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.

Insight of autonomic dysfunction in CLN3 disease: a study on episodes resembling paroxysmal sympathetic hyperactivity (PSH).

BACKGROUND: Recurrent non-epileptic episodes resembling paroxysmal sympathetic hyperactivity (PSH) have been observed in adolescents with Juvenile Ceroid Lipofuscinosis (CLN3-disease) and a possible association to an autonomic dysfunction has been suggested. The objective of the present study was to investigate the dynamics of the autonomic activity up to, during, and in the time after individual attacks. We include all seven suitable CLN3 patients in Denmark ≥ 15 years of age. HRV parameters were assessed from continuous heart rate monitoring during seven consecutive days and a particular focus of HRV parameters was obtained in close temporal context to clinically recurrent PSH-like episodes. In addition, the likelihood of PSH was assessed by caregiver's description and by video documentation. RESULTS: Respectively eight and five episodes were recorded in two patients (18 and 20 years of age). The episodes were all safely superior to the cut off values of the clinical assessment score to be considered PSH-like episodes. During all 13 episodes, HRV revealed a statistically significant decrease in root mean square of successive differences (RMSSD) and standard deviation of the Poincaré-Plot interval (SD1) in the minutes prior to the clinical onset of the episodes, both indicating a sudden decrease in parasympathetic activity in advance of the onset. The reduced activity remained low during the episodes, and 15-30 min following the attack cessation, the parasympathetic activity had returned to pre-attacks levels. The sympathetic HRV parameters were unchanged resulting in a sympathetic overactivity during the episodes. In a third participant (32 years of age), in whom severity of PSH-like episodes had been gradually reduced during the last years, five episodes were registered. A similar temporally related reduction of the parasympathetic activity was found, but because the sympathetic activity decreased as well, no sympathetic dominance developed, which most reasonable is the reason to the clinically reduced expression of the episodes. CONCLUSION: The documented transient withdrawal of parasympathetic activity leading to a paroxysmal unbalanced sympathetic hyperactivity most probably accounts for the PSH-like episodes occurring in post-adolescent CLN3 patients. The findings shed new light on both aetiology and possible preventative and therapeutic measures.

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.

Influence of autonomic nervous dysfunction on eating during hemodialysis sessions: An observational study.

Although some studies have indicated that eating during hemodialysis may induce hypotension and cardiovascular events, some patients still consume food during their treatment. This prospective study was conducted to determine whether the need to eat during hemodialysis treatment was related to abnormal glucose metabolism and autonomic nerve dysfunction. Seventy patients were enrolled in this study, and their demographic features and various laboratory parameters were analyzed. At each routine hemodialysis visit, predialysis, intradialysis, and postdialysis blood pressure measurements were systematically conducted. A 24-hour ambulatory electrocardiogram (ECG) was performed during the hemodialysis interval, and heart rate variability (HRV) values were calculated. Additionally, whether the patients ate during the hemodialysis treatments was recorded. Another 20 people who underwent physical examinations during the same period and were matched for sex and age were included in the control group. The HRV values of the hemodialysis patients were generally lower than those of the control group. Univariate analysis revealed significant differences in sex, age, calcium antagonist use, blood calcium levels, insulin levels, diastolic blood pressure (DBP) measurements, and HRV indices between hemodialysis patients who ate and those who did not eat during hemodialysis (P < .05), whereas there were no significant differences in diabetes status or in the hemoglobin, albumin, blood glucose and C-peptide levels (P > .05). Multivariate analysis revealed that low values for very low frequency (VLF) and postdialysis DBP were risk factors for fasting intolerance during hemodialysis treatments. Autonomic dysfunction may affect whether hemodialysis patients tolerate fasting during dialysis. VLF evaluation may provide information that can be used to develop a more reasonable intradialytic nutritional supplementation method.

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.

Hypertension and its correlation with autonomic nervous system dysfunction, heart rate variability and chronic inflammation.

OBJECTIVE: This study investigates the relationship between hypertension, dysregulation of the autonomic nervous system, heart rate variability (HRV), and chronic inflammation. METHODS: We analysed a cohort of 50 hypertensive patients treated at the affiliated Hospital of Jianghan University. The average systolic and diastolic blood pressures (BPs) in this group were 155.26 and 95.32 mmHg, respectively. A control group of 50 healthy volunteers, undergoing routine physical examinations at the same hospital, was also analysed. RESULTS: The average systolic BP of the control group was 115.64 ± 10.27 mmHg, and the average diastolic BP was 75.33 ± 8.25 mmHg. In contrast, the experimental group exhibited an average systolic BP of 155.26 ± 20.13 mmHg and an average diastolic BP of 95.32 ± 12.16 mmHg. Both systolic and diastolic BPs were significantly higher in the hypertensive group (p < 0.05). The experimental group also demonstrated reduced HRV and skin conductance response, alongside increased BP variability (BPV), urinary epinephrine levels and prolonged pupillary light reaction time compared to controls (p < 0.05). Notably, Standard Deviation of Normal to Normal Intervals (SDNN) and Root Mean Square of Successive Differences (RMSSD) values were significantly lower in the experimental group (p < 0.05). Furthermore, levels of inflammatory markers such as CRP, TNF-α, IL-6 and IL-1ß were markedly elevated in hypertensive patients (p < 0.05). Negative correlations were observed between systolic and diastolic BP with HRV metrics, while positive correlations were found between BP and BPV as well as urinary adrenaline levels. CONCLUSIONS: The findings indicate that hypertension is closely associated with autonomic nervous system dysfunction, reduced HRV and increased chronic inflammation. A comprehensive approach to hypertension management should integrate these interrelated physiological and pathological mechanisms, with potential therapeutic interventions targeting autonomic function and inflammatory states.

Hypertension represents a global health challenge. Autonomic nervous system dysfunction and chronic inflammation assumes a pivotal role in hypertension pathogenesis. Reduced heart rate variability (HRV) is a surrogate marker of autonomic dysfunction. This study endeavours to elucidate the intricate relationship between hypertension and autonomic dysfunction, HRV and chronic inflammation, thereby advancing our comprehension of hypertension pathophysiology.

Comparison of autonomic nervous system dysfunction, arterial stiffness, and heart rate recovery according to spinal cord injury level.

OBJECTIVE: To investigate the differences in autonomic nervous system (ANS) dysfunction, arterial stiffness, and the degree of delay in post-exercise heart rate recovery (HRR) according to the level of spinal cord injury (SCI), and propose preventive measures against cardiovascular diseases after SCI. METHODS: This retrospective study included 51 patients with SCI. Based on the neurological level of injury (NLI), patients were divided into two groups: Group A (NLI at and above T6) and Group B (NLI below T6). To assess ANS dysfunction, the head-up tilt test and 24-hour ambulatory blood pressure monitoring were conducted. Arterial stiffness was measured using the pulse wave velocity test. The exercise tolerance test was conducted to measure post-exercise HRR. RESULTS: Group A had significantly higher values in the head-up tilt test and 24-hour ambulatory blood pressure monitoring. In the pulse wave velocity test, both sides (left and right) had significantly higher values in Group B. One minute after the exercise tolerance test, Group A had significantly slower HRR (18.8 ± 11.1 beats/minute) than Group B. CONCLUSION: Understanding the impact of ANS dysfunction and arterial stiffness on HRR in SCI according to NLI may provide insights for clinical management and preventative strategies for cardiovascular diseases.

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.

Direct current stimulation as a non-invasive therapeutic alternative for treating autonomic or non-autonomic neurological disorders affecting breathing.

Direct current stimulation (DCS) is a non-invasive approach to stimulate the nervous system that is now considered a powerful tool for treating neurological diseases such as those affecting cognitive or locomotor functions. DCS, as applied clinically today, is an approach built on early uses in antiquity and knowledge gained over time. Its current use makes use of specific devices and takes into account knowledge of the mechanisms by which this approach modulates functioning of the nervous system at the cellular level. Over the last 20 years, although there are few studies, it has been shown that DCS can also modulate the breathing autonomic function. In this narrative review, after briefly providing the historical perspective and describing the principles and the main cellular and molecular effects, we summarize the currently available data regarding the modulation of ventilation, and propose that DCS could be used to treat autonomic or non-autonomic neurological disorders affecting breathing.

Monoaminergic degeneration, cognition, and autonomic symptom trajectory in early Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) encompasses a range of non-motor symptoms attributed to deficits in various neurotransmitter systems. This study aimed to investigate the associations between cognitive and autonomic symptoms and the degeneration of brainstem monoaminergic nuclei, particularly the serotonergic and noradrenergic nuclei, in a prospective cohort of early PD patients. METHODS: Twenty-eight early PD patients (with an average disease duration of approximately three years) underwent baseline [18F]FP-CIT positron emission tomography (PET) scans, Montreal Cognitive Assessment (MoCA), and Composite Autonomic Symptom Scale-31 (COMPASS-31) evaluations, followed by repeat MoCA and COMPASS-31 assessments three years later. Regression models were utilized to analyze both cross-sectional and longitudinal changes in non-motor symptoms relative to baseline degeneration of the noradrenergic locus coeruleus (LC) and serotonergic raphe, normalized by striatal dopaminergic terminal loss. RESULTS: Baseline LC and raphe degeneration in early PD was cross-sectionally associated with poorer MoCA performances. Over the three-year follow-up, gastrointestinal symptoms exhibited progression, while cognitive scores remained stable. Profound baseline degeneration of the LC and raphe, relative to nigrostriatal terminal loss, were predictive of subsequent accelerated deterioration in gastrointestinal symptoms. CONCLUSION: Brainstem non-dopaminergic dysfunction in early PD is linked to cognitive dysfunction and predicts progression in gastrointestinal symptoms, offering potential indicators for worsening non-motor trajectories.

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.

Carotid baroreceptor dysfunction after carotid body tumour resections.

OBJECTIVE: Carotid body tumours (CBTs) and baroreceptor failure (BRF) are two distinct but interrelated conditions, affecting the carotid body and its regulatory mechanisms. We aim to describe and quantify BRF after unilateral and bilateral CBT resections. METHODS: Prospective cohort study. We included all patients with unilateral or bilateral CBT undergoing resection from April 2021 to January 2023. Demographics and CBTs characteristics were analysed; baroreceptor sensitivity assessment was conducted using the Composite Autonomic Severity Score (CASS). Statistical analyses were performed using R. Significance level was set at a 2-tailed α = 0.05. RESULTS: A total of 30 patients with CBT underwent surgical resection, twenty-three were included in the study (18 unilateral and 5 bilateral CBTs). All 23 (100 %) were females, median age of 60 years. Regarding patients with unilateral CBT; preoperatively, 13 had BRF, the most common dysfunction subtype was mixed. Postoperatively, the most common dysfunction subtype was sympathetic failure. With regards to bilateral CBTs; 2 patients did not have autonomic dysfunction preoperatively. After bilateral surgical resection one patient remained without autonomic dysfunction; however, all other patients persisted with BRF. CONCLUSION: BRF was present in 13 patients with unilateral CBT and 3 patients with bilateral tumours preoperatively; most will remain with BRF and will only change the characteristics postoperatively. No associations were found between type, severity of BRF and Shamblin classification or laterality. It is paramount that research in this area continues as many features are yet unknown regarding CBT pathogenesis, hence, BRF may be present yet not affect significantly quality of life.

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.

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.

Cardiovascular autonomic and peripheral sensory neuropathy in women with obesity.

Introduction: A higher incidence of neural dysfunction in people with obesity has been described. We determined the prevalence of neuropathic lesions in obese women and evaluated their potential association with anthropometric and laboratory parameters. Patients and methods: In our cross-sectional study, we enrolled female patients with obesity and without diabetes before obesity treatment. Voluntary female subjects were controls with a normal body mass index (BMI). Autonomic function was assessed by Ewing's cardiovascular reflex tests, while comprehensive peripheral neuropathic assessments were conducted utilizing the Neurometer®, Tiptherm®, Monofilament®, and Rydel-Seiffer tuning fork tests. Sudomotor function was assessed by the Neuropad®-test. Body composition was examined using the InBody 770. Results: 71 patients (mean ± SD; age: 36.1 ± 8.3 years; BMI: 40.2 ± 8.5 kg/m2) and 36 controls (age: 36.4 ± 13.3 years; BMI: 21.6 ± 2.1 kg/m2) were enrolled. Patients had significantly higher systolic (patients vs. controls; 137.5 ± 16.9 vs. 114.6 ± 14.8 mmHg, p<0.001) and diastolic (83.0 ± 11.7 vs.69.8 ± 11.2 mmHg, p<0.001) blood pressure compared to controls. Among autonomic tests, only the heart rate response to Valsalva maneuver (Valsalva-ratio) revealed significant impairment in patients (1.4 ± 0.2 vs. 1.7 ± 0.4, p<0.001). Neurometer® at the median nerve revealed increased current perception threshold (CPT) values at all stimulating frequencies in patients (CPT at 2000 Hz: 204.6 ± 70.9 vs. 168.1 ± 66.9, p=0.013; 250 Hz: 84.4 ± 38.9 vs. 56.5 ± 34.8, p<0.001; CPT at 5 Hz: 58.5 ± 31.2 vs 36.9 ± 29.1, p<0.001). The Rydel-Seiffer tuning fork test has revealed a significant impairment of vibrational sensing on the lower limb in patients (right hallux: 6.8 ± 0.9 vs. 7.4 ± 0.8, p=0.030; left hallux: 6.9 ± 0.8 vs. 7.3 ± 0.9, p=0.029). The Neuropad® testing showed a significant impairment of sudomotor function in women with obesity. A negative correlation was found in patients between BMI and the 25-hydroxy-D3/D2-vitamin levels (r=-0.41, p=0.00126) and a positive correlation between the BMI and resting systolic blood pressure (r=0.26, p=0.0325). Conclusion: Peripheral sensory neuronal and sudomotor function impairments were detected in female patients with obesity compared to the controls with normal BMI. Cardiovascular autonomic dysfunction was also revealed by the Valsalva-ratio in these patients, suggesting the presence of parasympathetic dysfunction. The negative correlation between BMI and the 25-hydroxy-D3/D2-vitamin highlights the potential deficiency of vitamin D in the population affected by obesity.

Sleep Apnea, Autonomic Disturbances, and Blood Pressure Variability.

Augmented blood pressure variability has emerged as a quantity predictive of adverse cardiovascular outcomes. Among the range of intrinsic and extrinsic factors shown to increase night-time, circadian, short-term, and long-term blood pressure variations, the presence and severity of obstructive sleep apnea have emerged as one of the most prevalent and potent. Obstructive sleep apnea alters acutely the normal nocturnal equilibrium between sympathetic and parasympathetic tone, magnifying nocturnal blood pressure oscillations, and induces sustained autonomic aftereffects with the capacity to amplify short-term and intersessional blood pressure variabilities. The object of this brief review is to synthesize the current understanding of the potential interrelations between obstructive sleep apnea, the acute and sustained autonomic disturbances that it elicits, and beat-to-beat blood pressure fluctuation during sleep, nocturnal dipping status, and day-to-day blood pressure variability and the consequences of these perturbations for cardiovascular risk.

Autonomic Dysfunction in Amyotrophic Lateral Sclerosis - A Case-Control Study.

INTRODUCTION: This study aimed to explore autonomic nervous system involvement in amyotrophic lateral sclerosis (ALS) patients by evaluating sympathetic skin response (SSR). MATERIALS AND METHODS: The study included 35 sporadic (ALS) patients (cases), and 35 healthy age and sex-matched participants (controls) aged <60 years. SSR was recorded in the electrophysiology lab of the Neurology Department of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Patients with diseases associated with peripheral or autonomic neuropathy were excluded. Prolonged latency (delayed SSR) or an absent response was considered abnormal SSR. RESULTS: SSR was found to be abnormal in 17 (48.6 %) ALS cases, with an absent response in the upper limbs of six cases (17.1%). Abnormal SSR was more prevalent in the lower limbs, with 33 (94.3%) and 20 (57.1%) cases having a delayed or absent response, respectively. In comparison, SSR was normal in all control participants (P-value <0.05). Abnormal SSR was significantly more common in the lower limbs of ALS cases with bulbar palsy than those without bulbar palsy (P-value=0.04). There was no association of SSR with disease severity and duration. CONCLUSION: ALS is significantly associated with abnormal SSR, indicating autonomic nervous system involvement. There could also be an association between bulbar palsy and abnormal SSR among ALS patients. Further studies should be carried out to determine the association of abnormal SSR with disease severity, duration, and type.

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.