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1.
J Sleep Res ; 33(1): e13891, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37039398

RESUMEN

Sleep problems are common among veterans with post-traumatic stress disorder and closely associated with hyperarousal symptoms. Transcutaneous vagus nerve stimulation (tVNS) may have potential to improve sleep quality in veterans with PTSD through effects on brain systems relevant to hyperarousal and sleep-wake regulation. The current pilot study examines the effect of 1 h of tVNS administered at "lights out" on sleep architecture, microstructure, and autonomic activity. Thirteen veterans with PTSD completed two nights of laboratory-based polysomnography during which they received 1 h of either active tVNS (tragus) or sham stimulation (earlobe) at "lights out" with randomised order. Sleep staging and stability metrics were derived from polysomnography data. Autonomic activity during sleep was assessed using the Porges-Bohrer method for calculating respiratory sinus arrhythmia (RSAP-B ). Paired t-tests revealed a small decrease in the total sleep time (d = -0.31), increase in N3 sleep (d = 0.23), and a small-to-moderate decrease in REM sleep (d = -0.48) on nights of active tVNS relative to sham stimulation. tVNS was also associated with a moderate reduction in cyclic alternating pattern (CAP) rate (d = -0.65) and small-to-moderate increase in RSAP-B during NREM sleep. Greater NREM RSAP-B was associated with a reduced CAP rate and NREM alpha power. This pilot study provides preliminary evidence that tVNS may improve sleep depth and stability in veterans with PTSD, as well as increase parasympathetically mediated nocturnal autonomic activity. These results warrant continued investigation into tVNS as a potential tool for treating sleep disturbance in veterans with PTSD.


Asunto(s)
Trastornos por Estrés Postraumático , Estimulación del Nervio Vago , Veteranos , Humanos , Trastornos por Estrés Postraumático/terapia , Estimulación del Nervio Vago/métodos , Proyectos Piloto , Sueño
2.
Artículo en Inglés | MEDLINE | ID: mdl-38758056

RESUMEN

OBJECTIVE: Identification of biomarkers of cognitive recovery after traumatic brain injury (TBI) will inform care and improve outcomes. This study assessed the utility of neurofilament (NF-L and pNF-H), a marker of neuronal injury, informing cognitive performance following moderate-to-severe TBI (msTBI). SETTING: Level 1 trauma center and outpatient via postdischarge follow-up. PARTICIPANTS: N = 94. Inclusion criteria: Glasgow Coma Scale score less than 13 or 13-15 with clinical evidence of moderate-to-severe injury traumatic brain injury on clinical imaging. Exclusion criteria: neurodegenerative condition, brain death within 3 days after injury. DESIGN: Prospective observational study. Blood samples were collected at several time points post-injury. Cognitive testing was completed at 6 months post-injury. MAIN MEASURES: Serum NF-L (Human Neurology 4-Plex B) pNF-H (SR-X) as measured by SIMOA Quanterix assay. Divided into 3 categorical time points at days post-injury (DPI): 0-15 DPI, 16-90 DPI, and >90 DPI. Cognitive composite comprised executive functioning measures derived from 3 standardized neuropsychological tests (eg, Delis-Kaplan Executive Function System: Verbal Fluency, California Verbal Learning Test, Second Edition, Wechsler Adult Intelligence Scale, Third Edition). RESULTS: pNF-H at 16-90 DPI was associated with cognitive outcomes including a cognitive-executive composite score at 6 months (ß = -.430, t34 = -3.190, P = .003). CONCLUSIONS: Results suggest that "subacute" elevation of serum pNF-H levels may be associated with protracted/poor cognitive recovery from msTBI and may be a target for intervention. Interpretation is limited by small sample size and including only those who were able to complete cognitive testing.

3.
NMR Biomed ; 36(7): e4897, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-36628927

RESUMEN

Obesity is associated with adverse effects on brain health, including an increased risk of neurodegenerative diseases. Changes in cerebral metabolism may underlie or precede structural and functional brain changes. While bariatric surgery is known to be effective in inducing weight loss and improving obesity-related medical comorbidities, few studies have examined whether it may be able to improve brain metabolism. In the present study, we examined changes in cerebral metabolite concentrations in participants with obesity who underwent bariatric surgery. Thirty-five patients with obesity (body mass index ≥ 35 kg/m2 ) were recruited from a bariatric surgery candidate nutrition class. They completed single voxel proton magnetic resonance spectroscopy at baseline (presurgery) and within 1 year postsurgery. Spectra were obtained from a large medial frontal brain region using a PRESS sequence on a 3-T Siemens Verio scanner. The acquisition parameters were TR = 3000 ms and TE = 37 ms. Tissue-corrected metabolite concentrations were determined using Osprey. Paired t-tests were used to examine within-subject change in metabolite concentrations, and correlations were used to relate these changes to other health-related outcomes, including weight loss and glycated hemoglobin (HbA1c ), a measure of blood sugar levels. Bariatric surgery was associated with a reduction in cerebral choline-containing compounds (Cho; t [34] = - 3.79, p < 0.001, d = -0.64) and myo-inositol (mI; t [34] = - 2.81, p < 0.01, d = -0.47) concentrations. There were no significant changes in N-acetyl-aspartate, creatine, or glutamate and glutamine concentrations. Reductions in Cho were associated with greater weight loss (r = 0.40, p < 0.05), and reductions in mI were associated with greater reductions in HbA1c (r = 0.44, p < 0.05). In conclusion, participants who underwent bariatric surgery exhibited reductions in cerebral Cho and mI concentrations, which were associated with improvements in weight loss and glycemic control. Given that elevated levels of Cho and mI have been implicated in neuroinflammation, reduction in these metabolites after bariatric surgery may reflect amelioration of obesity-related neuroinflammatory processes. As such, our results provide evidence that bariatric surgery may improve brain health and metabolism in individuals with obesity.


Asunto(s)
Cirugía Bariátrica , Humanos , Obesidad/cirugía , Creatina/metabolismo , Espectroscopía de Protones por Resonancia Magnética , Pérdida de Peso , Colina/metabolismo , Inositol/metabolismo
4.
Artículo en Inglés | MEDLINE | ID: mdl-36380553

RESUMEN

INTRODUCTION: Autonomic dysfunction is an important feature of Lewy Body Dementia (DLB), but measurement of autonomic symptoms has been limited in both previous research and clinical practice. Accurate measurement of autonomic dysfunction has the potential to improve our understanding of the course and progression of DLB, given that autonomic symptoms typically precede cognitive impairment and are associated with functional impairment. The primary aim of this study was to examine the psychometric properties of the two versions (3.0 and 3.1) of the NACC LBD-module Autonomic Symptom Checklist (ASC). METHODS: Psychometric analyses of the ASC (internal consistency, reliability, factor structure, and validity) were conducted on data acquired from 245 individuals with DLB from the NACC database. ASC V3.0 was contrasted on these attributes to V3.1. RESULTS: Results suggested an underlying factor structure for the ASC, and confirmatory factor analysis (CFA) revealed 3 factors, which generally aligned with discrete autonomic systems. The ASC V3.0 and CFA-identified scales were comparable in terms of reliability, which were both improved relative to the ASC V3.1. In terms of ecological validity, CFA-identified items related to gastrointestinal/thermoregulation symptoms were significantly more associated with functional outcomes compared to the unitary ASC. CONCLUSION: Findings underscore the importance of differentiation within the autonomic system. Future research into autonomic symptom classes and lab-based pathophysiological measurement of autonomic dysfunction in DLB has the potential to support early identification and inform treatment planning.


Asunto(s)
Disfunción Cognitiva , Enfermedad por Cuerpos de Lewy , Humanos , Psicometría , Lista de Verificación , Reproducibilidad de los Resultados , Disfunción Cognitiva/complicaciones
5.
Cogn Behav Neurol ; 35(1): 32-39, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35239597

RESUMEN

BACKGROUND: Healthy people have a leftward spatial attentional bias, called pseudoneglect. Individuals with end-stage renal disease (ESRD) who are receiving hemodialysis often demonstrate an increase in their leftward spatial attentional bias. Whereas a successful kidney transplant often improves the cognitive functions of individuals who previously received hemodialysis, the effect of a kidney transplant on this abnormal allocation of spatial attention has not been investigated. OBJECTIVE: To investigate the effects of kidney transplant on individuals who were being treated with dialysis and had an increase in their left spatial attentional bias. METHOD: The performance of 20 hemodialyzed individuals with ESRD on the line bisection test was compared to that of 17 demographically matched individuals with ESRD, who had received a kidney transplant, and 23 demographically matched healthy controls (HC). RESULTS: All of the participants exhibited a left spatial bias on the line bisection task. When compared with the HC, the hemodialyzed individuals demonstrated a significantly greater left spatial bias. There was, however, no difference in spatial bias between the HC and the individuals who had received a kidney transplant. CONCLUSION: A successful kidney transplant can improve patients' abnormal leftward allocation of spatial attention. However, future studies are needed to better understand the mechanisms of this spatial attentional bias in hemodialyzed individuals and the normalization of bias following transplantation.


Asunto(s)
Sesgo Atencional , Fallo Renal Crónico , Trasplante de Riñón , Femenino , Lateralidad Funcional , Humanos , Fallo Renal Crónico/terapia , Masculino , Percepción Espacial
6.
Cogn Behav Neurol ; 34(1): 26-37, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33652467

RESUMEN

Posttraumatic stress disorder (PTSD) is prevalent among veterans with a history of traumatic brain injury (TBI); however, the relationship between TBI and PTSD is not well understood. We present the case of a 31-year-old male veteran with PTSD who reported TBI before entering the military. The reported injury appeared to be mild: He was struck on the head by a baseball, losing consciousness for ∼10 seconds. Years later, he developed severe PTSD after combat exposure. He was not receiving clinical services for these issues but was encountered in the context of a research study. We conducted cognitive, autonomic, and MRI assessments to assess brain function, structure, and neurophysiology. Next, we compared amygdala volume, uncinate fasciculus diffusion, functional connectivity, facial affect recognition, and baroreceptor coherence with those of a control group of combat veterans (n = 23). Our veteran's MRI revealed a large right medial-orbital prefrontal lesion with surrounding atrophy, which the study neuroradiologist interpreted as likely caused by traumatic injury. Comparison with controls indicated disrupted structural and functional connectivity of prefrontal-limbic structures and impaired emotional, cognitive, and autonomic responses. Detection of this injury before combat would have been unlikely in a clinical context because our veteran had reported a phenomenologically mild injury, and PTSD is a simple explanation for substance abuse, sleep impairment, and psychosocial distress. However, it may be that right prefrontal-limbic disruption imparted vulnerability for the development of PTSD and exacerbated our veteran's emotional response to, and recovery from, PTSD.


Asunto(s)
Conmoción Encefálica/psicología , Trastornos por Estrés Postraumático/etiología , Adulto , Humanos , Masculino , Trastornos por Estrés Postraumático/psicología
7.
Brain Inj ; 35(8): 922-933, 2021 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-34053386

RESUMEN

OBJECTIVE: Disrupted sleep is common following combat deployment. Contributors to risk include posttraumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI); however, the mechanisms linking PTSD, mTBI, and sleep are unclear. Both PTSD and mTBI affect frontolimbic white matter tracts, such as the uncinate fasciculus. The current study examined the relationship between PTSD symptom presentation, lateralized uncinate fasciculus integrity, and sleep quality. METHOD: Participants include 42 combat veterans with and without PTSD and mTBI. Freesurfer and Tracula were used to establish specific white matter ROI integrity via 3-T MRI. The Pittsburgh Sleep Quality Index and PTSD Checklist were used to assess sleep quality and PTSD symptoms. RESULTS: Decreased fractional anisotropy in the right uncinate fasciculus (ß = -1.11, SE = 0.47, p < .05) and increased hyperarousal symptom severity (ß = 3.50, SE = 0.86, p < .001) were associated with poorer sleep quality. CONCLUSION: Both right uncinate integrity and hyperarousal symptom severity are associated withsleep quality in combat veterans. The right uncinate is a key regulator of limbic behavior and sympathetic nervous system reactivity, a core component of hyperarousal. Damage to this pathway may be one mechanism by which mTBI and/or PTSD could create vulnerability for sleep problems following combat deployment.


Asunto(s)
Trastornos por Estrés Postraumático , Veteranos , Sustancia Blanca , Nivel de Alerta , Humanos , Sueño , Trastornos por Estrés Postraumático/diagnóstico por imagen , Sustancia Blanca/diagnóstico por imagen
8.
Stress ; 22(5): 530-547, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31161843

RESUMEN

Psychiatric illnesses and cardiovascular disease (CVD) contribute to significant overall morbidity, mortality, and health care costs, and are predicted to reach epidemic proportions with the aging population. Within the Veterans Administration (VA) health care system, psychiatric illnesses such as post-traumatic stress disorder (PTSD) and CVD such as heart failure (HF), are leading causes of hospital admissions, prolonged hospital stays, and resource utilization. Numerous studies have demonstrated associations between PTSD symptoms and CVD endpoints, particularly in the Veteran population. Not only does PTSD increase the risk of HF, but this relationship is bi-directional. Accordingly, a VA-sponsored conference entitled "Cardiovascular Comorbidities in PTSD: The Brain-Heart Consortium" was convened to explore potential relationships and common biological pathways between PTSD and HF. The conference was framed around the hypothesis that specific common systems are dysregulated in both PTSD and HF, resulting in a synergistic acceleration and amplification of both disease processes. The conference was not intended to identify all independent pathways that give rise to PTSD and HF, but rather identify shared systems, pathways, and biological mediators that would be modifiable in both disease processes. The results from this conference identified specific endocrine, autonomic, immune, structural, genetic, and physiological changes that may contribute to shared PTSD-CVD pathophysiology and could represent unique opportunities to develop therapies for both PTSD and HF. Some recommendations from the group for future research opportunities are provided.


Asunto(s)
Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/fisiopatología , Trastornos por Estrés Postraumático/complicaciones , Trastornos por Estrés Postraumático/fisiopatología , Adulto , Anciano , Encéfalo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trastornos por Estrés Postraumático/psicología , Estados Unidos , United States Department of Veterans Affairs , Veteranos/psicología
9.
J Int Neuropsychol Soc ; 25(1): 65-71, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30486914

RESUMEN

OBJECTIVE: The objective of this study was to evaluate the impact of directed and sustained attention on the allocation of visuospatial attention. Healthy people often have left lateral and upward vertical spatial attentional biases. However, it is not known whether there will be an increase in bias toward the attended portion of the stimulus when volitional spatial attention is allocated to a portion of a stimulus, whether there are asymmetrical spatial alterations of these biases, and how sustained attention influences these biases. METHODS: We assessed spatial bias in 36 healthy, right-handed participants using a variant of horizontal and vertical line bisections. Participants were asked to focus on one or the other end of vertical or horizontal lines or entire vertical or horizontal lines, and then to bisect the line either immediately or after a 20 second delay. RESULTS: We found a significant main effect of attentional focus and an interaction between attentional focus and prolonged viewing with delayed bisection. Focusing on a certain portion of the line resulting in a significant deviation toward the attended portion and prolonged viewing of the line prior to bisection significantly enhanced the degree of deviation toward the attended portion. CONCLUSIONS: The enhanced bias with directed and sustained attention may be useful modifications of the line bisection test, particularly in clinical populations. Thus, future studies should determine whether prolonged viewing with delayed bisection and spatially focused attention reveals attentional biases in patients with hemispheric lesions who perform normally on the traditional line bisection test. (JINS, 2019, 25, 65-71).


Asunto(s)
Atención/fisiología , Percepción Espacial/fisiología , Percepción Visual/fisiología , Adolescente , Adulto , Femenino , Humanos , Masculino , Adulto Joven
10.
J Int Neuropsychol Soc ; 25(10): 1044-1050, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31543083

RESUMEN

OBJECTIVES: Healthy young adults often demonstrate a leftward spatial bias called "pseudoneglect" which often diminishes with aging. One hypothesis for this phenomenon is an age-related deterioration in right hemisphere functions (right hemi-aging). If true, then a greater rightward bias should be evident on all spatial attention tasks regardless of content. Another hypothesis is a decrease in asymmetrical hemispheric activation with age (HAROLD). If true, older participants may show reduced bias in all spatial tasks, regardless of leftward or rightward biasing of specific spatial content. METHODS: Seventy right-handed healthy participants, 33 younger (21-40) and 37 older (60-78), were asked to bisect solid and character-letter lines as well as to perform left and right trisections of solid lines. RESULTS: Both groups deviated toward the left on solid line bisections and left trisections. Both groups deviated toward the right on right trisections and character line bisections. In all tasks, the older participants were more accurate than the younger participants. CONCLUSIONS: The finding that older participants were more accurate than younger participants across all bisection and trisection conditions suggests a decrease in the asymmetrical hemispheric activation of these specialized networks important in the allocation of contralateral spatial attention or spatial action intention.


Asunto(s)
Envejecimiento/fisiología , Atención/fisiología , Lateralidad Funcional/fisiología , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Juicio/fisiología , Masculino , Persona de Mediana Edad , Adulto Joven
11.
Cogn Behav Neurol ; 32(1): 11-15, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30896572

RESUMEN

BACKGROUND AND OBJECTIVE: Salience of emotional autobiographical memories may have temporal patterns associated with valence. Recall of negative emotional memories is often important in survival and well-being. Based on the possible survival value of negative memories, we posited that when given an open-ended request to recall either a sad or a happy memory, people are more likely to recall an older sad memory than a happy one. METHODS: We asked 20 healthy participants, aged 18-63 years, to freely recall happy and sad emotional memories and estimate the length of time that had passed since the recalled event had occurred. We analyzed the age of each memory based on valence. RESULTS: Sixteen of 20 participants volunteered a more remote sad than happy memory (P<0.05). Older participants' sad memories were more remote (P<0.05), but the ratio of happy to sad memories was not affected by age. CONCLUSIONS: Self-selected free retrieval of autobiographical happy and sad emotional memories reveals a time bias. Although the reason for this temporal dichotomy is unknown, it may be that engaging systems involved in defense and survival alters the encoding and/or retrieval characteristics of the memory that modify salience.


Asunto(s)
Envejecimiento/psicología , Felicidad , Memoria a Largo Plazo , Recuerdo Mental , Tristeza , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
12.
J Int Neuropsychol Soc ; 24(10): 1121-1124, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30165918

RESUMEN

OBJECTIVES: Healthy individuals often have a leftward and upward attentional spatial bias; however, there is a reduction of this leftward bias with aging. The right hemisphere mediates leftward spatial attention and age-related reduction of right hemispheric activity may account for this reduced leftward bias. The right hemisphere also appears to be responsible for upward bias, and this upward bias might reduce with aging. Alternatively, whereas the dorsal visual stream allocates attention downward, the ventral stream allocates attention upward. Since with aging there is a greater atrophy of the dorsal than ventral stream, older participants may reveal a greater upward bias. The main purpose of this study was to learn if aging influences the vertical allocation of spatial attention. METHODS: Twenty-six young (17 males; mean age 44.62±2.57 years) and 25 healthy elderly (13 males; mean age 72.04±.98 years), right-handed adults performed line bisections using 24 vertical lines (24 cm long and 2 mm thick) aligned with their midsagittal plane. RESULTS: Older adults had a significantly greater upward bias than did younger adults. CONCLUSIONS: Normal upward attentional bias increases with aging, possibly due to an age-related reduction of the dorsal attentional stream that is responsible for the allocation of downward attention. (JINS, 2018, 24, 1121-1124).


Asunto(s)
Atención/fisiología , Envejecimiento Cognitivo/fisiología , Envejecimiento Cognitivo/psicología , Adulto , Anciano , Atrofia , Encéfalo/crecimiento & desarrollo , Encéfalo/patología , Dominancia Cerebral , Femenino , Lateralidad Funcional , Humanos , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana Edad , Vías Nerviosas/crecimiento & desarrollo , Vías Nerviosas/fisiología , Desempeño Psicomotor , Percepción Espacial/fisiología
13.
Neuroimage ; 162: 249-256, 2017 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-28882635

RESUMEN

Tissue composition impacts the interpretation of magnetic resonance spectroscopy metabolite quantification. The goal of applying tissue correction is to decrease the dependency of metabolite concentrations on the underlying voxel tissue composition. Tissue correction strategies have different underlying assumptions to account for different aspects of the voxel tissue fraction. The most common tissue correction is the CSF-correction that aims to account for the cerebrospinal fluid (CSF) fraction in the voxel, in which it is assumed there are no metabolites. More recently, the α-correction was introduced to account for the different concentrations of GABA+in gray matter and white matter. In this paper, we show that the selected tissue correction strategy can alter the interpretation of results using data from a healthy aging cohort with GABA+ measurements in a frontal and posterior voxel. In a frontal voxel, we show an age-related decline in GABA+ when either no tissue correction (R2 = 0.25, p < 0.001) or the CSF-correction is applied (R2 = 0.08, p < 0.01). When applying the α-correction to the frontal voxel data, we find no relationship between age and GABA+ (R2 = 0.02, p = 0.15). However, with the α-correction we still find that cognitive performance is correlated with GABA+ (R2 = 0.11, p < 0.01). These data suggest that in healthy aging, while there is normal atrophy in the frontal voxel, GABA+ in the remaining tissue is not decreasing on average. This indicates that the selection of tissue correction can significantly impact the interpretation of MRS results.


Asunto(s)
Lóbulo Frontal/metabolismo , Interpretación de Imagen Asistida por Computador/métodos , Espectroscopía de Resonancia Magnética/métodos , Ácido gamma-Aminobutírico/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ácido gamma-Aminobutírico/análisis
14.
Cogn Behav Neurol ; 30(1): 30-36, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28323684

RESUMEN

BACKGROUND AND OBJECTIVE: Many patients who have signs of neglect immediately after a right hemisphere stroke remain disabled even when they improve on tests of neglect. Few patients are tested for attentional persistence and fatigue despite their importance in many instrumental activities. To investigate whether stimulus repetition might alter the allocation of attention, we repeatedly tested a patient 16 weeks after she developed hemispatial neglect from a right hemisphere stroke. METHODS: During each of three testing sessions given in 1 day, we asked the patient to bisect 90 lines of two lengths, presented in 30-trial blocks in three locations: left, center, and right of her midsagittal plane, partially counterbalanced across sessions. We adjusted multiple regression analyses and analysis of variance as well as post hoc regression and t tests for persistence in the repeated measures using variance-sample size analysis to estimate self-similarity, a measure related to the fractal correlation dimension. RESULTS: In each session, the patient's line bisections revealed transient leftward bias in her left peripersonal space, and constant rightward bias in her right peripersonal space. Her leftward bias shifted to a rightward bias over repeated trials in her left space. CONCLUSIONS: The patient's left-to-right shift with repeated trials suggests either fatigue from an attempted compensation for leftward inattention or habituation of a contralesional spatial attentional attraction, revealing contralesional left-sided neglect in both the left and right spaces. Future studies are needed to learn if other patients show similar or different deficits with repetition, and how best to treat them.


Asunto(s)
Atención , Fatiga Mental/psicología , Trastornos de la Percepción/rehabilitación , Estimulación Luminosa/métodos , Rehabilitación de Accidente Cerebrovascular/métodos , Femenino , Fractales , Lateralidad Funcional , Habituación Psicofisiológica , Humanos , Persona de Mediana Edad , Trastornos de la Percepción/psicología , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/psicología , Accidente Cerebrovascular/cirugía , Tomografía Computarizada por Rayos X
15.
Cogn Behav Neurol ; 30(4): 176-181, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29256913

RESUMEN

BACKGROUND AND OBJECTIVE: Patients with end-stage renal disease (ESRD) who are receiving dialysis often have cognitive and behavioral changes, including impairments in sustained attention. Impairments in sustained attention appear to be the consequence of right hemisphere dysfunction. Right hemisphere brain networks are also important for the allocation of spatial attention. Therefore, the objective of this study was to learn whether patients with ESRD receiving dialysis might also have a spatial attentional bias. PARTICIPANTS AND METHODS: Eighteen nondemented patients with ESRD receiving dialysis but without any neurologic diseases (age range: 20 to 60 years) and 18 demographically matched healthy controls participated in this study. Participants performed a standard line bisection task using 24 horizontal lines (24 cm long and 2 mm thick) that were sequentially placed at eye level on a white board. RESULTS: Patients receiving dialysis had a significantly greater leftward bias than healthy controls. CONCLUSIONS: Patients with ESRD receiving dialysis appear to have an impaired ability to correctly allocate their spatial attention (spatial neglect). Although the reason for the patients' leftward bias needs to be elucidated, ESRD and/or dialysis may have induced right frontal-subcortical dysfunction that disinhibited the right parietal lobe, producing a left-sided attentional bias. Further studies are needed to test this hypothesis.


Asunto(s)
Lateralidad Funcional/fisiología , Fallo Renal Crónico/complicaciones , Diálisis Renal/métodos , Percepción Espacial/fisiología , Adulto , Sesgo , Femenino , Humanos , Fallo Renal Crónico/patología , Masculino , Persona de Mediana Edad , Adulto Joven
16.
Cogn Behav Neurol ; 29(1): 18-23, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27008246

RESUMEN

BACKGROUND AND OBJECTIVE: Healthy adults often deviate leftward on line bisection tasks (allocentric pseudoneglect) but rightward on body part bisection tasks (egocentric pseudoneglect). People visually estimate distance in peripersonal space by comparing the distance to the length of a body part such as an arm's length (an egocentric reference) or using standard units of distance such as inches (an allocentric reference). Our objective was to learn whether people have pseudoneglect when estimating distances in peripersonal space using egocentric versus allocentric reference frames. METHODS: Twelve healthy participants standing either next to or 5 feet away from a wall were asked to move away from or toward the wall such that their shoulder would be what they judged to be an arm's length or a distance of 1, 2, or 3 feet from the wall. RESULTS: The participants estimated their arm's length more accurately than the standard units of distance (possibly related to learning and practice). Participants were more precise when estimating the length of their left than their right arm. When estimating standard units of distance, participants underestimated the distances on their left side more than on their right. CONCLUSIONS: Our results support the postulate that left pseudoneglect is an allocentric phenomenon related to a hemispheric asymmetry in computing allocentric distances. The participants underestimated 2 and 3 feet, but overestimated 1 foot. This dichotomy may relate to using focused versus distributed attention. The brain mechanisms leading to these asymmetries remain to be determined.


Asunto(s)
Cognición/fisiología , Percepción de Distancia/fisiología , Trastornos de la Percepción/fisiopatología , Anciano , Atención , Femenino , Humanos , Aprendizaje , Masculino , Persona de Mediana Edad , Autoimagen , Percepción Espacial/fisiología
17.
J Int Neuropsychol Soc ; 21(5): 373-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26073665

RESUMEN

Right hemispheric damage (RHD) caused by strokes often induce attentional disorders such as hemispatial neglect. Most patients with neglect over time have a reduction in their ipsilesional spatial attentional bias. Despite this improvement in spatial bias, many patients remain disabled. The cause of this chronic disability is not fully known, but even in the absence of a directional spatial attentional bias, patients with RHD may have an impaired ability to accurately and precisely allocate their spatial attention. This inaccuracy and variable directional allocation of spatial attention may be revealed by repeated performance on a spatial attentional task, such as line bisection (LBT). Participants with strokes of their right versus left (LHD) hemisphere along with healthy controls (HC) performed 24 consecutive trials of 24 cm horizontal line bisections. A vector analysis of the magnitude and direction of deviations from midline, as well as their standard deviations (SD), were calculated. The results demonstrated no significant difference between the LHD, RHD and HC groups in overall spatial bias (mean bisection including magnitude and direction); however, the RHD group had a significantly larger variability of their spatial errors (SD), and made larger errors (from midline) than did the LHD and HC groups. There was a curvilinear relationship between the RHD participants' performance variability and their severity of their inaccuracy. Therefore, when compared to HC and LHD, the RHD subjects' performance on the LBT is more variable and inaccurate.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/etiología , Daño Encefálico Crónico/complicaciones , Lateralidad Funcional/fisiología , Percepción Espacial/fisiología , Adulto , Anciano , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
18.
Neurocase ; 21(3): 345-50, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-24611440

RESUMEN

The semantic variant of primary progressive aphasia (PPA-S) is characterized by impairments in confrontation naming and single word comprehension. Although episodic memory may be relatively spared, there can be impairment in verbal learning tasks. We report a patient with PPA-S and impaired verbal learning who was tested to learn if when provided with semantic categories, her learning would improve. A 70-year-old right-handed woman with a 2-year history of progressive difficulties with word finding, naming, and memory was tested for language and memory deficits using the Hopkins Verbal Learning Test-Revised (HVLT-R). She was then retested with the HVLT-R after being provided with the three semantic categories to which these words belonged. Confrontation naming was impaired on the Boston Naming Test. Sentence repetition was normal. Comprehension testing with word picture matching and sentence comprehension was normal. On a test of semantic associations, Pyramids and Palm Trees, she was impaired. She was also impaired on tests of verbal learning (HVLT-R) (total: 13) but not recall. When a different version of the HVLT-R was given with the semantic categories of the words given beforehand, her scores improved (total: 26). This patient with PPA-S had an impairment of verbal learning, but not delayed recall. When given a semantic category cue beforehand, her verbal learning performance improved. This observation suggests that this patient did not spontaneously use semantic encoding. Using a semantic cueing strategy may help other patients with PPA-S improve their capacity for verbal learning.


Asunto(s)
Afasia Progresiva Primaria/rehabilitación , Terapia Cognitivo-Conductual/métodos , Señales (Psicología) , Semántica , Aprendizaje Verbal , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Pruebas Neuropsicológicas , Lóbulo Temporal/patología
19.
Neurocase ; 21(4): 501-8, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25073971

RESUMEN

Global attention requires disengagement from focal elements of stimuli. Since people with Parkinson's disease (PD) may reveal impaired disengagement, this study attempted to learn if people with PD may be impaired at allocating global attention. Healthy adults and people with PD attempted to bisect lines of uniform thickness and lines composed of two segments of unequal thickness and length. When the longer line segment was to the right of the shorter segment, the group with PD demonstrated an increased deviation toward the longer segment, supporting the postulate that people with PD have an impaired ability to disengage focal attention and engage global spatial attention.


Asunto(s)
Atención , Enfermedad de Parkinson/psicología , Trastornos de la Percepción/psicología , Percepción Espacial , Anciano , Femenino , Humanos , Masculino , Enfermedad de Parkinson/complicaciones , Trastornos de la Percepción/etiología , Estimulación Luminosa
20.
J Relig Health ; 54(3): 1091-8, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25245631

RESUMEN

Secular portraits are likely to show more of the left than right side of the face (hemiface). Prior research has shown that emotions are more strongly expressed by the left hemiface. In addition, the valence theory of emotion proposes that the right hemisphere is dominant for mediating negative emotions, and the left hemisphere for positive emotions. Since religious art depicting a scene such as the Resurrection of Jesus is more likely to be associated with positive emotions, we postulated that there would be a significant smaller percentage number of artistic works of the Resurrection that reveal the left side of the face of Jesus than in those art works portraying the Crucifixion. Thus, we analyzed artistic portrayals of the Resurrection of Jesus and compared them to the artistic scenes of the Crucifixion. This analysis revealed that the left side of the face of Jesus is less commonly depicted in portraits of the Resurrection than the Crucifixion. In addition, both the right hemiface, and forward-facing faces were also more commonly portrayed in painting of the Resurrection than the Crucifixion. Whereas this right-left hemiface, Resurrection-Crucifixion dichotomy may be related to right-left hemispheric difference in the mediation of emotional valence other factors such as agency, action-intention, and biblical text may have influenced these differences.


Asunto(s)
Arte/historia , Emociones , Asimetría Facial/historia , Personajes , Cara , Expresión Facial , Historia Antigua , Humanos
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