Postural orthostatic tachycardia syndrome in a Thai male patient.

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous autonomic disorder. All patients have exaggerated tachycardia upon standing, but the pathophysiology may be diverse. We present a young adult Thai male with a chief complaint of palpitations while in an upright posture since childhood. The patient underwent a modified Ewing test battery which included standing test, deep breathing, and Valsalva maneuver. His heart rate increased more than 30 beats per minute (bpm) during repeated active stand tests (65 to 110 bpm and 77 to 108 bpm), while upright diastolic blood pressure increased more than 10 mmHg. Normal Valsalva ratio (2.01 and 1.86) and baseline heart rate variability (HFRRI = 4030.24 ms2 and 643.92 ms2) indicated intact vagal function. High low-frequency systolic blood pressure variability (LFSBP = 20.93 mmHg2), increased systolic blood pressure overshoot in phase IV of Valsalva (42 mmHg), and increased upright diastolic blood pressure indicated a hyperadrenergic state. In conclusion, the overall autonomic profile was compatible with hyperadrenergic POTS. Thus, we confirmed the first male POTS case reported in Thailand. We demonstrated the importance of autonomic function testing with continuous measurements to confirm POTS. There is a need for further research in POTS in Thailand.

A Pilot Study of Autonomic Function Screening Tests for Differentiating Complex Regional Pain Syndrome Type II and Traumatic Neuropathic Pain.

Background and Objectives: One of the most challenging tasks in a clinical setting is to differentiate between complex regional pain syndrome (CRPS) type II and traumatic neuropathic pain (NeP). CRPS is characterized by several dysautonomic manifestations, such as edema, hyper/hypohidrosis, skin color change, and tachycardia. This study compared the outcomes of autonomic function screening tests in patients with CRPS type II and traumatic NeP for diagnostic differentiation. Materials and Methods: CRPS type II was diagnosed according to the Budapest research criteria, while NeP was diagnosed according to the updated grading system suggested by the International Association for the Study of Pain Special Interest Group on Neuropathic Pain in 2016. Twenty patients with CRPS type II and twenty-five with traumatic NeP were investigated. Results: Twelve patients with CRPS type II presented abnormal results for the quantitative sudomotor axon reflex test (QSART). Abnormal QSART results were more common in the CRPS type II group. Conclusions: Analysis of QSART combined with other ancillary tests can help in the differential diagnosis of CRPS type II and traumatic NeP if factors influencing abnormal QSART are sufficiently controlled.

Correlation between cotinine urinary levels & cardiovascular autonomic function tests among smokeless tobacco chewers: A cross-sectional study.

BACKGROUND & OBJECTIVES: Cardiovascular disease (CVD), the leading cause of death worldwide is responsible for over 17 million deaths globally, of which 10 per cent deaths have been expected due to consumption of tobacco. The association between CVD and chewing of tobacco is limited and remains arguable. The aim of this study was to find out the correlation between urinary cotinine level and cardiovascular autonomic function tests of tobacco chewers. METHODS: In the present study, 600 participants, 300 smokeless tobacco chewers (STC) and 300 non-tobacco chewers (NTC), between 18 and 65 yr were selected. Various parameters such as anthropometric, systolic blood pressure (SBP), diastolic blood pressure (DBP), autonomic function tests and urinary cotinine levels were measured. RESULTS: Significant difference (P<0.001) was noted in STC and NTC for anthropometric parameters, SBP, DBP and urinary cotinine levels. Sympathetic and parasympathetic autonomic function test showed significant difference on comparison in STC and NTC groups, except in Valsalva ratio. Correlations with urinary cotinine levels were significant for sympathetic autonomic functions, SBP fall (r=0.138, P=0.016), DBP rise (r=-0.141, P≤0.014); parasympathetic autonomic function, heart rate (HR) response to standing (r=-0.208, P≤0.003), deep breathing (r=-0.473, P≤0.001) and Valsalva ratio (r=-0.396, P≤0.0001). INTERPRETATION & CONCLUSIONS: Correlation between urinary cotinine levels and autonomic function tests elucidates the linkage involving autonomic nervous system damage which can be considered as an important associated relationship for early diagnosis of CVD health risk factors among smokeless tobacco (ST) users.

Heart rate variability and baroreflex sensitivity abnormalities in Guillain-Barré syndrome: a pilot study.

OBJECTIVE: The current study aimed to investigate autonomic dysfunction in Guillain-Barré syndrome (GBS) patients and describe the results of computational heart rate variability (HRV)/baroreflex sensitivity (BRS) and autonomic challenge tests. METHODS: GBS patients were consecutively recruited and the results were compared to age- and gender-matched healthy controls. A series of autonomic function tests including computation-dependent tests (power spectrum analysis of HRV and BRS at rest) and challenge maneuvers (deep breathing, eyeball compression, active standing, the Valsalva maneuver, sustained handgrip, and the cold pressor test) were performed. RESULTS: Ten GBS patients (six men; mean age = 40.1 ± 13.9 years) and ten gender- and age-matched healthy controls were recruited. The mean GBS functional grading scale at disease plateau was 3.4 ± 1.0. No patients required intensive care unit admission or mechanical ventilation. Low-frequency HRV (p = 0.027), high-frequency HRV (p = 0.008), and the total power spectral density of HRV (p = 0.015) were significantly reduced in patients compared to controls. The mean up slope (p = 0.034), down slope (p = 0.011), and total slope (p = 0.024) BRS were significantly lower in GBS patients. The diastolic rise in blood pressure in the cold pressor test was significantly lower in GBS patients compared to controls (p = 0.008). INTERPRETATION: Computation-dependent tests (HRV and BRS) were more useful for detecting autonomic dysfunction in GBS patients, whereas the cold pressor test was the only reliable challenge test, making it useful as a bedside measure of autonomic function in GBS patients.

Potential Association of Triglyceride Glucose Index with Cardiac Autonomic Neuropathy in Type 2 Diabetes Mellitus Patients.

Cardiac autonomic neuropathy (CAN) is a common and most neglected complication of diabetes, estimated to be roughly 8% in recently diagnosed patients and greater than 50% in patients with chronic disease history. The insulin resistance (IR) itself is bidirectionally associated with increased risk of type 2 diabetes mellitus (T2DM) and CAN is a predisposing factor. The primary objective of the present study was aimed to find a correlation of triglyceride glucose index (TyG index) in CAN patients along with the prevalence of CAN in T2DM patients as a secondary objective. This prevalence study was conducted on 202 patients visiting the diabetic clinic of Hamdard Institute of Medical Sciences and Research, Jamia Hamdard (HIMSR) teaching hospital in New Delhi, India who fulfilled the inclusion criteria. The Ewings autonomic function test was used for diagnosis of CAN. TyG index was calculated for patients based on fasting levels of glucose and triglyceride. The CAN was diagnosed in 62 participants out of 202 T2DM patients (overall prevalence 30.7%). The mean ± standard deviation (SD) for TyG index was 10.3 ± 0.2 and 9.5 ± 0.2 in CAN positive, T2DM patients, respectively. The difference of TyG index, in CAN positive and T2DM patients, was highly significant (P < 0.001). Further correlation analysis was performed to find an association of TyG index, duration, and age with patient groups. TyG index showed a positive correlation with heart rate during deep breathing (HRD), heart rate variation during standing (HRS), blood pressure (BP) response to handgrip and BP response to standing. Our finding highlights the TyG index, low-cost IR index, might be useful as an alternative tool for the early screening of patients at a high risk of diabetic neuropathy.

[Autonomic nervous system alteration in multiple sclerosis patients with urinary symptoms. Clinical, urodynamic and cardiovascular study]. / Dysautonomie et troubles urinaires au cours de la sclérose en plaques. Étude clinique, urodynamique et cardiovasculaire.

OBJECTIVE: To assess symptoms related to autonomic nervous system alteration in a population of patients suffering from multiple sclerosis (MS) and presenting with urinary symptoms. PATIENTS AND METHODS: We investigated 65 patients (mean age 47.5 years) suffering from MS, and presenting with urological dysfunction by means of symptom scores, urodynamic investigation, cardiovascular autonomic function tests (orthostatic hypotension testing, Valsalva test, deep breath test, cold pressor test) and sympathetic skin responses. RESULTS: Forty-five (69%) patients suffered from overactive bladder, 48 (73%) from voiding dysfunction, 14 (21%) from urinary retention and 13 (20%) from fecal incontinence. Urodynamic investigation demonstrated overactive detrusor in 46 (70%) cases, and underactive detrusor in four (6%) cases. Twenty-five (38%) patients had dysautonomia without correlation neither with clinical or urodynamic data, nor gravity of multiple sclerosis (EDSS). CONCLUSION: In this series, the prevalence of dysautonomia was high in patients suffering from MS and presenting with urinary disorders.

A Review on Autonomic Functional Assessment in Diabetic Patients.

In today's world, science has progressed significantly, yet most people are still unaware of diabetes. Lack of obesity, physical work, and lifestyle changes are the main factors. Diabetes is becoming more common all around the globe. Type 2 diabetes may go unnoticed for years, resulting in serious consequences and high healthcare expenses. The goal of this study is to look at a wide range of studies in which the autonomic function of diabetic people has been studied with the help of various autonomic function tests (AFTs). AFT is a non-invasive approach to assessing patients for testing sympathetic and parasympathetic responses to stimuli. AFT findings give us comprehensive knowledge of the autonomic physiology reactions in normal and in autonomic diseases like diabetes. This review will concentrate on AFTs that are scientifically valid, trustworthy, and clinically beneficial, according to experts.

The Relationship between Paresthesia and the Presence of Cardiac Dysautonomia in Patients with Post-COVID-19 Syndrome: A Preliminary Observational Study.

INTRODUCTION: Post-Coronavirus disease 2019 (Post-COVID-19) syndrome has neurological symptoms related to the dysfunction of the autonomous nerve system. However, a pathogenic relationship between post-COVID-19 syndrome and dysautonomia still remains to be demonstrated. Establishing a pathogenic relationship between paresthesia and the presence of cardiac dysautonomia in patients with post-COVID-19 syndrome is the objective of this study. PARTICIPANTS AND METHODS: This observational study was carried out in the neurophysiology service wing of the Juan Bruno Zayas Hospital, Santiago de Cuba, in Cuba. The patients were recruited through a post-COVID-19 clinic at the same hospital. A variability study of cardiac frequency and a test of autonomic cardiovascular reflexes was carried out, which is composed of deep breathing, orthostatism, and the Valsalva maneuver. RESULTS: The variability parameters of the cardiac frequency, the expiration-inspiration ratio between deep breaths, and the Valsalva Index showed no statistically significant differences between healthy participants and those with post-COVID-19 syndrome. During the Valsalva maneuver, there was a greater cardiac frequency response in participants with post-COVID-19 syndrome than in healthy subjects. The difference in supine and standing blood pressure was significantly minor in patients with post-COVID-19 syndrome. The logarithm of high frequency (log HF) increased significantly in patients with paresthesia when compared to patients without paresthesia. CONCLUSIONS: In the autonomic function tests, no signs of dysautonomia were found in patients with post-COVID-19 syndrome. The presence of paresthesias is associated with differences in cardiac vagal activity, which may suggest that damage to peripheral sensory nerve fibers could be associated with an affectation to autonomic fibres.

Cardiovascular Autonomic Function Tests in Patients of Obsessive-Compulsive Disorder: A Cross-Sectional Study.

Background: Patients with psychiatric disorders are at an increased risk of developing cardiovascular disease, reducing life expectancy. Autonomic dysfunction has been linked to this increased risk; many studies have found reductions in heart rate variability (HRV). Only a few studies have systematically explored the relationship between obsessive-compulsive disorder (OCD) and autonomic function, and they have found contradicting results. The present study is intended to explore comprehensive autonomic functions in OCD patients and compare them with healthy controls. Methods: A total of 18 OCD patients meeting Diagnostic and Statistical Manual of Mental Disorders - 5 (DSM-5) criteria were enrolled to undergo comprehensive autonomic function testing, and the results were compared with 25 age- and sex-matched healthy controls. Results: Time-domain parameters of HRV such as standard deviation of the RR intervals, coefficient of variance of RR intervals, standard deviation of differences between adjacent RR intervals, root square of the mean of the sum of the squares of differences between adjacent RR intervals, and percentage of number of RR interval differences ≥ 50 ms were significantly lower in OCD patients, indicating lesser parasympathetic tone. Frequency-domain parameters such as total power and very low frequency were significantly lower in OCD patients, indicating a significant decrease in autonomic tone. Nonlinear parameters such as dispersion of points perpendicular to the line of identity and dispersion of points along the line of identity were significantly lower in OCD patients, indicating altered vagal and sympathetic tone. In autonomic reactivity tests, the fall in systolic blood pressure during the lying to standing test and change in diastolic blood pressure during the cold pressor test were significantly altered in OCD patients, indicating abnormal sympathetic reactivity. There was no significant correlation between autonomic parameters and the severity of OCD. Conclusion: OCD is characterized by a decreased parasympathetic tone and abnormal sympathetic reactivity compared to normal controls.

Establishment of Normative Data for Autonomic Function Tests in Indian Population.

Background: Normative data for autonomic function tests (AFT) is not available for Indian population. Objective: The aim of the study was to establish normative data in AFT and its correlation with age, gender, and body mass index. Material and Methods: The study was done on 254 healthy subjects of age ≥18 years. All AFTs were done in autonomic laboratory at the Department of Neurology, Christian Medical College and Hospital, Ludhiana. Cardiovascular tests (heart rate response to deep breathing, HR changes in Valsalva maneuver and head-up tilt test (HUT)) and quantitative sudomotor axon reflex testing (QSART) were performed in all the subjects. Fifty subjects underwent thermoregulatory sweat test (TST). Results: The mean age (SD) of study participants was 43 (16.0) years (range 20-84), and 129 (50.8%) were men. The normative value range (2.5-97.5 percentile) for HR difference, E: I ratio, and Valsalva ratio (VR) was 3.5-47.0, 1.05-1.93, and 1.11-2.64, respectively, for all the subjects. HR difference and E: I ratio showed an significant inverse relation with age (r = -0.623 and r = -0.584, respectively). VR also showed an inverse relation with age (r = -0.575, P =< 0.001), and female had a lower value than male (1.63 vs 1.78, P =< 0.001). In QSART, mean (SD) sweat volume was higher in males 0.630 (0.230) compared to females 0.513 (0.132) for all sites, P < 0.001, and similar trend was noticed for sweat area in TST. Discussion and Conclusion: Normative AFT data has been established for Indian population for the first time. The values are comparable to previously published studies.

Autonomic and enteric function profiling can predict disordered gastric emptying in diabetic gastropathy.

Gastric emptying tests (GET) are the gold standard for diagnosing gastroparesis, but many patients do not have delayed emptying. We aimed to examine the combination of autonomic nervous system testing (ANS) and the enteric measure (ENS) of electrogastrography (EGG) to predict disordered GET. Seventy-six patients (47 F, 29 M mean age 40 years) with diabetes mellitus underwent evaluation for end-organ failure including gastroparesis. ANS testing assessed autonomic function by finger capillary pulse to positional changes (PAR), vasoconstriction to cold (VC), and EKG R-R interval change (RRI) with deep breathing; the ENS measures of cutaneous EGG assessed gastric myoelectrical activity. Solid (S) GET subgroups were based on 50% emptying (TS50). Via linear regression analysis: VC, PAR, and EGG had a significant inverse correlation with GET TS50 and decreased in response to a delay in gastric emptying (p < 0.05). Via ordinal logistic regression RRI and EGG-predicted gastric emptying (p < 0.01). Patients with a higher RRI and EGG value were 0.93 and 0.14 times more likely to be diagnosed with rapid gastric emptying. The areas under the curve for receiver operator characteristics (AUROC) for all measures were 0.72 in comparison to 0.59 with EGG. Based on the results, four components (RRI, VC, PAR, and EGG) quantitatively describe gastric emptying in patients with signs of diabetic gastropathy better than EGG alone.

The Effect of High Temperature on Cardiovascular Autonomic Function Tests in Steel Plant Furnace Worker.

BACKGROUND: The high temperature in the working environment could be one of the risk factors for cardiovascular diseases in steel plant workers. The excessive high temperature at the working place leads to altered autonomic activity and is related to more cardiovascular risk. AIMS AND OBJECTIVES: The effect of high temperature on cardiovascular autonomic function tests in steel plant furnace worker. MATERIAL AND METHOD: This was a case-control study for which 50 steel plant furnace workers and 50 controls were selected. The cardiovascular sympathetic function status in worker and control were analyzed by three tests: (i) Blood pressure (BP) response to sustained isometric handgrip test, (ii) BP response to the cold pressor test, and (iii) BP response to standing from a supine position (orthostasis). Statistical analysis was done by using an independent t-test. RESULTS: Diastolic BP (DBP) response to sustained isometric handgrip and systolic BP (SBP) and DBP response to the cold pressor test showed that the increase BP in workers were more than controls but the difference was not statistically significant (P > 0.05). SBP response to standing from the supine position showed statistically significant (P < 0.001) greater fall in steel plant workers. CONCLUSION: The sympathetic autonomic dysfunction was seen in steel furnace workers in response to environmental stressor-excessive heat.

Association of Postural Instability with Autonomic Dysfunction in Early Parkinson's Disease.

BACKGROUND: There have been several pathologic data that support an association between postural instability (PI) and autonomic dysfunction in Parkinson's disease (PD). The purpose of this study was to investigate the correlation of PI and autonomic deficits in early PD. METHODS: We collected 17 patients with a diagnosis of early PD. PI was assessed by computerized dynamic posturography (CDP). Standardized autonomic function test (AFT) and time and frequency domain spectral analysis of heart rate variability (HRV) were performed. CDP data obtained from the 21 patients were compared to that from age- and sex-matched healthy controls. We collected HRV data from 18 other age- and sex-matched controls. All patients were evaluated in the "OFF" state. We used Mann-Whitney U-test to compare parameters of CDP between the early PD and control groups. Spearman correlation was used for correlation analysis between parameters of CDP and autonomic function test in PD patients. RESULTS: Most patients (76.5%) showed mild or moderate autonomic dysfunction in the standardized AFT. In CDP, sensory ratios of equilibrium score (e.g., visual and vestibular) and composite scores were significantly lower in PD patients than in controls. In HRV, the low-frequency/high-frequency ratio during the tilt and the gap of low- frequency/high-frequency ratio from supine to tilt were significantly different in both groups. The parameters of time and frequency domains of HRV reflecting parasympathetic function were correlated with equilibrium scores for somatosensory organization test in CDP. DISCUSSION: PI was associated with parasympathetic autonomic dysfunction in early PD. This result was in accordance with a previous assumption that PI in PD is related to parasympathetic cholinergic neuron loss in the brainstem.

Nonlinear parameter of heart rate variability can diagnose early cardiac autonomic neuropathy.

This is a case of a 63-year-old female presenting with diabetes mellitus, hypertension, hypothyroidism, and postmenopausal osteoporosis with findings showing abnormal AFT with reduced heart rate variability (HRV) and multiple lobed Poincaré plot, pointing to premature atrial contractions.

Autonomic Function Tests and MIBG in Parkinson's Disease: Correlation to Disease Duration and Motor Symptoms.

AIMS: Disorders of the autonomic nervous system (ANS) have a variable degree of clinical relevance in patients with Parkinson's disease (PD). Here, we assessed whether subclinical autonomic dysfunction, as evaluated by a complete battery of autonomic function tests (AFTs), correlates with PD progression. METHODS: A series of 27 consecutive patients with PD underwent extensive ANS investigations including the head-up tilt test (HUTT), Valsalva maneuver, deep-breathing test, and handgrip test (HG); further, they performed 123I-meta-iodobenzylguanidine (MIBG) scintigraphy. RESULTS: Seven of the 27 patients showed orthostatic hypotension (OH) at HUTT and pathological responses to the deep-breathing and HG test and Valsalva maneuver. The majority of the remaining 20 patients with PD showed pathological responses to deep-breathing (n = 13) and/or HG (n = 11). Only 3 of 27 suffered relevant OH. MIBG uptake of myocardium was decreased in 19 patients with PD (H/M ratio 1.3 ± 0.2). Prolonged clinical observation (>3 years), persistent response to levodopa, and MIBG repetition allowed us to exclude negative MIBG as attributable to atypical Parkinsonism. MIBG uptake did not correlate with OH and other AFTs. Both HG test response and MIBG did correlate with the Unified Parkinson's Disease Rating Scale (UPDRS) motor score and disease duration. A positive correlation emerged between diastolic blood pressure (DBP) response to HG test and MIBG and with systolic blood pressure (SBP) response at tilt test. CONCLUSIONS: Our investigation suggests that ANS impairment affects the majority of patients with PD, even those PD patients showing negative MIBG, irrespective of clinical neurovegetative symptoms. The strict correlation that has been revealed with disease progression supports the routine utilization of AFTs as a reliable and inexpensive tool for monitoring peripheral sympathetic dysfunction in PD and optimizing therapy.

Clinical classification and neuro-vestibular evaluation in chronic dizziness.

OBJECTIVE: This study attempts to clarify the clinical characteristics of chronic dizziness and its relationships with specific vestibular, oculomotor, autonomic and psychiatric dysfunctions. METHODS: 73 Patients with idiopathic chronic dizziness were recruited and classified based on history taking and clinical examination into the following four clinical subgroups; vestibular migraine (VM), dysautonomia, psychogenic, and unspecified groups. They were also evaluated using oculomotor, otolithic and autonomic function tests, and psychologic investigation. RESULTS: Patients in the VM group showed a high proportion of abnormality on smooth pursuit and otolithic function testing compared to the other groups. The dysautonomia group revealed significant abnormalities in sympathetic and cardiovagal autonomic function, while the psychogenic group had a high frequency of abnormality in sympathetic autonomic testing and in Beck's anxiety inventory scale. The unspecified group showed abnormalities on saccade, smooth pursuit and autonomic function testing. CONCLUSIONS: Clinical classification of patients with chronic dizziness was relevant and they showed a correlation with disease-specific abnormal results in oculomotor, otolithic, autonomic function and psychology testing. SIGNIFICANCE: Appropriate diagnostic investigation based on precise clinical diagnosis of chronic dizziness reduces the need for extensive laboratory testing, neuroimaging, and other low-yield tests.