Hemispheric Utilization of Alpha Oscillatory Dynamics as a Unique Biomarker of Neural Compensation in Females with Fragile X Syndrome.

Fragile X syndrome (FXS) is a neurodevelopmental disorder caused by a trinucleotide expansion on the FMR1 gene and characterized by intellectual disability, sensory hypersensitivity, executive function difficulties, and social anxiety. Recently, efforts to define neural biomarkers for FXS have highlighted disruptions to power in the alpha frequency band; however the dynamic mechanisms supporting these findings are poorly understood. The current study aimed to explore the temporal and hemispheric dynamics supporting alpha phenotypes in FXS and their relationship with neural phenotypes related to auditory processing using electroencephalography during an auditory evoked task. Adolescents and adults (N = 36) with FXS and age/sex matched typically developing controls (N = 40) completed an auditory chirp task. Frontal alpha power in the prestimulus period was decomposed into "bursts" using percentile thresholding, then assessed for number of bursts per second (burst count) and burst length. Data were compared across left and right hemispheres to assess lateralization of neural activity. Individuals with FXS showed more differences in alpha power compared to TDC primarily in the right hemisphere. Notably, alpha hemisphere outcomes in males with FXS were driven by the number of times they entered a dynamically relevant period of alpha (burst count) rather than length of time spent in alpha. Females with FXS showed reduced burst counts but remained in sustained high alpha states for longer periods of time. Length of time spent in alpha may reflect a modulatory or compensatory mechanism capable of recovering sensory processing abilities in females with FXS resulting in a less severe clinical presentation. Right hemisphere abnormalities may impact sensory processing differences between males and females with FXS. The relationship between alpha burst length, count, sex, and hemisphere may shed light on underlying mechanisms for previously observed alpha power abnormalities in FXS and their variation by sex.

Evolución longitudinal y cambios de función cerebral entre fases del trastorno bipolar / Longitudinal evolution and changes in brain function between phases of bipolar disorder

Mediante resonancia magnética funcional (fMRI) se han señalado alteraciones en el sistema límbico y en el lóbulo prefrontal del cerebro de los pacientes bipolares sobre todo durante episodios de manía y depresivos, aunque también en la eutimia. La relación entre cambios funcionales cerebrales y las distintas fases del trastorno bipolar (TB) es menos clara y la manera ideal de investigarlos es examinar a los mismos pacientes en fases distintas de la enfermedad. Se presentan los resultados de dos estudios longitudinales que examinaron mediante fMRI las activaciones y desactivaciones cerebrales durante una tarea de memoria de trabajo (n-back) en pacientes durante un episodio afectivo agudo que luego alcanzaron la eutimia. Entre otros hallazgos, la corteza dorsal prefrontal (dlPFC) se mostró hipoactivada durante el episodio de manía y se normalizaba durante la eutimia, mientras que el área ventromedial de la corteza prefrontal (vmPFC) mostró un fracaso en la desactivación durante la tarea n-back, tanto durante la manía y la depresión, como en la eutimia. Teniendo en cuenta que el área vmPFC es uno de los nodos principales de la red neuronal por defecto, los resultados sugieren una disfunción de esta red neuronal más como rasgo que como marcador de estado en el TB (AU)

Functional magnetic resonance imaging (fMRI) has revealed alterations in the limbic system and the prefrontal lobe of the brain in bipolar patients, especially during episodes of mania and depression, but also in euthymia. The relationship between functional brain changes and the different phases of bipolar disorder (BD) is less clear and the ideal way to investigate them is to examine the same patients in different phases of the illness. We present the results of two longitudinal studies that examined by fMRI the brain activations and deactivations during a working memory task (n-back) in patients during an affective acute episode who later reached euthymia. Among other findings, during the manic episode the dorsal prefrontal cortex (dlPFC) showed hypoactivation during the task, but it normalised during the euthymia, while the ventromedial prefrontal cortex (vmPFC) showed a failure to deactivate both during mania and depression, as well as in euthymia. Considering that the vmPFC area is one of the main nodes of the default neural network (DMN), the results suggest dysfunction of this neural network more as a trait than as a state marker in TB (AU)

Obesity risk is associated with altered cerebral glucose metabolism and decreased µ-opioid and CB1 receptor availability.

BACKGROUND: Obesity is a pressing public health concern worldwide. Novel pharmacological means are urgently needed to combat the increase of obesity and accompanying type 2 diabetes (T2D). Although fully established obesity is associated with neuromolecular alterations and insulin resistance in the brain, potential obesity-promoting mechanisms in the central nervous system have remained elusive. In this triple-tracer positron emission tomography study, we investigated whether brain insulin signaling, µ-opioid receptors (MORs) and cannabinoid CB1 receptors (CB1Rs) are associated with risk for developing obesity. METHODS: Subjects were 41 young non-obese males with variable obesity risk profiles. Obesity risk was assessed by subjects' physical exercise habits, body mass index and familial risk factors, including parental obesity and T2D. Brain glucose uptake was quantified with [18F]FDG during hyperinsulinemic euglycemic clamp, MORs were quantified with [11C]carfentanil and CB1Rs with [18F]FMPEP-d2. RESULTS: Subjects with higher obesity risk had globally increased insulin-stimulated brain glucose uptake (19 high-risk subjects versus 19 low-risk subjects), and familial obesity risk factors were associated with increased brain glucose uptake (38 subjects) but decreased availability of MORs (41 subjects) and CB1Rs (36 subjects). CONCLUSIONS: These results suggest that the hereditary mechanisms promoting obesity may be partly mediated via insulin, opioid and endocannabinoid messaging systems in the brain.

Early and Bi-hemispheric seizure onset in a rat glioblastoma Multiforme model.

GBM is the most life-threatening neurological disease with annual incidence of âˆ¼ 5 cases per 100,000 people and a median survival of less than 15 months. Seizures are the first clinical symptoms in 40%-45% of patients with GBM and its epileptogenic mechanisms are poorly understood, largely due to the challenge to develop a clinically-relevant animal model and the unknown latent period. In this study, we used continuous video-EEG monitoring to detect the earliest interictal and ictal events in a CRISPR- IUE GBM rat model that shares pathological and clinical features with those observed in human patients. To our best knowledge, we showed for the first time that interictal epileptiform discharges emerged during early postnatal weeks and the first ictal event occurred during the fourth postnatal week. We also showed GBM animals showed independent bi-hemispheric epileptogenic events, suggesting a widespread circuitry dysregulation. Together, our work identified the temporal- and spatial frame of epileptogenic network in a highly clinically-relevant GBM animal model, paving ways for mechanistic studies at molecular, cellular and circuitry levels.

Monitoring and modifying brain oxygenation in patients at risk of hypoxic ischaemic brain injury after cardiac arrest.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Coronary artery disease and its impact on the pulsatile brain: A functional NIRS study.

Recent studies have reported that optical indices of cerebral pulsatility are associated with cerebrovascular health in older adults. Such indices, including cerebral pulse amplitude and the pulse relaxation function (PRF), have been previously applied to quantify global and regional cerebral pulsatility. The aim of the present study was to determine whether these indices are modulated by cardiovascular status and whether they differ between individuals with low or high cardiovascular risk factors (LCVRF and HCVRF) and coronary artery disease (CAD). A total of 60 older adults aged 57-79 were enrolled in the study. Participants were grouped as LCVRF, HCVRF, and CAD. Participants were asked to walk freely on a gym track while a near-infrared spectroscopy (NIRS) device recorded hemodynamics data. Low-intensity, short-duration walking was used to test whether a brief cardiovascular challenge could increase the difference of pulsatility indices with respect to cardiovascular status. Results indicated that CAD individuals have higher global cerebral pulse amplitude compared with the other groups. Walking reduced global cerebral pulse amplitude and PRF in all groups but did not increase the difference across the groups. Instead, walking extended the spatial distribution of cerebral pulse amplitude to the anterior prefrontal cortex when CAD was compared to the CVRF groups. Further research is needed to determine whether cerebral pulse amplitude extracted from data acquired with NIRS, which is a noninvasive, inexpensive method, can provide an index to characterize the cerebrovascular status associated with CAD.

Unilateral Spatial Neglect without Hemiplegia: The Output-Mode Effect Revisited.

BACKGROUND: The occurrence of unilateral spatial neglect (USN) in non-hemiplegic right-hemisphere damaged patients is rare. Earlier studies of such patients revealed a significant advantage when typical neglect tests were performed by the patient's left hand as compared to the dominant right hand. The mechanism underlying this "output-mode effect" remains elusive. METHODS: We analyzed the temporal dynamics of this effect using line-bisection task in 9 non-hemiplegic stroke patients with left-USN. RESULTS: In 4 patients tested shortly after stroke onset (≤ 6 weeks), the impact of hand laterality was variable (left-hand advantage in one patient; right-hand advantage in 2 patients; similar performance in both hands in one patient). Only later (> 6 weeks) a clear advantage of the left hand emerged in the majority of patients, similar to the earlier reports which were all based on late testing. CONCLUSIONS: We found variable dynamics in the expression of the output-mode effect in the first weeks following stroke onset, which may reflect changes of inter-hemispheric balance, related to recovery processes. We propose that therapeutic interventions aiming to manipulate the inter-hemispheric balance (e.g., by non-invasive brain stimulation) take into account the existence of such dynamics and their highly variate nature.

Alterations in cerebral and cardiac mitochondrial function in a porcine model of acute carbon monoxide poisoning.

OBJECTIVES: The purpose of this study is the development of a porcine model of carbon monoxide (CO) poisoning to investigate alterations in brain and heart mitochondrial function. DESIGN: Two group large animal model of CO poisoning. SETTING: Laboratory. SUBJECTS: Ten swine were divided into two groups: Control (n = 4) and CO (n = 6). INTERVENTIONS: Administration of a low dose of CO at 200 ppm to the CO group over 90 min followed by 30 min of re-oxygenation at room air. The Control group received room air for 120 min. MEASUREMENTS: Non-invasive optical monitoring was used to measure cerebral blood flow and oxygenation. Cerebral microdialysis was performed to obtain semi real time measurements of cerebral metabolic status. At the end of the exposure, both fresh brain (cortical and hippocampal tissue) and heart (apical tissue) were immediately harvested to measure mitochondrial respiration and reactive oxygen species (ROS) generation and blood was collected to assess plasma cytokine concentrations. MAIN RESULTS: Animals in the CO group showed significantly decreased Complex IV-linked mitochondrial respiration in hippocampal and apical heart tissue but not cortical tissue. There also was a significant increase in mitochondrial ROS generation across all measured tissue types. The CO group showed a significantly higher cerebral lactate-to-pyruvate ratio. Both IL-8 and TNFα were significantly increased in the CO group compared with the Control group obtained from plasma. While not significant there was a trend to an increase in optically measured cerebral blood flow and hemoglobin concentration in the CO group. CONCLUSIONS: Low-dose CO poisoning is associated with early mitochondrial disruption prior to an observable phenotype highlighting the important role of mitochondrial function in the pathology of CO poisoning. This may represent an important intervenable pathway for therapy and intervention.

Differentiating syndrome of inappropriate ADH, reset osmostat, cerebral/renal salt wasting using fractional urate excretion.

OBJECTIVES: Clinical and laboratory data of reset osmostat (RO) and cerebral/renal salt wasting (C/RSW) mimic syndrome of inappropriate antidiuretic hormone (SIADH) and can pose diagnostic challenges because of significant overlapping between clinical and laboratory findings. Failure to correctly diagnose hyponatremia may result in increased mortality risk, longer hospital stay, and is cost-effective. We aim to illustrate clinical and laboratory similarities and difference among patients with hyponatremic disorders and discuss the diagnostic value of factional uprate excretion (FEurate) to differentiate SIADH from RO and C/RSW. CASE PRESENTATIONS: We report the use of FEurate in the evaluation of three patients with hyponatremia and elevated urine osmolality in the absence of edema or clinical evidence of dehydration to differentiate SIADH from RO and C/RSW. CONCLUSIONS: Measurement of FEurate may offset in part the diagnostic confusion imparted by the diagnoses of SIADH, RO, and C/RSW.

Correlation Between Speech Repetition Function and the Arcuate Fasciculus in the Dominant Hemisphere Detected by Diffusion Tensor Imaging Tractography in Stroke Patients with Aphasia.

BACKGROUND Repetition disorder can be used as an important criterion for aphasia classification, and damaged arcuate fasciculus in the dominate hemisphere has been reported to be closely related to repetition disorder, but the underlying neurological mechanism remains unclear. MATERIAL AND METHODS Fifteen stroke patients with poststroke aphasia and 9 healthy controls were included in the study. The value of fractional anisotropy (FA) in the dominate arcuate fasciculus in stroke patients and healthy controls were measured using DTI. We also assessed their repetition dysfunction with the Aphasia Battery of Chinese (ABC) assessment and calculated the correlation between the FA values in the dominate arcuate fasciculus and ABC scores of word repetition and sentence repetition. RESULTS There was a moderate correlation between the total score of repetition evaluation and the FA value of injured arcuate fasciculus in the dominant hemisphere (r=0.551, P=0.033). We found no correlation between the score of word repetition and the FA value of injured arcuate fasciculus in the dominant hemisphere (r=0.330, P=0.230), but there was a strong correlation between the score of sentence repetition and the FA value of injured arcuate fasciculus in the dominant hemisphere (r=0.795, P≤0.001). CONCLUSIONS We found that unintegrated left arcuate fasciculus might be related to the repetition dysfunction after stroke, especially sentence repetition deficit, which suggests that sentence repetition evaluation could be used to indicate the integrity of the arcuate fasciculus in the dominant hemisphere after stroke.

Network change point detection in resting-state functional connectivity dynamics of mild cognitive impairment patients / Detección de puntos de cambios en redes de conectividad funcional dinámica en situación de reposo en pacientes con deterioro cognitivo leve

BACKGROUND/OBJECTIVE: This study aims to characterize the differences on the short-term temporal network dynamics of the undirected and weighted wholebrain functional connectivity between healthy aging individuals and people with mild cognitive impairment (MCI). The Network Change Point Detection algorithm was applied to identify the significant change points in the resting-state fMRI register, and we analyzed the fluctuations in the topological properties of the subnetworks between significant change points. METHOD: Ten MCI patients matched by gender and age in 1:1 ratio to healthy controls screened during patient recruitment. A neuropsychological evaluation was done to both groups as well as functional magnetic images were obtained with a Philips 3.0T. All the images were preprocessed and statistically analyzed through dynamic point estimation tools. RESULTS: No statistically significant differences were found between groups in the number of significant change points in the functional connectivity networks. However, an interaction effect of age and state was detected on the intra-participant variability of the network strength. CONCLUSIONS: The progression of states was associated to higher variability in the patient's group. Additionally, higher performance in the prospective and retrospective memory scale was associated with higher median network strength

ANTECEDENTES/OBJETIVO: Este estudio tiene como objetivo caracterizar las diferencias en la red dinámica de conectividad funcional no dirigida entre un grupo de personas sanas y otro con deterioro cognitivo leve. Se aplicó un algoritmo de detección de puntos de cambio en redes complejas para identificarlos en registros fMRI en estado de reposo y se analizaron las fluctuaciones en las propiedades topológicas de las subredes entre puntos de cambio significativos. MÉTODO: Diez pacientes emparejados por sexo y edad en proporción 1:1 a controles sanos. Se realizó una evaluación neuropsicológica a ambos grupos y se obtuvieron imágenes funcionales con un Philips Ingenia 3.0T. Todas las imágenes fueron preprocesadas y analizadas estadísticamente a través de herramientas de estimación dinámica de puntos. RESULTADOS: No se encontraron diferencias estadísticamente significativas entre ambos grupos en el número de puntos de cambio en las redes de conectividad funcional. Se detectó un efecto de interacción entre edad y la variabilidad intra-sujeto en algunos indicadores de complejidad (strength) de la red dinámica. CONCLUSIONES: La progresión de la conectividad se asoció a una mayor variabilidad en el grupo de pacientes. Además, se puede asociar un mayor rendimiento en la escala de memoria prospectiva y retrospectiva con un mayor valor de la mediana de strength de la red

Effect of age on the gap-prepulse inhibition of the cortical N1-P2 complex in humans as a step towards an objective measure of tinnitus.

The gap-prepulse inhibition of the acoustic startle reflex has been widely used as a behavioral method for tinnitus screening in animal studies. The cortical-evoked potential gap-induced inhibition has also been investigated in animals as well as in human subjects. The present study aimed to investigate the effect of age on the cortical N1-P2 complex in the gap-prepulse inhibition paradigm. Fifty-seven subjects, aged 20 to 68 years, without continuous tinnitus, were tested with two effective gap conditions (embedded gap of 50- or 20-ms duration). Retest sessions were performed within one month. A significant gap-induced inhibition of the N1-P2 complex was found in both gap durations. Age differently affected the inhibition, depending on gap duration. With a 50-ms gap, the inhibition decreased significantly with the increase in age. This age-inhibition relationship was not found when using a 20-ms gap. The results were reproducible in the retest session. Our findings suggest that the interaction between age and gap duration should be considered when applying the gap-induced inhibition of the cortical-evoked potential as an objective measure of tinnitus in human subjects. Further studies with tinnitus patients are warranted to identify gap duration that would minimize the effects of age and maximize the difference in the inhibition between those with and without tinnitus.

An Integrative Review of Cerebral Salt Wasting Syndrome.

BACKGROUND: Although cerebral salt wasting syndrome (CSWS) is widely recognized, its clinical characteristics, diagnostic criteria, and management have not been clearly defined. This study was undertaken to comprehensively review current literature and provide a more complete picture of CSWS. This review also aimed to provide information for nurses on how to differentiate cerebral salt wasting syndrome from syndrome of inappropriate antidiuretic hormone secretion. METHODS: An integrative review was performed. Searches were conducted between May and July 2018. The primary information sources were CINAHL, Google Scholar, MEDLINE, PubMed, Scopus, and Web of Science. Included articles were published from 1954 to July 2018. RESULTS: The essential features of CSWS are hyponatremia, hypovolemia, and increased urine output. Treatment regimens may be determined based on the acuity and severity of hyponatremia and hypovolemia as well as evident symptoms and signs. CONCLUSION: This review may help neuroscience nurses become knowledgeable about CSWS for the drafting of appropriate nursing care plans and also be able to differentiate CSWS from syndrome of inappropriate antidiuretic hormone secretion as early as possible for timely and proper management.

Advantages of methohexital over amobarbital in determining hemispheric language and memory lateralization in the Wada test - A retrospective study.

OBJECTIVE: Due to supply shortage, amobarbital, the traditional anesthetic agent in Wada testing, was replaced by methohexital in many epilepsy centers. This study aimed to compare the two barbiturates to identify possible advantages or disadvantages of methohexital as compared to amobarbital with regard to the adequacy of language and memory testing during the Wada test. METHODS: Data from 75 patients with temporal lobe epilepsy who underwent bilateral Wada tests using either amobarbital (n = 53) or methohexital (n = 22) as part of presurgical work-up were analyzed retrospectively. The two subgroups were compared regarding hemispheric language and memory lateralization results and Wada testing characteristics, and the adequacy of language and memory testing was assessed. RESULTS: We observed shorter durations of motor-, speech-, and EEG recovery after each injection in patients receiving methohexital compared to amobarbital. In addition, significantly more items could be presented during effective hemispheric inactivation in the methohexital group. Moreover, significant correlations of Wada memory scores with standard neuropsychological memory test scores could be found in the methohexital group. SIGNIFICANCE: Our findings confirm that methohexital is not only equally suitable for Wada testing but has several advantages over amobarbital. Wada testing can be performed more efficiently and under more constant hemispheric inactivation using methohexital. Furthermore, the adequacy of language and memory testing during the Wada test might be affected by the anesthetic agent used.

PREMIO SIXTO OBRADOR SENEC 2019: El uso de la secuencia Tensor de difusión como herramienta pronóstica en los pacientes con traumatismo craneoencefálico grave y moderado. Parte II: Análisis longitudinal de las características del Tensor de difusión y su relación con la evolución de los pacientes / SIXTO OBRADOR SENEC PRIZE 2019: Utility of diffusion tensor imaging as a prognostic tool in moderate to severe traumatic brain injury. Part II: Longitudinal analysis of DTI metrics and its association with patient's outcome

ANTECEDENTES Y OBJETIVOS: La lesión axonal traumática es considerada la principal causa de las alteraciones cognitivas y neuropsicológica de los pacientes tras traumatismo craneoencefálico (TCE). Además, existen algunas evidencias sobre la evolución dinámica de la lesión axonal traumática. La secuencia de RM Tensor de difusión (DTI, diffusion tensor imaging) se considera una técnica útil para la caracterización de la lesión axonal traumática, pero son escasos los estudios que hayan evaluado los cambios longitudinales de las características del DTI y su relación con la evolución de los pacientes. MATERIALES Y MÉTODOS: Ciento dieciocho pacientes con TCE moderado y grave fueron estudiados mediante RM-DTI en la fase subaguda precoz (<60 días) y otros estudios sucesivos a los 6 y/o 12 meses tras TCE. Se ha medido la anisotropía fraccionada, difusión axial y radial en las 3 porciones del cuerpo calloso (rodilla, cuerpo y esplenio) y se han comparado con los valores de un grupo control. Además, se ha determinado la situación clínica de los pacientes mediante la Glasgow Outcome Scale Extended al alta hospitalaria, 6 y 12 meses tras TCE. Para el análisis longitudinal de las características del DTI y su correlación con la evolución de los pacientes se han empleado pruebas no paramétricas y un análisis de regresión ordinal. RESULTADOS: A pesar de haber detectado cambios dinámicos en las características del DTI en las 3 porciones del cuerpo calloso, los pacientes continuaron mostrando valores de anisotropía fraccionada y difusión axial significativamente inferiores y valores de difusión radial mayores en comparación con los controles al final del periodo de estudio. También hemos encontrado diferencias en el patrón de cambio del DTI entre subgrupos de pacientes que presentaron evolución favorable. CONCLUSIONES: El perfil temporal del cambio en las características del DTI parece proporcionar información importante sobre la recuperación clínica de los pacientes tras TCE

BACKGROUND AND OBJECTIVES: Traumatic axonal injury is the main cause of the cognitive and neuropsychological situation of patients after head trauma (TBI). Additionally, there are some evidences about the dynamic evolution of traumatic axonal injury. Although the diffusion tensor MRI (DTI) sequence is considered a useful technique for modifying the extent of the traumatic axonal injury, few studies have evaluated the longitudinal changes in the characteristics of the DTI and its relation to evolution of patients. MATERIALS AND METHODS: We performed a prospective observational study in 118 patients with moderate to severe TBI. The study included clinical outcome assessment based on the Glasgow Outcome Scale Extended and serial DTI studies in the early subacute setting (< 60 days) and 6 and 12 months after injury. Fractional anisotropy, axial and radial diffusivities were measured in the 3 portions of corpus callosum (genu, body, splenium) at each time point and compared to normalized values from an age-matched control group. Longitudinal fractional anisotropy analysis and its correlation with patient improvement was also done by non-parametric testing and ordinal regression analysis. RESULTS: Although dynamic changes in DTI characteristics have been detected in the 3 portions of corpus callosum, patients continue to show lower fractional anisotropy and axial diffusivities values and higher radial diffusivities values compared to controls at the end of the period of study. We have also found differences in the pattern of DTI metrics change between subgroups of patients according with their favorable outcome CONCLUSIONS: The temporal profile of the change in DTI characteristics seems to provide important information about the clinical recovery of patients after TBI

Common and separable neural alterations in substance use disorders: A coordinate-based meta-analyses of functional neuroimaging studies in humans.

Delineating common and separable neural alterations in substance use disorders (SUD) is imperative to understand the neurobiological basis of the addictive process and to inform substance-specific treatment strategies. Given numerous functional MRI (fMRI) studies in different SUDs, a meta-analysis could provide an opportunity to determine robust shared and substance-specific alterations. The present study employed a coordinate-based meta-analysis covering fMRI studies in individuals with addictive cocaine, cannabis, alcohol, and nicotine use. The primary meta-analysis demonstrated common alterations in primary dorsal striatal, and frontal circuits engaged in reward/salience processing, habit formation, and executive control across different substances and task-paradigms. Subsequent sub-analyses revealed substance-specific alterations in frontal and limbic regions, with marked frontal and insula-thalamic alterations in alcohol and nicotine use disorders respectively. Examining task-specific alterations across substances revealed pronounced frontal alterations during cognitive processes yet stronger striatal alterations during reward-related processes. Finally, an exploratory meta-analysis revealed that neurofunctional alterations in striatal and frontal reward processing regions can already be determined with a high probability in studies with subjects with comparably short durations of use. Together the findings emphasize the role of dysregulations in frontostriatal circuits and dissociable contributions of these systems in the domains of reward-related and cognitive processes which may contribute to substance-specific behavioral alterations.

Correlatos cerebrales del trastorno formal del pensamiento en la esquizofrenia: examinando la hipótesis frontal/disejecutiva / Brain functional correlates of formal thought disorder in schizophrenia: examining the frontal/dysexecutive hypothesis

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Amusia congénita y sus efectos en habilidades no musicales / Congenital amusia and its effects on non-musical skills

INTRODUCCIÓN: La amusia congénita es una condición específica en la que el individuo afectado es incapaz de reconocer variaciones tonales en las piezas musicales. Esto no puede explicarse por una lesión encefálica previa, una pérdida auditiva, un déficit cognitivo, un trastorno socioafectivo o una falta de estimulación ambiental. Actualmente se estima una prevalencia del 1,5% de la población mundial, con un importante componente genético entre los afectados. Se ha descrito que en las personas con amusia puede haber afectación de ciertas habilidades cognitivas en el campo emocional, espacial y del lenguaje. OBJETIVO: Revisar la bibliografía donde se describen los efectos en las habilidades no musicales que pueden coexistir en individuos con amusia congénita. DESARROLLO: Varios estudios de neuroimagen han permitido observar cambios morfológicos y funcionales en el lóbulo temporal, así como en las conexiones de la sustancia blanca entre el giro temporal superior y el giro frontal inferior. Partiendo de estas regiones afectadas, podría existir un déficit en habilidades cognitivas relacionadas con áreas adyacentes. CONCLUSIONES: La amusia congénita se ha relacionado con un pobre desempeño en diferentes habilidades cognitivas no musicales, como el procesamiento visuoespacial, el procesamiento del lenguaje, alteraciones de la lectura, el reconocimiento de rostros y aspectos emocionales

INTRODUCTION: Congenital amusia is a specific condition in which the individual is unable to recognise tonal variations in a piece of musical. This cannot be explained by a previous brain injury, hearing loss, cognitive deficit, socio-affective disorder or lack of environmental stimulation. The current estimated prevalence is 1.5% of the world population, with a significant genetic component among those who suffer from it. It has been claimed that certain cognitive abilities in the emotional, spatial and language fields may be affected in people with amusia. AIM: To review the literature describing the effects on non-musical skills that may coexist in individuals with congenital amusia. DEVELOPMENT: Several neuroimaging studies have observed morphological and functional changes in the temporal lobe, as well as in the white matter connections between the superior temporal gyrus and the inferior frontal gyrus. From these affected regions, there may be a deficit in cognitive skills related to adjacent areas. CONCLUSIONS: Congenital amusia has been associated with poor performance in different non-musical cognitive skills, such as visuospatial processing, language processing, reading difficulties, face recognition and emotional aspects

Subcortical Brain Volume, Regional Cortical Thickness, and Cortical Surface Area Across Disorders: Findings From the ENIGMA ADHD, ASD, and OCD Working Groups.

OBJECTIVE: Attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) are common neurodevelopmental disorders that frequently co-occur. The authors sought to directly compare these disorders using structural brain imaging data from ENIGMA consortium data. METHODS: Structural T1-weighted whole-brain MRI data from healthy control subjects (N=5,827) and from patients with ADHD (N=2,271), ASD (N=1,777), and OCD (N=2,323) from 151 cohorts worldwide were analyzed using standardized processing protocols. The authors examined subcortical volume, cortical thickness, and cortical surface area differences within a mega-analytical framework, pooling measures extracted from each cohort. Analyses were performed separately for children, adolescents, and adults, using linear mixed-effects models adjusting for age, sex, and site (and intracranial volume for subcortical and surface area measures). RESULTS: No shared differences were found among all three disorders, and shared differences between any two disorders did not survive correction for multiple comparisons. Children with ADHD compared with those with OCD had smaller hippocampal volumes, possibly influenced by IQ. Children and adolescents with ADHD also had smaller intracranial volume than control subjects and those with OCD or ASD. Adults with ASD showed thicker frontal cortices compared with adult control subjects and other clinical groups. No OCD-specific differences were observed across different age groups and surface area differences among all disorders in childhood and adulthood. CONCLUSIONS: The study findings suggest robust but subtle differences across different age groups among ADHD, ASD, and OCD. ADHD-specific intracranial volume and hippocampal differences in children and adolescents, and ASD-specific cortical thickness differences in the frontal cortex in adults, support previous work emphasizing structural brain differences in these disorders.