Raquel Vilar-López

Description of quality of life and its predictors in patients with aneurysmal subarachnoid hemorrhage.

Background: According to previous studies, the quality of life is usually substantially altered in patients who have suffered a subarachnoid hemorrhage of an aneurysmal origin. Some studies have attempted to find out which factors predict the deterioration in quality of life. Our study will try to describe the quality of life of these patients and discover which variables may predict it in each of its dimensions. Methods: The participants were 70 patients with aneurysmal subarachnoid hemorrhage between 15 and 85 years of age. The instrument used to measure the quality of life is the SF-36 with its eight dimensions. The predictor variables introduced into the multiple linear regressions are neurological condition on admission [World Federation of Neurological Surgeons (WFNS) scale and Hunt and Hess scale], extension of the hemorrhage (Fisher scale), sex, age, physical handicaps, and the Glasgow Outcome Scale (GOS) on release. Results: The results showed that 42.9% of the patients had a deteriorated quality of life after 4 months, and that the most affected dimension was the Physical Role (60%). The two factors that predict quality of life are sex and physical handicaps. Other factors that intervene are the GOS on release and the WFNS. Conclusions: The patients who have experienced an aneurysmal subarachnoid hemorrhage show greater difficulty in performing daily activities, and they present more depression and anxiety. The absence of handicaps and being male are predictor factors for an unaffected quality of life.

Altered adaptive but not veridical decision-making in substance dependent individuals

Drug addiction is associated with impaired judgment in unstructured situations in which success depends on self-regulation of behavior according to internal goals (adaptive decision-making). However most executive measures are aimed at assessing decision-making in structured scenarios, in which success is determined by external criteria inherent to the situation (veridical decision-making). The aim of this study was to examine the performance of Substance Abusers (SA, n = 97) and Healthy Comparison participants (HC, n = 81) in two behavioral tasks that mimic the uncertainty inherent in real-life decision-making: the Cognitive Bias Task (CB) and the Iowa Gambling Task (IGT) (administered only to SA). A related goal was to study the interdependence between performances on both tasks. We conducted univariate analyses of variance (ANOVAs) to contrast the decision-making performance of both groups; and used correlation analyses to study the relationship between both tasks. SA showed a marked context-independent decision-making strategy on the CBs adaptive condition, but no differences were found on the veridical conditions in a subsample of SA (n = 34) and HC (n = 22). A high percentage of SA (75%) also showed impaired performance on the IGT. Both tasks were only correlated when no impaired participants were selected. Results indicate that SA show abnormal decision-making performance in unstructured situations, but not in veridical situations.

Ecological validity of the Multiple Errands Test using predictive models of dysexecutive problems in everyday life

The“dysexecutive syndrome” is composed of a range of cognitive, emotional, and behavioral deficits that are difficult to evaluate using traditional neuropsychological tests. The Multiple Errands Test (MET) was originally developed to systematize the assessment of the more elusive manifestations of the dysexecutive syndrome. The aims of this study were to examining the reliability of the MET and to investigate the predictive ability of its indices to explain a range of “dysexecutive”-related symptoms in everyday life. Thirty patients with acquired brain injury participated in this study. The MET showed an adequate inter-rater reliability and ecological validity. The main performance indices from the MET were able to significantly predict severity of everyday life executive problems, with different indices predicting particular manifestations of different components of executive functions.

Ventral and Dorsal Striatum Networks in Obesity: Link to Food Craving and Weight Gain.

BACKGROUND The food addiction model proposes that obesity overlaps with addiction in terms of neurobiological alterations in the striatum and related clinical manifestations (i.e., craving and persistence of unhealthy habits). Therefore, we aimed to examine the functional connectivity of the striatum in excess-weight versus normal-weight subjects and to determine the extent of the association between striatum connectivity and individual differences in food craving and changes in body mass index (BMI). METHODS Forty-two excess-weight participants (BMI > 25) and 39 normal-weight participants enrolled in the study. Functional connectivity in the ventral and dorsal striatum was indicated by seed-based analyses on resting-state data. Food craving was indicated with subjective ratings of visual cues of high-calorie food. Changes in BMI between baseline and 12 weeks follow-up were assessed in 28 excess-weight participants. Measures of connectivity in the ventral striatum and dorsal striatum were compared between groups and correlated with craving and BMI change. RESULTS Participants with excess weight displayed increased functional connectivity between the ventral striatum and the medial prefrontal and parietal cortices and between the dorsal striatum and the somatosensory cortex. Dorsal striatum connectivity correlated with food craving and predicted BMI gains. CONCLUSIONS Obesity is linked to alterations in the functional connectivity of dorsal striatal networks relevant to food craving and weight gain. These neural alterations are associated with habit learning and thus compatible with the food addiction model of obesity.

Increased corticolimbic connectivity in cocaine dependence versus pathological gambling is associated with drug severity and emotion-related impulsivity.

Neural biomarkers for the active detrimental effects of cocaine dependence (CD) are lacking. Direct comparisons of brain connectivity in cocaine‐targeted networks between CD and behavioural addictions (i.e. pathological gambling, PG) may be informative. This study therefore contrasted the resting‐state functional connectivity networks of 20 individuals with CD, 19 individuals with PG and 21 healthy individuals (controls). Study groups were assessed to rule out psychiatric co‐morbidities (except alcohol abuse and nicotine dependence) and current substance use or gambling (except PG). We first examined global connectivity differences in the corticolimbic reward network and then utilized seed‐based analyses to characterize the connectivity of regions displaying between‐group differences. We examined the relationships between seed‐based connectivity and trait impulsivity and cocaine severity. CD compared with PG displayed increased global functional connectivity in a large‐scale ventral corticostriatal network involving the orbitofrontal cortex, caudate, thalamus and amygdala. Seed‐based analyses showed that CD compared with PG exhibited enhanced connectivity between the orbitofrontal and subgenual cingulate cortices and between caudate and lateral prefrontal cortex, which are involved in representing the value of decision‐making feedback. CD and PG compared with controls showed overlapping connectivity changes between the orbitofrontal and dorsomedial prefrontal cortices and between amygdala and insula, which are involved in stimulus–outcome learning. Orbitofrontal–subgenual cingulate cortical connectivity correlated with impulsivity and caudate/amygdala connectivity correlated with cocaine severity. We conclude that CD is linked to enhanced connectivity in a large‐scale ventral corticostriatal–amygdala network that is relevant to decision making and likely to reflect an active cocaine detrimental effect.

Cocaine‐specific neuroplasticity in the ventral striatum network is linked to delay discounting and drug relapse

AIMS To contrast functional connectivity on ventral and dorsal striatum networks in cocaine dependence relative to pathological gambling, via a resting-state functional connectivity approach; and to determine the association between cocaine dependence-related neuroadaptations indexed by functional connectivity and impulsivity, compulsivity and drug relapse. DESIGN Cross-sectional study of 20 individuals with cocaine dependence (CD), 19 individuals with pathological gambling (PG) and 21 healthy controls (HC), and a prospective cohort study of 20 CD followed-up for 12 weeks to measure drug relapse. SETTING AND PARTICIPANTS CD and PG were recruited through consecutive admissions to a public clinic specialized in substance addiction treatment (Centro Provincial de Drogodependencias) and a public clinic specialized in gambling treatment (AGRAJER), respectively; HC were recruited through community advertisement in the same area in Granada (Spain). MEASUREMENTS Seed-based functional connectivity in the ventral striatum (ventral caudate and ventral putamen) and dorsal striatum (dorsal caudate and dorsal putamen), the Kirby delay-discounting questionnaire, the reversal-learning task and a dichotomous measure of cocaine relapse indicated with self-report and urine tests. FINDINGS CD relative to PG exhibit enhanced connectivity between the ventral caudate seed and subgenual anterior cingulate cortex, the ventral putamen seed and dorsomedial pre-frontal cortex and the dorsal putamen seed and insula (P≤0.001, kE=108). Connectivity between the ventral caudate seed and subgenual anterior cingulate cortex is associated with steeper delay discounting (P≤0.001, kE=108) and cocaine relapse (P≤0.005, kE=34). CONCLUSIONS Cocaine dependence-related neuroadaptations in the ventral striatum of the brain network are associated with increased impulsivity and higher rate of cocaine relapse.

Use of specific malingering measures in a Spanish sample

There are an increasing number of tests available for detecting malingering. However, these tests have not been validated for using in Spanish speakers. The purpose of this study is to explore the value of three specific malingering tests in the Spanish population. This study used a known-groups design, together with a group of analog students. The results show that both the Victoria Symptom Validity Test and the b Test can be used to detect malingering in Spanish population. However, some restrictions must be applied when the Rey 15-Item Test is administered and interpreted.

Effect of craving induction on inhibitory control in opiate dependence

RationaleCurrent neurobiological models of addiction posit that drug seeking is much more likely to occur during emotionally charged states (such as craving), as deficits in inhibitory control become more pronounced during heightened motivational states.ObjectiveThe purpose of this study was to examine the effect of cue-induced craving states on attention and inhibitory control within addicted individuals.MethodsWe tested the performance of 39 opiate-dependent individuals on cognitive measures of attention (Digit Span, Digit Symbol, and Telephone Search) and inhibitory control (Counting Stroop and Go-No-Go) both before and after exposure to an autobiographical craving script. A non-drug using healthy control group (n = 19) performed the same tasks before and after listening to a relaxation tape.ResultsFollowing craving induction, opiate-dependent individuals demonstrated improved performance on tests of processing speed and attentional span (consistent with the practice effect observed in controls) and increased their response errors on the Stroop task (in contrast to controls), while selective attention was unaffected. Individual differences in compulsivity mediated the association between craving and Stroop performance, such that low-compulsive (but not high-compulsive) individuals committed more response errors after craving induction.ConclusionsThese findings challenge the notion of cue-induced craving as a primary trigger of disrupted cognition and drug-seeking behavior in addicted individuals, and raise the need to explore individual differences in compulsivity when addressing the links between craving and loss of control within research and clinical settings.

Neuropsychological test performance of Spanish speakers: Is performance different across different Spanish-speaking subgroups?

Even though theories and research have pointed out the importance of variables such as age, gender, or education on neuropsychological assessment, much less emphasis has been placed on language and culture. With the increasing population of Spanish speakers in North America and the limited amount of clinical and scholarly information currently available, neuropsychological assessment of this group has similarly become of increasing importance. Though several studies have been published over the last two decades, an assumption exists that all Spanish speakers, holding education and age constant, would perform similarly regardless of their origin. To address this assumption, a sample of 126 participants was tested from four different countries (Chile, Dominican Republic, Puerto Rico, and Spain). Participants were compared on the following commonly used neuropsychological tests: Verbal Serial Learning Curve, Rey– Osterrieth Complex Figure Test, Verbal Phonemic Fluency Test, the Stroop Color and Word Test, and the Trail Making Test. Analyses revealed significant differences across the groups in two of the five tests administered. Significant differences were observed in the delayed recall of the Serial Learning Test and in the Verbal Fluency Test. The findings highlight the importance of within-group differences between Spanish speakers.

Cingulate biochemistry in heroin users on substitution pharmacotherapy

Objective: High doses of opiate substitution pharmacotherapy are associated with greater treatment retention and lower illicit drug consumption, although the neurobiological bases of these benefits are poorly understood. Dysfunction of the anterior cingulate cortex (ACC) is associated with greater addiction severity and mood dysregulation in opiate users, such that the beneficial effects of substitution pharmacotherapy may relate to normalisation of ACC function. This study aimed to investigate the differential impact of methadone compared with buprenorphine on dorsal ACC biochemistry. A secondary aim was to explore the differential effects of methadone and buprenorphine on dorsal ACC biochemistry in relation to depressive symptoms. Methods: Twenty-four heroin-dependent individuals stabilised on methadone (n=10) or buprenorphine (n=14) and 24 healthy controls were scanned using proton Magnetic Resonance Spectroscopy and compared for metabolite concentrations of N-acetylaspartate, glutamate/glutamine, and myo-inositol. Results: (1) Methadone was associated with normalisation of dorsal ACC biochemistry (increased N-acetylaspartate and glutamate/glutamine levels, and decreased myo-inositol levels) in a dose-dependent manner; (2) buprenorphine-treated individuals had higher myo-inositol and glutamate/glutamine levels than methadone-treated patients in the right dorsal ACC; and (3) myo-inositol levels were positively correlated with depressive symptoms in participants stabilised on buprenorphine. Conclusions: These findings point to a beneficial role of high-dose methadone on dorsal ACC biochemistry, and suggest a link between elevated myo-inositol levels and depressive symptoms in the context of buprenorphine treatment.