Pattern of Nonmotor Symptoms in Patients with Idiopathic Parkinson's Disease in a Tertiary Care Hospital of Rural Eastern India.

BACKGROUND: Idiopathic Parkinson's disease (IPD) is associated with a spectrum of nonmotor symptoms (NMS) that contribute as much to the burden of the disease as the more obvious motor abnormalities. There is a paucity of literature determining the association between NMS and the severity of IPD, especially in rural eastern parts of India. AIMS OF STUDY: This study explores the frequency of NMS in patients with IPD and determines the association between NMS and the severity of IPD. MATERIALS AND METHODS: A cross-sectional observational study involving 65 serially enrolled IPD patients (diagnosed as per United Kingdom Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria) was conducted over a period of 18 months. The patients were evaluated for disease severity as per the Hoehn and Yahr scale (original) and were subsequently evaluated with a predesigned and validated Parkinson's Disease Non-Motor Symptoms Questionnaire. Pearson's Chi-squared test for independence of attributes or Fisher's exact test was used for comparison of categorical variables across the groups. Continuous variables were compared using a one-way analysis of variance (ANOVA) test. RESULTS: The most common presenting NMS of IPD was low mood (n = 61; 93.85%), followed by apathy (n = 59; 90.77%), impaired concentration (n = 58; 89.23%), restless leg (n = 54; 83.08%), and tenesmus (n = 54; 83.08%). A majority of the neuropsychiatric symptoms, autonomic dysfunctions, sleep abnormalities, gastrointestinal manifestations, and sensory abnormalities individually showed a statistically significant relation with the severity of IPD. CONCLUSION: Common presenting NMS include neuropsychiatric manifestations, autonomic symptoms, sleep-related symptoms, and gastrointestinal manifestations. Most of the NMS are significantly related to disease severity.

Cranial Autonomic Symptoms in Migraine Patient Presenting in the Department of Neurology of a Tertiary Care Center: A Descriptive Cross-sectional Study.

INTRODUCTION: Cranial autonomic symptoms (CAS) are typically associated with trigeminal autonomic cephalagias (TACs) and are also a part of TACs' diagnostic criteria. However, they have also been commonly reported in migraine patients. This study aimed to find the prevalence of CAS in Migraine patients who presented to the Department of Neurology in a tertiary care center. METHODS: This descriptive cross-sectional study was conducted among migraine patients who visited the Department of Neurology of a tertiary care center from September 2023 to December 2023 after obtaining ethical approval from the Institutional Review Committee. Neurologists used ICHD-3 beta criteria to diagnose migraine and the presence of cranial autonomic symptoms in patients with migraine through face-to-face interviews using a structured questionnaire. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. RESULTS: Among 119 migraine patients, at least one cranial autonomic symptom was seen in 76 (63.86%) (55.23-72.51, at 95% Confidence Interval). Lacrimation 34 (44.73%) and conjunctival injection 27 (35.52%) were the two most commonly reported symptoms. Bilateral CAS was present in 60 (78.94%) patients. CONCLUSIONS: The prevalence of at least one CAS in migraine patients was found to be similar to other studies done in similar settings.

A Comparative Analysis of Heart Rate Variability Indices in Patients with Liver Cirrhosis.

BACKGROUND: Cardiac autonomic dysfunction (AD) in reference to chronic liver disease (CLD) has become widely accepted as a symptomatic burden. This study will be undertaken to measure heart rate variability (HRV) indices and detect the severity of cardiac autonomic dysfunction in CLD patients. MATERIALS AND METHODS: This study was conducted on 150 patients with liver cirrhosis and compared with 110 healthy controls. Information concerning medical history, radiological and laboratory findings was extracted for interpretation and association among both groups. The HRV was assessed by recording with a polygraph (RMS Polyrite D, version 1.0), which was based on the principle of electrocardiography. RESULTS: Heart rate variability indices like standard deviation of each interval normal-to-normal (SDNN), percentage of successive RR intervals that differ by >50 ms (pNN50%), high frequency (HF), low frequency (LF), and the LF/HF ratio were found to be remarkably low in cases with CLD in comparison to the healthy control group (p < 0.05). The Child-Pugh (CP) score was class C (10-15) in 52%, class B (7-9) in 30%, and class A (5-6) in 18% of patients. The CP score in CLD patients had a statistically significant negative correlation with SDNN (r = -0.5429, p < 0.001), root mean square of successive differences (RMSSD) (r = -0.375, p < 0.001), pNN50% (r = -0.6037, p < 0.001), HF (r = -0.2033, p = 0.0125), and LF (r = -0.3674, p < 0.001). SDNN, pNN50%, and LF parameters were lowest in alcohol-related CLD, highest in hepatitis C virus (HCV)-related CLD, and intermediate in hepatitis B virus (HBV)-related CLD. CONCLUSION: Our study concluded that liver cirrhosis patients have reduced HRV compared to healthy individuals. A decrease in HRV highlights people at risk of death. This is a variable that can be used to track patients over time and aid in transplant selection.

A Study of Cardiac Autonomic Neuropathy in Patient with Diabetes Mellitus.

BACKGROUND: Atherosclerotic coronary artery disease, diabetic cardiomyopathy, and cardiac autonomic neuropathy (CAN) are the three categories into which the cardiovascular consequences of diabetes can be grouped. After all other potential causes have been ruled out, cardiovascular autonomic neuropathy-often referred to as CAN in the literature-is defined as the impairment of autonomic regulation of the cardiovascular system. Finding people with CAN is crucial because, if detected early enough, comprehensive therapies focusing on lifestyle, glucose management, and cardiovascular risk factors can reverse the course of CAN and delay its progression. In order to better understand CAN in individuals with diabetes mellitus (DM) and how it relates to risk factors, the current study was conducted. MATERIALS AND METHODS: Sixty consecutive diabetic patients were selected to be included in our study, diagnosed as per the American Diabetes Association (ADA) and the European Association for the Study of Diabetes. The presence of CAN was assessed with the help of Ewing's Battery, composed of five bedside tests. OBSERVATIONS: Out of 60 patients, a total of 53 patients (88.3%) with DM had CAN. Of these, 38.3% showed early CAN, 38.3% showed definite CAN, and 7% showed severe CAN. The abnormal E:I (exhalation/inhalation) ratio, noticed in 75% of patients, was the most frequently observed abnormal autonomic function test that tests the parasympathetic nervous system. The ECG's QTc interval prolongation provides good specificity for diagnosing CAN as well as assessing its severity, but the majority of cases showed low sensitivity. CONCLUSION: Since CAN has a significant association with mortality, every patient diagnosed with DM should be evaluated for CAN at the time of diagnosis as well as on an annual basis thereafter, as recommended by the ADA. Optimal glycemic management and lifestyle modification at the initial stages of diabetes may prevent CAN-related complications.

Presence of neuropathy in children and adolescents with type 1 diabetes evaluated with bedside modalities.

AIMS: To investigate the prevalence of diabetic polyneuropathy (DPN), cardiac autonomic neuropathy (CAN) and sudomotor dysfunction in children and adolescents with type 1 diabetes using bedside modalities. Secondly, to evaluate the co-existence of these types of diabetes neuropathies. METHODS: Cross-sectional study including 221 children and adolescents with type 1 diabetes. DPN was assessed by vibration sensation threshold and sural nerve conductance, CAN by cardiac reflex tests and sudomotor function by electrochemical skin conductance. RESULTS: Median (interquartile range) age was 14.2 (11.9, 16.5) years, diabetes duration 4.8 (2.7, 7.7) years and Hba1c 7.1 (6.6, 7.9) %, (54: 49, 63 mmol/mol). Three had retinopathy; all had normal albuminuria. DPN was present in 40 %, early CAN in 17 %, established CAN in 3 % and sudomotor dysfunction in the feet in 5 %. Of these, 60 % had one type of neuropathy, while 35 % had two types. Only 1 participant manifested all three types of neuropathies. CONCLUSIONS: Bedside modalities demonstrated a high prevalence of neuropathy in children and adolescents with type 1 diabetes, despite good glycemic outcome, short diabetes duration and absence of complications. A lack of co-existing neuropathies was shown, underscoring the need for multiple screening modalities.

Paroxysmal Sympathetic Hyperactivity in Childhood Tuberculous Meningitis: A New Association.

BACKGROUND: We sought to estimate the prevalence and clinical characteristics of paroxysmal sympathetic hyperactivity (PSH) in childhood tuberculous meningitis. METHODS: Hospital records of children (6 months to 14 years) with tuberculous meningitis were retrospectively analyzed from September 2019 through January 2022. In September 2019, the first case of paroxysmal sympathetic hyperactivity in tuberculous meningitis was identified in our division. Since then, all admitted children with tuberculous meningitis have been screened for paroxysmal sympathetic hyperactivity using the Paroxysmal Sympathetic Hyperactivity Assessment Measure (PSH-AM). Paroxysmal sympathetic hyperactivity is suspected when any of the following are present: recurrence of fever after initial defervescence, episodic posturing, dystonia, or unexplained tachycardia. Outcome at 3 months was prospectively scored according to the Pediatric Cerebral Performance Category score. RESULTS: Forty-one hospital records of children with tuberculous meningitis were analyzed, and 6 of them had paroxysmal sympathetic hyperactivity (probable paroxysmal sympathetic hyperactivity, 5/6; possible paroxysmal sympathetic hyperactivity, 1/6). Paroxysmal sympathetic hyperactivity appeared after a mean duration of 17 weeks (range: 12-25 weeks) from the diagnosis of tuberculous meningitis in 4 of 6 children and at 4 weeks in 2 of 6 children. Children with tuberculous meningitis who developed paroxysmal sympathetic hyperactivity were younger (median age: 5 years) compared with the nonparoxysmal sympathetic hyperactivity tuberculous meningitis cohort (median age: 10 years). A high proportion of children who developed paroxysmal sympathetic hyperactivity had hydrocephalus at presentation (5 of 6 [83.3%] vs 12 of 35 [34.3%], P = .035). Hospital stay was significantly prolonged in children with probable paroxysmal sympathetic hyperactivity (mean: 71.2 ± 26.8 days) compared with tuberculous meningitis without paroxysmal sympathetic hyperactivity (mean: 20.8 ± 11.6 days; P < .0001). CONCLUSION: Paroxysmal sympathetic hyperactivity is a late complication of tuberculous meningitis observed in 14.6% cases and should be anticipated in children with reappearance of fever or neurologic worsening without any apparent cause.

Autonomic dysfunction as manifestation of ICANS: A case report.

RATIONALE: Anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy is a successful treatment for B-cell malignancies associated with cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Cardiovascular toxicities have also been reported in this setting. However, there is scarce data regarding development of autonomic disorders after CAR-T cell therapy. PATIENT CONCERNS: We report a case with a patient with non-Hodgkin B-cell lymphoma, refractory to 2 prior lines of immunochemotherapy, treated with CAR-T therapy. DIAGNOSES: Orthostatic hypotension secondary to autonomic dysfunction was diagnosed as manifestation of ICANS. INTERVENTIONS: The patient received metilprednisolone 1000 mg IV daily for 3 days and anakinra 100 mg IV every 6h. OUTCOMES: The vast majority of autonomic symptoms ceased and 4 months after CAR-T therapy, autonomic dysfunction was resolved. LESSONS: New-onset autonomic dysfunction can occur as manifestation of ICANS in patients who experience persistent neurologic and cardiovascular symptoms after resolution of acute neurotoxicity and should be early recognized. Differences in differential diagnosis, mechanisms and treatment approaches are discussed.

Harlequin sign due to an upper thoracic paravertebral lesion. A systematic review of the literature.

INTRODUCTION: Harlequin syndrome (HS) is an uncommon condition affecting the sympathetic nervous system, characterized by asymmetrical flushing and sweating impairment, which can affect the face or half of the body. When the dysfunction results from external factors like damage or compression, it's referred to as Harlequin Sign. Our objective was to document an exceedingly rare presentation of Harlequin Sign caused by a T3-T4 paravertebral mass and conduct the first systematic literature review on this subject. METHODS: We conducted a systematic review of English-language studies using PubMed, Scopus, and Embase databases. We excluded abstracts, posters, congenital and idiopathic Harlequin Syndrome cases, as well as iatrogenic and secondary Harlequin Sign cases related to pathologies other than upper thoracic lesions. RESULTS: We employed the PRISMA protocol and reviewed 1,538 papers, identifying 8 single case reports describing the Harlequin sign resulting from upper thoracic paravertebral lesions. The mean age of the patients was 41.25 years, with 6 (75 %) being female. The average time from onset to presentation was 8 months, and all patients (100 %) exhibited hemifacial flushing, while 4 (50 %) also had hemifacial anhidrosis. Stress or exercise exacerbated these symptoms in 50 % of cases. Additionally, 3 patients (37.5 %) presented with associated Horner Syndrome. The most commonly used diagnostic tool was a CT scan (50 %), revealing an average tumor diameter of 3.95 cm, with 50 % of cases located at T2-T3. Diagnosis indicated 57 % of cases as schwannomas and 29 % as lung adenocarcinoma (Superior Sulcus). Unfortunately, surgical treatment resolved symptoms in only 25 % of patients. CONCLUSIONS: Hemifacial or hemibody autonomic symptoms should raise concern for paraspinal lesions in the thoracic spine. In addition to the first comprehensive review on this topic, we present a rare case of a T3/4 paraspinal schwannoma causing Harlequin Syndrome successfully managed with neurosurgical intervention.

Prevalence of cardiovascular autonomic neuropathy in an admixed population of patients with type 1 diabetes. Lessons from a pioneer multicentre study in Brazil.

AIMS: To evaluate the prevalence of cardiovascular autonomic neuropathy (CAN) and its associated factors in Brazilian patients with type 1 diabetes (T1D). METHODS: This cross-sectional, multicentre study was conducted in 14 public clinics in ten Brazilian cities. From 1760 patients, 1712 were included (97.3 %): 953 females (55.7 %), 930 (54.3 %) Caucasians, aged 29.9 ±11.9 years and with diabetes duration of 15.4 ± 9.2 years. CAN was evaluated using cardiovascular autonomic reflex tests. RESULTS: The prevalence of CAN was 23.4 %. Multivariable hierarchical logistic regression showed CAN associated with age, smoking, lower socioeconomic status, higher yearly medical appointments, insulin therapeutic regimens, higher levels of HbA1c, total cholesterol, uric acid, diastolic blood pressure and heart rate, presence of retinopathy, diabetic kidney disease and a tendency to be associated with severe hypoglycemia. Lower health-related quality of life was also found in univariate analysis in these patients. CONCLUSIONS: Patients with T1D presented an important prevalence of CAN that was associated with other diabetes-related chronic complications, and also with demographic, clinical and laboratorial traditional risk factors. Considering lack of formal policy, our data could be used for guiding public health approach to awareness and CAN's screening, diagnosis and clinical management in patients with T1D in Brazil.

Heart rate deceleration capacity as a marker of perioperative risk: identifying relevant patient phenotypes and surgical procedures.

Loss of regulation of the autonomic nervous system is found in many diseases from the age of 50 to 60 yr and even more so in older patients. The imbalance is usually manifested by an increase in sympathetic tone, long considered to be the most deleterious element in terms of cardiac rhythmic risk, but also by a reduction in the effectiveness of short-term regulation of the baroreflex arc (partial loss of parasympathetic control). Techniques for analysing this autonomic disorder by analysing heart rate regulation are widely available in outpatient clinics and provide interesting indicators of cardiovascular and cerebrovascular risk. Deceleration capacity of cardiac autonomic control has been identified for its prognostic role in high-risk patients and in the general population. Further research is indicated to assess the value of this marker in anaesthetic risk management by targeting procedures with greater risk of intraoperative and postoperative autonomic dysfunction.

Power modulation spectrum - a promising approach for the indispensable quality control of electrocardiogram signals from monitoring units for the detection of autonomic dysfunction.

OBJECTIVE: Electrocardiogram (ECG) is essential for evaluating the autonomic nervous system. Ensuring the quality of real-world ECG datasets is critical, but manual control of large datasets is impractical. Thus, automated quality control is necessary. This paper introduces a new quality index, the peak-distance quality index (PDQI), based on the modulation spectrum approach. METHODS: Real-life data from 1000 ECG recordings, each 600 s long, were collected at the stroke unit of the University Hospital Tulln. Each ECG was visually evaluated, including the duration of the signal, artefacts and noise, and the number of extrasystoles. The power-modulation spectrum, the percentage of ECG in each signal, and modulation spectrum-based quality index (MS-QI) and PDQI were calculated. The area under the curve (AUC) for the detection of high-quality ECGs was calculated for both quality indices, as well as the optimal threshold for each index. RESULTS: The percentage of ECG signals in the recordings based on the modulation spectrum correlates with expert rating (r = 0.99, p < 0.001). The AUC for PDQI for the detection of extrasystoles is 0.96, and the AUC for MSQI for the detection of artefacts is 0.83. The optimal thresholds for PDQI and MSQI are 0.44 and 0.17, respectively CONCLUSION: The power modulation spectrum can be applied to large amounts of data to detect ECG signals within biosignals and calculate quality indices. MSQI can be used for artefact detection and PDQI for extrasystole detection in ECG signals. A combined approach using both quality indices can provide a picture of the underlying data quality.

Compromised cardiac autonomic function in non-diabetic subjects with 1 h post-load hyperglycemia: a cross-sectional study.

BACKGROUND: A compromised cardiac autonomic function has been found in subjects with insulin resistance related disorders such as obesity, impaired glucose tolerance (IGT) and type 2 diabetes and confers an increased risk of adverse cardiovascular outcomes. Growing evidence indicate that 1 h plasma glucose levels (1hPG) during an oral glucose tolerance test (OGTT) ≥ 155 mg/dl identify amongst subjects with normal glucose tolerance (NGT) a new category of prediabetes (NGT 1 h-high), harboring an increased risk of cardiovascular organ damage. In this study we explored the relationship between 1 h post-load hyperglycemia and cardiac autonomic dysfunction. METHODS: Presence of cardiac autonomic neuropathy (CAN) defined by cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV), assessed by 24-h electrocardiography were evaluated in 88 non-diabetic subjects subdivided on the basis of OGTT data in: NGT with 1 h PG < 155 mg/dl (NGT 1 h-low), NGT 1 h-high and IGT. RESULTS: As compared to subjects with NGT 1 h-low, those with NGT 1 h-high and IGT were more likely to have CARTs defined CAN and reduced values of the 24 h time domain HVR parameters including standard deviation of all normal heart cycles (SDNN), standard deviation of the average RR interval for each 5 min segment (SDANN), square root of the differences between adjacent RR intervals (RMSSD), percentage of beats with a consecutive RR interval difference > 50 ms (PNN50) and Triangular index. Univariate analyses showed that 1hPG, but not fasting and 2hPG, was inversely associated with all the explored HVR parameters and positively with CARTs determined presence of CAN. In multivariate regression analysis models including several confounders we found that 1hPG was an independent contributor of HRV and presence of CAN. CONCLUSION: Subjects with 1hPG ≥ 155 mg/dl have an impaired cardiac autonomic function.

Autonomic neuropathy in dialysis patients - investigations with a new symptom score (COMPASS 31).

BACKGROUND: Symptoms of autonomic neuropathy (AN) are common in patients with diabetes and advanced renal disease. As yet different domains of autonomic neuropathy cannot be detected by a singular laboratory or invasive test. COMPASS 31, a new self-assessment test, has shown reliable results not only in cardiac autonomic neuropathy but also in different sub-domains when judging manifestation of AN by scores. METHODS: One hundred eighty-three patients with or without diabetes were enrolled, one hundred nineteen of them were treated with permanent dialysis therapy (HD), sixty-four patients served as controls (eGFR > 60 ml/min.) Using COMPASS 31 different symptoms of AN were assessed (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, pupillomotor changes) and transferred into AN-scores. RESULTS: AN was more pronounced in dialysis patients compared with controls (AN-score 27,5 vs. 10,0; p < 0,01). These differences were present also in every sub-domain of AN (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, pupillomotor changes; p < 0,05 for all sub-domains). In diabetic patients there was a strong correlation between symptoms of AN and diabetes duration (correlation coefficient r = 0,45, p < 0,001). Current glycemic control (HbA1c), body mass index (BMI), sex, and height had no influence on AN when comparing dialysis patients and controls. C-reactive protein (CRP) showed a positive linear correlation with AN-scores (correlation coefficient r = 0,21; p < 0,05). CONCLUSION: Symptoms of AN are more pronounced in dialysis patients not only in total but also in all different domains of neuropathic changes. Longlasting diabetic disease promotes development of AN, as duration of diabetes was positively correlated with AN. Future longitudinal studies might help to identify the high cardiovascular and mortality risk in dialysis patients by the easy-to-use COMPASS 31 without need of invasive and time-spending methods for diagnosing AN.

Harlequin syndrome in a patient with probable hemicrania continua and exertional headache - is there a link? a case report.

BACKGROUND: The harlequin syndrome is a rare disorder of the autonomic nervous system characterized by unilateral diminished flushing and sweating of the face following exposure to heat or physical activity. It results from sympathetic dysfunction and most commonly occurs idiopathically. A secondary development due to an underlying pathology (e.g., carotid artery dissection, tumors) must be excluded at first appearance. There is evidence that the cranial autonomic system is involved in the pathophysiology of trigeminal autonomic headaches like hemicrania continua. Therefore, an overlap in the pathophysiology of harlequin syndrome and trigeminal autonomic headache disorders seems plausible. However, the association of a harlequin syndrome with hemicrania continua was never reported. CASE PRESENTATION: This work describes the case of a 42-year-old female patient presenting to our headache unit. The patient reported persisting unilateral headache of the right side of dragging or squeezing character accompanied by trigeminal autonomic symptoms, including lacrimation, nasal congestion, conjunctival injection and Horner's syndrome, and was responsive to treatment with 75mg/d indomethacin. Five months after the initial consultation, the patient noted that the upper right quadrant of her face was pale after jogging. A harlequin syndrome was diagnosed. Further, she developed a short-lasting, bilateral headache of pulsatile character during strenuous exercise consistent with exertional headache. Comprehensive diagnostic evaluations, encompassing cranial and cervical MRI scans, laboratory tests, and biopsies, culminated in the diagnosis of Sjögren's syndrome. This finding suggests that the trigemino-autonomic dysfunction may either be idiopathic or a direct manifestation of Sjögren's syndrome. CONCLUSIONS: This report documents the case of a rare combination of a headache resembling probable hemicrania continua and the harlequin syndrome (and even exertional headache). It illustrates the underlying anatomy of the autonomic nervous system in a clinical context and emphasizes the hypothesis of a pathophysiological link between abnormal sympathetic activity and trigeminal autonomic headaches.

Reduced autonomic function in patients with long-COVID-19 syndrome is mediated by cardiorespiratory fitness.

BACKGROUND: Long-COVID-19 syndrome (LCS) exhibits neurological problems such as peripheral neuropathy and autonomic nervous system (ANS) dysfunction. Exercise intolerance and, consequently, low cardiorespiratory fitness (CRF) are some of the most common symptoms of LCS. We describe a series of individuals exhibiting LCS symptoms compared to a control group and posit that this condition may be related to the exercise capacity-mediated disruption of the ANS resulting particularly in exercise intolerance. METHODS: This study included 87 individuals with LCS and 71 control participants without COVID-19 diagnoses. Heart rate variability (HRV) in supine position is commonly measured to diagnose autonomic dysregulation and subsequently analyzed using the Kubios software (Kuopio, Finland). CRF (peak VO2), post-COVID-19 patient-reported symptoms, maximal muscle strength (grip strength, bilateral leg press, leg extension, pectoral press, and back press exercises), and body composition were also measured. Analysis of covariance (ANCOVA) and mediation analysis were employed to assess the associations among LCS, peak VO2, and HRV indicators. Two-sided p < 0.05 was considered as significant. RESULTS: The HRV parameters-RR interval, RMSSD, SDNN, PNS index, LF, HF, total power, SD1, and SD2-were significantly elevated (p < 0.05) in the control group when compared to the LCS patients. In contrast, the HR, stress index, and SNS index parameters were significantly higher (p < 0.05) in the LCS group. When adjusted for RR intervals, these parameters remained statistically significant (p < 0.05). A partially mediated effect was found between peak VO2 and RMSSD (mediation effect = 24.4%) as well as peak VO2 and SDNN (mediation effect = 25.1%) in the LCS patients. CONCLUSIONS: These findings contribute new insights on the interplay between CRF and HRV indicators as well as endorse that dysautonomia may be related to the low peak VO2 observed in long COVID-19 patients.

Clinical Assessment of the Autonomic Nervous System.

This review explores standardized clinical assessments for evaluating autonomic nervous system function. Here, we emphasize components of the autonomic medical history as the first pivotal test of the autonomic assessment. We further focus on standard noninvasive cardiovascular autonomic tests including heart rate responses to deep breathing, Valsalva maneuvers, and orthostatic challenges, along with insights from neurochemical tests and quantitative sudomotor axon reflex testing. The article also covers practical aspects of cardiovascular autonomic monitoring, including patient set-up using beat-to-beat blood pressure and ECG, specific assessment protocols, and their respective clinical interpretations that provide insight into adrenergic, cardiovagal, and sudomotor function.

The association of diabetic peripheral neuropathy with cardiac autonomic neuropathy in individuals with diabetes mellitus: A systematic review.

This systematic review aimed to explore the relationship between diabetic peripheral neuropathy (DPN) and cardiac autonomic neuropathy (CAN) in individuals with type 1 and 2 diabetes mellitus (DM). METHODS: The systematic review follow the protocol registered in Prospero (CRD42020182899). Two authors independently searched the PubMed, Scopus, Embase, Cochrane, and Web of Science databases. Discrepancies were resolved by a third author. The review included observational studies investigating the relationship between CAN and DPN in individuals with DM. RESULTS: Initially, out of 1165 studies, only 16 were selected, with 42.8 % involving volunteers with one type of diabetes, 14.3 % with both types of diabetes and 14.3 % not specify the type. The total number of volunteers was 2582, mostly with type 2 DM. It was analyzed that there is a relationship between CAN and DPN. It was observed that more severe levels of DPN are associated with worse outcomes in autonomic tests. Some studies suggested that the techniques for evaluating DPN might serve as risk factors for CAN. CONCLUSION: The review presents a possible relationship between DPN and CAN, such as in their severity.

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.