Utility of a Short Neuropsychological Protocol for Detecting HIV-Associated Neurocognitive Disorders in Patients with Asymptomatic HIV-1 Infection.

Human Immunodeficiency Virus type 1 (HIV-1) infection is a chronic disease that affects ~40 million people worldwide. HIV-associated neurocognitive disorders (HAND) are common in individuals with HIV-1 Infection, and represent a recent public health problem. Here we evaluate the performance of a recently proposed short protocol for detecting HAND by studying 60 individuals with HIV-1-Infection and 60 seronegative controls from a Caribbean community in Barranquilla, Colombia. The short evaluation protocol used significant neuropsychological tests from a previous study of asymptomatic HIV-1 infected patients and a group of seronegative controls. Brief screening instruments, i.e., the Mini-mental State Examination (MMSE) and the International HIV Dementia Scale (IHDS), were also applied. Using machine-learning techniques, we derived predictive models of HAND status, and evaluated their performance with the ROC curves. The proposed short protocol performs exceptionally well yielding sensitivity, specificity, and overall prediction values >90%, and better predictive capacity than that of the MMSE and IHDS. Community-specific cut-off values for HAND diagnosis, based on the MMSE and IHDS, make this protocol suitable for HAND screening in individuals from this Caribbean community. This study shows the effectivity of a recently proposed short protocol to detect HAND in individuals with asymptomatic HIV-1-Infection. The application of community-specific cut-off values for HAND diagnosis in the clinical setting may improve HAND screening accuracy and facilitate patients' treatment and follow-up. Further studies are needed to assess the performance of this protocol in other Latin American populations.

Virtual Reality During Brain Mapping for Awake-Patient Brain Tumor Surgery: Proposed Tasks and Domains to Test.

BACKGROUND: Virtual reality (VR) use in health care has increased over the past few decades, with its utility expanding from a teaching tool to a highly reliable neuro-technology adjunct in multiple fields including neurosurgery. Generally, brain tumor surgery with the patient awake has only been performed for mapping of language and motor areas. With the rise of VR and advancing surgical techniques, neurosurgical teams are developing an increased understanding of patients' anatomo-functional connectivity. Consequently, more specific cognitive tasks are being required for the mapping and preservation of deeper layers of cognition. METHODS: An extensive literature review was conducted with the inclusion criteria of manuscripts that described the use of VR during awake neurosurgery mapping. RESULTS: We identified 3 recent articles that met our inclusion criteria, yet none of them addressed the specific use of VR for cognition mapping. Consequently, a cognitive task phase was performed to search and craft the tasks and domains that better filled the spotted niche of this need inside the operating room. A proposed protocol was developed with 5 potential uses of VR for brain mapping during awake neurosurgery, each of them with a specific proposed example of use. CONCLUSIONS: The authors advocate for the use of a VR protocol as a feasible functional tool in awake-patient brain tumor surgery by using it as a complement during cognitive screening in addition to language testing.

Velocidad de procesamiento de la información en la enfermedad de Alzheimer / Information processing speed in Alzheimer's disease

Resumen Introducción: El enlentecimiento en la velocidad de procesamiento de la información (VPI) es un hallazgo frecuente en una gran variedad de patologías cerebrales. Desde un punto de vista clínico la evaluación de la VPI reviste gran interés ya que puede afectar al procesamiento cognitivo con importantes repercusiones en las actividades de la vida diaria. El objetivo fue estudiar el tiempo de realización de diferentes tareas ejecutivas como medida de la velocidad de procesamiento de la información, en sujetos con enfermedad de Alzheimer de diferente grado de severidad. También hemos analizado el número de errores en las diferentes tareas. Método: 50 pacientes con enfermedad de Alzheimer con deterioro cognitivo leve (n = 17), moderado (n = 17) y moderadamente grave (n = 16), según la Escala de Deterioro Global y 60 sujetos sin deterioro cognitivo. Se utlizó el Trail-Making Test, el Test del Mapa del Zoo y el Stroop. Resultados: Existen diferencias estadísticamente significativas entre los grupos en todas las medidas analizadas, tiempo de ejecución y números de errores del Trail-Making Test; tiempo de ejecución y número de errores en el Test del mapa del Zoo y en la condiciones del Stroop palabras, colores y palabras-colores (p < 0,01 ). Conclusiones: Nuestros resultados indican que el procesamiento de la información en pacientes con enfermedad de Alzheimer está lentificado, en los que se evidencia un mayor tiempo de ejecución y en un mayor número de errores, en relación a los sujetos sin deterioro cognitivo.

Introduction: Slowdown of information processing speed (ISP) is a common finding in a variety of brain pathologies. From a clinical point of view, assessment of ISP is of great interest since cognitive processing can be affected and, consequently, show consequences on daily living activities. The aim was to study the time in performing different executive tasks, as measures of information processing speed, in subjects with different severity of Alzheimer's Disease. Number of mistakes in the different taks has also been analysed. Method: 50 patients with Alzheimer's Disease presenting mild (n = 17), moderate (n = 17) and moderately severe (n = 16) cognitive impairment, according to Global Deterioration Scale; and 60 subjects with no cognitive impairment. Trail-Making test, Zoo Map test and Stroop test were administered. Results: Statistically significant differences were found between all groups in all measures performed, time of performance and number of mistakes in Trail-Making test; time of performance and number of mistakes in the Zoo Map test; and words, color and, word-color conditions in Stroop test (p < 0,01). Conclusions: Our results suggest that information processing in patients with Alzheimer's Disease is slower compared to patients with no cognitive impairment, since a higher time of performance and rate of mistakes are presented.

Language disorders in victims of domestic violence in children's homes.

Studies that deal with child maltreatment have become relevant during these past years. One important aspect to consider is the impact of maltreatment on the cognitive functioning and more precisely on language. Our objective is to analyze the different components in the comprehension and production of language in children victims of domestic abuse in Childrens Homes. PARTICIPANTS: The sample consists of 104 participants divided in two groups. A group of children who have just been institutionalized due to domestic abuse (VG) (Age: 8 years 2 months with a standard deviation of 1, 5 years) without previous treatment; a group of comparison (CG) made up by children who have not been victim of domestic violence (Age: 8 years 6 months with a standard deviation of 2 years and a month), with similar characteristics of gender, age and schooling. MATERIAL: The Child Neuropsychological Assessment by Matute, Rosselli, Ardila and Ostrosky (2007) was applied. This test includes metalinguistic, oral and written comprehension and expression skills. RESULTS: The VG group showed low scores in all components of the analyzed language with exception to the discourse, syllable and non-word dictation compared to the CG children. CONCLUSIONS: The alterations of the language observed in these children semantic suggest a lack of consolidation of phonological coding and a low use of code. From our findings an early language evaluation in these children can be of especial interest to apply timely intervention programs with the aim of diminishing the impact caused by domestic violence on school failure which is a frequent trait in these children.

Executive functioning in obese individuals waiting for clinical treatment / Funcionamiento ejecutivo en sujetos obesos en espera de tratamiento clínico

BACKGROUND: Executive functions have an important role in human behavioural regulation and can be a determinant of eating behaviour. Our aim was to study the different components of executive functions in obese individuals waiting for clinical treatment, comparing them with normoweight subjects with similar socio-demographic characteristics. METHOD: A total of 114 adults (76 obese and 38 normoweight) completed a neuropsychological battery that included tasks of conceptualization and abstraction, motor programming, response maintenance, inhibition and resistance, problem solving, cognitive flexibility, and verbal fluency. RESULTS: There was a statistically significant difference between groups for all the dimensions of the executive functions evaluated, with the obese group showing poorer performance compared to normoweight. CONCLUSIONS: Obese individuals demonstrated poorer executive functions than normoweight individuals

ANTECEDENTES: las funciones ejecutivas tienen un papel importante en la regulación del comportamiento humano y pueden ser un determinante en la conducta alimentaria. El objetivo fue estudiar diferentes componentes de las funciones ejecutivas en individuos obesos en espera de tratamiento clínico, comparándolos con individuos con normopeso con características sociodemográficas similares. MÉTODO: participaron 114 adultos (76 obesos y 38 con normopeso) que completaron una batería neuropsicológica que incluyó tareas de conceptualización y abstracción, programación motora, manutención de respuesta, control inhibitorio, resolución de tareas, flexibilidad cognitiva y fluencia verbal. RESULTADOS: existen diferencias estadísticamente significativas entre los grupos en todas las tareas del funcionamiento ejecutivo evaluadas. El grupo de los obesos obtuvo puntuaciones más bajas que el grupo con normopeso. CONCLUSIONES: los individuos sujetos obesos revelan peor funcionamiento ejecutivo que los con normopeso

Frontal gamma noise power and cognitive domains in schizophrenia.

The cognitive deficit profile is different among individuals with schizophrenia. We quantified the amount of electroencephalographic activity unlocked to stimuli onset (noise power) over frontal regions regarding deficit in cognitive domains. Forty-six patients with schizophrenia and 27 healthy controls underwent clinical, cognitive and electrophysiological assessments. Noise power studies may be considered complementary but not equivalent to induced power studies. We compared gamma and theta noise power magnitude during a P300 paradigm between subsets of patients divided according to cognitive deficit in key domains and controls. Patients displayed higher gamma noise power activity at Fz site and significantly lower performance in all cognitive domains when compared to controls. The subset of patients with cognitive deficit for working memory and problem solving/executive functions domains displayed significantly higher frontal-lateral noise power values in comparison to the subset of patients without cognitive deficit and controls. Patients with significant cognitive deficits in domains with greater frontal contribution are also characterized by an abnormally higher gamma band noise power over the frontal region. Our data may endorse various biological subsets within schizophrenia, characterized by the presence or absence of a significant cognitive deficit in frontal domains.

Hemispheric asymmetry in recognition memory: effects of retention level on the recognition of Portuguese words.

Early findings from Broca and Wernicke led to the classical view of hemispheric specialization, where the main idea relates to left-hemisphere language capabilities compared to right-hemisphere visual capabilities. Federmeier and Benjamin (2005) have suggested that semantic encoding for verbal information in the right hemisphere can be more effective when memory demands are higher. In light of this, our main goal was to study the effect of retention level of verbal information on hemispheric processes. However, regarding the cross-linguistic differences in orthography and their subsequent effects on word recognition (Frost, Katz, & Bentin, 1987), our intent was also to test prior predictions of Federmeier and Benjamin (2005) for a "shallow" orthography language, where words have a clear correspondence between graphemes and phonemes, as opposed to English, which is a "deep" orthography language. Portuguese concrete nouns were selected. The participants were submitted to a visual half-field word presentation using a continuous recognition memory paradigm. The retention level included 1, 2, 4, 8, 20 or 40 words. Results showed that recognition accuracy was higher for words studied in the right visual field, compared to those studied in the left visual field, when the retention interval included 2, 4, or 20 words. No significant differences were found for the remaining intervals. Further analysis on accuracy data for intermediate retention levels showed that recognition accuracy was higher for the 2 words retention level than for the levels including 4, 8, or 20 words; it was higher for left-hemisphere encoding as well. Our results also indicated that reaction times were slower for left-hemisphere encoding and for the 40 words retention level when compared to that of 20 words. In summary, the current results are in partial agreement with those of Federmeier and Benjamin (2005) and suggest different hemispheric memory strategies for the semantic encoding of verbal information.