Optimization of hepatological clinical guidelines interpretation by large language models: a retrieval augmented generation-based framework.

Large language models (LLMs) can potentially transform healthcare, particularly in providing the right information to the right provider at the right time in the hospital workflow. This study investigates the integration of LLMs into healthcare, specifically focusing on improving clinical decision support systems (CDSSs) through accurate interpretation of medical guidelines for chronic Hepatitis C Virus infection management. Utilizing OpenAI's GPT-4 Turbo model, we developed a customized LLM framework that incorporates retrieval augmented generation (RAG) and prompt engineering. Our framework involved guideline conversion into the best-structured format that can be efficiently processed by LLMs to provide the most accurate output. An ablation study was conducted to evaluate the impact of different formatting and learning strategies on the LLM's answer generation accuracy. The baseline GPT-4 Turbo model's performance was compared against five experimental setups with increasing levels of complexity: inclusion of in-context guidelines, guideline reformatting, and implementation of few-shot learning. Our primary outcome was the qualitative assessment of accuracy based on expert review, while secondary outcomes included the quantitative measurement of similarity of LLM-generated responses to expert-provided answers using text-similarity scores. The results showed a significant improvement in accuracy from 43 to 99% (p < 0.001), when guidelines were provided as context in a coherent corpus of text and non-text sources were converted into text. In addition, few-shot learning did not seem to improve overall accuracy. The study highlights that structured guideline reformatting and advanced prompt engineering (data quality vs. data quantity) can enhance the efficacy of LLM integrations to CDSSs for guideline delivery.

Non-Invasive Recording of Ocular-Following Responses in Children: A Promising Tool for Stereo Deficiency Evaluation.

Background: The ability to merge the two retinal images to perceive depth (stereopsis) plays an important role in human vision. Its proper development requires binocular alignment and good visual acuity in both eyes during childhood. Because treatments are more effective when applied early, early diagnosis is important. Unfortunately, assessing stereo deficiencies in infants and young children remains challenging. Recently, it has been shown that ocular-following responses (OFRs; reflexive, short-latency eye movements induced by the sudden motion of a large textured pattern) are sensitive to changes in interocular correlation, making them potentially useful for stereo deficiency assessments. To test this hypothesis, we measured OFRs elicited by dichoptic stimulation in children with normal and compromised stereopsis (due to amblyopia). Methods: Two groups of six children (age- and sex-matched: 3M/3F aged 7-12 yo), one with compromised stereopsis and one with normal stereopsis, were included. OFRs were recorded using a custom high-resolution video eye-tracking system. The relative differences between eye displacement induced by correlated stimuli (up-correlated-down-correlated) and anticorrelated (up-anticorrelated-down-anticorrelated) were compared. Results: We found significant differences between OFRs induced by two dichoptic conditions (correlated and anticorrelated stimuli) in most children with normal stereopsis, whereas no differences were observed in children with compromised stereopsis, indicating a lack of disparity detectors. Conclusions: OFRs might thus be exploited as a diagnostic tool for the objective identification of stereo deficiencies in children. This might lead to improved early diagnosis and treatment outcomes for conditions like amblyopia and strabismus.

Shoulder tensiomyography and isometric strength in swimmers before and after a fatiguing protocol.

CONTEXT.: Shoulder muscles are active during front crawl swimming to provide propulsion and stabilize the glenohumeral and scapulothoracic joints. It has been proposed that fatigue might contribute to altered activation of these muscles and represent a risk factor for injuries. Tensiomyography (TMG) might represent a non-invasive tool to detect exercise-induced neuromuscular fatigue changes in contractile parameters of the skeletal muscles, and it has never been used in the shoulder muscles in swimmers. OBJECTIVE.: The aim of this study was to assess the effects of a fatiguing swimming protocol on shoulder muscles TMG parameters and isometric strength in competitive swimmers. DESIGN.: A cross-sectional study. SETTING.: A swimming pool facility. PATIENTS OR OTHER PARTICIPANTS.: Sixteen young front crawl competitive swimmers were invited to participate in the study, and 14 of them (21 y, range 17-26, 11 males 3 females) completed all the assessments before and after a 30-min high-intensity swimming training. MAIN OUTCOME MEASURE(S).: The main outcome included the TMG assessment which was performed on seven muscles of the shoulder according to front crawl biomechanics and applicability of the technique, in order to obtain data such as time to contraction and muscle belly radial displacement (Dm), whereas isometric strength was assessed with a digital dynamometer during shoulder flexion, extension, external rotation and internal rotation. RESULTS.: Fatigue induced a smaller Dm (-0.5 mm, 95% CI: -0.7 - -0.3, p< 0.001, pη2= 0.692), mostly observable in latissimus dorsi and pectoralis major muscles. Only shoulder extension showed a significant isometric strength reduction after the fatiguing protocol (-0.03 N/kg, 95% CI: -0.05 - -0.01, p= 0.045, pη2= 0.275). CONCLUSIONS.: This study provides preliminary evidence for the usefulness of TMG to detect fatigue-induced changes in contractile properties of the shoulder muscles in swimmers, in particular the latissimus dorsi, pectoralis major and lower trapezius.

Inertial Sensors and Pressure Pain Threshold to Evaluate People with Primary Adhesive Capsulitis: Comparison with Healthy Controls and Effects of a Physiotherapy Protocol.

Inertial sensors (IMUs) have been recently widely used in exercise and rehabilitation science as they can provide reliable quantitative measures of range of motion (RoM). Moreover, the pressure pain threshold (PPT) evaluation provides an objective measure of pain sensation in different body areas. The aim of this study was to evaluate the efficacy of physiotherapy treatment in people with adhesive capsulitis in terms of RoM and pain improvement measured by IMUs and the PPT. A combined prospective cohort/cross-sectional study was conducted. Nineteen individuals with adhesive capsulitis (10/19 females, 54 ± 8 years) and nineteen healthy controls (10/19 females, 51 ± 6 years) were evaluated for active glenohumeral joint RoM and PPT on shoulder body areas. Then, individuals with adhesive capsulitis were invited to 20 sessions of a physiotherapy protocol, and the assessments were repeated within 1 week from the last session. The range of motion in the flexion (p = 0.001) and abduction (p < 0.001) of the shoulder increased significantly after the physiotherapy protocol. Similarly, the PPT was found to increase significantly in all the assessed shoulder body areas, leading to no significant differences compared to the healthy controls. IMU and PPT assessments could be used to evaluate the efficacy of physical therapy in people with adhesive capsulitis.

Sleep Spindle-Related EEG Connectivity in Children with Attention-Deficit/Hyperactivity Disorder: An Exploratory Study.

Attention-deficit/hyperactivity disorder (ADHD) is a neurobehavioral disorder with known brain abnormalities but no biomarkers to support clinical diagnosis. Recently, EEG analysis methods such as functional connectivity have rekindled interest in using EEG for ADHD diagnosis. Most studies have focused on resting-state EEG, while connectivity during sleep and spindle activity has been underexplored. Here we present the results of a preliminary study exploring spindle-related connectivity as a possible biomarker for ADHD. We compared sensor-space connectivity parameters in eight children with ADHD and nine age/sex-matched healthy controls during sleep, before, during, and after spindle activity in various frequency bands. All connectivity parameters were significantly different between the two groups in the delta and gamma bands, and Principal Component Analysis (PCA) in the gamma band distinguished ADHD from healthy subjects. Cluster coefficient and path length values in the sigma band were also significantly different between epochs, indicating different spindle-related brain activity in ADHD.

Inertial sensors-based assessment to detect hallmarks of chronic ankle instability during single-leg standing: Is the healthy limb "healthy"?

BACKGROUND: Chronic ankle instability can be common in sportsmen and can increase the risk of damaging the articular surfaces and result in negative consequences to joint health. Balance assessment is often used to evaluate ankle instability characteristics and guide rehabilitation protocols. This study aims to investigate balance-related parameters in people with chronic ankle instability and healthy-matched controls, using inertial sensors. METHODS: Ten young adults with a history of multiple ankle sprains (30 y, 25-34, 5 females) and ten matched healthy controls (30 y, 23-39, 5 females) were invited to participate in the study. Inertial sensors were placed on the head of the astragalus and on the chest to collect kinematic parameters during a 20-s single-leg stance performed on the leg with ankle instability (and corresponding for the healthy controls) and on the contralateral leg, randomly. Outcomes were calculated with MATLAB and subsequently analyzed. FINDINGS: A significant group effect was found only for the inversion angle (F1,15 = 12.514, p = 0.003, pη2 = 0.455), consisting of individuals with ankle instability being characterized by higher inversion angles (4.999 degrees, 95% CI: 1.987-8.011, p = 0.003) without significant side differences. No significant side x group effects were found for the assessed parameters. INTERPRETATION: Results from this study suggest that young adults with chronic ankle instability might be characterized by worse single-stance control in terms of inversion angle, and such worse performance could also be found in the contralateral leg. As such, inertial sensors could be used to assess kinematic parameters during balance tasks in people with chronic ankle instability.

Cerebral hypoperfusion in post-COVID-19 cognitively impaired subjects revealed by arterial spin labeling MRI.

Cognitive impairment is one of the most prevalent symptoms of post Severe Acute Respiratory Syndrome COronaVirus 2 (SARS-CoV-2) state, which is known as Long COVID. Advanced neuroimaging techniques may contribute to a better understanding of the pathophysiological brain changes and the underlying mechanisms in post-COVID-19 subjects. We aimed at investigating regional cerebral perfusion alterations in post-COVID-19 subjects who reported a subjective cognitive impairment after a mild SARS-CoV-2 infection, using a non-invasive Arterial Spin Labeling (ASL) MRI technique and analysis. Using MRI-ASL image processing, we investigated the brain perfusion alterations in 24 patients (53.0 ± 14.5 years, 15F/9M) with persistent cognitive complaints in the post COVID-19 period. Voxelwise and region-of-interest analyses were performed to identify statistically significant differences in cerebral blood flow (CBF) maps between post-COVID-19 patients, and age and sex matched healthy controls (54.8 ± 9.1 years, 13F/9M). The results showed a significant hypoperfusion in a widespread cerebral network in the post-COVID-19 group, predominantly affecting the frontal cortex, as well as the parietal and temporal cortex, as identified by a non-parametric permutation testing (p < 0.05, FWE-corrected with TFCE). The hypoperfusion areas identified in the right hemisphere regions were more extensive. These findings support the hypothesis of a large network dysfunction in post-COVID subjects with cognitive complaints. The non-invasive nature of the ASL-MRI method may play an important role in the monitoring and prognosis of post-COVID-19 subjects.

Characterization of a Novel Approach for Neonatal Hematocrit Screening Based on Penetration Velocity in Lateral Flow Test Strip.

Hematocrit (HCT) is a crucial parameter for both adult and pediatric patients, indicating potentially severe pathological conditions. Most common methods for HCT assessment are microhematocrit and automated analyzers; however, developing countries present specific needs often not addressed by these technologies. Paper-based devices can be suitable for those environments being inexpensive, rapid, easy to use, and portable. The aim of this study is to describe and validate against a reference method, a novel HCT estimation method based on penetration velocity in lateral flow test strips complying with the requirements in low- or middle-income country (LMIC) scenarios. To calibrate and test the proposed method, 145 blood samples of 105 healthy neonates with gestational age greater than 37 weeks were collected (29 calibration set, 116 test set) in the range of HCT values (31.6-72.5%). The time difference (Δt) from the whole blood sample loading into the test strip instant till the nitrocellulose membrane saturation instant was measured by a reflectance meter. A nonlinear relation was observed between HCT and Δt and was estimated by a third-degree polynomial equation (R2 = 0.91) valid in 30% to 70% HCT interval. The proposed model was subsequently used to estimate HCT values on the test set showing a good agreement between the estimated HCT and the HCT measured by the reference method (r = 0.87, p < 0.001), with a low mean difference of 0.53 ± 5.04% and a slight trend of overestimation for higher hematocrit values. The mean absolute error was 4.29%, while the maximum absolute error was 10.69%. Although the proposed method did not present a sufficient accuracy to be used for diagnostic purposes, it could be suitable as a fast, low-cost, easy-to-use screening tool especially in LMIC scenarios.

Ocular-following responses in school-age children.

Ocular following eye movements have provided insights into how the visual system of humans and monkeys processes motion. Recently, it has been shown that they also reliably reveal stereoanomalies, and, thus, might have clinical applications. Their translation from research to clinical setting has however been hindered by their small size, which makes them difficult to record, and by a lack of data about their properties in sizable populations. Notably, they have so far only been recorded in adults. We recorded ocular following responses (OFRs)-defined as the change in eye position in the 80-160 ms time window following the motion onset of a large textured stimulus-in 14 school-age children (6 to 13 years old, 9 males and 5 females), under recording conditions that closely mimic a clinical setting. The OFRs were acquired non-invasively by a custom developed high-resolution video-oculography system, described in this study. With the developed system we were able to non-invasively detect OFRs in all children in short recording sessions. Across subjects, we observed a large variability in the magnitude of the movements (by a factor of 4); OFR magnitude was however not correlated with age. A power analysis indicates that even considerably smaller movements could be detected. We conclude that the ocular following system is well developed by age six, and OFRs can be recorded non-invasively in young children in a clinical setting.

A Novel Non-Invasive Thermometer for Continuous Core Body Temperature: Comparison with Tympanic Temperature in an Acute Stroke Clinical Setting.

There is a growing research interest in wireless non-invasive solutions for core temperature estimation and their application in clinical settings. This study aimed to investigate the use of a novel wireless non-invasive heat flux-based thermometer in acute stroke patients admitted to a stroke unit and compare the measurements with the currently used infrared (IR) tympanic temperature readings. The study encompassed 30 acute ischemic stroke patients who underwent continuous measurement (Tcore) with the novel wearable non-invasive CORE device. Paired measurements of Tcore and tympanic temperature (Ttym) by using a standard IR-device were performed 3−5 times/day, yielding a total of 305 measurements. The predicted core temperatures (Tcore) were significantly correlated with Ttym (r = 0.89, p < 0.001). The comparison of the Tcore and Ttym measurements by Bland−Altman analysis showed a good agreement between them, with a low mean difference of 0.11 ± 0.34 °C, and no proportional bias was observed (B = −0.003, p = 0.923). The Tcore measurements correctly predicted the presence or absence of Ttym hyperthermia or fever in 94.1% and 97.4% of cases, respectively. Temperature monitoring with a novel wireless non-invasive heat flux-based thermometer could be a reliable alternative to the Ttym method for assessing core temperature in acute ischemic stroke patients.

Toward a diagnostic CART model for Ischemic heart disease and idiopathic dilated cardiomyopathy based on heart rate total variability.

Diagnosis of etiology in early-stage ischemic heart disease (IHD) and dilated cardiomyopathy (DCM) patients may be challenging. We aimed at investigating, by means of classification and regression tree (CART) modeling, the predictive power of heart rate variability (HRV) features together with clinical parameters to support the diagnosis in the early stage of IHD and DCM. The study included 263 IHD and 181 DCM patients, as well as 689 healthy subjects. A 24 h Holter monitoring was used and linear and non-linear HRV parameters were extracted considering both normal and ectopic beats (heart rate total variability signal). We used a CART algorithm to produce classification models based on HRV together with relevant clinical (age, sex, and left ventricular ejection fraction, LVEF) features. Among HRV parameters, MeanRR, SDNN, pNN50, LF, LF/HF, LFn, FD, Beta exp were selected by the CART algorithm and included in the produced models. The model based on pNN50, FD, sex, age, and LVEF features presented the highest accuracy (73.3%). The proposed approach based on HRV parameters, age, sex, and LVEF features highlighted the possibility to produce clinically interpretable models capable to differentiate IHD, DCM, and healthy subjects with accuracy which is clinically relevant in first steps of the IHD and DCM diagnostic process.

A Deep Learning Method for Automatic Identification of Drusen and Macular Hole from Optical Coherence Tomography.

Deep Learning methods have become dominant in various fields of medical imaging, including ophthalmology. In this preliminary study, we investigated a method based on Convolutional Neural Network for the identification of drusen and macular hole from Optical Coherence Tomography scans with the aim to assist ophthalmologists in diagnosing and assessing retinal diseases.

Wake-up Stroke Outcome Prediction by Interpretable Decision Tree Model.

Outcome prediction in wake-up ischemic stroke (WUS) is important for guiding treatment strategies, in order to improve recovery and minimize disability. We aimed at producing an interpretable model to predict a good outcome (NIHSS 7-day<5) in thrombolysis treated WUS patients by using Classification and Regression Tree (CART) method. The study encompassed 104 WUS patients and we used a dataset consisting of demographic, clinical and neuroimaging features. The model was produced by CART with Gini split criterion and evaluated by using 5-fold cross-validation. The produced decision tree model was based on NIHSS at admission, ischemic core volume and age features. The predictive accuracy of model was 86.5% and the AUC-ROC was 0.88. In conclusion, in this preliminary study we identified interpretable model based on clinical and neuroimaging features to predict clinical outcome in thrombolysis treated wake-up stroke patients.

Comprehensive telemedicine solution for remote monitoring of Parkinson's disease patients with orthostatic hypotension during COVID-19 pandemic.

OBJECTIVE: Orthostatic hypotension (OH) represents a frequent but under-recognized phenomenon in Parkinson's disease (PD). During COVID-19 pandemic, Information and Communication Technologies (ICT) have become pivotal in the management of chronic diseases like PD, not only to assess motor impairment, but also for vital signs monitoring. This pilot study aimed to propose a real-time remote home-monitoring system and protocol for PD patients with OH. METHODS: Vital parameters were acquired by wireless devices and transmitted to an ICT platform, providing data and smart notifications to the healthcare provider through an interactive web portal. Eight patients with idiopathic PD and OH underwent 5-day monitoring. Data about OH episodes, therapeutic interventions, impact on daily activities, and patient satisfaction were collected and analyzed. RESULTS: The proposed solution allowed the identification of 65 OH episodes and subsequent medical interventions. Thirty-five episodes were asymptomatic, especially in the postprandial and in the afternoon recordings. Systolic-blood-pressure (SBP) and diastolic-blood-pressure (DBP) were significantly lower in symptomatic episodes, while the pressure drops resulted significantly higher in presence of symptoms. High usability and patient satisfaction scores were observed. CONCLUSION: The proposed home-monitoring system and protocol have proved to provide useful information and to allow prompt interventions in the management of PD patients with OH during COVID-19 pandemic.

Influence of smoking and other cardiovascular risk factors on heart rate circadian rhythm in normotensive and hypertensive subjects.

Circadian heart rate (HR) is influenced by hypertension and other cardiovascular risk factors particularly smoking, obesity and dyslipidemia. Until now, to evaluate the HR changes due to presence of these risk factors, a single HR office measure or a mean evaluated on day time or night time or 24h was used. However, since HR shows a circadian behavior, a single value represents only a rough approximation of this behavior. In this study, we analyzed the influence of smoking, obesity and dyslipidemia on the circadian rhythm in normotensive and hypertensive subject groups presenting only one of these risk factors. The 24h HR recordings of 170 normotensive (83 without risk factors, 20 smokers, 44 with dyslipidemia, 23 obese) and 353 hypertensive (169 without risk factors, 32 smokers, 99 with dyslipidemia, 53 obese) subjects were acquired using a Holter Blood Pressure Monitor. Results highlighted a specific circadian behavior with three characteristic periods presenting different HR means and rates of HR change in the eight subject groups. The slopes could be used both to estimate the morning HR surge associated with acute cardiovascular effects in the awakening and to evaluate the decline during the night. Moreover, we suggest to use three HR mean values (one for each identified period of the day) rather than two HR values to better describe the circadian HR behavior. Furthermore, smoking increased and dyslipidemia decreased mean HR values from 10:00 to 04:00, both in normotensive and hypertensive subjects in comparison with subjects without risk factors. In this time interval, hypertensive obese subjects showed higher values while normotensive ones presented quite similar values than subjects without risk factors. During the awakening (05:00-10:00) the slopes were similar among all groups with no significant difference among the mean HR values.

Influence of hypertension and other risk factors on the onset of sublingual varices.

BACKGROUND: Sublingual varices (SV) are dilatations of tortuous veins that increased with age. Previous studies showed that this pathology could be correlated to some risk factors such as hypertension, age, gender and diabetes mellitus. In this study we evaluated, on a large number of subjects, the relationship between SV and different grades of hypertension as well as some risk factors extending the analysis to new risk factors such as dyslipidemia, obesity and antihypertensive therapy, modelling a possible dependence of SV on all these factors. METHODS: In the study 1008 subjects, 284 with and 724 without SV, were examined. The blood pressure was measured in office condition and, to exclude subjects with white coat syndrome or masked hypertension, also using a 24 h Holter pressure monitor. Hypertensive subjects were divided in resistant, drugs controlled (compensated) and patients with prior unknown hypertension (new diagnosed) groups. The presence or absence of SV as well as of the risk factors was assessed clinically. We tested the influence of age on the presence of SV by using the chi-square test and the relation between each risk factor and SV by the Cochran-Mantel-Haenszel test. Finally, we carried out a multivariate regression tree analysis in order to predict the presence of SV. RESULTS: We confirmed the influence of age on SV and found a significant relationship between SV and both the compensated and resistant hypertension grades. We highlighted a relationship between SV and dyslipidemia in subjects with new diagnosed hypertension, and between SV and smoking in subjects with compensated hypertension grade. The regression tree showed a classification accuracy of about 75% using as variables hypertension grades, age and antihypertensive treatment. CONCLUSIONS: We confirmed the SV dependence on age, resistant hypertension and smoking, highlighting a new association with dyslipidemia in new diagnosed hypertensive subjects and new relations depending on the hypertension grades. Thus, the SV inspection could be used to suggest a lipidologist as well as a hypertension specialist visit for a pharmacological and pressure check particularly in subjects presenting SV and dyslipidemia. However, further parameters are to be considered to improve the sensitivity of the prognostic tree model.

e-Health solution for home patient telemonitoring in early post-acute TIA/Minor stroke during COVID-19 pandemic.

BACKGROUND: When it comes to critical early post-acute TIA/stroke phase, there is a lack of a comprehensive multi-parametric telemonitoring system. The COVID-19 emergency, its related global mobility restrictions and fear of hospitalization further highlighted the need of a comprehensive solution. OBJECTIVE: We aimed to design and test a pragmatic e-Health system based on multiparametric telemonitoring to support of TIA/stroke patients in sub-acute phase during the COVID-19 pandemic. METHODS: We proposed a telemonitoring system and protocol for TIA/minor stroke patients during COVID-19 pandemic for patients at risk of stroke recurrence. This system involves the use of portable devices for BP/HR/SpO2/temperature sensing, panic-button, gateway, and a dedicated ICT platform. The protocol is a 14-day multiparametric telemonitoring, therapy, and emergency intervention based on vital sign alteration notifications. We conducted a proof-of-concept validation test on 8 TIA/minor stroke patients in the early post-acute phase (< 14 days from ischemic event). RESULTS: The proposed solution allowed to promptly and remotely identify vital sign alterations at home during the early post-acute phase, allowing therapy and behavioral intervention adjustments. Also, we observed a significant improvement of quality of life, as well as a significant reduction of anxiety and depression status. TUQ showed ease of use, good interface quality and high user satisfaction of the proposed solution. The 3-month follow-up showed total adherence of prescribed therapy and no stroke/TIA recurrence or other emergency department admissions. CONCLUSION: The proposed e-Health solution and telemonitoring protocol may be highly useful for early post-acute remote patient management, thus supporting constant monitoring and patient adherence to the treatment pathway, especially during the COVID-19 emergency.

CT perfusion in hyper-acute ischemic stroke: the acid test for COVID-19 fear.

PURPOSE: The fear of COVID-19 infection may discourage patients from going to the hospital even in case of sudden onset of disabling symptoms. There is growing evidence of the reduction of stroke admissions and higher prevalence of severe clinical presentation. Yet, no studies have investigated the perfusion pattern of acute strokes admitted during the lockdown. We aimed to evaluate the effects of the COVID-19 pandemic on hyper-acute stroke CT perfusion (CTP) pattern during the first months of the pandemic in Italy. METHODS: In this retrospective observational study, we analyzed CTP images and clinical data of ischemic stroke patients admitted between 9 March and 2 June 2020 that underwent CTP (n = 30), to compare ischemic volumes and clinical features with stroke patients admitted during the same period in 2019 (n = 51). In particular, CTP images were processed to calculate total hypoperfused volumes, core volumes, and mismatch. The final infarct volumes were calculated on follow-up CT. RESULTS: Significantly higher total CTP hypoperfused volume (83.3 vs 18.5 ml, p = 0.003), core volume (27.8 vs 1.0 ml, p < 0.001), and unfavorable mismatch (0.51 vs 0.91, p < 0.001) were found during the COVID-19 period compared to no-COVID-19 one. The more unfavorable perfusion pattern at admission resulted in higher infarct volume on follow-up CT during COVID-19 (35.5 vs 3.0 ml, p < 0.001). During lockdown, a reduction of stroke admissions (- 37%) and a higher prevalence of severe clinical presentation (NIHSS ≥ 10; 53% vs 36%, p = 0.029) were observed. CONCLUSION: The results of CTP analysis provided a better insight in the higher prevalence of major severity stroke patients during the COVID-19 period.

Early EEG Alterations Correlate with CTP Hypoperfused Volumes and Neurological Deficit: A Wireless EEG Study in Hyper-Acute Ischemic Stroke.

Brain electrical activity in acute ischemic stroke is related to the hypoperfusion of cerebral tissue as manifestation of neurovascular coupling. EEG could be applicable for bedside functional monitoring in emergency settings. We aimed to investigate the relation between hyper-acute ischemic stroke EEG changes, measured with bedside wireless-EEG, and hypoperfused core-penumbra CT-perfusion (CTP) volumes. In addition, we investigated the association of EEG and CTP parameters with neurological deficit measured by NIHSS. We analyzed and processed EEG, CTP and clinical data of 31 anterior acute ischemic stroke patients registered within 4.5 h from symptom onset. Delta/alpha ratio (DAR), (delta + theta)/(alpha + beta) ratio (DTABR) and relative delta power correlated directly (ρ = 0.72; 0.63; 0.65, respectively), while alpha correlated inversely (ρ = - 0.66) with total hypoperfused volume. DAR, DTBAR and relative delta and alpha parameters also correlated with ischemic core volume (ρ = 0.55; 0.50; 0.59; - 0.51, respectively). The same EEG parameters and CTP volumes showed significant relation with NIHSS at admission. The multivariate stepwise regression showed that DAR was the strongest predictor of NIHSS at admission (p < 0.001). The results of this study showed that hyper-acute alterations of EEG parameters are highly related to the extent of hypoperfused tissue highlighting the value of quantitative EEG as a possible complementary tool in the evaluation of stroke severity and its potential role in acute ischemic stroke monitoring.

Influence of ageing on circadian rhythm of heart rate variability in healthy subjects.

BACKGROUND: The analysis of the circadian rhythm of heart rate variability (HRV) represents a relevant physiological tool to assess the vagal system. However, the influence of age (mostly >75 years) on HRV is not widely known. AIMS: The aim of this study was to evaluate the influence of age on HRV, particularly in the elderly and to identify a model of this relationship. The study was carried out by examining linear and nonlinear parameters extracted from HRV, including individuals over 75 years for which there is no research available. METHODS: Data from 140 healthy subjects were sex matched and divided into young (young group: 15-39 years old), adult (adult group: 40-64 years old) and senior (senior group: 65-90 years old) groups. 24-h Holter monitoring was used and several HRV parameters were extracted from time, and spectral and nonlinear analyses were examined. RESULTS: Time-domain parameters, mainly standard deviation of the NN interval (SDNN) and number of successive differences of intervals which differ by more than 50 ms, presented significant differences between the young group and the other two groups during the 24-h period, while normalized spectral parameters (LFn, HFn and low frequency/high frequency), as well as nonlinear parameters, mainly ß exponent and fractal dimension, showed significant difference between the senior group and the other two groups. All these parameters showed a similar circadian rhythm with significant differences between the mean day and night values, especially in young and adult group cohorts. Moreover, a parabolic relationship between these parameters and age was highlighted with an opposite trend over about 60 years compared with younger people. CONCLUSION: A progressive physiological autonomic imbalance is present in ageing. The inverse trend in the relation between HRV parameters and age found in the senior group could be mainly due to a faster fluctuation of RR. This should be considered when studying changes in the cardiac autonomic nervous control.