Advances in Understanding Fractals in Affective and Anxiety Disorders.

In this chapter, we review the research that has applied fractal measures to the study of the most common psychological disorders, that is, affective and anxiety disorders. Early studies focused on heart rate, but diverse measures have also been examined, from variations in subjective mood, or hand movements, to electroencephalogram or magnetoencephalogram data. In general, abnormal fractal dynamics in different physiological and behavioural outcomes have been observed in mental disorders. Despite the disparity of variables measured, fractal analysis has shown high sensitivity in discriminating patients from healthy controls. However, and because of this heterogeneity in measures, the results are not straightforward, and more studies are needed in this promising line.

Metabolomic Signatures of Exposure to Nitrate and Trihalomethanes in Drinking Water and Colorectal Cancer Risk in a Spanish Multicentric Study (MCC-Spain).

We investigated the metabolomic profile associated with exposure to trihalomethanes (THMs) and nitrate in drinking water and with colorectal cancer risk in 296 cases and 295 controls from the Multi Case-Control Spain project. Untargeted metabolomic analysis was conducted in blood samples using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. A variety of univariate and multivariate association analyses were conducted after data quality control, normalization, and imputation. Linear regression and partial least-squares analyses were conducted for chloroform, brominated THMs, total THMs, and nitrate among controls and for case-control status, together with a N-integration model discriminating colorectal cancer cases from controls through interrogation of correlations between the exposure variables and the metabolomic features. Results revealed a total of 568 metabolomic features associated with at least one water contaminant or colorectal cancer. Annotated metabolites and pathway analysis suggest a number of pathways as potentially involved in the link between exposure to these water contaminants and colorectal cancer, including nicotinamide, cytochrome P-450, and tyrosine metabolism. These findings provide insights into the underlying biological mechanisms and potential biomarkers associated with water contaminant exposure and colorectal cancer risk. Further research in this area is needed to better understand the causal relationship and the public health implications.

Excess Weight in Relation to Lifestyle Habits in Spanish First-Year University Students: Differences between Pre- and Post-COVID-19-A Serial Cross-Sectional Study Based on uniHcos Project.

The objective of this research was to study the relationship between the body weight and diet, physical activity, and other habits among freshmen students by sex, and to determine whether these habits have changed during the post-era of the COVID-19 pandemic. A serial cross-sectional study with data from 11 Spanish universities was carried out. In total, 10,096 first-year university students (73.2% female, mean age = 19.0 ± 1.5 years) completed an online self-administered questionnaire between 2012 and 2022. For some analyses, questionnaires were categorized by the year in which the survey was filled out as Before COVID-19, Lockdown, and New Normal. In total, 72.9% of participants were within the normal weight range, and 17.7% of men and 11.8% of women were overweight (p < 0.001). The students who did not meet the WHO criteria of physical activity, spent more than 7 h per day sitting, and skipped breakfast had a higher prevalence of obesity (p < 0.05). According to the period of study, the prevalence of overweight/obesity Before COVID-19 was 16.1% (95% CI: 15.4-16.9%), while in Lockdown the prevalence was significantly higher (20.2, 95% CI: 17.1-23.8) and in New Normal it was 18.9% (CI: 15.7-22.5). Moreover, the study suggests that during the Lockdown period, there was a reduction in the practice of physical activity and an increase in the prevalence of a healthy diet. For all these, it is necessary to propose public health interventions that improve the lifestyles of university students.

Electrophysiological correlates of dispositional mindfulness: A quantitative and complexity EEG study.

While growing evidence supports that dispositional mindfulness relates to psychological health and cognitive enhancement, to date there have been only a few attempts to characterize its neural underpinnings. In the present study, we aimed at exploring the electrophysiological (EEG) signature of dispositional mindfulness using quantitative and complexity measures of EEG during resting state and while performing a learning task. Hundred twenty participants were assessed with the Five Facet Mindfulness Questionnaire and underwent 5 min eyes-closed resting state and 5 min at task EEG recording. We hypothesized that high mindfulness individuals would show patterns of brain activity related to (a) lower involvement of the default mode network (DMN) at rest (reduced frontal gamma power) and (b) a state of 'task readiness' reflected in a more similar pattern from rest to task (reduced overall q-EEG power at rest but not at task), as compared to their low mindfulness counterparts. Dispositional mindfulness was significantly linked to reduced frontal gamma power at rest and lower overall power during rest but not at task. In addition, we found a trend towards higher entropy during task performance in mindful individuals, which has recently been reported during mindfulness meditation. Altogether, our results add to those from expert meditators to show that high (dispositional) mindfulness seems to have a specific electrophysiological pattern characteristic of less involvement of the DMN and mind-wandering processes.

Risk of thromboembolic events in relation to the management of anticoagulant and antiagregant therapy in patients subjected to endoscopic retrograde cholangiopancreatography. / Riesgo de eventos tromboembólicos en función del manejo de la terapia anticoagulante y antiagregante en pacientes sometidos a colangiopancreatografía retrógrada endoscópica.

BACKGROUND AND OBJECTIVES: The main clinical practice guidelines recommend adequate periprocedural withdrawal and reintroduction of antithrombotic drugs in case of invasive techniques. The main objective of this study was to assess whether, in patients receiving anticoagulant or antiplatelet therapy, the suppression or reduction of the pharmacological dose for the performance of endoscopic retrograde cholangiopancreatography (ERCP) implies a greater risk of thromboembolic events. PATIENTS AND METHODS: A prospective observational study was carried out, which included 644ERCP performed with therapeutic intention during 2019 at the Reina Sofía University Hospital with follow-up during the 30days after the endoscopic intervention. RESULTS: Six patients presented a thromboembolic event, finding no differences between the incorrect withdrawal/reintroduction of antithrombotic treatment and a higher proportion of thromboembolic or hemorrhagic events after the procedure (P>.05). The incidence of thrombotic events was significantly higher in patients treated with heparin or apixaban (P=.001), as well as with a history of atrial fibrillation (P=.05), rheumatic valve disease (P=.037) and recurrent pulmonary embolism (P=.035), this being also an independent risk factor. Likewise, the incidence of hemorrhage in the 30days post-sphincterotomy was significantly lower in those with implantation of a biliary prosthesis (P=.04). CONCLUSIONS: Inadequate periprocedural management of antithrombotic therapy is not associated with a significant increase in the incidence of thromboembolic events in the 30days after ERCP. However, close follow-up and surveillance during the days after this is essential in those patients with a condition that significantly increases the risk of thrombosis.

Impact of the COVID-19 Pandemic on the Evolution of Prevalence and Patterns of Cannabis Use among First-Year University Students in Spain-UniHcos Project.

Among university students there has been evidence that the COVID-19 pandemic increased their psychological distress, exacerbated by social restrictions. The main objective of this study was to explore the impact of the COVID-19 pandemic on the prevalence and patterns of cannabis use among university students, in contrast to previous trends since 2012. Data from 10,522 first-year university students (73.3% female, Mage 19 (SD = 1.6)) from eleven Spanish universities collected between 2012 and May 2022 was analysed. Prevalences of cannabis use and their differences by sex were studied, as well as changes in patterns of use and its use for coping during the pandemic. It was found that during lockdown, all prevalence rates of cannabis use decreased in both sexes, showing no statistically significant differences and increasing again in the new normal period in both. Among regular cannabis users, 79.7% reported maintaining or increasing their cannabis use during the pandemic, and of these, half reported using cannabis to cope. Moreover, cannabis use in the usual household increased during the lockdown. These results show that although the overall prevalence of cannabis use was reduced during the lockdown, regular users tended to maintain or increase cannabis use. This could imply two different patterns of use among students, one social and occasional versus the other regular, providing new lines of research for prevention and the implementation of social policies.

Endoscopic findings unrelated to portal hypertension in patients with liver cirrhosis undergoing a varicose vein screening programme. / Hallazgos endoscópicos no relacionados con hipertensión portal en pacientes con cirrosis hepática sometidos a un programa de cribado de varices.

AIM: To determine the prevalence of endoscopic lesions unrelated with portal hypertension in patients with cirrhosis. PATIENTS AND METHODS: Cross-sectional study including a consecutive cohort of patients with liver cirrhosis enrolled in a screening program of oesophageal varices who underwent an upper gastrointestinal endoscopy from November, 2013, to November, 2018. Clinical predictors of endoscopic lesions unrelated to portal hypertension were analyzed by univariate and multivariate logistic regression. RESULTS: A total of 379 patients were included. The most frequent aetiology of liver disease was alcohol consumption (60.4%). The prevalence of endoscopic lesions unrelated with portal hypertension was 39.6% (n=150). Among 96 patients with peptic lesions, urease was obtained in 56.2% of patients (positive in 44.4% of them). The prevalence of endoscopic lesions unrelated to portal hypertension was not associated with age, gender, liver function or ultrasound findings of portal hypertension. The prevalence of endoscopic lesions unrelated to portal hypertension was not associated with age, gender, liver function or ultrasound findings of portal hypertension. Smokers had a trend to increased prevalence of endoscopic lesions unrelated to portal hypertension (43.2% vs. 34.6%; p=0.09), particularly peptic ulcer (6.4% vs. 0.6%; p=0.05) and peptic duodenitis (17.3% vs. 6.3%; p=0.002). Active smoking was the only independent predictor of peptic ulcer or duodenitis (OR=2.56; p=0.017). CONCLUSION: Active smoking is a risk factor for endoscopic lesions unrelated to portal hypertension. This finding should be further investigated to reassess endoscopic screening programs in cirrhotic smokers.

The role of calcium and vitamin D dietary intake on risk of colorectal cancer: systematic review and meta-analysis of case-control studies.

PURPOSE: The aim of this study is to analyze the current evidence about the relationships between calcium/vitamin D and CRC based on case-control studies according to sex, tumor location and continental region to complement the information obtained in meta-analyses of other designs. METHODS: The articles were located in three databases (PUBMED, EMBASE and SCOPUS), they should be written in English language, with a case and control design and published between 1 January 1970 and 31 October 2019. RESULTS: There were 37 selected studies, 32 for intake of calcium, that involved 24,353 CRC cases and 30,650 controls, and 23 for that of VIT D, with a total of 19,076 cases and 36.746 controls included. For dietary calcium intake, the overall OR was 0.94 (95% CI 0.92-0.97), suggesting a reducing effect with a 6% decrease in CRC risk for every 300 mg of calcium ingested daily. Regarding vitamin D intake a global OR of 0.96 (95% CI 0.93-0.98) was observed, what means a 4% decrease in the risk of CRC per 100 IU/day of vitamin D. CONCLUSION: Higher dietary intakes of calcium and vitamin D are associated to a decreased risk of CRC.

[Discrimination and its relationship with risk behaviors and perceived health in spanish university students: a cross-sectional study.] / Discriminación y su relación con las conductas de riesgo y la salud percibida en estudiantes universitarios españoles: un estudio transversal.

OBJECTIVE: Discrimination during vital moments, such as the university period, can generate a high impact on people's behavior and health. The aim of this study was to analyze the possible association of discrimination with perceived health and with different risk behaviors, as well as to describe gender differences in Spanish university students. Discrimination during vital moments, such as college, can have a high impact on people's behavior and health. METHODS: A cross-sectional study was carried out with data from first-year university students from 11 Spanish universities (n=9,862). Discrimination, perceived health, alcohol consumption, smoking, consumption of illegal substances, leisure time connected to the Internet, risky sexual relations, family function, risk of mental health problems and risk of eating disorders were assessed. Prevalences with their 95% confidence intervals were obtained and for quantitative variables the mean and standard deviation were calculated. Odds ratios with 95% confidence intervals were calculated to determine the relationship between discrimination and the other variables. RESULTS: An association was found between discrimination and fair or poor perceived health (OR: 1.7; p=0.0001), consumption of illegal substances (OR: 1.3; p=0.002), problematic internet use (OR: 1.3; p=0.004), family dysfunction (OR: 1.8; p=0.0001), risk of mental health problems (OR: 1.9; p=0.0001) and eating disorders (OR: 1.5; p=0.0001). Regarding gender differences, higher prevalence of discrimination was observed in men with health status perceived as fair or worse (OR: 2.2; p=0.0001), family dysfunction (OR: 1.8; p=0.0001), risk of mental health problems (OR: 2.2; p=0.0001) and eating disorders (OR: 1.9; p=0.002). Women, apart from the previous variables, presented association of discrimination with consumption of illegal substances (OR: 1.3; p=0.005) and problematic internet use (OR: 1.4; p=0.002). CONCLUSIONS: The study findings underline that there is an association between discrimination and risk behaviors among Spanish university students. In turn, discrimination was associated with poor or fair perceived health, this relationship being similar in both men and women.

OBJETIVO: La discriminación durante los momentos vitales, como el periodo universitario, puede generar un alto impacto en la conducta y en el estado de salud de las personas. El estudio tuvo como objetivo analizar la posible asociación de la discriminación con la salud percibida y con distintas conductas de riesgo, así como describir las diferencias de género en estudiantes universitarios españoles. METODOS: Se realizó un estudio transversal con datos de estudiantes universitarios de primera matrícula de primer curso de 11 universidades españolas (n=9.862). Se valoró la discriminación, la salud percibida, el consumo de alcohol, el hábito tabáquico, el consumo de sustancias ilegales, el tiempo de ocio conectado a internet, la práctica de relaciones sexuales de riesgo, la función familiar, el riesgo de problemas de salud mental y el riesgo de trastornos de la conducta alimentaria. Se obtuvieron las prevalencias con sus intervalos de confianza al 95% y para las variables cuantitativas la media y desviación estándar. Se calcularon las Odds Ratio con los intervalos de confianza al 95% para conocer la relación entre la discriminación y las otras variables. RESULTADOS: Se encontró asociación entre la discriminación y una regular o mala salud percibida (OR: 1,7; p=0,0001), el consumo de sustancias ilegales (OR: 1,3; p=0,002), el uso problemático de internet (OR: 1,3; p=0,004), la disfunción familiar (OR: 1,8; p=0,0001), el riesgo de problemas de salud mental (OR: 1,9; p=0,0001) y de trastornos de la conducta alimentaria (OR: 1,5; p=0,0001). En cuanto a las diferencias de género, se apreciaron mayores prevalencias de discriminación en hombres con estado de salud percibida como regular o peor (OR: 2,2; p=0,0001), disfunción familiar (OR: 1,8; p=0,0001), riesgo de problemas de salud mental (OR: 2,2; p=0,0001) y de trastornos de la conducta alimentaria (OR: 1,9; p=0,002). Las mujeres, además de las variables anteriores, mostraron asociación de la discriminación con el consumo de sustancias ilegales (OR: 1,3; p=0,005) y el uso problemático de internet (OR: 1,4; p=0,002). CONCLUSIONES: Los hallazgos del estudio subrayan que existe asociación entre la discriminación y las conductas de riesgo de los estudiantes universitarios españoles. A su vez, la discriminación se asoció con una mala o regular salud percibida, siendo esta relación similar tanto en hombres como en mujeres.

Exposure to widespread drinking water chemicals, blood inflammation markers, and colorectal cancer.

BACKGROUND: Trihalomethanes (THMs) and nitrate are widespread chemicals in drinking water associated with colorectal cancer risk but mechanisms are not well understood. OBJECTIVES: We explored the association between exposure to THMs and nitrate in drinking water and inflammation markers, and the link with colorectal cancer risk. METHODS: A subset of 198 colorectal cancer cases and 205 controls from the multicase-control study MCC-Spain were included. Average concentration of THMs (chloroform, bromodichloromethane, dibromochloromethane, bromoform) and nitrate in tap water at the residence was estimated from age 18 until 2 years before the interview ("long term") and for a recent period (3 years before diagnosis). Serum levels of EGF, eotaxin, G-CSF, IL-17E, IL-1rA, IL-8, IP-10, MDC, MPO, periostin, VEGF, and C-reactive protein (CRP) were measured. We estimated the linear association between inflammation markers and exposure among controls, and the odds ratio of colorectal cancer associated with THM and nitrate exposure, and inflammation markers. A mediation analysis was conducted to identify inflammation markers in the pathway between THM/nitrate exposure and colorectal cancer. RESULTS: Serum concentrations of EGF, IL-8, IL-17E and eotaxin increased with recent residential levels of brominated THMs, chloroforom and/or total THM. No associations were observed for nitrate and for long-term residential THM levels. All residential exposures except chloroform were positively associated with colorectal cancer. Serum concentrations of VEGF and periostin were positively associated with colorectal cancer, while EGF was inversely associated. One protein-exposure combination (periostin-recent ingested brominated THMs) slightly mediated the association with colorectal cancer risk. DISCUSSION: Results suggest that estimated THM exposure is involved in inflammation processes. However, the study design was limited to stablish etiologically relevant associations between the protein levels and colorectal cancer risk. The lack of association between nitrate exposure and inflammation markers suggests other biological mechanisms are involved in the link with colorectal cancer.

Mutual Information of Multiple Rhythms for EEG Signals.

Electroencephalograms (EEG) are one of the most commonly used measures to study brain functioning at a macroscopic level. The structure of the EEG time series is composed of many neural rhythms interacting at different spatiotemporal scales. This interaction is often named as cross frequency coupling, and consists of transient couplings between various parameters of different rhythms. This coupling has been hypothesized to be a basic mechanism involved in cognitive functions. There are several methods to measure cross frequency coupling between two rhythms but no single method has been selected as the gold standard. Current methods only serve to explore two rhythms at a time, are computationally demanding, and impose assumptions about the nature of the signal. Here we present a new approach based on Information Theory in which we can characterize the interaction of more than two rhythms in a given EEG time series. It estimates the mutual information of multiple rhythms (MIMR) extracted from the original signal. We tested this measure using simulated and real empirical data. We simulated signals composed of three frequencies and background noise. When the coupling between each frequency component was manipulated, we found a significant variation in the MIMR. In addition, we found that MIMR was sensitive to real EEG time series collected with open vs. closed eyes, and intra-cortical recordings from epileptic and non-epileptic signals registered at different regions of the brain. MIMR is presented as a tool to explore multiple rhythms, easy to compute and without a priori assumptions.

Accuracy of Self-Reported Items for the Screening of Depression in the General Population.

INTRODUCTION: Though self-reported items (SRD, self-reported depression) are commonly used in health surveys and cohort studies, their metric properties as a depression indicator remain unclear. The aims were to evaluate the measurement properties of SRD using the Patient Health Questionnaire-8 (PHQ-8) as reference and to identify factors related to the agreement between both indicators. METHODS: Data from the European Health Interview Survey in Spain in 2014/2015 (n = 22,065) were analyzed. Two indicators of depression were considered: SRD based on two items yes/no (positive: both yes), and the PHQ-8 (positive ≥ 10). Socioeconomic factors and use of health services were considered as independent variables. The prevalence of depression, sensitivity, specificity, global agreement, and positive and negative predictive values (PPV and NPV) of SRDs were evaluated using the PHQ-8 as a reference. Logistic regression models were fitted to determine factors associated with the agreement between indicators. RESULTS: The prevalence of depression was lower when assessed with PHQ-8 (5.9%) than with SRD (7.7%). SRD sensitivity and PPV were moderate-low (52.9% and 40.4%, respectively) whereas global agreement, specificity, and NPV were high (92.7%, 95.1%, and 97.0%, respectively). Positive agreement was associated with marital status, country of birth, employment status, and social class. Negative agreement was related to all independent variables except country of birth. CONCLUSIONS: SRD items tend to overestimate the current prevalence of depression. While its use in health surveys and cohorts may be appropriate as a quick assessment of possible depression, due to their low sensitivity, its use in clinical contexts is questionable.

Association between Polyphenol Intake and Gastric Cancer Risk by Anatomic and Histologic Subtypes: MCC-Spain.

Several anticancer properties have been largely attributed to phenolics in in vivo and in vitro studies, but epidemiologic evidence is still scarce. Furthermore, some classes have not been studied in relation to gastric cancer (GC). The aim of this study was to assess the relationship between the intake of phenolic acids, stilbenes, and other phenolics and the risk of developing GC and its anatomical and histological subtypes. We used data from a multi-case-control study (MCC-Spain) obtained from different regions of Spain. We included 2700 controls and 329 GC cases. Odds ratios (ORs) were calculated using mixed effects logistic regression considering quartiles of phenolic intake. Our results showed an inverse association between stilbene and lignan intake and GC risk (ORQ4 vs. Q1 = 0.47; 95% CI: 0.32-0.69 and ORQ4 vs. Q1 = 0.53; 95% CI: 0.36-0.77, respectively). We found no overall association between total phenolic acid and other polyphenol class intake and GC risk. However, hydroxybenzaldehydes (ORQ4 vs. Q1 = 0.41; 95% CI: 0.28-0.61), hydroxycoumarins (ORQ4 vs. Q1 = 0.49; 95% CI: 0.34-0.71), and tyrosols (ORQ4 vs. Q1 = 0.56; 95% CI: 0.39-0.80) were inversely associated with GC risk. No differences were found in the analysis by anatomical or histological subtypes. In conclusion, a diet high in stilbenes, lignans, hydroxybenzaldehydes, hydroxycoumarins, and tyrosols was associated with a lower GC risk. Further prospective studies are needed to confirm our results.

Incidence of Anorexia Nervosa in Women: A Systematic Review and Meta-Analysis.

Background: Anorexia nervosa (AN) among the general population is a rare but often fatal illness. Objective: To summarize the incidence of AN using a systematic review and meta-analysis. Methods: Four online databases (PubMed, Scopus, WoS and Embase) were consulted. The review was conducted according to with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was limited to women. The methodological quality of the studies was assessed by the Newcastle-Ottawa Scale (NOS). Results: A total of 31 articles were included in the study. The incidence rate of AN ranged from 0.5 to 318.0 cases per 100,000 women-years. The incidence in studies based on outpatient healthcare services (OHS) was higher than those based on hospital admissions (HA) (8.8 95% CI: 7.83-9.80 vs. 5.0 95% CI: 4.87-5.05). In young women, the incidence in OHS was higher than HA (63.7, 95% CI 61.21-66.12 vs. 8.1 95% CI 7.60-8.53). The linear trend in the incidence of AN was increasing in all ages of women and young women, both in studies with hospital admission records, and in those based on outpatient healthcare services. Conclusion: The incidence of AN depends on the methodology, the type of population and the diagnostic criteria used.

Flavonoids and the Risk of Gastric Cancer: An Exploratory Case-Control Study in the MCC-Spain Study.

Several epidemiological studies have investigated the association between the dietary flavonoid intake and gastric cancer (GC) risk; however, the results remain inconclusive. Investigating the relationship between the different classes of flavonoids and the histological types and origin of GC can be of interest to the research community. We used data from a population-based multi-case control study (MCC-Spain) obtained from 12 different regions of Spain. 2700 controls and 329 GC cases were included in this study. Odds ratios (ORs) were calculated using the mixed effects logistic regression considering quartiles of flavonoid intakes and log2. Flavonoid intake was associated with a lower GC risk (ORlog2 = 0.76; 95% CI = 0.65-0.89; ORq4vsq1 = 0.60; 95%CI = 0.40-0.89; ptrend = 0.007). Inverse and statistically significant associations were observed with anthocyanidins, chalcones, dihydroflavonols and flavan-3-ols. The isoflavanoid intake was positively associated with higher cancer risk, but without reaching a statistical significance. In general, no differences were observed in the GC risk according to the location and histological type. The flavonoid intake seems to be a protective factor against GC within the MCC-study. This effect may vary depending on the flavonoid class but not by the histological type and location of the tumor. Broader studies with larger sample size and greater geographical variability are necessary.

Psychological Distress, Family Support and Employment Status in First-Year University Students in Spain.

Mental disorders are consistently and closely related to psychological distress. At the start of the university period, the relationship between a student's psychological distress, family support, and employment status is not well-known. The aims of this study were: To determine the prevalence of psychological distress in first-year university students and to analyze its relationship with family support and the student's employment status. Data from 4166 first-year university students from nine universities across Spain were considered. The prevalence of psychological distress was obtained using the GHQ-12, a valid and reliable screening tool to detect poor mental health. To analyze the relationship between psychological distress, family support, and employment status, logistic regression models were fitted. Regarding the prevalence found, 46.9% of men and 54.2% of women had psychological distress. In both genders, psychological distress levels increased as family support decreased. Among women, psychological distress was associated with their employment status. The prevalence of psychological distress among first-year university students in Spain is high. In addition, family support, and employment status for women, could be factors to take into account when developing psychological distress prevention strategies at the beginning of the university period.

Validity, Reliability, and Responsiveness of the Spanish Version of the OPTIMAL Instrument.

BACKGROUND: The Outpatient Physical Therapy Improvement in Movement Assessment Log (OPTIMAL) is a self-report instrument developed to measure the ability to perform mobility actions. OBJECTIVE: To validate a Spanish version of the OPTIMAL instrument. DESIGN: Cross-cultural adaptation and validation study. SETTING: Primary and specialized outpatient care settings. PARTICIPANTS: Three hundred seven patients beginning physical therapy treatment and 30 subjects from the general population. METHODS: A 2-part study was designed based on guidelines for cultural adaptation of patient-reported outcome measures. OUTCOMES: Reliability was estimated by internal consistency (Cronbach α), SE of measurement, and test-retest reliability (intraclass correlation coefficient) at 2 weeks. Confirmatory factor analysis was performed to examine structural validity. The association with the Physical Functioning Subscale was assessed with Spearman correlation coefficients. OPTIMAL scores across different groups were compared with Mann-Whitney U and Kruskal-Wallis tests. Effect size, standardized response mean, and minimal detectable change were determined for responsiveness. RESULTS: The Spanish version of the OPTIMAL instrument showed a similar structure to the original English questionnaire. Cronbach α was 0.95 for the difficulty and confidence scales. Intraclass correlation coefficient was 0.91 (95% CI 0.87-0.94) for the difficulty scale and 0.90 (95% CI 0.85-0.93) for the confidence scale. The SE of measurement was 5.11 for the difficulty scale and 6.54 for the confidence scale. The association with the Physical Functioning Subscale was strong and significant (P < .001). The 2 scales showed significantly different scores for each of the established patient groups. The effect size was 0.61 (95% CI 0.48-0.74) for the difficulty scale and 0.53 (95% CI 0.38-0.69) for the confidence scale. The standardized response mean was 0.97 (95% CI 0.78-1.13) for the difficulty scale and 0.76 (95% CI 0.48-1.01) for the confidence scale. The minimal detectable change, of a possible score of 100, was 14.2 for the difficulty scale and 18.1 for the confidence scale. CONCLUSION: The Spanish version of the OPTIMAL has appropriate reliability, validity, and responsiveness and it is an adequate self-report instrument for the assessment of mobility actions. LEVEL OF EVIDENCE: III.

Differential Effects of Simulated Cortical Network Lesions on Synchrony and EEG Complexity.

Brain function has been proposed to arise as a result of the coordinated activity between distributed brain areas. An important issue in the study of brain activity is the characterization of the synchrony among these areas and the resulting complexity of the system. However, the variety of ways to define and, hence, measure brain synchrony and complexity has sometimes led to inconsistent results. Here, we study the relationship between synchrony and commonly used complexity estimators of electroencephalogram (EEG) activity and we explore how simulated lesions in anatomically based cortical networks would affect key functional measures of activity. We explored this question using different types of neural network lesions while the brain dynamics was modeled with a time-delayed set of 66 Kuramoto oscillators. Each oscillator modeled a region of the cortex (node), and the connectivity and spatial location between different areas informed the creation of a network structure (edges). Each type of lesion consisted on successive lesions of nodes or edges during the simulation of the neural dynamics. For each type of lesion, we measured the synchrony among oscillators and three complexity estimators (Higuchi's Fractal Dimension, Sample Entropy and Lempel-Ziv Complexity) of the simulated EEGs. We found a general negative correlation between EEG complexity metrics and synchrony but Sample Entropy and Lempel-Ziv showed a positive correlation with synchrony when the edges of the network were deleted. This suggests an intricate relationship between synchrony of the system and its estimated complexity. Hence, complexity seems to depend on the multiple states of interaction between the oscillators of the system. Our results can contribute to the interpretation of the functional meaning of EEG complexity.