Fronto-Subcortical Circuits for Cognition and Motivation: Dissociated Recovery in a Case of Loss of Psychic Self-Activation

In humans and non-humans primates, extensive evidence supports the existence of subcortico-cortical circuits for cognition and behavior. Lesions studies are critical to understand the clinical significance of these functionally segregated circuits. Mapping these circuits from lesion studies is difficult given the heterogeneous etiology of the lesions, the lack of long-term and systematic testing of cognitive and behavioral disturbances, as well as the scarcity of neuroimaging data for identifying the precise location and extent of subcortical lesions. Here, we report the long-term follow-up study of a patient who developed a loss of psychic self-activation associated to a dysexecutive syndrome following resuscitation from cardiac arrest. Neuroimaging revealed extensive bilateral lesions in the putamen, with a relative spare of the caudate, and exhibiting a dorsoventral gradient that was predominantly rostrally to the anterior commissure and spared most of the ventral striatum. In comprehensive neuropsychological and neuropsychiatric assessments, we observed dissociation between the improvement of the self-activation deficits and the stability of the dysexecutive syndrome. The pattern of recovery after this lesion lends support to current models proposing the existence of two main subcortico-cortical circuits: a dorsal circuit, mostly mediating cognitive processes, and a ventral circuit, implicated in motivation

A neoliberal revolution: the educational policy in Chile since the military dictatorship

El artículo propone una lectura analítica del sistema educacional chileno a partir de la dictadura cívico-militar, encabezada por Augusto Pinochet (1973-1990), en la que se transforma el modelo social, económico y político del país, imponiendo un Estado neoliberal incluso antes de que este modelo se vislumbrara como el horizonte en el resto de la región. Se recorre el proceso de transformación del sistema de educación chileno, los cambios en la morfología del sistema escolar y sus consecuencias, así como la consolidación de esta matriz durante los gobiernos democráticos de la coalición de centro izquierda, la Concertación (1990-2010). Si bien el desarrollo de este proyecto educacional se inicia con fuertes tensiones ideológicas entre el catolicismo y el liberalismo, estos logran converger en el principio de libertad de enseñanza. Bajo esta premisa, se articulan numerosas reformas que dan forma a un sistema educacional neoliberal. En consecuencia, se dará cuenta de la configuración de un nuevo orden educativo, hoy arraigado en la sociedad chilena, en el que la educación se establece como un bien individual bajo la égida de la competencia generalizada, el objetivo de la eficiencia y la cultura de la evaluación. Este artículo surge en el marco del desarrollo de mi tesis doctoral y se basa principalmente en el análisis de literatura académica y textos oficiales.This article presents an analytical reading of the Chilean education system since the civic military dictatorship, led by Augusto Pinochet (1973-1990), in which the social, economic and political systems of the country are transformed by imposing a neoliberal State even before such model was glimpsed as the horizon in the rest of the region. It reviews the transformation process of the Chilean education system, the changes in the morphology of the school system and their consequences, as well as the consolidation of this matrix during the democratic governments of the center-left coalition, “La Concertación” (1990-2010). Even though the development of this education project starts with strong ideological tensions between Catholicism and liberalism, they manage to converge in the principle of freedom of teaching. Under this premise, several reforms are implemented in order to shape a neoliberal education system. Consequently, the configuration of a new educational order will be discussed, ingrained in the Chilean society nowadays, in which education is considered an individual good under the aegis of general competition, efficiency objectives and the evaluation culture. This article emerges within the framework of the development of my PhD and it is mainly based on the analysis of academic literature and official documents

neuroanatomical basis of behavioral disturbances in patients with prefrontal lesions

The role of the frontal lobe in control of behavioral and cognitive abilities is explored in a group of 34 patients with brain lesions restricted to the prefrontal cortex. The scores in both structured behavioral questionnaires and standard neuropsychological tests were analyzed using the injured area of the frontal lobe as the independent variable. Our results show that patients with simultaneous lesions in supero– and inferomedial areas of the prefrontal cortex exhibit higher behavioral disturbances. Bilateral lesions also are associated with greater behavioral troubles. On the contrary, cognitive abilities are globally impaired in prefrontal patients. Results are discussed in relation to current models of the organization of the prefrontal cortex and its role on behavior control

Usefulness of a brief informant interview to detect dementia, translated into Spanish (AD8-Ch)

Cartas al Edito

Utility of the Neuropsychiatric Inventory Questionnaire (NPI-Q) in the assessment of a sample of patients with Alzheimer’s disease in Chile

ABSTRACT The Neuropsychiatric Inventory Questionnaire (NPI-Q) is an informant-based instrument that measures the presence and severity of 12 Neuropsychiatric Symptoms (NPS) in patients with dementia, as well as informant distress. Objective: To measure the psychometric properties of the NPI-Q and the prevalence of NPS in patients with Alzheimer's disease (AD) in Chile. Methods: 53 patients with AD were assessed. Subjects were divided into two different groups: mild AD (n=26) and moderate AD (n=27). Convergent validity was estimated by correlating the outcomes of the NPI-Q with Neuropsychiatric Inventory (NPI) scores and with a global cognitive efficiency test (Addenbrooke's Cognitive Examination - Revised - ACE-R). Reliability of the NPI-Q was analysed by calculating its internal consistency. Prevalence of NPS was estimated with both the NPI and NPI-Q. Results: Positive and significant correlations were observed between the NPI-Q, the NPI, and the ACE-R (r=0.730; p<0.01 and 0.315; p<0.05 respectively). The instrument displayed an adequate level of reliability (Cronbach's alpha=0.783). The most prevalent NPS were apathy/indifference (62.3%) and dysphoria/depression (58.5%). Conclusion: The NPI-Q exhibited acceptable validity and reliability indicators for patients with AD in Chile, indicating that it is a suitable instrument for the routine assessment of NPS in clinical practice

Utility of the Neuropsychiatric Inventory Questionnaire (NPI-Q) in the assessment of a sample of patients with Alzheimer’s disease in Chile

The Neuropsychiatric Inventory Questionnaire (NPI-Q) is an informant-based instrument that measures the presence and severity of 12 Neuropsychiatric Symptoms (NPS) in patients with dementia, as well as informant distress.Objective: To measure the psychometric properties of the NPI-Q and the prevalence of NPS in patients with Alzheimer's disease (AD) in Chile.Methods: 53 patients with AD were assessed. Subjects were divided into two different groups: mild AD (n=26) and moderate AD (n=27). Convergent validity was estimated by correlating the outcomes of the NPI-Q with Neuropsychiatric Inventory (NPI) scores and with a global cognitive efficiency test (Addenbrooke's Cognitive Examination - Revised - ACE-R). Reliability of the NPI-Q was analysed by calculating its internal consistency. Prevalence of NPS was estimated with both the NPI and NPI-Q.Results: Positive and significant correlations were observed between the NPI-Q, the NPI, and the ACE-R (r=0.730; p&lt;0.01 and 0.315; p&lt;0.05 respectively). The instrument displayed an adequate level of reliability (Cronbach's alpha=0.783). The most prevalent NPS were apathy/indifference (62.3%) and dysphoria/depression (58.5%).Conclusion: The NPI-Q exhibited acceptable validity and reliability indicators for patients with AD in Chile, indicating that it is a suitable instrument for the routine assessment of NPS in clinical practice.</p

Cultural validity of cognitive markers for Alzheimer's disease (AD) : evidence for global strategies

Background: Availability of culture-free cognitive tests with marker properties for AD has proved a barrier to global harmonization strategies. The European Neurodegenerative Diseases Working Group suggested that the Short-Term Memory Binding Test (STMBT) and the Free and Cued Selective Reminding Test (FCSRT) are useful tests for the early detection of AD (Costa et al., 2017). Yassuda et al. (2019) showed that STMB is insensitive to age and education among healthy Brazilian adults. Parra et al. (2019) suggested that these tests should enter global strategies to aid the early detection of AD. Evidence is still needed to ascertain that such a validity translates to the assessment of affected individuals from underrepresented populations. The current study aimed to shed new light on such an outstanding question. Methods: We recruited 64 healthy controls (HC), 60 patients with Mild Cognitive Impairment (MCI), and 63 patients with mild AD from [Lima at the regional area health clinics of the “Dirección Regional de Salud (DIRESA)” of the “Gobierno Regional del Callao” between June 2018 and May 2019]. They were all illiterate. We considered Illiterate individuals who (1) attended no school or were enrolled for less than one year and (2) could not read or write (a booklet was given which showed a simple sentence). We assessed them with the STMBT, the visual FCSRT, and a brief clinical-neuropsychological protocol. Results: The assessment confirmed the healthy (CDR=0.0, pFAQ=2.2, BDI=5.9), MCI (CDR=0.5, pFAQ=3.7, BDI=6.2), and dementia (CDR=1.3, pFAQ=16.5, BDI=7.2) status of our groups. Significant between-group differences were found with both the STMBT (F(2,184)=590.1, p>>MCI>>>AD. ROC analysis with STMB revealed AUC=0.98 for HC vs. MCI, AUC=1.00 for HC vs. AD, and AUC=0.97 for MCI vs. AD. For the visual FCSRT, an AUC=1.00 was found for HC vs (MCI & AD), and AUC=0.99 for MCI vs AD. Conclusion: The two cognitive markers recently recommended for harmonisation of neuropsychological assessment in neurodegenerative dementias in Europe seem suitable to support such practices in illiterate populations. Parra et al. (2019) recently suggested that only global strategies will help meet global challenges. Here we provide evidence of cognitive markers for AD that can reliably enter such strategies

Cognitive impairment and Alzheimer’s disease: Links with oxidative stress and cholesterol metabolism

Oxidative stress has been implicated in the progression of a number of neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease and amyotrophic lateral sclerosis. We carried out an in-depth study of cognitive impairment and its relationships with oxidative stress markers such as ferric-reducing ability of plasma (FRAP), plasma malondialdehyde and total antioxidative capacity (TAC), as well as cholesterol parameters, in two subsets of subjects, AD patients (n = 59) and a control group of neurologically normal subjects (n = 29), attending the University Hospital Salvador in Santiago, Chile. Cognitive impairment was assessed by a set of neuropsychological tests (Mini-Mental State Examination, Boston Naming Test, Ideomotor Praxia by imitation, Semantic Verbal Fluency of animals or words with initial A, Test of Memory Alteration, Frontal Assessment Battery), while the levels of those oxidative stress markers and cholesterol metabolism parameters were determined according with standard bioassays in fresh plasma samples of the two subgroups of patients. No significant differences were observed when the cholesterol parameters (low-, high-density lipoprotein, total cholesterol) of the AD group were compared with normal controls. Interestingly, a correlation was evidenced when the levels of cognitive impairment were analyzed with respect to the plasma antioxidant capacity (AOC) of patients. In this context, the subset of subjects exhibiting cognitive impairment were divided into two subgroups according with their Global Dementia Scale performance: a subgroup with mild AD and a subgroup with moderate to severe AD. Significant differences in AOC were found between subgroups. The different correlations between cognitive impairment of subgroups of subjects with the oxidative stress profile are discussed in the context of AD pathogenesis