female), 17 met the BT criteria. We found no significant comorbidity-related differences in hypertension or diabetes between the BT(+) and BT(-) groups. Orthostatic hypotension was more prevalent in the BT(+) group than in the BT(-) group (47.1% vs 7.7%, p = 0.003). BT(+) patients were older with a lower early and delayed MIBG uptake; however, no significant differences were observed in DAT accumulation. Phenoconversion was observed in seven (41.2%) BT(+) and seven (26.9%) BT(-) patients. Three deaths were recorded in the BT(+) group (17.6%) and three in the BT(-) group (11.5%). No significant differences were observed in the risk of phenoconversion or mortality between the groups. CONCLUSIONS: We have identified the possibility that BT reflects cardiac sympathetic neurogenic denervation in patients with iRBD. Future research is needed to elucidate the potential prognostic value of BT.

Effect of positional change on cerebral perfusion in Parkinson's disease with orthostatic hypotension.

Objective: Orthostatic hypotension (OH) is one of the most common autonomic dysfunctions in Parkinson's disease (PD) patients. However, many patients with OH are asymptomatic. Conversely, orthostatic dizziness (OD) is not always associated with OH. We investigated the effect of positional changes on cerebral perfusion in patients with PD and OH. Methods: We enrolled 43 patients, of whom 31 were PD patients and 11 were healthy controls (HC). All subjects underwent the following clinical assessments: OH Questionnaire, head-up tilt test (HUTT) with transcranial Doppler (TCD), near-infrared spectroscopy, measurement of the change in oxygenated hemoglobin (Δ Hboxy) during the squat-to-stand test (SST), measurement of the time derivative of total hemoglobin (DHbtot), and time taken to reach the peak (peak time, PT) of DHbtot after re-standing. Results: The mean flow velocity change (ΔMFV) in the TCD during the HUTT failed to differentiate between the PD-OH(+) and PD-OH(-) groups. The change in oxygenated hemoglobin Δ Hboxy was greater in the PD-OH(+) group, which persisted for 9 min until the end of the HUTT only in the left hemisphere. During SST, PT was significantly delayed in PD-OH (+) in the left hemisphere. Conclusion: Although TCD demonstrated no significant difference in ΔMFV, the parameters measured by NIRS, such as Δ Hboxy during HUTT and PT during SST, showed significantly increased Δ Hboxy or delayed PT in the left hemisphere of PD-OH(+). Positional changes have a detrimental effect on cerebral hemodynamics in patients with PD and OH, especially in the left hemisphere.

Orthostatic hypotension and subjective symptomatic orthostasis in Parkinson's disease: Associations and correlations.

Background: Both measured orthostatic hypotension and symptomatic orthostasis are common in PD but their relationship is unclear. Objective: We aim to determine clinical predictors of both measured orthostatic hypotension and reported symptomatic orthostasis in PD, including the impact of "on"/"off" status and seasons, and to determine the correlation between measured OH and subjective orthostasis. Methods: We analyzed BP readings, demographic and disease state predictors for both 1. Measured blood pressure OH criteria and 2. The subjective report of orthostatic symptoms, using logistic regression analyses from an initial "on" motor state clinical visit in all PD patient visits. We then correlated subjective orthostasis symptoms with BP measurements. We also compared intra-subject BP measures in PD patients seen in both "on" and "off" states, and when seen "on" in both summer and winter. Results: 723 consecutive visits over 2 years identified 250 unique PD individuals. Subjective orthostasis was reported by 44 % and "on" measured OH (>20 drop in SBP or 10 DBP upon standing) was seen in 30 %. Measured OH did not significantly correlate with any assessed clinical feature or specific medicine. Subjective orthostasis correlated most with older age, dementia, and L-dopa use. Subjective orthostasis correlated equally with absolute lower measured standing SBP and the drop in SBP from sitting to standing. Compared to the "off" state, "on" state showed lower sitting and standing SBP, more than DBP, but no significant change in BP drop upon standing. Seasons did not impact measured BP. Conclusions: Both OH and symptomatic orthostasis are common. Dopaminergic medications did not cause traditionally defined OH but lowered all SBP (sitting and standing) and thus reduced pulse pressure, possibly by increasing arteriole compliance simply by reducing motor tone, as this BP-lowering effect may be specific to Parkinsonism.

Orthostatic Hypotension and Risk of Mild Cognitive Impairment and Dementia in Parkinson's Disease.

BACKGROUND: Orthostatic hypotension (OH) is a common condition in Parkinson's disease (PD) with a possible link to cognitive decline. OBJECTIVE: The aim was to explore the association between OH and PD-associated mild cognitive impairment (PD-MCI) and dementia (PDD) over 9 years in a population-based incident PD cohort. METHODS: We prospectively followed up patients from PD diagnosis with serial blood pressure measurements, clinical examinations, and neuropsychological assessments. We defined OH using (1) consensus-based criteria and (2) clinically significant OH by mean arterial pressure (MAP) in standing position ≤75 mmHg. PD-MCI and PDD were diagnosed according to acknowledged criteria. We applied generalized estimating equations models to investigate associations between OH measurements and cognitive impairment over time. Weibull accelerated failure time regression models were used to study if early OH (≤3 years of PD diagnosis) accelerates the time to incident PD-MCI and PDD. RESULTS: Of 186 enrolled patients, consensus-based OH affected 68.8%, clinically significant OH 33.9%, PD-MCI 60.8%, and PDD 31.2%. Consensus-based OH was associated with PD-MCI (odds ratio [OR]: 2.04, 95% confidence interval: 1.44-2.90, P < 0.001), whereas clinically significant OH was associated with both PD-MCI (OR: 1.95, 1.11-3.43, P = 0.020) and PDD (OR: 3.66, 1.95-6.86, P < 0.001). Early clinically significant OH, but not early consensus-based OH, reduced time to incident PD-MCI by 54% (P = 0.021) and time to PDD by 44% (P = 0.003) independently of potential confounders, including supine hypertension and cardiovascular disease. CONCLUSIONS: MAP in standing position emerged as a stronger predictor of cognitive decline than OH determined using consensus-based criteria. These findings have implications for both research and clinical practice.

Postprandial hypotension is more common than orthostatic hypotension in older adults with dementia with lewy bodies: a cross-sectional study.

Cardiovascular autonomic dysfunction is one of the supportive clinical features in dementia with Lewy bodies (DLB). This study aimed to investigate the frequency of postural and postprandial hypotension in people with DLB. The study group comprised 125 patients with DLB (76 females; mean age 78.4 ± 7.1 years) and 122 controls (88 females; mean age 74.4 ± 6.9 years). Postprandial blood pressure changes were assessed by ambulatory 24-hour blood pressure monitorization. Postural blood pressure changes were assessed via the head-up tilt table test. The frequency of postprandial hypotension (PPH) and orthostatic hypotension (OH) was higher in patients with DLB compared to controls (89.4% vs 51.7%; p < 0.001, and 45.5% vs 27.9%; p = 0.004, respectively) whereas the frequency of supine hypertension (SH), and orthostatic hypertension (OHT) was similar. However, SH in non-hypertensive participants was higher in DLB patients than in controls (48.9%, 25.7%; p = 0.035). PPH and OH were independently associated with a diagnosis of DLB (odds ratio [OR]:10.26 confidence interval [CI]%95 3.02-34.82; p < 0.001, and OR:2.22 CI%95 1.2-4.12; p = 0.012, respectively) after adjustment for age, number of medications, use of anti-psychotics drugs, angiotensin receptor blockers, and beta blockers. In conclusion, the study demonstrated that PPH was the most common finding of cardiovascular autonomic dysfunction, followed by OH and SH in older patients with DLB. Given the potential complications of postural blood pressure changes and PPH in such patients, cardiovascular autonomic dysfunction should be evaluated in patients with DLB.

Orthostatic Intolerance in Children With Long COVID Utilizing a 10-Minute Passive Standing Test.

Despite there being a wide variety of symptoms reported in pediatric long COVID, one condition that has become increasingly recognized is orthostatic intolerance (OI), which can cause significant morbidity, limiting activities of daily living. This study examines rates of OI in 92 children with long COVID who underwent a bedside passive standing test in a pediatric post-COVID-19 rehabilitation clinic. Seventy-one percent met criteria for an orthostatic condition, including postural orthostatic tachycardia syndrome (POTS), orthostatic tachycardia (OT), classic orthostatic hypotension (OH), delayed OH, and orthostatic hypertension. Our findings suggest that OI is common in pediatric long COVID, necessitating appropriate clinical screening and treatment.

Advice to People with Parkinson's in My Clinic: Orthostatic Hypotension.

Orthostatic hypotension (OH) is the most common manifestation of cardiovascular autonomic dysfunction in Parkinson's disease. In this viewpoint, we discuss five practical questions regarding OH in Parkinson's disease: 1) How common is the problem? 2) Why should people with Parkinson's disease and providers care about OH? 3) What are the symptoms of OH? 4) How to confirm a diagnosis of OH? And 5) How to treat OH? OH is an important non-motor symptom of Parkinson's disease for which we have available treatments to significantly mitigate morbidity and possibly positively impact the disease course.

Pathophysiology of Syncope:Current Concepts and Their Development.

Syncope is a symptom in which transient loss of consciousness occurs as a consequence of a self-limited, spontaneously-terminating, period of cerebral hypoperfusion. Many circulatory disturbances (e.g. brady- or tachyarrhythmias, reflex cardioinhibition-vasodepression-hypotension) may trigger a syncope or near-syncope episode, and identifying the cause(s) is often challenging. Some syncope may involve multiple etiologies operating in concert, whereas in other cases multiple syncope events may be due to various differing causes at different times. In this communication we address current understanding of the principal contributors to syncope pathophysiology including examination of the manner in which concepts evolved, and an overview of factors that constitute consciousness and loss of consciousness, and aspects of neural-vascular control and communication that are impacted by cerebral hypo perfusion leading to syncope . Emphasis focuses on: 1) current understanding of the way transient systemic hypotension impacts brain blood flow and brain function, 2) the complexity and temporal sequence of vascular, humoral and cardiac factors that may accompany the most common causes of syncope, 3) the range of circumstances and disease states that may lead to syncope, and 4) clinical features associated with syncope and in particular the reflex syncope syndromes.

Quantitative analysis of systemic perfusion and cerebral blood flow in the modeling of aging and orthostatic hypotension.

Introduction: Orthostatic hypotension (OH) is common among the older population. The mechanism hypothesized by OH as a risk factor for cognitive decline and dementia is repeated transient cerebral blood flow deficiency. However, to our knowledge, quantitative evaluation of cardiac output and cerebral blood flow due to acute blood pressure changes resulting from postural changes is rare. Methods: We report a new fluid-structure interaction model to analyze the quantitative relationship of cerebral blood flow during OH episodes. A device was designed to simulate the aging of blood vessels. Results and Discussion: The results showed that OH was associated with decreased transient cerebral blood flow. With the arterial aging, lesions, the reduction in cerebral blood flow is accelerated. These findings suggest that systolic blood pressure regulation is more strongly associated with cerebral blood flow than diastolic blood pressure, and that more severe OH carries a greater risk of dementia. The model containing multiple risk factors could apply to analyze and predict for individual patients. This study could explain the hypothesis that transient cerebral blood flow deficiency in recurrent OH is associated with cognitive decline and dementia.

Orthostatic Vital Signs After Sport-Related Concussion: A Cohort Study.

BACKGROUND: The 6th International Consensus Statement on Concussion in Sport guidelines identified that measuring autonomic nervous system dysfunction using orthostatic vital signs (VSs) is an important part of the clinical evaluation; however, there are limited data on the frequency of autonomic nervous system dysfunction captured via orthostatic VSs after concussion. PURPOSE: To compare orthostatic changes in heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) between athletes with acute sport-related concussion (SRC) and control athletes. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: We compared 133 athletes (mean age, 15.3 years; age range, 8-28 years; 45.9% female) with acute SRC (<30 days after injury) with 100 control athletes (mean age, 15.7 years; age range, 10-28 years; 54.0% female). Given the broad age range eligible for study inclusion, participants were subdivided into child (younger than 13 years of age), adolescent (13-17 years of age), and adult (18 years of age and older) age groups for subanalyses. Participants completed a single standard orthostatic VS evaluation including HR, SBP, and DBP in the supine position then immediately and 2 minutes after standing. Linear regression was used to compare delayed supine-to-standing changes in HR, SBP, and DBP as a continuous variable (ΔHR, ΔSPB, and ΔDBP) between groups, and logistic regression was used to compare patients with positive orthostatic VS changes (sustained HR increase ≥30 beats per minute [bpm], SBP decrease ≥20 mm Hg, and DBP ≥10 mm Hg at 2 minutes) between groups, accounting for age and sex. RESULTS: Between-group differences were present for delayed ΔHR (18.4 ± 12.7 bpm in patients with SRC vs 13.2 ± 11.0 bpm in controls; P = .002) and ΔSPB (-3.1 ± 6.6 bpm in patients with SRC vs -0.4 ± 6.5 bpm in controls; P = .001), with positive orthostatic HR changes present more frequently in patients with SRC (18% vs 7%; odds ratio, 2.79; P = .027). In the SRC group, a weak inverse relationship was present between age and ΔHR (r = -0.171; P = .049), with positive orthostatic HR findings occurring primarily in the child and adolescent SRC subgroups. CONCLUSION: Patients with acute SRC had greater orthostatic VS changes compared with controls, the most prominent being sustained HR elevations. Clinical evaluation of autonomic change after SRC via standard orthostatic VS assessment may be a helpful clinical biomarker in the assessment of SRC, especially in children and adolescents.

Efficacy, safety, and response predictors of Astragalus in patients with mild to moderate Alzheimer's disease: A study protocol of an assessor-blind, statistician-blind open-label randomized controlled trial.

Background: This pragmatic clinical trial aims to determine the efficacy and safety of add-on Astragalus membranaceus (AM) for cognition and non-cognition in patients with of mild to moderate Alzheimer's disease complicated with orthostatic hypotension in orthostatic hypotension, elucidate the underlying mechanisms, identify related response predictors, and explore effective drug components. Methods: This is an add-on, assessor-blinded, parallel, pragmatic, randomized controlled trial. At least 66 adults with mild to moderate Alzheimer's disease (AD) and OH aged 50-85 years will be recruited. Participants will be randomized in a 1:1:1 ratio to receive 24 weeks of routine care or add-on low dose AM or add-on high dose AM group. The primary efficacy outcome will be measured by the Alzheimer's Disease Assessment Scale-Cognitive Subscale, Chinese version. Secondary efficacy outcome assessment will include neuropsychological tests, blood pressure, plasma biomarkers, multimodal electroencephalograms, and neuroimaging. Safety outcome measures will include physical examinations, vital signs, electrocardiography, laboratory tests (such as hematologic and blood chemical tests), and adverse event records. Ethics and dissemination: This trial was approved and supervised by Fujian Medical University Union Hospital (2021KJCX040). Independent results, findings will be published in peer-reviewed journals and presented at national and international conferences. Trial registration number: NCT05647473; ClinicalTrials.gov Identifier.

Pyridostigmine for the Management of Neurogenic Orthostatic Hypotension: A Systemic Review.

BACKGROUND: Pyridostigmine is hypothesized to improve neurogenic orthostatic hypotension (nOH) symptoms without causing or exacerbating supine hypertension. The objective of this review was to evaluate the safety and efficacy of pyridostigmine for management of nOH. METHODS: A literature search of PubMed, Embase, and CENTRAL was performed in December 2023 for prospective trials with a placebo or active comparator. RESULTS: Four randomized and two non-randomized studies were reviewed. Three studies utilizing a single dose, crossover design found significant differences of orthostatics using adjunctive pyridostigmine. Two studies assessing longer-term endpoints demonstrated conflicting efficacy of pyridostigmine with one trial finding significant improvement in orthostatics and symptoms after three months of therapy. Use of pyridostigmine did not lead to supine hypertension with most adverse effects being cholinergic. CONCLUSION: Pyridostigmine may be considered as an adjunctive medication in individuals with nOH refractory to standard treatment options as it carries a favorable safety profile with low risk for supine hypertension.

Ocular vestibular-evoked myogenic potential assists in differentiation of multiple system atrophy from Parkinson's disease.

Vestibular-evoked myogenic potentials (VEMPs) can help assess otolithic neural pathway in the brainstem that may also participate in cardiovascular autonomic function. Parkinson's disease (PD) is associated with altered VEMP responses; however, the association between VEMP abnormalities and multiple system atrophy (MSA) remains unknown. Therefore, we compared the extent of otolith dysfunction using ocular (oVEMP) and cervical VEMP (cVEMP) between MSA and PD. We analyzed the clinical features and VEMP and head-up tilt table test (HUT) findings using the Finometer in 24 patients with MSA and 52 with de-novo PD, who had undergone neurotologic evaluation in a referral-based university hospital in South Korea from January 2021 to March 2023. MSA was associated with bilateral oVEMP abnormality (odds ratio [95% confidence interval] = 9.19 [1.77-47.76], p=0.008). n1-p1 amplitude was negatively correlated with Unified Multiple System Atrophy Rating Scale I-II scores in patients with MSA (r=-0.571, p=0.033), whereas it did not correlate with Movement Disorder Society-Unified Parkinson's Disease Rating Scale-III scores in patients with PD (r=-0.051, p=0.687). n1 latency was negatively correlated with maximum changes in systolic blood pressure within 15 s during HUT in patients with PD (r=-0.335, p=0.040) but not in those with MSA (r=0.277, p=0.299). In conclusion, bilaterally abnormal oVEMP responses may indicate the extent of brainstem dysfunction in MSA. oVEMP reflects the integrity of otolith-autonomic interplay, reliably assists in differentiating between MSA and PD, and helps infer clinical decline.

Perfection is the enemy of good. A Letter to the Editor on "Orthostatic hypotension in Parkinson's disease: Sit-to-stand vs. supine-to-stand protocol and clinical correlates".

Orthostatic hypotension (OH) is prevalent in Parkinson's disease. Lim et al. report a higher OH detection rate with the supine-to-stand test compared to the sit-to-stand test. While they favour the supine-to-stand test, we argue that the sit-to-stand test, with adjusted blood pressure thresholds, remains a valuable and practical screening tool.

A pathophysiological biomarker combination separates Lewy body from non-Lewy body neurogenic orthostatic hypotension ​.

PURPOSE: Neurogenic orthostatic hypotension (nOH) results from deficient reflexive delivery of norepinephrine to cardiovascular receptors in response to decreased cardiac venous return. Lewy body (LB) forms of nOH are characterized by low 18F-dopamine-derived radioactivity (a measure of cardiac noradrenergic deficiency), olfactory dysfunction by the University of Pennsylvania Smell Identification Test (UPSIT), and increased deposition of alpha-synuclein (α-syn) in dermal sympathetic noradrenergic nerves by the α-syn-tyrosine hydroxylase (TH) colocalization index. This observational, cross-sectional study explored whether combinations of these biomarkers specifically identify LB forms of nOH. METHODS: Clinical laboratory data were reviewed from patients referred for evaluation at the National Institutes of Health for chronic autonomic failure between 2011 and 2023. The cutoff value for low myocardial 18F-dopamine-derived radioactivity was 6000 nCi-kg/cc-mCi, for olfactory dysfunction an UPSIT score ≤ 28, and for an increased α-syn-TH colocalization index ≥ 1.57. RESULTS: A total of 44 patients (31 LB, 13 non-LB nOH) had data for all three biomarkers. Compared to the non-LB group, the LB nOH group had low myocardial 18F-dopamine-derived radioactivity, low UPSIT scores, and high α-syn-TH colocalization indexes (p < 0.0001 each). Combining the three biomarkers completely separated the groups. Cluster analysis identified two distinct groups (p < 0.0001) independently of the clinical diagnosis, with one cluster corresponding exactly to LB nOH. CONCLUSION: LB forms of nOH feature cardiac noradrenergic deficiency, olfactory dysfunction, and increased α-syn-TH colocalization in skin biopsies. Combining the data for these variables efficiently separates LB from non-LB nOH. Independently of the clinical diagnosis, this biomarker triad identifies a pathophysiologically distinct cluster of nOH patients.

Valsalva maneuver pressure recovery time is prolonged following spinal cord injury with correlations to autonomically-influenced secondary complications.

PURPOSE: This work's purpose was to quantify rapid sympathetic activation in individuals with spinal cord injury (SCI), and to identify associated correlations with symptoms of orthostatic hypotension and common autonomically mediated secondary medical complications. METHODS: This work was a cross-sectional study of individuals with SCI and uninjured individuals. Symptoms of orthostatic hypotension were recorded using the Composite Autonomic Symptom Score (COMPASS)-31 and Autonomic Dysfunction following SCI (ADFSCI) survey. Histories of secondary complications of SCI were gathered. Rapid sympathetic activation was assessed using pressure recovery time of Valsalva maneuver. Stepwise multiple linear regression models identified contributions to secondary medical complication burden. RESULTS: In total, 48 individuals (24 with SCI, 24 uninjured) underwent testing, with symptoms of orthostatic hypotension higher in those with SCI (COMPASS-31, 3.3 versus 0.6, p < 0.01; ADFSCI, 21.2 versus. 3.2, p < 0.01). Pressure recovery time was prolonged after SCI (7.0 s versus. 1.7 s, p < 0.01), though poorly correlated with orthostatic symptom severity. Neurological level of injury after SCI influenced pressure recovery time, with higher injury levels associated with more prolonged time. Stepwise multiple linear regression models identified pressure recovery time as the primary explanation for variance in number of urinary tract infections (34%), histories of hospitalizations (12%), and cumulative secondary medical complication burden (24%). In all conditions except time for bowel program, pressure recovery time outperformed current clinical tools for assessing such risk. CONCLUSIONS: SCI is associated with impaired rapid sympathetic activation, demonstrated here by prolonged pressure recovery time. Prolonged pressure recovery time after SCI predicts higher risk for autonomically mediated secondary complications, serving as a viable index for more "autonomically complete" injury.

Determinants of Orthostatic Hypotension in Type 2 Diabetes: Is Cardiac Autonomic Neuropathy the Main Factor?

OBJECTIVES: To evaluate the determinants of orthostatic hypotension (OH) in type 2 diabetes (T2D) and the usefulness of Δheart rate (HR)/Δsystolic blood pressure (SBP), index of cardiac baroreflex function, in identifying neurogenic OH. METHODS: In 208 participants with T2D, we diagnosed early cardiovascular autonomic neuropathy (CAN) and confirmed CAN according to 1 and 2 HR-based cardiovascular reflex tests (HR-CARTs). Through OH test we defined OH as SBP falls of ≥20 and ≥30 mm Hg with supine SBPs of <140 and ≥140 mm Hg, respectively. In participants with OH, we used the lying-to-standing and OH test and its diagnostic accuracy for neurogenic OH (as OH plus confirmed HR-CAN). RESULTS: OH was present in 25 participants and associated with lower HR-CART scores, higher glycosylated hemoglobin level, the presence of CAN, retinopathy, and peripheral vascular disease, the absence of hypertension, and physical activity (all, P < .05) but not with interfering drugs and ß-blockers. In a multiple logistic regression, HR-CAN was the main determinant of OH (odds ratio, 4.74) with physical activity and hypertension (odds ratios, 0.16 and 0.23; R2 = 0.22). ΔHR/ΔSBP had a good diagnostic accuracy for neurogenic OH (area under the receiver operating characteristic curve, 0.816 ± 0.087) and, at the cutoff of 0.5 bpm/mm Hg, a sensitivity of 100% and specificity of 63.2%. CONCLUSION: CAN remains the primary determinant of OH in T2D but does not explain all its variance. The index ΔHR/ΔSBP may represent a useful clinical tool to identify neurogenic OH.

Syncope in the Emergency Department: A Practical Approach.

Syncope is a common condition encountered in the emergency department (ED), accounting for about 0.6-3% of all ED visits. Despite its high frequency, a widely accepted management strategy for patients with syncope in the ED is still missing. Since syncope can be the presenting condition of many diseases, both severe and benign, most research efforts have focused on strategies to obtain a definitive etiologic diagnosis. Nevertheless, in everyday clinical practice, a definitive diagnosis is rarely reached after the first evaluation. It is thus troublesome to aid clinicians' reasoning by simply focusing on differential diagnoses. With the current review, we would like to propose a management strategy that guides clinicians both in the identification of conditions that warrant immediate treatment and in the management of patients for whom a diagnosis is not immediately reached, differentiating those that can be safely discharged from those that should be admitted to the hospital or monitored before a final decision. We propose the mnemonic acronym RED-SOS: Recognize syncope; Exclude life-threatening conditions; Diagnose; Stratify the risk of adverse events; Observe; decide on the Setting of care. Based on this acronym, in the different sections of the review, we discuss all the elements that clinicians should consider when assessing patients with syncope.

Home-based monitoring of cerebral oxygenation in response to postural changes using near-infrared spectroscopy.

Orthostatic hypotension (OH) is prevalent in older adults and can cause falls and hospitalization. Diagnostic intermittent blood pressure (BP) measurements are only a proxy for cerebral perfusion and do not reflect daily-life BP fluctuations. Near-infrared spectroscopy (NIRS)-measured cerebral oxygenation potentially overcomes these drawbacks. This study aimed to determine feasibility, face validity, and reliability of NIRS in the home environment. Ten participants with OH (2 female, mean age 77, SD 3.7) and 11 without OH (5 female, mean age 78, SD 6.7) wore a NIRS sensor at home on two different days for 10-11 h per day. Preceded by a laboratory-situated test, cerebral oxygenation was measured during three standardized supine-stand tests per day and during unsupervised daily life activities. Data availability, quality, and user experience were assessed (feasibility), as well as differences in posture-related oxygenation responses between participants with and without OH and between symptomatic (dizziness, light-headedness, blurred vision) and asymptomatic postural changes (face validity). Reliability was assessed through repetitive supine-stand tests. Up to 80% of the standardized home-based supine-stand tests could be analyzed. Oxygenation recovery values were lower for participants with OH (p = 0 .03-0.15); in those with OH, oxygenation showed a deeper maximum drop for symptomatic than asymptomatic postural changes (p = 0.04). Intra-class correlation coefficients varied from 0.07 to 0.40, with no consistent differences over measurements. This proof-of-concept study shows feasibility and face validity of at-home oxygenation monitoring using NIRS, confirming its potential value for diagnosis and monitoring in OH and OH-related symptoms. Further data are needed for conclusions about reliability.