Presymptomatic Testing for Huntington's Disease in Mexico: 28 Years of Experience.

INTRODUCTION: Huntington's disease (HD) is a genetic neurodegenerative disorder with dominant inheritance. Our center in Mexico City has offered presymptomatic testing (PT) since 1995. OBJECTIVE: To describe the main clinical and demographic characteristics of at-risk HD individuals who applied to the PT program, the reasons for seeking it, and the molecular results. METHODS: A cross-sectional study was conducted with sociodemographic and clinical data of all PT applicants from 1995-2023. Reasons for seeking PT were assessed using a modified questionnaire. In addition, anxiety, and depressive symptoms before and after PT were evaluated with Beck's instruments; cognitive impairment (CI) was assessed with the Mini-Mental State Examination (MMSE) and molecular results. RESULTS: 214 people applied for PT (2.1% of the at-risk population identified in our center); 63% were women (mean age of 37.11 years). 204 (95.3%) were accepted and 190 received results. 70% indicated that the main reason for applying for PT was to inform their offspring about the risk of inheriting HD. Significant differences were observed in the reasons for seeking PT by age group. Although some subjects received treatment, Beck's instrument scores did not indicate special attention or pharmacological treatment. The MMSE showed probable CI in 20 subjects. Of those who received results, 37% were carriers of a full penetrance allele. CONCLUSION: Our center has the only formal PT program for HD in Mexico. The reasons for seeking PT are varied and age-related. Although PT is offered to all subjects at risk for HD, uptake remains low.

Teleneuropsychology intervention in phonological awareness for children with specific learning disorder with reading and mathematical difficulties.

Specific learning disorder (SLD) is a neurodevelopmental disorder that affects 5-15% of school-aged children worldwide. Often, difficulties in reading (SLD-RD) and mathematics (SLD-MD) occur together. Deficits in phonological awareness (PA) have been identified as the common factor between the two difficulties. Intervention in PA has been shown to be effective in SLD-RD; however, it is not clear whether it is also effective in SLD-MD. Neuropsychological intervention is usually conducted face-to-face, but when the patient is in a remote location or during extraordinary situations such as the COVID-19 pandemic, tele neuropsychology (TeleNP) may be a suitable alternative. The objective of this study was to evaluate the efficacy of a telerehabilitation program for PA to improve math skills in children with SLD-RD/SLD-MD. The study had an N-of-1 SCED design, and included six children aged 10-12 years with SLD-RD/SLD-MD. After four baseline measurements with an arithmetic verification paradigm, they were treated with TeleNP-PA. The effect on each participant was evaluated using visual analysis and the reliable change index. After the intervention, all participants showed improvement in arithmetic tasks, suggesting that the PA intervention had a positive influence on these skills.

SARS-CoV-2's brain impact: revealing cortical and cerebellar differences via cluster analysis in COVID-19 recovered patients.

BACKGROUND: COVID-19 is a disease known for its neurological involvement. SARS-CoV-2 infection triggers neuroinflammation, which could significantly contribute to the development of long-term neurological symptoms and structural alterations in the gray matter. However, the existence of a consistent pattern of cerebral atrophy remains uncertain. OBJECTIVE: Our study aimed to identify patterns of brain involvement in recovered COVID-19 patients and explore potential relationships with clinical variables during hospitalization. METHODOLOGY: In this study, we included 39 recovered patients and 39 controls from a pre-pandemic database to ensure their non-exposure to the virus. We obtained clinical data of the patients during hospitalization, and 3 months later; in addition we obtained T1-weighted magnetic resonance images and performed standard screening cognitive tests. RESULTS: We identified two groups of recovered patients based on a cluster analysis of the significant cortical thickness differences between patients and controls. Group 1 displayed significant cortical thickness differences in specific cerebral regions, while Group 2 exhibited significant differences in the cerebellum, though neither group showed cognitive deterioration at the group level. Notably, Group 1 showed a tendency of higher D-dimer values during hospitalization compared to Group 2, prior to p-value correction. CONCLUSION: This data-driven division into two groups based on the brain structural differences, and the possible link to D-dimer values may provide insights into the underlying mechanisms of SARS-COV-2 neurological disruption and its impact on the brain during and after recovery from the disease.

Relationship between APOE, PER2, PER3 and OX2R Genetic Variants and Neuropsychiatric Symptoms in Patients with Alzheimer's Disease.

Alzheimer's disease (AD) is characterized by the presence of neuropsychiatric or behavioral and psychological symptoms of dementia (BPSD). BPSD have been associated with the APOE_ε4 allele, which is also the major genetic AD risk factor. Although the involvement of some circadian genes and orexin receptors in sleep and behavioral disorders has been studied in some psychiatric pathologies, including AD, there are no studies considering gene-gene interactions. The associations of one variant in PER2, two in PER3, two in OX2R and two in APOE were evaluated in 31 AD patients and 31 cognitively healthy subjects. Genotyping was performed using real-time PCR and capillary electrophoresis from blood samples. The allelic-genotypic frequencies of variants were calculated for the sample study. We explored associations between allelic variants with BPSD in AD patients based on the NPI, PHQ-9 and sleeping disorders questionnaires. Our results showed that the APOE_ε4 allele is an AD risk variant (p = 0.03). The remaining genetic variants did not reveal significant differences between patients and controls. The PER3_rs228697 variant showed a nine-fold increased risk for circadian rhythm sleep-wake disorders in Mexican AD patients, and our gene-gene interaction analysis identified a novel interaction between PERIOD and APOE gene variants. These findings need to be further confirmed in larger samples.

Multi-site, multi-country randomized clinical trial of an acute traumatic brain injury caregiver transition assistance program in Latin America.

BACKGROUND: Individuals with traumatic brain injury (TBI) in Latin America experience high levels of disability and extremely poor functional outcomes, and their informal caregivers play a key role in their rehabilitation and care. OBJECTIVE: To improve TBI rehabilitation through stronger informal caregiving, this study developed and evaluated an evidence-based and culturally appropriate Transition Assistance Program (TAP) for informal caregivers of individuals with TBI in Latin America, specifically targeting the time period before and after the transition from hospital to home. METHODS: A sample of 89 people with a new TBI and their primary informal caregiver (n = 178) was recruited from two hospitals in Mexico City, Mexico, and in Cali, Colombia. Caregivers were randomly assigned to either the TAP group or to a control group receiving the standard care provided by the hospital. Caregivers completed measures of depression and burden, and individuals with TBI completed measures of depression and self-perceived burden on caregivers before hospital discharge and at 2- and 4-month follow ups. RESULTS: Caregivers in the TAP group reported significantly lower burden than those in the control group and marginally lower depression. Individuals with TBI whose caregivers had been in the TAP group reported significantly lower depression than those whose caregivers had been in the control group, and a non-significant but lower self-perceived burden on their caregivers. CONCLUSION: The results suggest that the TAP has strong potential to benefit both TBI caregivers and individuals with TBI during the transition from acute TBI hospitalization to home in Latin America, generally showing small-or medium-sized effects on key outcomes.

Quality of life and mental health in multiple sclerosis patients during the COVID-19 Pandemic.

BACKGROUND: The COVID-19 pandemic had a profound impact on mental health symptoms and quality of life (QoL) in the general population due to necessary public health restrictions such as social distancing. The psychosocial effect of the pandemic on vulnerable groups such as people living with Multiple Sclerosis (PwMS) has been scarcely explored in countries with additional socioeconomical burdens such as access to healthcare disparities METHODS: A questionnaire exploring sociodemographic variables, quality of life, mental health determinants and sleep quality was applied to 92 PwMS to explore changes prior and during the pandemic regarding these domains RESULTS: 58.8% of the subjects were female, median age was 37.1 (± 8.5) years and relapsing-remitting MS was the predominant clinical subtype (83.5%). Unemployment rate significantly increased during the pandemic (12.3% vs 27.8%; p= 0.001). Only 46.4% received medical follow-up care during the pandemic. QoL was affected predominantly due to limitations in instrumented activities of daily life (IADL). Neuropsychiatric symptoms, requiring healthcare during the pandemic, anxiety prior to the pandemic and restricted IADL were predictors of MS-related physical impact worsening, while decreased physical/emotional wellbeing selfcare, neuropsychiatric symptoms, bad sleep quality, anxiety prior to the pandemic and restricted non-instrumental ADL predicted aggravation of MS-related psychological impact measured by the MSIS-29. Curiously, specific items regarding anxiety were more prevalent prior to the pandemic (anxious mood; p=0.02, helplessness; p=0.01), sleep problems; p=0.001 and cardiovascular symptoms; p=0.001, nevertheless, stability was observed for most items. Importantly, 77.3% of PwMS reported at least one neuropsychiatric symptom CONCLUSION: The deleterious effects of the COVID-19 pandemic on psychosocial wellbeing in PwMS, QoL and mental health outcomes are frequently overseen in vulnerable populations such as PwMS. Albeit the limitations of this study, our results may help implement policies that prevent negative outcomes on psychosocial wellbeing due to public health measures (e.g., social distancing) in MS and other neurological diseases that inexorably need constant follow-up.

Attentional impairment in Parkinson's disease is modulated by side of onset: Neurophysiological evidence.

OBJECTIVE: Neurophysiological studies exploring involuntary attention have reported that electroencephalographic (EEG) measures can indicate impaired neural processing from initial stages of Parkinson's disease (PD). Since involuntary attention is regulated by right hemisphere networks and PD generally initiates its motor symptomatology unilaterally, whether involuntary attention is impaired depending on the onset side of PD remains unknown. METHODS: We compared the neurophysiological correlates of involuntary attention among a PD group with left-side onset (L-PD), a PD group with right-side onset (R-PD) symptomatology, and a healthy control group (HC). All participants performed an auditory involuntary attention task while a digital EEG was recorded. RESULTS: Our main finding was a reduction both in the P3a amplitude and evoked delta-theta phase alignment in the L-PD group compared to the HC. Further, there was a significant correlation between P3a amplitude and disease duration in the R-PD, but not in the L-PD group. Behaviorally, both clinical groups, and in particular L-PD, showed reduced orientation towards novel stimuli, and no reduction of distraction effects during the experiment. CONCLUSIONS: Our results indicate that involuntary attention is differentially impaired in patients with left side onset of symptoms. Involuntary attention impairment might be present from initial stages of left onset PD and become progressively compromised in patients with right onset PD. SIGNIFICANCE: The onset side of symptomatology should be considered for attentional impairment in PD.

Attitudes about involvement in hypothetical clinical trial protocols in Mexican and Mexican-American at risk for autosomal dominant Alzheimer's disease.

BACKGROUND: The enrollment into clinical trials of persons at risk for autosomal dominant Alzheimer's disease (ADAD) in whom the onset of disease can be accurately predicted facilitates the interpretation of outcomes (e.g., biomarkers, treatment efficacy). Attitudes toward involvement in such studies are biased by intrinsic cultural and social characteristics. Our objective was to study how demographic factors such as country of residence, age, sex, schooling, parenthood, and urbanization affect attitudes towards participation in hypothetical clinical trials in Mexican families at risk for ADAD living either in Mexico or in the United States. METHODS: Participants were 74 members of different families known to harbor an ADAD mutation living in Mexico (n = 50) or in the United States (n = 24). Participants were asked, in a written questionnaire, their interest in participating in four hypothetical clinical trial scenarios of increasing perceived invasiveness. The questionnaire then asked about their willingness should there be a 50% chance of being assigned to a placebo group. The influences of demographic variables on decisions were performed using Wilcoxon rank-sum for continuous variables and Fisher's exact test for categorical variables. RESULTS: Participants who live in Mexico, who have or plan to have children, who do not attend or do not plan to attend school, and who live in rural areas gave more positive responses regarding their willingness to participate compared to those living in the U.S. The 50% chance of being in a placebo group increased the willingness to participate for family members living in Mexico. The main reason for participation was to help future generations, while the main reasons for refusal were not wanting to undergo genetic testing and consideration of adverse effects. CONCLUSIONS: We found a higher level of willingness to participate in clinical trials among persons living in rural Mexico and our data suggest that altruism towards future generations is a major motivation, though this was balanced against concerns regarding side effects. Our results emphasize the importance of sharing information and assessing its understanding in potential participants with diverse backgrounds in the nature of ADAD and regarding the design of clinical trials prior to their enrollment in such studies.

Las orexinas como biomarcadores para demencia tipo Alzheimer y relación con síntomas neuropsiquiátricos / Orexins as biomarkers for Alzheimer dementia and their relationship with neuropsychiatric symptoms

RESUMEN: Los biomarcadores más estudiados en la demencia tipo Alzheimer (DA) son los niveles elevados de Aβ42 y de proteína Tau en líquido cefalorraquídeo. Dada la complejidad de la sintomatología cognitiva y síntomas neuropsiquiátricos (SNP) de esta patología, algunos estudios recientes proponen sustancias como las orexinas, como blanco terapéutico de DA y SNP. El presente trabajo tiene como objetivo revisar publicaciones científicas recientes que hayan analizado la asociación entre orexinas, SNP y DA en humanos, algunos modelos animales y que hayan evaluado a las orexinas como posibles biomarcadores tanto para investigación como en el área clínica. En esta revisión también se describen los estudios que sugieren a las orexinas como un posible biomarcador en la DA, dada su relación con el Aβ42 y la proteína Tau, y otros estudios que las asocian con presencia de SNP, especialmente alteración del sueño. Se plantea la hipótesis de que la presencia de SNP en DA se asocia con las orexinas, debido a que este sistema influye en el funcionamiento hipotalámico y de forma indirecta en áreas cerebrales que regulan el comportamiento. Sin embargo, aún falta mayor investigación, principalmente de estudios longitudinales para conocer claramente la influencia de las orexinas en los SNP.

ABSTRACT The most studied biomarkers in Alzheimer's dementia (AD) are elevated levels of Aβ42 and Tau protein in cerebrospinal fluid. Given the complexity of the cognitive symptomatology and neuropsychiatric symptoms (NPS) of this pathology, some recent studies propose substances such as orexins as a therapeutic target for AD and NPS. The present work aims to review recent scientific publications that have analyzed the association between orexins, PNS and AD in humans. There are some animal models that have evaluated orexins as possible biomarkers both for research and in the clinical area. This review also describes studies that suggest orexins as possible biomarkers in AD, given their relationship with Aβ42 and Tau protein, and other studies that associate them with the presence of SNPs, especially sleep disturbance. It is hypothesized that the presence of SNPs in AD is associated with orexins, because this system influences hypothalamic functioning and indirectly in brain areas that regulate behavior. However, further research is still lacking, mainly longitudinal studies to clearly know the influence of orexins on SNPs.

Cognitive impairment in the co-occurrence of alcohol dependence and major depression: neuropsychological assessment and event-related potentials analyses.

To evaluate the putative detrimental effect of Major Depressive Disorder (MDD) on the cognitive impairment associated with Alcohol Dependence (AD), we contrasted the neuropsychological profile and behavioral responses of AD subjects, MDD individuals, and in those with a co-occurring AD-MDD diagnosis (DD). Patients and healthy subjects completed a comprehensive neuropsychological battery and were recorded for P200, P300, and N450 event-related potentials during memory and Stroop tasks. AD subjects exhibited a generalized detrimental neuropsychological performance; in contrast, in MDD individuals, impairment was limited to discrete domains. Notably, the deficits were distinctive in DD cases. A P200 increased amplitude in MDD, a decrease in P300 amplitude in AD, and increased latency of P300 in DD patients were the overt electrophysiological abnormalities identified. Dual patients also exhibited a distinct pattern of behavioral responses, particularly apparent during high-demand cognitive tasks. Specific ERP adjustments were associated with the short-term fluoxetine treatment in DD and MDD subjects; the SSRI also improved altered baseline performance in learning and cognitive flexibility in DD subjects. In conclusion, the neuropsychological and behavioral alterations detected in the co-occurrence of AD-MDD did not seem to be merely the sum of the negative contributions of the independent disorders.

Anosognosia in Amnestic Mild Cognitive Impairment Is Related to Diminished Hippocampal Volume Comparable to Alzheimer's Disease Dementia: Preliminary MRI Findings.

Although the presence of anosognosia in amnestic mild cognitive impairment (aMCI) may be predictive of conversion to Alzheimer's disease (AD), little is known about its neural correlates in AD and aMCI. Four different groups were compared using volumetric and diffusion magnetic resonance imaging metrics in regions of interest (hippocampus and cingulum cortex gray matter, cingulum bundle white matter): aMCI subjects with anosognosia (n = 6), aMCI subjects without anosognosia (n = 12), AD subjects with anosognosia (n = 6), and AD subjects without anosognosia (n = 9). aMCI subjects with anosognosia displayed a significantly lower gray matter density (GMD) in the bilateral hippocampus than aMCI subjects without anosognosia, which was accounted for by bilateral hippocampal differences. Furthermore, we identified that the mean hippocampal gray matter density of aMCI subjects with anosognosia was not statistically different than that of AD subjects. The groups of aMCI and AD subjects with anosognosia also displayed a lower GMD in the bilateral cingulum cortex compared to subjects without anosognosia, but these differences were not statistically significant. No statistically significant differences were found in the fractional anisotropy or mean diffusivity of the hippocampus or cingulum between subjects with and without anosognosia in aMCI or AD groups. While these findings are derived from a small population of subjects and are in need of replication, they suggest that anosognosia in aMCI might be a useful clinical marker to suspect brain changes associated with AD neuropathology.

Working Memory Impairment as an Endophenotypic Marker in Patients with Schizophrenia: Failures in Encoding or Maintenance?

INTRODUCTION: Although working memory (WM) dysfunction has been proposed as a schizophrenia (SZ) endophenotype, the specific impaired component (encoding or maintenance) in patients and unaffected relatives remains inconclusive. We compared auditory-verbal and visuospatial WM in patients with SZ, unaffected siblings (USs), and healthy controls under 2 response conditions: immediate (encoding condition) and delayed (maintenance condition). METHODS: We included 22 participants per group, similar in age and gender. Three WM tests (Spatial Span, Backward Digit Span, and Letter-Number Span) were administered under both conditions in a counterbalanced manner to all participants. RESULTS: Poorer performance was found in the SZ group for all tests (p < 0.001). USs showed a better performance than patients, but worse than controls (p < 0.05), except for the Backward Digit Span test, in which their performance was similar to that of the SZ group. The effect of the delayed response in all tasks was not significant in any group. CONCLUSION: Our results indicate that WM impairment, including auditory-verbal and visuospatial modalities, corresponds to a stable feature of the disease as it is present in USs, thus confirming its potential endophenotypic property in SZ patients. No effect of the delayed response was observed, suggesting failures in encoding in both patients and USs.

A Multi-Site Study of Traumatic Brain Injury in Mexico and Colombia: Longitudinal Mediational and Cross-Lagged Models of Family Dynamics, Coping, and Health-Related Quality of Life.

Latin America has high rates of traumatic brain injury (TBI), yet reduced mental and physical health outcomes due to limited rehabilitation services. To understand the psychosocial adjustment process in TBI patients in Latin America, the incorporation of cultural values including family-based variables is imperative. The current study examined relations among healthy family dynamics, coping, and mental and physical health related quality of life (HRQL) among a sample of TBI patients across three sites and two countries over the first 4 months post-injury. A sample of 109 acute TBI patients from Mexico and Colombia were recruited, and a series of longitudinal mediation and cross-lag panel analyses were run. Mental and physical HRQL were positively associated with each other, as well as healthy family dynamics and coping. Coping partially mediated the effects of healthy family dynamics on both mental and physical HRQL. Family dynamics showed the strongest cross-lag relationships with coping going from 2 months to 4 months. Similarly, coping showed the strongest cross-lag relationships with both mental and physical HRQL going from baseline to 2 months. Results provide empirical support for the importance of a rehabilitation workforce that has been trained in and can effectively implement family-based interventions for individuals with TBI in Latin America.

Relationship Satisfaction and Depression After Traumatic Brain Injury: An Actor-Partner Interdependence Model of Patients and Caregivers in Mexico and Colombia.

OBJECTIVE: Traumatic brain injury represents a major public health concern, particularly in low- and middle-income countries like in Latin America. Family members are often caregivers for individuals with traumatic brain injury, which can result in significant stress. Research is needed to examine depression and quality of the caregiving relationship in these dyads. This study examined relationship quality and depression longitudinally after traumatic brain injury within the caregiving relationship. DESIGN: Dyads (N = 109) composed of individuals with traumatic brain injury and their caregivers were recruited from three hospitals in Mexico and Colombia. They self-reported depression and relationship satisfaction during hospitalization and at 2 and 4 mos after hospitalization. RESULTS: A 2-lag Actor Partner Interdependence Model demonstrated that patients and caregivers reporting high relationship satisfaction at baseline experienced lower depression 2 mos later, which then predicted higher caregiver relationship satisfaction at 4 mos. Moreover, patients with high relationship satisfaction at baseline had caregivers with lower depression at 2 mos, which was then associated with patients' higher satisfaction at 4 mos. CONCLUSIONS: Within individuals with traumatic brain injury and caregivers, depression and relationship satisfaction seem to be inversely related. Furthermore, patients' and caregivers' depression and relationship satisfaction impact each other over time, demonstrating interdependence within the caregiving relationship.

Auditory mismatch detection, distraction, and attentional reorientation (MMN-P3a-RON) in neurological and psychiatric disorders: A review.

Involuntary attention allows for the detection and processing of novel and potentially relevant stimuli that lie outside of cognitive focus. These processes comprise change detection in sensory contexts, automatic orientation toward this change, and the selection of adaptive responses, including reorientation to the original goal in cases when the detected change is not relevant for task demands. These processes have been studied using the Event-Related Potential (ERP) technique and have been associated to the Mismatch Negativity (MMN), the P3a, and the Reorienting Negativity (RON) electrophysiological components, respectively. This has allowed for the objective evaluation of the impact of different neuropsychiatric pathologies on involuntary attention. Additionally, these ERP have been proposed as alternative measures for the early detection of disease and the tracking of its progression. The objective of this review was to integrate the results reported to date about MMN, P3a, and RON in different neurological and psychiatric disorders. We included experimental studies with clinical populations that reported at least two of these three components in the same experimental paradigm. Overall, involuntary attention seems to reflect the state of cognitive integrity in different pathologies in adults. However, if the main goal for these ERP is to consider them as biomarkers, more research about their pathophysiological specificity in each disorder is needed, as well as improvement in the general experimental conditions under which these components are elicited. Nevertheless, these ERP represent a valuable neurophysiological tool for early detection and follow-up of diverse clinical populations.

Theory of mind impairment in Huntington's disease patients and their relatives.

Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. METHODS We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. RESULTS The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. CONCLUSION The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

Theory of mind impairment in Huntington's disease patients and their relatives / Déficits en teoría de la mente en pacientes con enfermedad de Huntington y sus familiares

ABSTRACT Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. Methods: We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. Results: The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. Conclusion: The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

RESUMEN La enfermedad de Huntington (EH) es una enfermedad genética autosómica dominante caracterizada por trastornos del movimiento, deterioro cognitivo y síntomas psiquiátricos. Los familiares de las personas con EH experimentan gran carga dado que los pacientes sufren de conducta social alterada y deterioro de relaciones interpersonales. La Teoría de la mente (ToM) consiste en la habilidad para atribuir estados mentales (a uno mismo o a otros). Se piensa que déficits en ToM tienen un rol en los cambios en empatia y en las dificultades interpersonales que los pacientes con EH enfrentan. Métodos: Condujimos un estudio transversal para comparar el desempeño en puntajes de tareas de ToM en pacientes con EH leve a moderada, sus familiares (pareja o familiar en riesgo con prueba genética negativa) y controles sanos. Se excluyó a sujetos con demencia o depresión. La batería de pruebas de ToM incluyó versiones en español de la prueba de lectura de la mente en los ojos (RMET), Historias Extrañas de Happé (subpruebas Social y Física) y Hinting Task. Resultados: La serie consistió de 12 pacientes con EH, 12 familiares y 12 controles. Los pacientes con EH mostraron puntajes menores de tareas de ToM afectiva que los controles (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Los puntajes de tareas de ToM cognitiva fueron inferiores a los controles en los pacientes con EH (Historias Sociales de Happé 9 [2.6] vs 13 [1.9], p = 0.001; Hinting task 13.6 [3.4] vs 175 [4.0], p = 0.009). En la Hinting task los familiares de pacientes con EH mostraron puntajes inferiores que los de los controles (13 [3.2] vs 175 [4.0], p = 0.009) y puntajes similares a aquellos de los controles en el resto de la batería. Conclusión: Los pacientes con EH con enfermedad leve a moderada y sus familiares muestran déficits en tareas de ToM.

Perceived stress, resilience, and health-related quality of life among Parkinson's disease caregivers in Mexico.

The stress process model of caregiving posits that caregivers' internal psychosocial resources may serve as buffers between the stress associated with caregiving and well-being. Empirical support for the stress process model exists for several caregiving contexts, but little research has investigated the Parkinson's disease caregiving experience in Mexico. Using a cross-sectional, correlational design, the objective of this study was to examine whether resilience moderates the relation between perceived stress and health-related quality of life (HRQOL) among Parkinson's disease caregivers in Mexico. Data were collected from April 2015 to February 2016 during outpatient neurology appointments in Mexico City, Mexico. Participants included informal caregivers (N = 95) for a family member with Parkinson's disease. Participants completed a battery of questionnaires assessing their level of perceived stress, resilience, and HRQOL. Regression analyses indicated that resilience moderated the inverse relation between perceived stress and mental HRQOL. However, contrary to hypotheses, resilience did not moderate the relation between stress and physical HRQOL. Findings shed light on resilience as a potential protective factor for mental HRQOL among Parkinson's disease caregivers in Mexico and indicate that resilience may be beneficial to target in mental health promotion interventions.

A mixed-methods study of cultural beliefs about dementia and genetic testing among Mexicans and Mexican-Americans at-risk for autosomal dominant Alzheimer's disease.

Trials to prevent autosomal dominantly inherited Alzheimer's disease (ADAD) are critical and timely. However, cultural beliefs about AD and genetic testing may preclude informed consent and participation, especially among racial/ethnic minorities. This mixed-methods study examines cultural beliefs about AD and genetic screening among at-risk populations of Mexican heritage. We surveyed 86 Mexican and 37 Mexican-American family members of patients with ADAD and interviewed 18 respondents in Mexico to explore perceptions and knowledge regarding AD and genetic testing. While most respondents understood that AD is inherited in their families, they also had limited understanding of the genetic mechanisms behind AD. Many believed that AD is a normal part of aging or that it is a mental illness caused by bad habits. However, beliefs that AD is caused by a curse or God's will were uncommon. The interviews demonstrated that very few at-risk respondents understood their own risk for harboring the mutation causing AD in their family. Once informed, most expressed a strong interest in genetic testing, largely motivated by the desire to be better prepared for the development of AD. Health professionals treating and investigators enrolling members from families with ADAD cannot assume that they fully understand the nature of the illness; therefore, providers should provide comprehensive information about ADAD and genetic testing.

Multivariate Base Rates of Low Scores on Tests of Learning and Memory Among Latino Adult Populations.

OBJECTIVE: To determine the prevalence of low scores for two neuropsychological tests with five total scores that evaluate learning and memory functions. METHOD: N = 5402 healthy adults from 11 countries in Latin America and the commonwealth of Puerto Rico were administered the Rey-Osterrieth Complex Figure (ROCF) and the Hopkins Verbal Learning Test (HVLT-R). Two-thirds of the participants were women, and the average age was 53.5 ± 20.0 years. Z-scores were calculated for ROCF Copy and Memory scores and HVLT-R Total Recall, Delayed Recall, and Recognition scores, adjusting for age, age2, sex, education, and interaction variables if significant for the given country. Each Z-score was converted to a percentile for each of the five subtest scores. Each participant was categorized based on his/her number of low scoring tests in specific percentile cutoff groups (25th, 16th, 10th, 5th, and 2nd). RESULTS: Between 57.3% (El Salvador) and 64.6% (Bolivia) of the sample scored below the 25th percentile on at least one of the five scores. Between 27.1% (El Salvador) and 33.9% (Puerto Rico) scored below the 10th percentile on at least one of the five subtests. Between 5.9% (Chile, El Salvador, Peru) and 10.3% (Argentina) scored below the 2nd percentile on at least one of the five scores. CONCLUSIONS: Results are consistent with other studies that found that low scores are common when multiple neuropsychological outcomes are evaluated in healthy individuals. Clinicians should consider the higher probability of low scores when evaluating learning and memory using various sets of scores to reduce false-positive diagnoses of cognitive deficits.