Electrical Skin Conductance Research Articles

Sleep Quality Assessment in Correlation to Autonomic Nerve Function in Type 2 Diabetic Patients

Background and Objective Diabetes mellitus negatively impacts the quality of life of its patients. Autonomic dysfunction may disturb sleep quality by negatively affecting multiple systems, including, but not limited to, the cardiovascular, respiratory, and genitourinary tracts. The current study aims to assess sleep quality and examine the degree of correlation with autonomic nervous function in relatively well-controlled type 2 diabetic patients.Methods This study uses a cross-sectional design to assess sleep quality in 88 type 2 diabetic patients via the Pittsburg Sleep Quality Index (PSQI), accordingly dividing them into two groups: good or poor sleepers. Subsequently, the study evaluates autonomic nerves’ conductivity by measuring electrical skin conductance using Sudoscan for the hands and feet.Results Of 88 recruited patients, 53% showed poor sleep quality, with higher incidence in females. Autonomic nerve conductivity showed moderate damage in poor sleepers with 59.53 ± 13.35 μS and 59.68 ± 16.91 μS of hand and foot electrodes, respectively. Autonomic damage induces sleep disturbance mainly through increased nighttime voiding in 91.49% of the poor sleepers group compared to 41.46% in the good sleepers group. PSQI score was found to strongly and inversely correlate with autonomic nerve conductivity via hand electrodes, with a correlation coefficient of -0.62 and a determination coefficient of 0.39.Conclusion Poor sleep quality seems to be a significant problem even in relatively well-controlled type 2 diabetic patients with no diagnosed micro- or macrovascular complications. Autonomic dysfunction negatively affects the quality of sleep and leads to sleep disturbance by increasing nighttime micturition as one of its complications.

The Composite Autonomic Symptom Score 31 Questionnaire: A Sensitive Test to Detect Risk for Autonomic Neuropathy.

Autonomic neuropathy is a common but often neglected complication of diabetes, prediabetes, and even in individuals with an elevated risk of diabetes. The Composite Autonomic Symptom Score (COMPASS) 31 is a validated and easy-to-use questionnaire regarding autonomic symptoms. We aimed to use a digitally, Norwegian version of the COMPASS 31 in people with different durations of diabetes and healthy controls to consider feasibility and to investigate if scores could discriminate between positive and negative outcomes for established tests for diabetic neuropathy, including cardiovascular autonomic neuropathy (CAN) and a novel method of examining the gastrointestinal visceral sensitivity. We included 21 participants with longstanding type 2 diabetes, 15 with early type 2 diabetes, and 30 matched controls. The mean age for all groups was 69 years. Participants were phenotyped by cardiovascular autonomic reflex tests, electrical skin conductance, sural nerve electrophysiology, and the monofilament test. As a proxy for gastrointestinal visceral and autonomic nerve function, evoked potentials were measured following rapid rectal balloon distention. Participants with longstanding diabetes scored a median (IQR) of 14.9 (10.8-28.7) points, early diabetes of 7.3 (1.6-15.2), and matched controls of 8.6 (4.1-21.6), p = 0.04. Women and men scored 14.4 (5.5-28.7) and 7.8 (3.6-14.6) points, respectively, p = 0.01. Participants with definite or borderline CAN scored 14.3 (10.4-31.9) points, compared to participants with no CAN, 8.3 (3.2-21.5), p = 0.04. Lowering the diagnostic cut-off from 16 to 10 points increased the sensitivity from 0.33 to 0.83, with a decreased specificity from 0.68 to 0.55. We successfully used COMPASS 31 in Norwegian. Thus, following the guidelines, we suggest clinical implementation for the assessment of autonomic neuropathy. Participants with longstanding diabetes had an increased likelihood of symptoms and signs of autonomic neuropathy. For screening purposes, the sensitivity was improved by lowering the cut-off to 10 points, with a lower score nearly excluding the diagnosis.

The PanGut-study: Evoked potentials following rectal balloon distention, a way of evaluating diabetic autonomic neuropathy in the gut?

AimThere is a lack of methods for investigating the autonomic nerves of the gastrointestinal tract. Our aim was to explore a novel test measuring visceral sensory evoked potentials (EPs) in response to rapid balloon distention in the rectum and compare it to established tests for diabetic neuropathy. MethodParticipants with longstanding type 2 diabetes, newly onset, untreated diabetes <1 year, and matched controls, were included. Tests included cardiovascular reflex tests, orthostatic blood pressure, electrical skin conductance assessment, sural nerve testing and monofilament test. The rectal balloon distention pressure at earliest sensation and threshold of unpleasantness were identified and used to elicit mechanical EPs. ResultsThe pressure at earliest sensation was higher in people with diabetes, 0.038 (0.012) bar vs. controls 0.030 (0.009) bar, p = 0.002, and in people with signs of peripheral neuropathy, 0.045 (0.014) bar, p < 0.01. Clinical correlations between EP amplitude and latency, and other tests were found. ConclusionsRectal hyposensitivity was associated with both longstanding and early diabetes, indicating enteric sensory dysfunction already in early stages of diabetes. Correlation analyses may indicate that central afferent processing is affected in parallel with peripheral neuronal function.

Electrodermal Activity Implicating a Sympathetic Nervous System Response under the Perception of Sensing a Divine Presence—A Psychophysiological Analysis

Previous studies have suggested that religious worship experiences may recruit the autonomic nervous system (ANS) in an activating fashion. For this reason, we hypothesized that measurements of the electrodermal activity (EDA) would concur with the notion that the subjective experience of sensing the presence of God recruits a sympathetic nervous system response. We analyzed the EDA of 37 evangelical participants and calculated classic galvanic skin response (GSR) measures. Our experimental design included six conditions with and without music consisting of religious and non-religious songs plus a resting-state condition, which were used to induce a variance in the religious experience suitable for statistical analyses. Results showed that both tonic and phasic signals as well as the overall electrical skin conductance (SC) were positively associated with the religious experience, defined as sensing the presence of God. This implicates that we can accept the hypothesis that such a religious experience under the influence of worship seems to recruit the sympathetic nervous system.

Acupoints sensitization in people with and without chronic low back pain:A matched-sample cross-sectional study.

Acupoints are considered a dynamic functional area, which can reflect the internal condition of the body. In pathological states, disease-related acupoints are believed to be activated, which is known as acupoint sensitization. This study aimed to investigate the major manifestations of acupoint sensitization in patients with chronic low back pain (cLBP) to provide better understanding of acupoint sensitization phenomena in the context of cLBP. This study was a matched-sample cross-sectional study 16 participants diagnosed with cLBP and 16 healthy controls matched in age, sex, and ethnicity were included. The following aspects of sensitization phenomena of targeted points were compared: pressure pain threshold (PPT), skin temperature, surface electrical conductance, receptive field, and morphological change of skin. PPT at points of interest were significantly lower in cLBP participants compared with healthy controls (P< 0.05); in addition, receptive field was found to be larger at left BL 23 in cLBP participants (P< 0.05). There was no statistically significant difference in skin temperature, electrical conductance, or morphology between the two groups. Reduced PPT at all detected points and enlarged receptive field at left BL 23 were found in cLBP participants. These two features appear key in defining acupoint sensitization in cLBP, and provide evidence for selecting and locating acupuncture points in future clinical studies.

Low Electrical Resistance Properties of Acupoints: Roles of NOergic Signaling Molecules and Neuropeptides in Skin Electrical Conductance.

Early studies from several independent laboratories demonstrated that acupoints possess the characteristics of low electrical resistance. New devices are developing to increase the reliability of electrical skin impedance measurements for counteracting the factors including skin dryness, skin thickness, size of the sensing electrode, pressure applied on the electrode, interelectrode distance, room temperature, and humidity. Morphological studies have identified that blood vessels, hair follicles, and nervous components are enhanced in the meridians/acupoints, which represent areas of potentially high neuronal activity. Recent evidence shows that nitric oxide (NO) concentrations are enhanced in skin acupoints/meridians. L-arginine-derived NO synthesis modifies skin norepinephrine (NE) synthesis/release in acupoints/meridians, and NO-NE activations play an important role in mediating the skin conductance responses to electrical stimulation. NOergic signaling molecules interact with gap junction and transient receptor potential vanilloid type-1. Other studies reported that the high conductance at acupoints is a result of the release of the neuropeptides substance P and calcitonin gene-related peptide during neurogenic inflammation in the referred pain area. Pathological body conditions caused considerable changes in skin conductance or impedance at acupoints. Although systematic research with an improved equipment and research design to avoid the influencing factors are requested for a definite answer in this field, the results from anatomical and biochemical studies consistently show that acupoints exist higher levels of nervous components, and NOergic signaling molecules and neuropeptides involved in the skin low resistance at acupoints. The increased interest in the acupoints/meridians has led to an open-minded attitude towards understanding this system, which is fundamental important to establish the valid aspects of scientific basis of Chinese medicine mechanisms and therapies.

Combat and blast exposure blunt sympathetic response to acute exercise stress in specialised military men.

Electrodermal activity (EDA)-a measure of electrical skin conductance reflecting (exclusive) sympathetic control of the eccrine sweat gland-holds promise as an indicator of central sympathetic activation. The aim of this study was to determine whether combat and blast exposure modulate the EDA response to acute exercise stress in specialised military men. Fifty-one men (age M=36.1, SD=6.5) participated in this study as part of the Explosive Ordnance Disposal Operational Health Surveillance System. The EDA complex (i.e., tonic+phasic conductance) was continuously measured throughout a maximal effort, graded exercise test. As expected, exercise stress resulted in measurable, stepwise increases in EDA before tapering at higher exercise intensities. Individuals with more substantial combat exposure and those with blast exposure demonstrated blunted EDA patterns in comparison to their low/nonexposed counterparts. This blunted pattern might imply sub-optimal sympathetic nervous system function in the exposed cohorts and enhances our knowledge of factors influencing resilience in these men.

CARDIAC AUTONOMIC NEUROPATHY RISK ESTIMATED BY SUDOMOTOR FUNCTION IN YOUNG ADULTS WITH INTELLECTUAL DISABILITY

Objective: Young adults with Intellectual Disability (ID) are at higher risk of premature death, and present with increased prevalence of cardiovascular disease (CVD) than the general population. Cardiac autonomic neuropathy (CAN) is often associated with CVD risk factors including diabetes mellitus, metabolic syndrome and hypertension. Hence, it may be a predictor for cardiovascular morbidity and mortality. Screening for CAN risk through assessment of sudomotor function has been introduced as a method for early detection of autonomic dysfunction. Design and method: Adults with ID aged 18–45 years (n = 31) were compared to the general population (GP) (n = 29). Seated blood pressure, arterial stiffness (Pulse Wave Velocity [m/s] measured with Sphygmacor) and sudomotor function (measured with SUDOSCAN) were assessed. Results: Hand and feet electrical skin conductance (ESC) were lower in adults with ID ([Feet] ID = 72.8 microsiemens, GP = 80.4 microsiemens; p = 0.021 [Hands] ID = 65.6 microsiemens, GP = 76.8 microsiemens; p = 0.013) indicating elevated risk for CAN in the ID cohort. ESC in the ID population did not correlate with arterial stiffness, blood pressure nor body mass index (BMI), with both groups showing similar mean systolic blood pressures (ID = 127mmHg, GP = 122mmHg; p = 0.10) and PWV (ID = 8.0m/s, GP = 7.8m/s; p = 0.81), despite elevated BMI in the ID cohort (ID = 31.4 kg/m2, GP = 25.9 kg/m2; p = 0.002). However, ESC was related to Hb1Ac concentration, which was elevated in those with ID (ID = 34.4mmol/mol, GP = 29.7mmol/mol; p = 0.002). Conclusions: Our data indicates that sudomotor dysfunction is present in adults with ID and this was associated with impaired glucose metabolism. This suggest that CAN may play a role in the early development of CVD in young adults with ID. Given the increasing urgency to provide young individuals living with ID with the means to improve their health and wellbeing, screening for CAN could prove a useful tool in early detection of CVD risk, before the development of other typical risk factors including arterial stiffness and hypertension.

Withdrawal

Electrodermal activity (EDA) - a measure of electrical skin conductance reflecting (exclusive) sympathetic control of the eccrine sweat gland - holds promise as an indicator of central sympathetic activation. The aim of this study was to determine whether combat and blast exposure modulate the EDA response to acute exercise stress in specialized military men. Sixty-four men (Age M = 34.0, SD = 7.2) participated in this study as part of the Explosive Ordnance Disposal Operational Health Surveillance System. The EDA complex (i.e., tonic + phasic conductance) was continuously measured throughout a maximal effort, graded exercise test. As expected, exercise stress resulted in measurable, stepwise increases in EDA before tapering at higher exercise intensities. Individuals with more substantial combat exposure and those with blast exposure demonstrated blunted EDA patterns in comparison to their low/non-exposed counterparts. This blunted pattern might imply sub-optimal sympathetic nervous system function in the exposed cohorts and enhances our knowledge of factors influencing resilience in these men. This article is protected by copyright. All rights reserved.

CHARACTERISTICS OF SKIN ELECTRICAL CONDUCTANCE IN PATIENTS WITH BREAST CANCER AND HIGH RISK OF RADIATION THERAPY-RELATED COMPLICATIONS

Background. Radiation therapy (RT) is one of the main methods of treating cancer, including breast cancer (BC). This is one of the most knowledge-intensive medical industries, which is based on the latest advances in radiobiology, chemistry, radiation physics, engineering and others. Effective PT involves the use of fairly high doses of radiation, which is what determines the success of comprehensive treatment, in particular the increase in the number of patients who survived 5 years or more. In turn, the increase in survival after a course of combination treatment leads to an increase in the absolute number of patients with adverse treatment outcomes, including radiation-related complications (RC). The aim of the work was to characterize the changes in the skin electrical conductance in patients with breast cancer and an increased risk of RC. Materials and methods. The study was conducted on the basis of the clinic of the Grigoriev Institute of Medical Radiology and Oncology of NAMS of Ukraine. To study the skin electrical conductance, 16 patients with BC with an increased risk of RC were selected, with a mean age of 53.8 ± 3.7 (95% CI: 46.6–61.0) years. Studies of tissue electrical conductance were performed using the device "Electrodermatometer", measuring the indicators: modulus of complex impedance, impedance angle, complex impedance, and electrical capacity. Results and discussion. The study showed that in patients with BC and increased risk of RC, there was a decrease in the complex impedance of tissues at the study points during RT. The modulus of complex impedance at the mitral area decreased by only 6.8% (p &gt; 0.05), while at the aortic, pulmonic and tricuspid areas, this figure was significantly (p &lt; 0.05) decreased by 27.0%; 26.2% and 33.0%, respectively, relative to the initial indicators for RT. It was found that the most pronounced changes in the skin electrical conductance in patients with BC at risk of RC were observed at the projection points of the tricuspid and pulmonic areas, where these indicators were significantly (p &lt; 0.05) increased by 41.1% and 34.2% relative to the baseline and equaled 9.8 ± 0.89 pF and 9.8 ± 0.88 pF, respectively. Conclusions. In patients with breast cancer at risk of RC, there was a statistically significant decrease (p &lt; 0.05) in the value of the modulus of complex impedance by an average of 23.3% and a statistically significant increase (p &lt; 0.05) in the tissue electrical conductance by an average of 29.8% relative to the baseline during radiation therapy.

Point process temporal structure characterizes electrodermal activity

Electrodermal activity (EDA) is a direct readout of the body's sympathetic nervous system measured as sweat-induced changes in the skin's electrical conductance. There is growing interest in using EDA to track physiological conditions such as stress levels, sleep quality, and emotional states. Standardized EDA data analysis methods are readily available. However, none considers an established physiological feature of EDA. The sympathetically mediated pulsatile changes in skin sweat measured as EDA resemble an integrate-and-fire process. An integrate-and-fire process modeled as a Gaussian random walk with drift diffusion yields an inverse Gaussian model as the interpulse interval distribution. Therefore, we chose an inverse Gaussian model as our principal probability model to characterize EDA interpulse interval distributions. To analyze deviations from the inverse Gaussian model, we considered a broader model set: the generalized inverse Gaussian distribution, which includes the inverse Gaussian and other diffusion and nondiffusion models; the lognormal distribution which has heavier tails (lower settling rates) than the inverse Gaussian; and the gamma and exponential probability distributions which have lighter tails (higher settling rates) than the inverse Gaussian. To assess the validity of these probability models we recorded and analyzed EDA measurements in 11 healthy volunteers during 1 h of quiet wakefulness. Each of the 11 time series was accurately described by an inverse Gaussian model measured by Kolmogorov-Smirnov measures. Our broader model set offered a useful framework to enhance further statistical descriptions of EDA. Our findings establish that a physiologically based inverse Gaussian probability model provides a parsimonious and accurate description of EDA.

Modeling radio-frequency energy-induced heating due to the presence of transcranial electric stimulation setup at 3T

PurposeThe purpose of the present study was to develop a numerical workflow for simulating temperature increase in a high-resolution human head and torso model positioned in a whole-body magnetic resonance imaging (MRI) radio-frequency (RF) coil in the presence of a transcranial electric stimulation (tES) setup.MethodsA customized human head and torso model was developed from medical image data. Power deposition and temperature rise (ΔT) were evaluated with the model positioned in a whole-body birdcage RF coil in the presence of a tES setup. Multiphysics modeling at 3T (123.2 MHz) on unstructured meshes was based on RF circuit, 3D electromagnetic, and thermal co-simulations. ΔT was obtained for (1) a set of electrical and thermal properties assigned to the scalp region, (2) a set of electrical properties of the gel used to ensure proper electrical contact between the tES electrodes and the scalp, (3) a set of electrical conductivity values of skin tissue, (4) four gel patch shapes, and (5) three electrode shapes.ResultsSignificant dependence of power deposition and ΔT on the skin’s electrical properties and electrode and gel patch geometries was observed. Differences in maximum ΔT (> 100%) and its location were observed when comparing the results from a model using realistic human tissue properties and one with an external container made of acrylic material. The electrical and thermal properties of the phantom container material also significantly (> 250%) impacted the ΔT results.ConclusionSimulation results predicted that the electrode and gel geometries, skin electrical conductivity, and position of the temperature sensors have a significant impact on the estimated temperature rise. Therefore, these factors must be considered for reliable assessment of ΔT in subjects undergoing an MRI examination in the presence of a tES setup.

Anionic Surfactant–Induced Changes in Skin Permeability

Anionic surfactants compromise skin's barrier function by damaging stratum corneum lipids and proteins. The objective of this study was to examine anionic surfactant–induced changes in the skin's polar and transcellular pathways and the resulting impact on surfactant penetration into the skin. Three anionic surfactant formulations and one control formulation were each applied to split-thickness human cadaver skin in vitro for 24 h. Electrical conductivity of the skin, determined using a four-terminal resistance method, and water permeation across the skin, determined using a radiolabeled water tracer, were simultaneously measured at several points over the experimental period. Surfactant permeation across the skin was similarly measured using a radiolabeled sodium dodecyl sulfate tracer. Anionic surfactants rapidly enhanced skin electrical conductivity and water permeability in the excised human skin, resulting in nonlinear enhancements in surfactant permeation across the skin over time. Surfactant penetration into the skin was found to increase linearly with increasing surfactant monomer concentration. Surfactant zeta potential was found to correlate well with skin conductivity, water permeation across the skin, and surfactant permeation across the skin, particularly with long surfactant exposures. Micelle charge is a significant predictor of anionic surfactant–induced damage to the human skin, with more highly charged surfactants inducing the most damage.

A Circuit for Simultaneous Measurements of Skin Electrical Conductance, Susceptance, and Potential.

A circuit is presented that enables measurement of skin electrical conductance, susceptance, and potential simultaneously beneath the same monopolar electrode. Example measurements are shown to confirm the function of the circuit. The measurements are also in accordance with earlier findings that changes in skin conductance and potential do not always correspond and hence contain unique information.

Effects of the single supplementation and multiple doses of Passiflora incarnata L. on human anxiety: A Clinical Trial, Double-blind, Placebo-controlled, Randomized

Object: This study aimed to investigate the effects of Passiflora incarnata L. on anxiety in humans.&#x0D; Method: The individuals were randomly assigned to one of the following groups: Placebo or experimental, n =30, single dose, as well as Placebo or Experimental, n =15, multiple dose. The experimental human anxiety was induced by simulated public speaking test in the following phases: Basal (B), stressful (A), speech 1 (S1), speech 2 (S2) and Final (F). We evaluated the Systolic Blood Pressure (SBP), and Diastolic (DBP), Heart Rate (HR), Electrical Conductance of Skin and extremities temperature (ET) and filled The state-trait anxiety inventory (STAI S e T).&#x0D; Results: During the single dose, the HR was reduced at the end of the speech (86±2,0 to 74±3,0 bpm) the experimental group compared to the placebo group (p&lt;0,05); the STAI-S did not change. In the delineation of multiple doses, SBP was reduced, in mmHg, in the experimental group compared to the placebo group during all phases. Experimental: 106±1,0 (B), 111±1,0 (A), 121±2,0 (S1), 115±3 (S2), 104±2,0 (F) e Placebo: 121±3,0; 127±3,0; 130±3,0; 130±4,5; 117±3,0 (p&lt;0,05).&#x0D; Conclusions: It is suggested that supplementation using Passiflora incarnata L. Capsules (500 mg) decreased cardiovascular signals both in single and in multiple doses, associated with the stress of public speaking.

Lower Meridian Electrical Conductance in Patients with Cancer Who Have Poorer Nutritional Status

Abstract Background: Traditional Chinese Medicine (TCM) studies have shown that energy in the human body may be detected using the meridian energy analysis device (MEAD) through the measurement of skin electrical conductance of 24 hand and foot acupuncture points on the 12 meridians. Objective: This study investigated the association between meridian electrical conductance and nutritional status in patients with cancer. Materials and Methods: This cross-sectional study was conducted with 147 cancer cases at the Linsen Branch of Taipei City Hospital, Taipei, Taiwan, between March 7, 2012 and March 6, 2013. The main outcome measures were meridian electrical conductance tested using the MEAD, while nutritional status was assessed using the scored Patient-Generated Subjective Global Assessment (PG-SGA) questionnaire. Results: The odds ratio for the total meridian electrical conductance (0.98) indicated that a decrease in the conductance level was correlated with an increase in the odds of being severely malno...

Intubation in the delivery room: Experience with nasal midazolam

BackgroundNeonates are often intubated in the delivery room (DR) without anesthesia because vascular access is impossible. AimsTo assess neonatal comfort and adverse events after use of nasal midazolam (nMDZ) for intubation in the DR. Study designProspective data collection over 6months on the intubation of neonates with respiratory distress requiring tracheal instillation of surfactant. SubjectsTwenty-seven neonates with median (Q25–75) gestational age and birthweight of, respectively, 29 (27–33)weeks and 1270 (817–1942)g received a 0.1mg/kg dose of nMDZ, and intubation was performed at the onset of tonus resolution or apnea. Outcome measuresComfort was assessed with a scale of hetero-pain assessment and electrical skin conductance monitoring. Continuous pulse oximetry was recorded in the first postnatal hour, with oscillometric blood pressure measurement every 10min. ResultsSeventy percent of the patients required a single dose, with intubation performed 4.8 (3–9)min after administration. Combined electro-clinical assessment found adequate comfort during the procedure in 68% of neonates. Mean blood pressure decreased from 39 (34–44)mmHg before to 31 (25–33)mmHg 1h following nMDZ (p=0.011). ConclusionnMDZ provided rapid and effective sedation to intubate neonates in the DR but potentially exposed them to hypotension, thus requiring close hemodynamic monitoring.

Evaluation of EZSCAN as a screening tool for impaired glucose metabolism

AimsTo evaluate the performance of EZSCAN as a screening tool for impaired glucose metabolism (IGM), including impaired glucose tolerance, impaired fasting glucose and undiagnosed diabetes in a Chinese population. Methods876 subjects participated in the study. All subjects underwent tests of EZSCAN, glycated hemoglobin, fasting plasma glucose (FPG), and oral glucose tolerance test (OGTT). Correlation of electrical skin conductance (ESC) with glucose level was evaluated by Pearson correlation coefficient. EZSCAN performance was assessed by receiver operating characteristic curve. ResultsAmong the 876 subjects, 53% had normal glucose tolerance (NGT), and 47% had IGM. The ESC for the hands and feet was 72±10μS and 75±7μS, respectively, in NGT group; and 64±13μS and 67±11μS, respectively, in IGM group. The ESC at hands and feet was significantly correlated with both 2h-OGTT and FPG (p<0.001). NGT group demonstrated a EZSCAN score of 33±11%, which is significantly lower than that of IGM group (44±12%, p<0.001). The cut-off point of EZSCAN for IGM detection was 40% with a sensitivity of 80% and a specificity of 72%. ConclusionsEZSCAN is a useful screening tool for identifying subjects at increased risk for impaired glucose metabolism in prediabetes and diabetes. Diagnostic laboratory test should be performed in subjects with EZSCAN scores greater than 40%.

The 5-HT1D/1B receptor agonist sumatriptan enhances fear of simulated speaking and reduces plasma levels of prolactin

This study measured the effects of the preferential 5-HT1D/1B receptor agonist sumatriptan in healthy volunteers who performed the Simulated Public Speaking Test (SPST), which recruits the neural network involved in panic disorder and social anxiety disorder. In a double-blind, randomised experiment, 36 males received placebo (12), 50 mg (12) or 100 mg (12) of sumatriptan 2 h before the SPST. Subjective, physiological and hormonal measures were taken before, during and after the test. The dose of 100 mg of sumatriptan increased speech-induced fear more than either a 50mg dose of the drug or placebo. The largest dose of sumatriptan also enhanced vigilance more than placebo, without any change in blood pressure, heart rate or electrical skin conductance. Sumatriptan decreased plasma levels of prolactin. A significant but moderate increase in plasma cortisol after SPST occurred, independent of treatment. Because sumatriptan decreases 5-HT release into the extracellular space, the potentiation of SPST-induced fear caused by the drug supports the hypothesis that 5-HT attenuates this emotional state. As acute administration of antidepressants has also been shown to enhance speaking fear and increase plasma prolactin, in contrast to sumatriptan, the 5-HT regulation of stress-hormone release is likely to be different from that of emotion.

Sex differences in fear conditioning in posttraumatic stress disorder

BackgroundWomen are twice as likely as men to develop Posttraumatic Stress Disorder (PTSD). Abnormal acquisition of conditioned fear has been suggested as a mechanism for the development of PTSD. While some studies of healthy humans suggest that women are either no different or express less conditioned fear responses during conditioning relative to men, differences in the acquisition of conditioned fear between men and women diagnosed with PTSD has not been examined. MethodsThirty-one participants (18 men; 13 women) with full or subsyndromal PTSD completed a fear conditioning task. Participants were shown computer-generated colored circles that were paired (CS+) or unpaired (CS−) with an aversive electrical stimulus and skin conductance levels were assessed throughout the task. ResultsRepeated measures ANOVA indicated a significant sex by stimulus interaction during acquisition. Women had greater differential conditioned skin conductance responses (CS + trials compared to CS− trials) than did men, suggesting greater acquisition of conditioned fear in women with PTSD. ConclusionsIn contrast to studies of healthy individuals, we found enhanced acquisition of conditioned fear in women with PTSD. Greater fear conditioning in women may either be a pre-existing vulnerability trait or an acquired phenomenon that emerges in a sex-dependent manner after the development of PTSD. Characterizing the underlying mechanisms of these differences is needed to clarify sex-related differences in the pathophysiology of PTSD.