Orthostatic Symptoms Research Articles

Quantitative Scale for Grading of Cardiovascular Autonomic Reflex Tests and Small Fibers from Skin Biopsies (QASAT)

Background: Orthostatic intolerance including dizziness and syncope is common and may reflect autonomic dysfunction. Cardiovascular reflex tests (deep breathing, Valsalva maneuver and tilt test) are established diagnostic methods for evaluation of orthostatic and autonomic symptoms. Small fiber neuropathy, a frequent underlying mechanism, is evaluated by the quantitative sudomotor axonal reflex test (QSART) and skin biopsies. The comprehensive quantitative scale to grade abnormalities in these tests is lacking. Methods: This study defines the QASAT - Quantitative scale for grading of cardiovascular reflex tests using heart rate, blood pressure, n transcranial Doppler, QSART and small fibers (intrapidermal sensory and sweat gland) densities from skin biopsies. The QASAT has three main categories: cardiovascular, cerebral blood flow (includes cerebral autoregulation/vasoreactivity score) and small fiber neuropathy. QASAT was validated in 612 participants with diabetes mellitus (92), Parkinson’s disease (88), multiple system atrophy (23) and other diagnoses (409). The QASAT was compared with the Composite Autonomic Severity Score using ANOVA, correlations and sensitivity/specificity analysis. Results: Scores of heart rate variability from deep breathing, orthostatic hypotension, orthostatic cerebral blood flow, sensory and sweat gland small fiber densities were disease specific (p<0.0001) and were correlated with the severity of autonomic failure (r=0.84, p<0.0001). Autonomic, sensory and cerebral blood flow abnormalities coexist and are correlated. Initial response to slow and fast tilt, baroreflex gain, QT interval, catecholamines and spectral analysis of the heart rate failed to correlate with severity of autonomic failure and therefore were not included in QASAT. Conclusion: QASAT is an objective and validated instrument for grading of dysautonomia, associated small fiber neuropathy and cerebral blood flow. QASAT quantifies both below (bradycardia, supine/orthostatic hypotension) and above (tachycardia, supine/orthostatic hypertension) normal values. Cardiovascular tests are enhanced by scoring the cerebral hypoperfusion which underlies orthostatic symptoms. Inclusion of epidermal and sweat gland fiber density scoring improves lesion localization.

Hemodynamic profiles and tolerability of modafinil in the treatment of postural tachycardia syndrome: a randomized, placebo-controlled trial.

Postural tachycardia syndrome (POTS) is characterized clinically not only by an exaggerated increase in heart rate (HR), but an associated cognitive impairment that disables many patients. Modafinil might be effective in improving the cognitive symptoms, but modafinil may stimulate the sympathetic nervous system and worsen tachycardia in POTS. We tested the hypothesis that modafinil would worsen tachycardia and orthostatic symptoms in POTS. Patients with POTS (n = 54) underwent a randomized crossover trial with modafinil 100 mg versus placebo. Heart rate and systolic blood pressure (SBP) were measured seated and standing before modafinil or placebo administration and then hourly for 4 hours. Over 4 hours, standing HR was not significantly different between the modafinil and placebo groups (analysis of variance [ANOVA] Pdrug = 0.328), but seated SBP was significantly higher in the modafinil group (mean [SD], 109 [12] mm Hg vs 104 [10] mm Hg; P = 0.004). Modafinil also significantly increased both the seated SBP (ANOVA Pdrug = 0.004) and the standing SBP (ANOVA Pdrug = 0.041) over time. There was no significant difference between modafinil and placebo over the 4-hour period with regard to POTS symptom burden scores (14 [12] vs 14 [12]; P = 0.962). Modafinil did not significantly worsen standing HR or acute orthostatic symptoms in patients with POTS compared with the placebo group and improved upright blood pressure. Therefore, modafinil could be tested as a potential treatment for the cognitive impairment in POTS.

Electrical stimulation-evoked contractions blunt orthostatic hypotension in sub-acute spinal cord-injured individuals: two clinical case studies.

Prospective study of two cases. To describe the effects of electrical stimulation (ES) therapy in the 4-week management of two sub-acute spinal cord-injured (SCI) individuals (C7 American Spinal Injury Association Impairment Scale (AIS) B and T9 AIS (B)). University Malaya Medical Centre, Kuala Lumpur, Malaysia. A diagnostic tilt-table test was conducted to confirm the presence of orthostatic hypotension (OH) based on the current clinical definitions. Following initial assessment, subjects underwent 4 weeks of ES therapy 4 times weekly for 1 h per day. Post-tests tilt table challenge, both with and without ES on their rectus abdominis, quadriceps, hamstrings and gastrocnemius muscles, was conducted at the end of the study (week 5). Subjects' blood pressures (BP) and heart rates (HR) were recorded every minute during pre-test and post-tests. Orthostatic symptoms, as well as the maximum tolerance time that the subjects could withstand head up tilt at 60°, were recorded. Subject A improved his orthostatic symptoms, but did not recover from clinically defined OH based on the 20-min duration requirement. With concurrent ES therapy, 60° head up tilt BP was 89/62 mm Hg compared with baseline BP of 115/71 mm Hg. Subject B fully recovered from OH demonstrated by BP of 105/71 mm Hg during the 60° head up tilt compared with baseline BP of 124/77 mm Hg. Both patients demonstrated longer tolerance time during head up tilt with concomitant ES (subject A: pre-test 4 min, post-test without ES 6 min, post-test with ES 12 min; subject B: pre-test 4 min, post-test without ES 28 min, post-test with ES 60 min). Weekly ES therapy had positive effect on OH management in sub-acute SCI individuals.

Orthostatic intolerance predicts mild cognitive impairment: incidence of mild cognitive impairment and dementia from the Swedish general population cohort Good Aging in Skåne.

IntroductionContradictory results have been reported on the relationship between orthostatic hypotension (OH) and mild cognitive impairment (MCI).ObjectiveTo study the incidence of MCI and dementia and their relationship to OH and subclinical OH with orthostatic symptoms (orthostatic intolerance).Study design and settingThis study used a prospective general population cohort design and was based on data from the Swedish Good Aging in Skåne study (GÅS-SNAC), they were studied 6 years after baseline of the present study, with the same study protocol at baseline and at follow-up. The study sample comprised 1,480 randomly invited subjects aged 60 to 93 years, and had a participation rate of 82% at follow-up. OH test included assessment of blood pressure and symptoms of OH.ResultsThe 6-year incidence of MCI was 8%, increasing from 12.1 to 40.5 per 1,000 person-years for men and 6.9 to 16.9 per 1,000 person-years for women aged 60 to >80 years. The corresponding 6-year incidence of dementia was 8%. Orthostatic intolerance during uprising was related to risk for MCI at follow-up (odds ratio [OR] =1.84 [1.20–2.80][95% CI]), adjusted for age and education independently of blood pressure during testing. After stratification for hypertension (HT), the corresponding age-adjusted OR for MCI in the non-HT group was 1.71 (1.10–2.31) and 1.76 (1.11–2.13) in the HT group. Among controls, the proportion of those with OH was 16%; those with MCI 24%; and those with dementia 31% (age-adjusted OR 1.93 [1.19–3.14]).ConclusionNot only OH, but also symptoms of OH, seem to be a risk factor for cognitive decline and should be considered in the management of blood pressure among the elderly population.

A prospective study of excessive postural heart rate change on head-up tilt.

Healthy subjects with asymptomatic postural tachycardia (≥30bpm) at baseline were evaluated over a 1-year period to determine whether they developed orthostatic symptoms. Subjects were evaluated at baseline and at 1year using the autonomic reflex screen and autonomic symptom profile (ASP). Heart rate increment on HUT did not differ at baseline (40.6±7.5bpm) or at 1year (37.1±11.1bpm; n=26; p>0.05). Orthostatic symptoms measured by the ASP did not reveal significant orthostatic dysfunction throughout follow-up (baseline, 7.88±7.61; 1year, 9.04±6.64; n=26; p>0.05). The ten autonomic domains of the ASP did not reveal a change in autonomic symptoms from baseline (13.56±13.66) to 1-year follow-up (15.12±11.62; n=26; p>0.05). Cardiovagal function was unchanged between baseline and follow-up for both heart rate variability to deep breathing (baseline, 23.9±11.6bpm; 1year, 23.0±9.3bpm; n=26; p>0.05) and Valsalva ratio (baseline, 2.16±0.39; 1year, 2.15±0.33; n=26; p>0.05). These findings further argue that heart rate criteria (≥30bpm) for Postural Tachycardia Syndrome (POTS) are not appropriate in younger individuals and higher postural heart rates do not predispose individuals to the development of POTS.

Differences in cardiac autonomic function contributes to heart rate abnormalities in POTS and IST.

Our objective was to examine the differences in cardiac autonomic function in Postural Tachycardia Syndrome (POTS) versus inappropriate sinus tachycardia (IST). Subjects (IST, n = 8; POTS, n = 12) were studied using standard measurements of the autonomic reflex screen, baroreflex function and spectral analysis. Data was compared to age/gender-matched controls (n = 20). The components of the autonomic reflex screen did not differ between groups. The exception was the significant but expected difference in postural heart rate increment on head-up tilt in POTS (47.9 ± 13.8; n = 12) compared to IST (30.9 ± 9.7; n = 8; p = 0.008). Accordingly the Orthostatic Intolerance Scale showed significantly greater orthostatic symptoms in POTS (2.6 ± 0.5; n = 12) versus IST patients (0.4 ± 0.5; n = 8; p < 0.001). Conversely, IST patients had a significantly higher resting heart rate (96 ± 12; n = 8) when compared to POTS patients (73 ± 12; n = 12; p = 0.001). There was a significant difference in vagal baroreflex sensitivity (BRSv) in POTS (8.21 ± 2.3, n = 12) compared to IST patients (5.30 ± 2.94, n = 8, p = 0.036) during the Valsalva maneuver. Only POTS subjects showed a significant increase in sympathovagal balance (LF/HF) with tilt (FFT, 8.29 ± 6.38; AR, 7.84 ± 5.24) compared to the supine position (FFT, 2.25 ± 1.75; AR, 1.99 ± 1.38; p < 0.05) for both frequency domains. Differences in cardiac autonomic function contribute to changes in positional and non-positional heart rate in postural tachycardia syndrome versus inappropriate sinus tachycardia. These findings shed further light on the autonomic dysfunction underlying POTS and IST.

Efficacy of atomoxetine versus midodrine for the treatment of orthostatic hypotension in autonomic failure.

The clinical presentation of autonomic failure is orthostatic hypotension. Severely affected patients require pharmacological treatment to prevent presyncopal symptoms or frank syncope. We previously reported in a proof of concept study that pediatric doses of the norepinephrine transporter blockade, atomoxetine, increases blood pressure in autonomic failure patients with residual sympathetic activity compared with placebo. Given that the sympathetic nervous system is maximally activated in the upright position, we hypothesized that atomoxetine would be superior to midodrine, a direct vasoconstrictor, in improving upright blood pressure and orthostatic hypotension-related symptoms. To test this hypothesis, we compared the effect of acute atomoxetine versus midodrine on upright systolic blood pressure and orthostatic symptom scores in 65 patients with severe autonomic failure. There were no differences in seated systolic blood pressure (means difference=0.3 mm Hg; 95% confidence [CI], -7.3 to 7.9; P=0.94). In contrast, atomoxetine produced a greater pressor response in upright systolic blood pressure (means difference=7.5 mm Hg; 95% CI, 0.6 to 15; P=0.03) compared with midodrine. Furthermore, atomoxetine (means difference=0.4; 95% CI, 0.1 to 0.8; P=0.02), but not midodrine (means difference=0.5; 95% CI, -0.1 to 1.0; P=0.08), improved orthostatic hypotension-related symptoms as compared with placebo. The results of our study suggest that atomoxetine could be a superior therapeutic option than midodrine for the treatment of orthostatic hypotension in autonomic failure.

Absence of clinically relevant cardiovascular interaction upon add-on of mirabegron or tamsulosin to an established tamsulosin or mirabegron treatment in healthy middle-aged to elderly men.

Tamsulosin and mirabegron may be used concomitantly in patients with lower urinary tract symptoms. Since alpha1-adrenoceptor antagonists are associated with cardiovascular side effects, potential pharmacokinetic and cardiovascular interactions were evaluated. This was an open-label, randomized, 2-arm, 2-sequence study in 48 healthy men (24/arm) aged 44 - 72 years. In arm 1, subjects received single-dose tamsulosin hydrochloride modified release capsules (0.4 mg) alone and with steady-state mirabegron oral controlled absorption system tablets (100 mg once daily) in random sequence. In arm 2, subjects received single-dose mirabegron alone and with steady-state tamsulosin. Samples for mirabegron and tamsulosin plasma concentrations were collected. Blood pressure (BP) and pulse rate (PR) were measured and orthostatic stress tests were performed. Mirabegron increased tamsulosin C(max) to 159% (90% confidence interval (CI) 143 - 177%), AUC(∞) to 161% (90% CI 149 - 173%), and t(1/2) to 116%. Tamsulosin reduced mirabegron C(max) to 85% (90% CI 71 - 103%) and AUC(∞) to 84% (90% CI 74 - 95%) without effect on t1/2. Mirabegron and tamsulosin co-treatment caused no statistically significant changes (p > 0.05) in PR or systolic BP versus mono-treatment up to 12 hours post-dose. Mean diastolic BP decreases of -2.1 (95% CI -4.1, -0.1) to -4.2 (-7.5, -0.9) mmHg in arm 1 and -3.0 (-5.7, -0.3) to -4.2 (-7.4, -1.0) mmHg in arm 2 were observed, statistically significant (p < 0.05) at several time points, not accompanied by orthostatic symptoms or increases in positive orthostatic stress tests. Adverse and orthostatic events were balanced across treatments. The observed pharmacokinetic interactions upon add-on of mirabegron or tamsulosin to existing tamsulosin or mirabegron therapy did not cause clinically relevant changes in cardiovascular safety or safety profiles.

Combination ergotamine and caffeine improves seated blood pressure and presyncopal symptoms in autonomic failure.

Severely affected patients with autonomic failure require pressor agents to counteract the blood pressure fall and improve presyncopal symptoms upon standing. Previous studies suggest that combination ergotamine and caffeine may be effective in the treatment of autonomic failure, but the efficacy of this drug has not been evaluated in controlled trials. Therefore, we compared the effects of ergotamine/caffeine on seated blood pressure and orthostatic tolerance and symptoms in 12 primary autonomic failure patients without history of coronary artery disease. Patients were randomized to receive a single oral dose of placebo, midodrine (5–10 mg), or ergotamine and caffeine (1 and 100 mg, respectively) in a single-blind, crossover study. Blood pressure was measured while patients were seated and after standing for up to 10 min, at baseline and at 1 h post-drug. Ergotamine/caffeine increased seated systolic blood pressure (SBP), the primary outcome, compared with placebo (131 ± 19 and 95 ± 12 mmHg, respectively, at 1 h post-drug; p = 0.003 for time effect). Midodrine also significantly increased seated SBP (121 ± 19 mmHg at 1 h post-drug; p = 0.015 for time effect vs. placebo), but this effect was not different from ergotamine/caffeine (p = 0.621). There was no significant effect of either medication on orthostatic tolerance; however, ergotamine/caffeine improved presyncopal symptoms (p = 0.034). These findings suggest that combination ergotamine and caffeine elicits a seated pressor response that is similar in magnitude to midodrine, and improves symptoms in autonomic failure. Thus, ergotamine/caffeine could be used as an alternate treatment for autonomic failure, in carefully selected patients without comorbid coronary artery disease.

Acute volume loading and exercise capacity in postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is associated with exercise intolerance, hypovolemia, and cardiac atrophy, which may contribute to reduced stroke volume and compensatory exaggerated heart rate (HR) increases. Acute volume loading with intravenous (iv) saline reduces HR and improves orthostatic tolerance and symptoms in POTS, but its effect on exercise capacity is unknown. In this study, we determined the effect of iv saline infusion on peak exercise capacity (VO2peak) in POTS. Nineteen patients with POTS participated in a sequential study. VO2peak was measured on two separate study days, following administration of placebo or 1 liter of i.v. saline (NaCl 0.9%). Patients exercised on a semirecumbent bicycle with resistance increased by 25 W every 2 min until maximal effort was achieved. Patients exhibited blood volume deficits (-13.4 ± 1.4% ideal volume), consistent with mild to moderate hypovolemia. At baseline, saline significantly increased stroke volume (saline 80 ± 8 ml vs. placebo 64 ± 4 ml; P = 0.010), increased cardiac output (saline 6.9 ± 0.5 liter/min vs. placebo 5.7 ± 0.2 liter/min; P = 0.021), and reduced systemic vascular resistance (saline 992.6 ± 70.0 dyn-s/cm(5) vs. placebo 1,184.0 ± 50.8 dyn-s/cm(5); P = 0.011), with no effect on HR or blood pressure. During exercise, saline did not produce differences in VO2peak (saline 26.3 ± 1.2 mg·kg(-1)·min(-1) vs. placebo 27.7 ± 1.8 mg·kg(-1)·min(-1); P = 0.615), peak HR [saline 174 ± 4 beats per minute (bpm) vs. placebo 175 ± 3 bpm; P = 0.672] or other cardiovascular parameters. These findings suggest that acute volume loading with saline does not improve VO2peak or cardiovascular responses to exercise in POTS, despite improvements in resting hemodynamic function.

Cardiac autonomic functions in children with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is the most common inherited autoinflammatory disease in the world. The long-term effects of subclinical inflammation in FMF are not well recognized. Some studies have suggested that FMF is associated with cardiac autonomic dysfunction in adult FMF patients. The objective of this study was to investigate the cardiac autonomic functions in pediatric FMF patients by using several autonomic tests. Thirty-five patients with FMF and 35 healthy controls were enrolled in this cross-sectional study. Demographic data, disease-specific data, and orthostatic symptoms were recorded. In all participants, 12-lead electrocardiography (ECG), 24h ambulatory electrocardiographic monitoring, transthoracic echocardiography, treadmill exercise test, and head upright tilt-table (HUTT) test were performed. The heart rate recovery (HRR) indices of the two groups were similar. Also, chronotropic response was similar in both groups. The time-domain parameters of heart rate variability (HRV) were similar in both groups, except mean RR (p = 0.024). Frequencies of ventricular and supraventricular ectopic stimuli were similar in both groups. There were no statistically significant differences between the groups in average QT and average corrected QT interval length, average QT interval dispersion, and average QT corrected dispersion. There was no significant difference between the two groups regarding the ratio of clinical dysautonomic reactions on HUTT. However, we observed a significantly higher rate of dysautonomic reactions on HUTT in patients with exertional leg pain than that in patients without (p = 0.013). When the fractal dimension of time curves were compared, FMF patients exhibited significantly lower diastolic blood pressure parameters than controls in response to HUTT. Cardiovascular autonomic dysfunction in children with FMF is not prominent. Particularly, patients with exertional leg pain are more prone to have dysautonomic features. Further studies are needed to elucidate the exact mechanisms leading to impaired cardiac autonomic functions in FMF.

Multiple system atrophy: prognostic indicators of survival.

Neurological and autonomic presentation in multiple system atrophy (MSA) may predict early mortality. Quantification of early autonomic failure as a mortality predictor is lacking. Early neurological and autonomic clinical features were retrospectively reviewed in 49 MSA cases (median age at onset, 56.1 years; 16 women) confirmed by autopsy at Mayo Clinic. When available, the 10-point composite autonomic severity score derived from the autonomic reflex screen provided quantification of the degree of autonomic failure and thermoregulatory sweat test quantitated body surface anhidrosis. Symptoms at onset were autonomic in 50%, parkinsonian in 30%, and cerebellar in 20% of cases. Survival (median [95% confidence interval]) was 8.6 [6.7-10.2] years. Survival was shorter in patients with early laboratory evidence of generalized (composite autonomic severity score ≥ 6) autonomic failure (7.0 [3.9-9.8] vs. 9.8 [4.6-13.8] years; P = 0.036), and early requirement of bladder catheterization (7.3 [3.1-10.2] vs. 13.7 [8.5-14.9] years; P = 0.003) compared with those without these clinical features. On Cox proportional analysis, prognostic indicators of shorter survival were older age at onset (hazard ratio [95% confidence interval], 1.04 [1.01-1.08]; P = 0.03), early requirement of bladder catheterization (7.9 [1.88-38.63]; P = 0.004), and early generalized (composite autonomic severity score ≥ 6) autonomic failure (2.8 [1.01-9.26]; P = 0.047). Gender, phenotype, and early development of gait instability, aid-requiring ambulation, orthostatic symptoms, neurogenic bladder, or significant anhidrosis (thermoregulatory sweat test ≥ 40%) were not indicators of shorter survival. Our data suggest that early development of severe generalized autonomic failure more than triples the risk of shorter survival in patients with MSA.

P459: Electro-clinical features of focal epilepsy patients with postictal generalized EEG suppression

P459: Electro-clinical features of focal epilepsy patients with postictal generalized EEG suppression

Model-free causality analysis of cardiovascular variability detects the amelioration of autonomic control in Parkinson's disease patients undergoing mechanical stimulation

We tested the hypothesis that causality analysis, applied to the spontaneous beat-to-beat variability of heart period (HP) and systolic arterial pressure (SAP), can identify the improvement of autonomic control linked to plantar mechanical stimulation in patients with Parkinson's disease (PD). A causality index, measuring the strength of the association from SAP to HP variability, and derived according to the Granger paradigm (i.e. SAP causes HP if the inclusion of SAP into the set of signals utilized to describe cardiovascular interactions improves the prediction of HP series), was calculated using both linear model-based (MB) and nonlinear model-free (MF) approaches. Univariate HP and SAP variability indices in time and frequency domains, and bivariate descriptors of the HP–SAP variability interactions were computed as well. We studied ten PD patients (age range: 57–78 years; Hoehn-Yahr scale: 2–3; six males, four females) without orthostatic hypotension or symptoms of orthostatic intolerance and ‘on-time’ according to their habitual pharmacological treatment. PD patients underwent recordings at rest in a supine position and during a head-up tilt before, and 24 h after, mechanical stimulation was applied to the plantar surface of both feet. The MF causality analysis indicated a greater involvement of baroreflex in regulating HP–SAP variability interactions after mechanical stimulation. Remarkably, MB causality and more traditional univariate or bivariate techniques could not detect changes in cardiovascular regulation after mechanical stimulation, thus stressing the importance of accounting for nonlinear dynamics in PD patients. Due to the higher statistical power of MF causality we suggest its exploitation to monitor the baroreflex control improvement in PD patients, and we encourage the clinical application of the Granger causality approach to evaluate the modification of the autonomic control in relation to the application of a pharmacological treatment, a rehabilitation procedure or external intervention.

Joint hypermobility syndrome subclassification in paediatrics: a factor analytic approach

ObjectiveTo determine if exploratory factor analysis can identify subtypes comprising recognisable clinical patterns of the presenting signs and symptoms of children with joint hypermobility syndrome (JHS).PatientsEighty-nine children with JHS aged...

Relationship among nausea, anxiety, and orthostatic symptoms in pediatric patients with chronic unexplained nausea.

This study evaluated the relationship among nausea, anxiety, and orthostatic symptoms in pediatric patients with chronic unexplained nausea. We enrolled 48 patients (36 females) aged 15 ± 2 years. Patients completed the Nausea Profile, State-Trait Anxiety Inventory for Children and underwent 70° head upright tilt testing (HUT) to assess for orthostatic intolerance (OI) and measure heart rate variability (HRV). We found nausea to be significantly associated with trait anxiety, including total nausea score (r = 0.71, p < 0.01) and 3 subscales: somatic (r = 0.64, p < 0.01), gastrointestinal (r = 0.48, p = 0.01), and emotional (r = 0.74, p < 0.01). Nausea was positively associated with state anxiety, total nausea (r = 0.55, p < 0.01), somatic (r = 0.48, p < .01), gastrointestinal (r = .30, p < .05), and emotional (r = .64, p < .01) subscales. Within 10 min of HUT, 27 patients tested normal and 21 demonstrated OI. After 45 min of HUT, only 13 patients (27%) remained normal. Nausea reported on the Nausea Profile before HUT was associated with OI measured at 10 min of tilt (nausea total r = 0.35, p < 0.05; nausea emotional subscale r = 0.40, p < 0.01) and lower HRV at 10 min of HUT (F = 6.39, p = 0.01). We conclude that nausea is associated with both anxiety symptoms and OI. The finding of decreased HRV suggests an underlying problem in autonomic nervous system function in children and adolescents with chronic unexplained nausea.

Lack of orthostatic symptoms in dementia patients with orthostatic hypotension.

Orthostatic hypotension (OH) is common and increases with age. OH is part of the autonomic dysfunction in dementia with Lewy bodies (DLB). Commonly OH is diagnosed when the patient falls which is a risk factor of premature death. Our objective was to systematically investigate the clinical symptoms associated with measurement of OH in different neurodegenerative dementias and normal controls (NC). 154 patients [50 DLB, 50 Alzheimer's disease (AD), 54 AD and vascular components (ADvasc)] were examined with systolic and diastolic blood pressure measurements in supine position, immediately after standing up and after 1, 3, 5 and 10 min of standing. They were compared with 50 NC. Orthostatic symptoms were registered according to a predefined protocol. Twenty-seven percent of all the investigated individuals reported OH symptoms during the measurement while 43% fulfilled the criteria of OH. Sixty-three percent of orthostatic patients did not have any symptoms during the measurement. The prevalence of any orthostatic symptoms during the measurement differed significantly (p < 0.001) between the diagnostic groups with 40% in DLB patients, 37% in ADvasc, 28% in AD and 2% in NC. The most frequent symptom was dizziness 13.7%. Classical orthostatic symptoms are absent in the majority of dementia patients with OH. The orthostatic reaction must therefore be routinely measured in this patient group. This is particularly important for patients with DLB where falls as a result of OH are common.

The pressor response to drinking water: a pilot study

headache, nausea, asthenia, chest pain, dyspnea, tremor, heat intolerance, diarrhea) , as well as the postural context (orthostatic symptoms only vs sitting position symptoms also vs supine symptoms also). Higher frequency of dyspnea and headache during the episodes and occurrence of supine symptoms were associated with a higher probability of symptoms recurrence on FUP (p<0,05 for all analysis). Conclusion: Simple clinical data (symptoms and their context) may be of value in symptoms recurrence preview, an important determinant of quality of life in pts with POTS.

A retrospective review of autonomic screening tests conducted at a Tertiary General Hospital

Autonomic screening tests (AST) are useful for assessing autonomic dysfunction. Our aim was to delineate the referral pattern, abnormalities, technical difficulties and final diagnoses of ASTs at a Tertiary General Hospital. Referring diagnoses was classified into: orthostatic symptoms, assessment of known/suspected disease associated with dysautonomia, thermoregulatory complaints and neurological disorders. Medication history, patient cooperation and test results were collated. Usefulness of AST in answering the clinical questions was ranked on a 3-point scale. 248 patients were studied. Orthostatic symptoms were the commonest referring diagnosis (71.4%) followed by assessment of a known/suspected disease associated with dysautonomia (13.3%), thermoregulatory complaints (7.7%) and neurological disorders (7.3%). 49.6% of ASTs were abnormal, 40.7% were normal and 9.7% were inconclusive. The first 2 referral categories had the highest proportion of abnormal ASTs while only 5.3% of patients with thermoregulatory complaints had abnormal AST. The most frequent final diagnosis was orthostatic hypotension (OH). It was seen in 31.7% of the cohort; however, 41% of these were attributed to medications. With regard to answering the clinical question, ASTs were very helpful in 56.0% and not helpful in 9.3%. 58.0% of inconclusive ASTs were attributed to poor performance of test maneuvers, 8.0% to medications, 17.0% to both and 17.0% to irregular heart rhythms and pacemakers. 34.7% of patients with diabetes mellitus and 38.2% of patients with Parkinsonism had signs of autonomic dysfunction. About 7% of diabetic and a quarter of Parkinsonism patients had OH secondary to medications. We believe these findings can contribute to better application of AST.

Postural tachycardia and orthostatic intolerance: chicken, egg or unrelated?

We have read with interest the paper Orthostatic intolerance without postural tachycardia—how much dysautonomia? recently published in CAR. It is perhaps of relevance to readers that we arrived at similar findings regarding the presentation of orthostatic intolerance in our study, although with a different design and in a geographically distant environment [1]. Similarly to Parsaik et al., we compared patients with persistent orthostatic symptoms with and without postural tachycardia and found no difference in demographic or clinical characteristics between groups (for reasons explained in the cited paper, a relatively lower cut-off for postural tachycardia was used). Furthermore, in our as yet unpublished work, no differences were found in heart rate variability, peripheral vasoconstriction, or serum hormone levels. We can therefore only agree with the Mayo Clinic group that orthostatic intolerance without postural tachycardia is a condition encountered in everyday practice and a relevant research topic.