Emotion recognition in Huntington's disease: A systematic review

Emotion recognition in amyotrophic lateral sclerosis in a dynamic environment

OBJECTIVE

The aim of our study was to measure the ability of ALS patients to process dynamic facial expressions as compared to a control group of healthy subjects and to correlate this ability in ALS patients with neuropsychological, clinical and neurological measures of the disease.

METHODS

Sixty-three ALS patients and 47 healthy controls were recruited. All the ALS patients also underwent i) the Geneva Emotion Recognition Test (GERT) in which ten actors express 14 types of dynamic emotions in brief video clips with audio, ii) the Edimburgh Cognitive and Behavioral ALS Screen (ECAS) test; iii) the ALS Functional Rating Scale Revised (ALSFRS-R) and iv) the Medical Research Council (MRC) for the evaluation of muscle strength. All the healthy subjects enrolled in the study underwent the GERT.

RESULTS

The recognition of irritation and pleasure was significantly different between ALS patients and the control group. The amusement, despair, irritation, joy, sadness and surprise had been falsely recognized differently between the two groups. Specific ALS cognitive impairment was associated with bulbar-onset phenotype (OR = 14,3889; 95%CI = 3,96-52,16). No association was observed between false emotion recognition and cognitive impairment (F(1,60)=,56,971, p=,45,333). The number of categorical errors was significantly higher in the ALS patients than in the control group (27,66 ± 7,28 vs 17,72 ± 5,29; t = 8723; p = 0.001).

CONCLUSIONS

ALS patients show deficits in the dynamic processing of a wide range of emotions. These deficits are not necessarily associated with a decline in higher cognitive functions: this could therefore lead to an underestimation of the phenomenon.

Huntington study group's neuropsychology working group position on best practice recommendations for the clinical neuropsychological evaluation of patients with Huntington disease

Objective: Neuropsychological evaluation is critical to detection and management of cognitive and neuropsychiatric changes associated with Huntington disease (HD). Accurate assessment of non-motor complications of HD is critical given the prominent impact on functional disability, frequently commensurate with or exceeding that of motor symptoms. The increasing emphasis on developing disease-modifying therapies targeting cognitive decline in HD requires consensus on clinical neuropsychological assessment methods. The Neuropsychology Working Group (NPWG) of the Huntington Study Group (HSG) sought to provide evidence and consensus-based, practical guidelines for the evaluation of cognitive and neuropsychiatric symptoms associated with HD. Method: The NPWG recruited a multi-disciplinary group of neuropsychologists, neurologists, and psychiatrists to inform best practices in assessing, diagnosing, and treating the non-motor symptoms in HD. A review was circulated among the NPWG, and in an iterative process informed by reviewed literature, best practices in neuropsychological evaluation of patients with HD were identified. Results: A brief review of the available literature and rational for a clinical consensus battery is offered. Conclusion: Clinical neuropsychologists are uniquely positioned to both detect and characterize the non-motor symptoms in HD, and further, provide neurologists and allied health professions with clinically meaningful information that impacts functional outcomes and quality of life. The NPWG provides guidance on best practices to clinical neuropsychologists in this statement. A companion paper operationalizing clinical application of previous research-based non-motor diagnostic criteria for HD is forthcoming, which also advises on non-motor symptom screening methods for the non-neuropsychologist working with HD.

Pharmacological characterization of SAGE-718, a novel positive allosteric modulator of N-methyl-d-aspartate receptors

BACKGROUND AND PURPOSE

Select neuroactive steroids tune neural activity by modulating excitatory and inhibitory neurotransmission, including the endogenous cholesterol metabolite 24(S)-hydroxycholesterol (24(S)-HC), which is an N-methyl-d-aspartate (NMDA) receptor positive allosteric modulator (PAM). NMDA receptor PAMs are potentially an effective pharmacotherapeutic strategy to treat conditions associated with NMDA receptor hypofunction.

EXPERIMENTAL APPROACH

Using in vitro and in vivo electrophysiological recording experiments and behavioural approaches, we evaluated the effect of SAGE-718, a novel neuroactive steroid NMDA receptor PAM currently in clinical development for the treatment of cognitive impairment, on NMDA receptor function and endpoints that are altered by NMDA receptor hypoactivity and assessed its safety profile.

KEY RESULTS

SAGE-718 potentiated GluN1/GluN2A-D NMDA receptors with equipotency and increased NMDA receptor excitatory postsynaptic potential (EPSP) amplitude without affecting decay kinetics in striatal medium spiny neurons. SAGE-718 increased the rate of unblock of the NMDA receptor open channel blocker ketamine on GluN1/GluN2A in vitro and accelerated the rate of return on the ketamine-evoked increase in gamma frequency band power, as measured with electroencephalogram (EEG), suggesting that PAM activity is driven by increased channel open probability. SAGE-718 ameliorated deficits due to NMDA receptor hypofunction, including social deficits induced by subchronic administration of phencyclidine, and behavioural and electrophysiological deficits from cholesterol and 24(S)-HC depletion caused by 7-dehydrocholesterol reductase inhibition. Finally, SAGE-718 did not produce epileptiform activity in a seizure model or neurodegeneration following chronic dosing.

CONCLUSIONS AND IMPLICATIONS

These findings provide strong evidence that SAGE-718 is a neuroactive steroid NMDA receptor PAM with a mechanism that is well suited as a treatment for conditions associated with NMDA receptor hypofunction.

An Exploratory Pilot Study of Neuropsychological Performance in Two Huntington Disease Centers of Excellence Clinics

OBJECTIVES

To describe the characteristics of patients receiving a clinical referral for neuropsychological evaluation in two Huntington's Disease Society of America Centers of Excellence (HDSA COE). In this exploratory pilot study, we used an empirically supported clinical neuropsychological battery to assess differences in cognitive performance between premanifest and manifest HD patient groups (compared with each other and normative expectations).

METHOD

Clinical data from 76 adult genetically confirmed patients referred for neuropsychological evaluations was retrospectively collected from two HDSA COEs. ANOVA and Chi-square tests were used to compare variables between pre-manifest (n = 14) and manifest (n = 62) groups for demographic, cognitive, neuropsychiatric, and disease severity variables.

RESULTS

Our clinics serviced a disproportionate number of motor manifest patients. Six measures were excluded from analyses due to infrequent administration. The full WAIS-IV Digit Span was disproportionately administered to the manifest group. The premanifest group showed stronger cognitive performance with effect sizes in the large range on subtests of the WAIS-IV Digit Span, HVLT-R, SDMT, and verbal fluency.

CONCLUSIONS

This is the first study to assess an empirically supported neuropsychological research battery in a clinical setting with a relatively large sample size given the rarity of HD. The battery adequately captured areas of impairment across the disease spectrum. Application of the current battery with larger premanifest samples is warranted.

Emotion in action: When emotions meet motor circuits

The brain is a remarkably complex organ responsible for a wide range of functions, including the modulation of emotional states and movement. Neuronal circuits are believed to play a crucial role in integrating sensory, cognitive, and emotional information to ultimately guide motor behavior. Over the years, numerous studies employing diverse techniques such as electrophysiology, imaging, and optogenetics have revealed a complex network of neural circuits involved in the regulation of emotional or motor processes. Emotions can exert a substantial influence on motor performance, encompassing both everyday activities and pathological conditions. The aim of this review is to explore how emotional states can shape movements by connecting the neural circuits for emotional processing to motor neural circuits. We first provide a comprehensive overview of the impact of different emotional states on motor control in humans and rodents. In line with behavioral studies, we set out to identify emotion-related structures capable of modulating motor output, behaviorally and anatomically. Neuronal circuits involved in emotional processing are extensively connected to the motor system. These circuits can drive emotional behavior, essential for survival, but can also continuously shape ongoing movement. In summary, the investigation of the intricate relationship between emotion and movement offers valuable insights into human behavior, including opportunities to enhance performance, and holds promise for improving mental and physical health. This review integrates findings from multiple scientific approaches, including anatomical tracing, circuit-based dissection, and behavioral studies, conducted in both animal and human subjects. By incorporating these different methodologies, we aim to present a comprehensive overview of the current understanding of the emotional modulation of movement in both physiological and pathological conditions.

What does social cognition look like in everyday social functioning in Huntington's disease? A protocol for a scoping review to explore and synthesise knowledge about social cognition alongside day-to-day social functioning of people with Huntington's disease

INTRODUCTION

Social cognition is problematic in Huntington's disease (HD). Despite the observations of clinicians and families, there is minimal empirical literature about how it presents in daily life and the impact on social functioning. This protocol forms the basis of a scoping review to synthesise both the quantitative knowledge and qualitative experiences of the HD community so that a visual and narrative map can address what is known and what is not known for the benefit of the community and clinicians and academics alike.

METHODS AND ANALYSES

An umbrella scoping review of previous work and a scoping review of newer studies of social cognition and social functioning will be undertaken. The electronic databases PubMed, Medline, PsycINFO, Web of Science, Scopus, Embase and CINAHL will be searched to identify eligible studies from starting from 2003 to June 2023. A grey literature search and grey data search will also be undertaken. Quality appraisal of the included documents will use the Critical Appraisal Skills Programme and Authority, Accuracy, Coverage, Objectivity, Date, Significance checklists. A data charting table will be used for data extraction, with analysis of qualitative data using the framework method. The review findings will be presented in a visual form and in a narrative summary.

ETHICS AND DISSEMINATION

Ethical review is not usually required as scoping reviews are produced via secondary data analysis, however, this protocol includes the use of grey data from a charity web forum and so in line with best practice for internet mediated research ethical review was sought and approved (STEM Ethical Review Committee, University of Birmingham-ERN_21-1028A). Review findings will be shared with service users and disseminated through a peer-reviewed publications, conference presentations and hosted via the website of the patient association charity the HD Association.

Are you angry? Neural basis of impaired facial expression recognition in pre-manifest Huntington's

INTRODUCTION

Early non-motor symptoms in Huntington's disease (HD), including visual perceptual difficulties, can have profound negative impacts on quality of life. In particular, deficits in emotion recognition may contribute to misinterpretation of social cues, and may adversely affect interpersonal relationships, work relationships and/or general well-being. This may be particularly salient during the pre-manifest period, a period prior to the onset of motor symptoms. We sought to evaluate impairments in emotion recognition in gene-positive individuals who did not meet criterial for a diagnosis of HD; we also sought to determine associations between emotion recognition processing and altered cortico-striatal circuitry.

METHODS

We used a standardized battery to evaluate performance on a facial expression recognition task in a cohort of motor pre-manifest HD (Pre-HD) individuals (N = 21). Functional MRI (fMRI) was then used to assess the face processing network in a subset (N = 15).

RESULTS

We found significantly decreased response accuracy to certain facial expressions, particularly of negative emotions (p < 0.001) in Pre-HDs. When Pre-HDs viewed faces with different emotions, activation within the Superior Temporal Sulcus (fSTS) was reduced compared to controls; in contrast, the level of evoked response within other face-selective cortical regions was comparable.

CONCLUSION

Early deficits in emotion recognition in Pre-HD appear to be associated with alterations in the fSTS response, a distinctly different pathway from that involved in face perception and provide support for early cognitive and behavioral interventions.

Disgust as a transdiagnostic index of mental illness: A narrative review of clinical populations

Disgust is a basic emotion of rejection, providing an ancestral defensive mechanism against illness. Based on research that documents altered experiences of disgust across several psychopathological conditions, we conducted a narrative review to address the hypothesis that altered disgust may serve as a transdiagnostic index of mental illness. Our synthesis of the literature from past decades suggests that, compared to healthy populations, patients with mental disorders exhibit abnormal processing of disgust in at least one of the analyzed dimensions. We also outline evidence of alterations in brain areas relevant to disgust processing, such as the insula and the interconnected limbic network. Overall, we provide preliminary support for the hypothesis that altered disgust processing may serve as a transdiagnostic index of mental illness.

Sleep, Circadian Rhythms, and Cognitive Dysfunction in Huntington's Disease

BACKGROUND

In healthy people, sleep and circadian disruption are linked to cognitive deficits. People with Huntington's disease (HD), who have compromised brain function and sleep and circadian disturbances, may be even more susceptible to these cognitive effects.

OBJECTIVE

To conduct a comprehensive review and synthesis of the literature in HD on the associations of cognitive dysfunction with disturbed sleep and circadian rhythms.

METHODS

We searched MEDLINE via OVID, CINAHL Plus, EMBASE via OVID, and PubMed in May 2023. The first author then screened by title and abstract and conducted a full review of remaining articles.

RESULTS

Eight studies investigating the influence of sleep and/or circadian rhythms on cognitive function in HD were found. In manifest HD, poorer sleep was associated with worse cognitive function. For behavioral 24-hour (circadian) rhythms, two studies indicated that later wake times correlated with poorer cognitive function. No reported studies in HD examined altered physiological 24-hour (circadian) rhythms and cognitive impairment.

CONCLUSION

Some associations exist between poor sleep and cognitive dysfunction in manifest HD, yet whether these associations are present before clinical diagnosis is unknown. Whether circadian disturbances relate to cognitive impairment in HD also remains undetermined. To inform sleep and circadian interventions aimed at improving cognitive symptoms in HD, future research should include a range of disease stages, control for external factors, and utilize robust cognitive batteries targeted to the aspects of cognitive function known to be adversely affected in HD.

Emotional prosody recognition is impaired in Alzheimer’s disease

Background

The ability to understand emotions is often disturbed in patients with cognitive impairments. Right temporal lobe structures play a crucial role in emotional processing, especially the amygdala, temporal pole (TP), superior temporal sulcus (STS), and anterior cingulate (AC). Those regions are affected in early stages of Alzheimer´s disease (AD). The aim of our study was to evaluate emotional prosody recognition (EPR) in participants with amnestic mild cognitive impairment (aMCI) due to AD, AD dementia patients, and cognitively healthy controls and to measure volumes or thickness of the brain structures involved in this process. In addition, we correlated EPR score to cognitive impairment as measured by MMSE. The receiver operating characteristic (ROC) analysis was used to assess the ability of EPR tests to differentiate the control group from the aMCI and dementia groups.

Methods

Eighty-nine participants from the Czech Brain Aging Study: 43 aMCI due to AD, 36 AD dementia, and 23 controls, underwent Prosody Emotional Recognition Test. This experimental test included the playback of 25 sentences with neutral meaning each recorded with different emotional prosody (happiness, sadness, fear, disgust, anger). Volume of the amygdala and thickness of the TP, STS, and rostral and caudal parts of AC (RAC and CAC) were measured using FreeSurfer algorithm software. ANCOVA was used to evaluate EPR score differences. ROC analysis was used to assess the ability of EPR test to differentiate the control group from the aMCI and dementia groups. The Pearson’s correlation coefficients were calculated to explore relationships between EPR scores, structural brain measures, and MMSE.

Results

EPR was lower in the dementia and aMCI groups compared with controls. EPR total score had high sensitivity in distinguishing between not only controls and patients, but also controls and aMCI, controls and dementia, and aMCI and dementia. EPR decreased with disease severity as it correlated with MMSE. There was a significant positive correlation of EPR and thickness of the right TP, STS, and bilateral RAC.

Conclusions

EPR is impaired in AD dementia and aMCI due to AD. These data suggest that the broad range of AD symptoms may include specific deficits in the emotional sphere which further complicate the patient’s quality of life.

Polymorphisms in the oxytocin receptor and their association with apathy and impaired social cognition in Huntington's disease

BACKGROUND

Huntington's disease (HD) is a neurodegenerative disorder characterized by cognitive, motor, and neuropsychiatric manifestations. Oxytocin is a neuropeptide studied for its role as a neuromodulator regulating multiple behaviors linked to social cognition. Genetic variation of oxytocin receptor (OXTR) might interact in the etiology and development of several impaired social behaviors. Our aim was to study OXTR polymorphisms and their relationship with apathy and social cognition in HD.

METHODS

OXTR was sequenced in 21 cases and 22 controls. We assessed apathy, anxiety, depression, and irritability (Hospital Anxiety and Depression Scale-Snaith Irritability scale, HADS-SIS) and social cognition (Ekman 60 faces test), motor symptoms and functionality with the total functional capacity (TFC), and the Unified HD rating Scale (UHDRS).

RESULTS

We identified ten variants in OXTR. Three variants were classified as possibly damaging (p.Arg40Gly) or probably damaging (p.Leu46Pro, p.Thr102Asn). Subjects carrying the wild-type genotype of the synonymous variant p.Val45 showed a significantly lower score in the HADS-SIS scale, related to lower irritability (p = 0.013). The only subject carrying the heterozygous genotype of the synonymous variant p.Leu62 showed a significantly higher score on Ekman scale, compared to wild-type (p = 0.049); however, this finding was not confirmed after bootstrapping.

CONCLUSION

Variations in OXTR could have a relevant role in the correct development of social and cognitive functions. Future approaches will include the molecular study of p.Arg40Gly, p.Leu46Pro, and p.Thr102Asn to confirm their pathogenicity, as well as the validation of the influence of p.Val45 and p.Leu62 variants for their involvement in irritability and social cognition in HD.

Using a Clinical Formulation to Understand Psychological Distress in People Affected by Huntington’s Disease: A Descriptive, Evidence-Based Model

Huntington’s disease (HD) is an inherited, life-limiting neurodegenerative condition. People with HD experience changes in cognitive, motor and emotional functioning, and can also, mainly at later stages, exhibit behaviours that professionals and carers might find distressing such as hitting others, throwing objects, swearing or making inappropriate comments. While clinical formulation (an individualised approach used by mental health professionals to describe an individual’s difficulties) is a helpful tool to conceptualise patients’ wellbeing, a specific formulation framework has not yet been developed for HD. However, evidence has shown that formulation can help guide clinical interventions and increase consistency of approach across multi-disciplinary teams, refine risk management, and improve staff or carers’ empathic skills and understanding of complex presentations. As a consequence, this paper proposes a new clinical formulation model for understanding distress among people with HD, based on a biopsychosocial framework. More specifically, this includes key elements centring on an individual’s past experience and personal narratives, as well as anticipatory cognitions and emotions about the future. In-depth discussions regarding the components of the model and their importance in HD formulations are included, and a fictional yet representative case example is presented to illustrate their application within the context of personalised care.

Dopaminergic Modulation of Dynamic Emotion Perception

Emotion recognition abilities are fundamental to our everyday social interaction. A large number of clinical populations show impairments in this domain, with emotion recognition atypicalities being particularly prevalent among disorders exhibiting a dopamine system disruption (e.g., Parkinson's disease). Although this suggests a role for dopamine in emotion recognition, studies employing dopamine manipulation in healthy volunteers have exhibited mixed neural findings and no behavioral modulation. Interestingly, while a dependence of dopaminergic drug effects on individual baseline dopamine function has been well established in other cognitive domains, the emotion recognition literature so far has failed to account for these possible interindividual differences. The present within-subjects study therefore tested the effects of the dopamine D2 antagonist haloperidol on emotion recognition from dynamic, whole-body stimuli while accounting for interindividual differences in baseline dopamine. A total of 33 healthy male and female adults rated emotional point-light walkers (PLWs) once after ingestion of 2.5 mg haloperidol and once after placebo. To evaluate potential mechanistic pathways of the dopaminergic modulation of emotion recognition, participants also performed motoric and counting-based indices of temporal processing. Confirming our hypotheses, effects of haloperidol on emotion recognition depended on baseline dopamine function, where individuals with low baseline dopamine showed enhanced, and those with high baseline dopamine decreased emotion recognition. Drug effects on emotion recognition were related to drug effects on movement-based and explicit timing mechanisms, indicating possible mediating effects of temporal processing. Results highlight the need for future studies to account for baseline dopamine and suggest putative mechanisms underlying the dopaminergic modulation of emotion recognition.SIGNIFICANCE STATEMENT A high prevalence of emotion recognition difficulties among clinical conditions where the dopamine system is affected suggests an involvement of dopamine in emotion recognition processes. However, previous psychopharmacological studies seeking to confirm this role in healthy volunteers thus far have failed to establish whether dopamine affects emotion recognition and lack mechanistic insights. The present study uncovered effects of dopamine on emotion recognition in healthy individuals by controlling for interindividual differences in baseline dopamine function and investigated potential mechanistic pathways via which dopamine may modulate emotion recognition. Our findings suggest that dopamine may influence emotion recognition via its effects on temporal processing, providing new directions for future research on typical and atypical emotion recognition.

Impairments of social cognition significantly predict the progression of functional decline in Huntington's disease: A 6-year follow-up study

This study sought to investigate if there was a significant difference between the Huntington's Disease gene expansion carriers who were impaired on the cognitive domains, social cognition and executive functions. Also, it was investigated which of the cognitive domains could predict the decrease in total functional capacity over a 6-year follow-up period. Premanifest and motor-manifest Huntington's Disease gene expansion carriers (N = 98), were examined with a neurological and neuropsychological examination at Time 1 (year 2012-2013). Regression-based normative data was used to classify impairments on the two cognitive domains. Follow-up participants (N = 80) had their functional capacity reexamined at Time 2 (year 2018-2020), to examine which cognitive domain could predict the decrease in functional capacity over the 6-year follow-up. More than 50% of the participants were impaired on the domain of social cognition. These participants were significantly different from the participants who were impaired on executive functions. The motor function and impairments on social cognition significantly predicted the decline in functional capacity. The Emotion Hexagon test was the only significant social cognitive task, that predicted the decline in functional capacity. Social cognition includes unique and separate functions in Huntington's Disease, unaffected by executive functions. This study emphasizes the importance of regular assessment of social cognition in Huntington's Disease and the clinical relevance of impaired social cognitive function.

Profiling Social Cognition in Premanifest Huntington's Disease

OBJECTIVE

Discrepancies exist in reports of social cognition deficits in individuals with premanifest Huntington's disease (HD); however, the reason for this variability has not been investigated. The aims of this study were to (1) evaluate group- and individual-level social cognitive performance and (2) examine intra-individual variability (dispersion) across social cognitive domains in individuals with premanifest HD.

METHOD

Theory of mind (ToM), social perception, empathy, and social connectedness were evaluated in 35 individuals with premanifest HD and 29 healthy controls. Cut-off values beneath the median and 1.5 × the interquartile range below the 25th percentile (P25 - 1.5 × IQR) of healthy controls for each variable were established for a profiling method. Dispersion between social cognitive domains was also calculated.

RESULTS

Compared to healthy controls, individuals with premanifest HD performed worse on all social cognitive domains except empathy. Application of the profiling method revealed a large proportion of people with premanifest HD fell below healthy control median values across ToM (>80%), social perception (>57%), empathy (>54%), and social behaviour (>40%), with a percentage of these individuals displaying more pronounced impairments in empathy (20%) and ToM (22%). Social cognition dispersion did not differ between groups. No significant correlations were found between social cognitive domains and mood, sleep, and neurocognitive outcomes.

CONCLUSIONS

Significant group-level social cognition deficits were observed in the premanifest HD cohort. However, our profiling method showed that only a small percentage of these individuals experienced marked difficulties in social cognition, indicating the importance of individual-level assessments, particularly regarding future personalised treatments.

Different depression: motivational anhedonia governs antidepressant efficacy in Huntington's disease

Depression is more common in neurodegenerative diseases such as Huntington's disease than the general population. Antidepressant efficacy is well-established for depression within the general population: a recent meta-analysis showed serotonin norepinephrine reuptake inhibitors, tricyclic antidepressants and mirtazapine outperformed other antidepressants. Despite the severe morbidity, antidepressant choice in Huntington's disease is based on Class IV evidence. We used complementary approaches to determine treatment choice for depression in Huntington's disease: propensity score analyses of antidepressant treatment outcome using the ENROLL-HD data set, and a dissection of the cognitive mechanisms underlying depression in Huntington's disease using a cognitive battery based on the Research Domain Criteria for Depression. Study 1 included ENROLL-HD 5486 gene-positive adult patients started on an antidepressant medication for depression. Our outcome measures were depression (Hospital Anxiety and Depression Scale or Problem Behaviours Assessment 'Depressed Mood' item) at first follow-up (primary outcome) and all follow-ups (secondary outcome). The intervention was antidepressant class. We used Svyglm&Twang in R to perform propensity scoring, using known variables (disease progression, medical comorbidity, psychiatric morbidity, sedatives, number of antidepressants, demographics and antidepressant contraindications) to determine the probability of receiving different antidepressants (propensity score) and then included the propensity score in a model of treatment efficacy. Study 2 recruited 51 gene-positive adult patients and 26 controls from the South Wales Huntington's Disease Management Service. Participants completed a motor assessment, in addition to measures of depression and apathy, followed by tasks measuring consummatory anhedonia, motivational anhedonia, learning from reward and punishment and reaction to negative outcome. We used generalised linear models to determine the association between task performance and depression scores. Study 1 showed selective serotonin reuptake inhibitors outperformed serotonin norepinephrine reuptake inhibitors on the primary outcome (P = 0.048), whilst both selective serotonin reuptake inhibitors (P = 0.00069) and bupropion (P = 0.0045) were superior to serotonin norepinephrine reuptake inhibitors on the secondary outcome. Study 2 demonstrated an association between depression score and effort for reward that was not explained by apathy. No other mechanisms were associated with depression score. We found that selective serotonin reuptake inhibitors and bupropion outperform serotonin norepinephrine reuptake inhibitors at alleviating depression in Huntington's disease. Moreover, motivational anhedonia appears the most significant mechanism underlying depression in Huntington's disease. Bupropion is improves motivational anhedonia and has a synergistic effect with selective serotonin reuptake inhibitors. This work provides the first large-scale, objective evidence to determine treatment choice for depression in Huntington's disease, and provides a model for determining antidepressant efficacy in other neurodegenerative diseases.

Aberrant Striatal Value Representation in Huntington's Disease Gene Carriers 25 Years Before Onset

BACKGROUND

In this study, we asked whether differences in striatal activity during a reinforcement learning (RL) task with gain and loss domains could be one of the earliest functional imaging features associated with carrying the Huntington's disease (HD) gene. Based on previous work, we hypothesized that HD gene carriers would show either neural or behavioral asymmetry between gain and loss learning.

METHODS

We recruited 35 HD gene carriers, expected to demonstrate onset of motor symptoms in an average of 26 years, and 35 well-matched gene-negative control subjects. Participants were placed in a functional magnetic resonance imaging scanner, where they completed an RL task in which they were required to learn to choose between abstract stimuli with the aim of gaining rewards and avoiding losses. Task behavior was modeled using an RL model, and variables from this model were used to probe functional magnetic resonance imaging data.

RESULTS

In comparison with well-matched control subjects, gene carriers more than 25 years from motor onset showed exaggerated striatal responses to gain-predicting stimuli compared with loss-predicting stimuli (p = .002) in our RL task. Using computational analysis, we also found group differences in striatal representation of stimulus value (p = .0004). We found no group differences in behavior, cognitive scores, or caudate volumes.

CONCLUSIONS

Behaviorally, gene carriers 9 years from predicted onset have been shown to learn better from gains than from losses. Our data suggest that a window exists in which HD-related functional neural changes are detectable long before associated behavioral change and 25 years before predicted motor onset. These represent the earliest functional imaging differences between HD gene carriers and control subjects.

Virtual reality facial emotion recognition in social environments: An eye-tracking study

BACKGROUND

Virtual reality (VR) enables the administration of realistic and dynamic stimuli within a social context for the assessment and training of emotion recognition. We tested a novel VR emotion recognition task by comparing emotion recognition across a VR, video and photo task, investigating covariates of recognition and exploring visual attention in VR.

METHODS

Healthy individuals (n = 100) completed three emotion recognition tasks; a photo, video and VR task. During the VR task, emotions of virtual characters (avatars) in a VR street environment were rated, and eye-tracking was recorded in VR.

RESULTS

Recognition accuracy in VR (overall 75%) was comparable to the photo and video task. However, there were some differences; disgust and happiness had lower accuracy rates in VR, and better accuracy was achieved for surprise and anger in VR compared to the video task. Participants spent more time identifying disgust, fear and sadness than surprise and happiness. In general, attention was directed longer to the eye and nose areas than the mouth.

DISCUSSION

Immersive VR tasks can be used for training and assessment of emotion recognition. VR enables easily controllable avatars within environments relevant for daily life. Validated emotional expressions and tasks will be of relevance for clinical applications.

Problems with Social Cognition and Decision-Making in Huntington's Disease: Why Is it Important?

Huntington’s disease starts slowly and progresses over a 15–20 year period. Motor changes begin subtly, often going unnoticed by patients although they are typically visible to those close to them. At this point, it is the early non-motor problems of HD that arguably cause the most functional impairment. Approximately 65% of gene carriers will experience a reduction in their occupational level, and just under half will feel unable to manage their finances independently before a clinical diagnosis is made. Understanding what drives this impairment in activities of daily living is the key to helping people with HD to live more independently for longer, especially in early disease. Early cognitive decline is likely to play a contributory factor although few studies have looked directly at this relationship. Recently, it has been shown that along with the well documented dysexecutive syndrome seen in HD, changes in social cognition and decision-making are more common than previously thought. Furthermore, some of the early neuropathological and neurochemical changes seen in HD disrupt networks known to be involved in social functioning. In this review, we explore how HD changes the way individuals interact in a social world. Specifically, we summarise the literature on both classical and social decision-making (value-based decision-making in a social context) along with studies of theory of mind, empathy, alexithymia, and emotion recognition in HD. The literature specific to HD is discussed and supported by evidence from similar neurodegenerative disorders and healthy individuals to propose future directions and potential therapeutic avenues to be explored.

Experiences of Mindfulness-Based Cognitive Therapy for Premanifest Huntington's Disease

BACKGROUND

Psychological difficulties such as anxiety, depression, and irritability are common in Huntington's disease, even for premanifest individuals. However, very little evidence exists of psychological approaches to manage this distress. We have conducted a feasibility study with an embedded qualitative component to investigate the possibility of using mindfulness-based cognitive therapy (MBCT) and present here the findings from the qualitative data.

OBJECTIVE

To investigate the experience of premanifest individuals learning and practising mindfulness through completing a course of MBCT.

METHODS

Twelve premanifest individuals completed a course of MBCT and attended three follow up reunion meetings over the following year. Eleven participants agreed to be interviewed post-course and ten participants one year post-course about their experience of the course and any impact on their lives. Seven participants nominated a friend or relative (supporter) to be involved in the research, of whom six agreed to be interviewed post-course and two at one year about the impact of the course on the participants. Data were analysed using reflexive thematic analysis.

RESULTS

Four themes were constructed from the data: 1) A meeting of minds: the group facilitating learning and support; 2) Mindfulness is hard, but enables more effective emotional management; 3) Mindfulness can change the relationship with self and others; and 4) Benefiting from mindfulness: the importance of persistence.

CONCLUSION

The participants who completed the course found it beneficial. Some participants reported reductions in psychological distress, a greater sense of calm and better emotion regulation, with some of these positive changes also noticed by supporters. MBCT is worthy of further investigation for this population.

Emotion Recognition and Traffic-Related Risk-Taking Behavior in Patients with Neurodegenerative Diseases

OBJECTIVES

Neurodegenerative diseases (NDDs), such as Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, and Huntington's disease, inevitably lead to impairments in higher-order cognitive functions, including the perception of emotional cues and decision-making behavior. Such impairments are likely to cause risky daily life behavior, for instance, in traffic. Impaired recognition of emotional expressions, such as fear, is considered a marker of impaired experience of emotions. Lower fear experience can, in turn, be related to risk-taking behavior. The aim of our study was to investigate whether impaired emotion recognition in patients with NDD is indeed related to unsafe decision-making in risky everyday life situations, which has not been investigated yet.

METHODS

Fifty-one patients with an NDD were included. Emotion recognition was measured with the Facial Expressions of Emotions: Stimuli and Test (FEEST). Risk-taking behavior was measured with driving simulator scenarios and the Action Selection Test (AST). Data from matched healthy controls were used: FEEST (n = 182), AST (n = 36), and driving simulator (n = 18).

RESULTS

Compared to healthy controls, patients showed significantly worse emotion recognition, particularly of anger, disgust, fear, and sadness. Furthermore, patients took significantly more risks in the driving simulator rides and the AST. Only poor recognition of fear was related to a higher amount of risky decisions in situations involving a direct danger.

CONCLUSIONS

To determine whether patients with an NDD are still fit to drive, it is crucial to assess their ability to make safe decisions. Measuring emotion recognition may be a valuable contribution to this judgment.

Abnormal visual scanning and impaired mental state recognition in pre-manifest Huntington disease

Huntington's disease (HD) is a genetic neurodegenerative disorder that affects not only the motor but also the cognitive and the neuropsychiatric domain. In particular, deficits in mental state recognition may emerge already at early pre-manifest stages of the disease. The aim of this research was to explore the relation between visual scanning behavior and complex mental state recognition in individuals with pre-manifest HD (preHD). Eighteen preHD and eighteen age- and gender-matched healthy controls took the revised "Reading the Mind in the Eyes" test while their eye-movements were tracked. In addition to the expected deficits in mental state recognition, preHD showed abnormalities concerning all three scanning variables we considered, namely the absolute number of fixations (FC), the average fixation duration (AFD), and the percentage of time spent fixating (FTR). In preHD, FC and FTR but not AFD predicted mental state recognition over and beyond general disease-related declines in cognition and motor functioning. Notably, preHD showed abnormal vertical and horizontal fixation patterns, and these patterns predicted mental state recognition, suggesting the involvement of mechanisms related to the embodied processing of emotional stimuli. Overall, our results suggest that impaired facial mental state recognition in pre-manifest HD is partly due to emotional-motivational factors affecting the visual scanning of facial expressions.

The Role of the Cerebellum in Huntington's Disease: a Systematic Review

Huntington's disease (HD) is a rare neurological disorder characterized by progressive motor, cognitive, and psychiatric disturbances. Although striatum degeneration might justify most of the motor symptoms, there is an emerging evidence of involvement of extra-striatal structures, such as the cerebellum. To elucidate the cerebellar involvement and its afferences with motor, psychiatric, and cognitive symptoms in HD. A systematic search in the literature was performed in MEDLINE, LILACS, and Google Scholar databases. The research was broadened to include the screening of reference lists of review articles for additional studies. Studies available in the English language, dating from 1993 through May 2020, were included. Clinical presentation of patients with HD may not be considered as the result of an isolated primary striatal dysfunction. There is evidence that cerebellar involvement is an early event in HD and may occur independently of striatal degeneration. Also, the loss of the compensation role of the cerebellum in HD may be an explanation for the clinical onset of HD. Although more studies are needed to elucidate this association, the current literature supports that the cerebellum may integrate the natural history of neurodegeneration in HD.

Age-related alteration of emotional regulation in the BACHD rat model of Huntington disease

Huntington's disease (HD) is a genetic neurodegenerative disorder, caused by an expanded CAG repeat in the gene encoding the huntingtin protein. At the premanifest phase, before motor symptoms occur, psychiatric and emotional disorders are observed with high prevalence in HD patients. Agitation, anxiety and irritability are often described but also depression and/or apathy, associated with a lack of emotional control. The aim of the present study was to better circumscribe and understand the emotional symptoms and assess their evolution according to the progression of the disease using a transgenic HD model, BACHD rats, at the age of 4, 12 and 18 months. To achieve this goal, we confronted animals to two types of tests: first, tests assessing anxiety like the light/dark box and the conflict test, which are situations that did not involve an obvious threat and tests assessing the reactivity to a present threat using confrontation with an unknown conspecific (social behavior test) or with an aversive stimulus (fear conditioning test). In all animals, results show an age-dependent anxiety-like behavior, particularly marked in situation requiring passive responses (light/dark box and fear conditioning tests). BACHD rats exhibited a more profound alteration than WT animals in these tests from an early stage of the disease whereas, in tasks requiring some kind of motivation (for food or for social contacts), only old BACHD rats showed high anxiety-like behavior compared to WT, may be partly due to the other symptoms' occurrence at this stage: locomotor difficulties and/or apathy.

Accuracy of automated amygdala MRI segmentation approaches in Huntington's disease in the IMAGE-HD cohort

Smaller manually-segmented amygdala volumes have been associated with poorer motor and cognitive function in Huntington's disease (HD). Manual segmentation is the gold standard in terms of accuracy; however, automated methods may be necessary in large samples. Automated segmentation accuracy has not been determined for the amygdala in HD. We aimed to determine which of three automated approaches would most accurately segment amygdalae in HD: FreeSurfer, FIRST, and ANTS nonlinear registration followed by FIRST segmentation. T1-weighted images for the IMAGE-HD cohort including 35 presymptomatic HD (pre-HD), 36 symptomatic HD (symp-HD), and 34 healthy controls were segmented using FreeSurfer and FIRST. For the third approach, images were nonlinearly registered to an MNI template using ANTS, then segmented using FIRST. All automated methods overestimated amygdala volumes compared with manual segmentation. Dice overlap scores, indicating segmentation accuracy, were not significantly different between automated approaches. Manually segmented volumes were most statistically differentiable between groups, followed by those segmented by FreeSurfer, then ANTS/FIRST. FIRST-segmented volumes did not differ between groups. All automated methods produced a bias where volume overestimation was more severe for smaller amygdalae. This bias was subtle for FreeSurfer, but marked for FIRST, and moderate for ANTS/FIRST. Further, FreeSurfer introduced a hemispheric bias not evident with manual segmentation, producing larger right amygdalae by 8%. To assist choice of segmentation approach, we provide sample size estimation graphs based on sample size and other factors. If automated segmentation is employed in samples of the current size, FreeSurfer may effectively distinguish amygdala volume between controls and HD.

New Perspectives on Emotional Processing in People with Symptomatic Huntington's Disease: Impaired Emotion Regulation and Recognition of Emotional Body Language†

OBJECTIVE

Emotion regulation and emotional body language (EBL) recognition represent two fundamental components of emotional processing that have recently seen a considerable surge in research interest, in part due to the role they play in optimizing mental health. This appears to be particularly true for clinical conditions that can profoundly affect emotional functioning. Among these is Huntington's disease (HD), a neurodegenerative disorder that is associated with several psychological difficulties and cognitive impairments, including well-established deficits in facial emotion recognition. However, although the theoretical case for impairments is strong, the current evidence in HD on other components such as emotion regulation and EBL recognition is sparse.

METHOD

In this study, it was hypothesized that emotion regulation and recognition of EBL are impaired in people with symptomatic HD, and that these impairments significantly and positively correlate with each other. A between-subjects design was adopted to compare 13 people with symptomatic HD with 12 non-affected controls matched for age and education.

RESULTS

The results showed that emotion regulation and EBL recognition were significantly impaired in individuals with HD. Moreover, a significant positive correlation was observed between facial and EBL recognition impairments, whereas EBL performance was negatively related to the disease stage. However, emotion regulation and recognition performances were not significantly correlated.

CONCLUSIONS

This investigation represents the first evidence of a deficit of emotion regulation and EBL recognition in individuals with HD. The clinical implications of these findings are explored, and indications for future research are proposed.

Social Cognition in the Real World: Reconnecting the Study of Social Cognition With Social Reality

The scientific study of social cognition is a growing field which promises to deliver valuable insights into how the brain underpins human’s social success. However, the poor ecological validity of many popular paradigms constrains the progress of social cognitive scientists. Highly simplistic and contrived stimuli are commonplace, despite the complexity and unpredictability of real-world social experiences. A shift toward a cognitive ethology approach would allow us to determine if, when, and how specific cognitive processes contribute to real-world functioning. This shift would enable us to break new ground in our understanding of the cognitions which underpin so much of the human experience. To address these questions, we must innovate and test social cognitions in dynamic, multimodal, context-embedded, and interactive environments. Furthermore, measuring responses dynamically and in terms of accuracy (rather than based on arbitrary criteria defined by the experimenter), would improve ecological validity. Finally, researchers should take into account sample diversity and participants’ motivation to ensure the generalizability of findings to everyday interactions. This article considers these issues in turn and outlines recent research which demonstrates how they might be overcome.

Specific cognitive theory of mind and behavioral dysfunctions in early manifest Huntington disease: a case report

Huntington's disease (HD) is a devastating illness, associated with progressive motor, behavioral and cognitive dysfunctions. However, some studies emphasized that social cognition impairment could occur prior to the onset of these other symptoms. Here, we report the case of a 47 years old patient with early manifest HD, whose complaint was mainly related to the behavioral sphere. He exhibited a significant impairment of Theory of Mind abilities as well as behavioral, and discrete motor symptoms without noticeable cognitive decline. This case study suggests that social cognition impairments and behavioral changes could be in some cases a feature of the disease and may represent a major disability, in early stages of manifest HD.

Emotion recognition and inhibitory control in manifest and pre-manifest Huntington's disease: evidence from a new Stroop task

Huntington's disease (HD) is a genetic neurodegenerative disorder that affects not only the motor but also the cognitive domain. In particular, cognitive symptoms such as impaired executive skills and deficits in recognizing other individuals' mental state may emerge many years before the motor symptoms. This study was aimed at testing two cognitive hypotheses suggested by previous research with a new Stroop task created for the purpose: 1) the impairment of emotion recognition in HD is moderated by the emotions' valence, and 2) inhibitory control is impaired in HD. Forty manifest and 20 pre-manifest HD patients and their age- and gender-matched controls completed both the traditional "Stroop Color and Word Test" (SCWT) and the newly created "Stroop Emotion Recognition under Word Interference Task" (SERWIT), which consist in 120 photographs of sad, calm, or happy faces with either congruent or incongruent word interference. On the SERWIT, impaired emotion recognition in manifest HD was moderated by emotion type, with deficits being larger in recognizing sadness and calmness than in recognizing happiness, but it was not moderated by stimulus congruency. On the SCWT, six different interference scores yielded as many different patterns of group effects. Overall our results corroborate the hypothesis that impaired emotion recognition in HD is moderated by the emotions' valence, but do not provide evidence for the hypothesis that inhibitory control is impaired in HD. Further research is needed to learn more about the psychological mechanisms underlying the moderating effect of emotional valence on impaired emotion recognition in HD, and to corroborate the hypothesis that the inhibitory processes involved in Stroop tasks are not impaired in HD. Looking beyond this study, the SERWIT promises to make important contributions to disentangling the cognitive and the psychomotor aspects of neurological disorders. The research was approved by the Ethics Committee of the "Istituto Leonarda Vaccari", Rome on January 24, 2018.

Psychological Interventions for People with Huntington's Disease: A Call to Arms

BACKGROUND

Although Huntington's disease (HD) can cause a wide range of psychological difficulties, no review has ever been carried out on the range of psychological interventions adopted with this population.

OBJECTIVE

To scope the literature on psychological interventions for psychological difficulties in people affected by HD.

METHODS

A systematic scoping review was performed across MEDLINE, PsycINFO, CINAHL, Academic Search Ultimate, and Cochrane Library up to 1 March 2020.

RESULTS

From an initial return of 1579 citations, a total of nine papers were considered eligible for review. These included a qualitative investigation, three case studies, two case series, two uncontrolled pretest-posttest designs, and only one randomised control trial (RCT). Despite the wide range of psychological difficulties which can be experienced by people affected by the HD gene expansion, the adopted interventions only accounted for five main psychological outcomes (anxiety, apathy, depression, irritability, and coping). Further discussion and suggestions for future research are provided for each outcome.

CONCLUSION

The current literature on psychological interventions in people affected by HD is extremely limited both in terms of methods and addressed clinical outcomes. Consequently, no conclusions can be offered yet as to which psychological therapy may help this population. As further more comprehensive research is urgently needed for this group, the ultimate aim of the present review is to act as a call to arms for HD researchers worldwide to help shed light on the most effective way to translate psychological theory into practice for the benefit of people affected by HD.

Apathy Associated With Impaired Recognition of Happy Facial Expressions in Huntington's Disease

OBJECTIVES

Previous research has demonstrated an association between emotion recognition and apathy in several neurological conditions involving fronto-striatal pathology, including Parkinson's disease and brain injury. In line with these findings, we aimed to determine whether apathetic participants with early Huntington's disease (HD) were more impaired on an emotion recognition task compared to non-apathetic participants and healthy controls.

METHODS

We included 43 participants from the TRACK-HD study who reported apathy on the Problem Behaviours Assessment - short version (PBA-S), 67 participants who reported no apathy, and 107 controls matched for age, sex, and level of education. During their baseline TRACK-HD visit, participants completed a battery of cognitive and psychological tests including an emotion recognition task, the Hospital Depression and Anxiety Scale (HADS) and were assessed on the PBA-S.

RESULTS

Compared to the non-apathetic group and the control group, the apathetic group were impaired on the recognition of happy facial expressions, after controlling for depression symptomology on the HADS and general disease progression (Unified Huntington's Disease Rating Scale total motor score). This was despite no difference between the apathetic and non-apathetic group on overall cognitive functioning assessed by a cognitive composite score.

CONCLUSIONS

Impairment of the recognition of happy expressions may be part of the clinical picture of apathy in HD. While shared reliance on frontostriatal pathways may broadly explain associations between emotion recognition and apathy found across several patient groups, further work is needed to determine what relationships exist between recognition of specific emotions, distinct subtypes of apathy and underlying neuropathology. (JINS, 2019, 25, 453-461).

Progressive microstructural changes of the occipital cortex in Huntington's disease

In this study we longitudinally investigated the rate of microstructural alterations in the occipital cortex in different stages of Huntington's disease (HD) by applying an automated atlas-based approach to diffusion MRI data. Twenty-two premanifest (preHD), 10 early manifest HD (early HD) and 24 healthy control subjects completed baseline and two year follow-up scans. The preHD group was stratified based on the predicted years to disease onset into a far (preHD-A) and near (preHD-B) to disease onset group. Clinical and behavioral measures were collected per assessment time point. An automated atlas-based DTI analysis approach was used to obtain the mean, axial and radial diffusivities of the occipital cortex. We found that the longitudinal rate of diffusivity change in the superior occipital gyrus (SOG), middle occipital gyrus (MOG), and inferior occipital gyrus (IOG) was significantly higher in early HD compared to both preHD and controls (all p's ≤ 0.005), which can be interpreted as an increased rate of microstructural degeneration. Furthermore, the change rate in the diffusivity of the MOG could significantly discriminate between preHD-B compared to preHD-A and the other groups (all p's ≤ 0.04). Finally, we found an inverse correlation between the Stroop Word Reading task and diffusivities in the SOG and MOG (all p's ≤ 0.01). These findings suggest that measures obtained from the occipital cortex can serve as sensitive longitudinal biomarkers for disease progression in preHD-B and early HD. These could in turn be used to assess potential effects of proposed disease modifying therapies.

'I have a feeling I can't speak to anybody': A thematic analysis of communication perspectives in people with Huntington's disease

OBJECTIVES

This study explored the perspectives of people affected by Huntington's disease (HD) on their own communicative abilities.

METHODS

Qualitative semi-structured interviews were carried out with eight people with early HD. The data were analysed through thematic analysis.

RESULTS

Four themes were constructed from the data, characterised by the following core topics: How HD directs and mediates communication; Regaining control to improve communication; Emotional outflows into communication and the struggle for separation; Sheltering as a way to boost confidence in communication.

DISCUSSION

Separating patients' identity as individuals from that of a person with a disease can help increase communicative control. Consistent with the general theory and model of self-regulation, patients should be allowed a wider range of choices to regain control over communication. Achieving better emotion regulation is of paramount importance for communication, and factors such as medication regimes, relationships and existing coping strategies should be strengthened. Consistent with previous research, feelings of safety and the idea of a safe place ('sheltering') represent an effective coping mechanism. Practical implications include the refinement of communication and relationships among clinicians, caregivers, and patients with HD by considering a wider range of medical, psychological and socio-environmental factors.

Emergence of Huntington Disease in a Man With a Premorbid Criminal Lifestyle

We present here a case in which Huntington disease (HD) was diagnosed upon forensic-psychiatric evaluation of a 34-year-old male repeat offender. Despite a family history of HD, as well as overt delusions and motor pathology, the disease had not been recognized at an earlier stage, and the patient was serving a prison sentence at the time of diagnosis. The case highlights difficulties court officials may face with regard to identifying severe psychiatric and neurological disorders in repeat offenders. Such offenders' gradually deteriorating status could be overlooked by the court, even in cases in which a tailored judicial process is warranted. Also, the present case highlights the risk of using antipsychotic medication to treat HD, since it may worsen sufferers' capacity to recognize emotions in others, thereby increasing the risk of altercations and criminal activity.

Effects of stimulus-related variables on mental states recognition in Huntington's disease

BACKGROUND

Cognitive abnormalities in Huntington's Disease (HD) can involve the specific impairment of the social perspective taking as well as difficulties in recognizing others' mental state many years before the onset of motor symptoms.

AIMS

At the scope of assessing how the difficulties in mental state recognition might be an HD early sign before motor symptoms appear, our study was aimed to investigate how the recognition of others' mental states in HD subjects is moderated by different stimulus related features (gender, difficulty (low, medium, high), and valence (positive, negative, neutral) of the mental states that are to be recognized).

METHODS

Subjects with premanifest (n = 20) and manifest (n = 40) HD performed the revised 'Reading the Mind in the Eyes Test' and were compared with age-matched healthy controls (HC, 40 subjects per cohort).

RESULTS

Our results highlight an early impairment in mental state recognition preceding manifest HD symptoms and a deterioration of these abilities with HD progression. Moreover, we found in HD premanifest subjects an impairment concerning the recognition of negative and neutral mental states, as well as of mental states with moderate recognition difficulty. Finally, we found that participant gender did not influence the performance in recognizing others' mental states, while all participants recognized mental states displayed by females more accurately than those displayed by males.

CONCLUSIONS

We conclude that difficulties in the recognition of complex mental states can be considered as an early sign of HD, before evident behavioral manifestations, and peculiar features of the stimulus influence it.

Task-switching abilities in pre-manifest Huntington's disease subjects

INTRODUCTION

Huntington's Disease (HD) cognitive dysfunction occurs before unequivocal motor signs become apparent. The predominant early cognitive abnormal domains may include deficits in psychomotor speed, negative emotion recognition and executive functioning. Our study is aimed to investigate the executive control of cognition in pre-manifest (pre) HD subjects, by means of a task-switching protocol.

METHODS

We recruited 30 pre-HD subjects and 18 age-, sex- and education-matched Healthy Controls (HC). Subjects were assigned to two experimental groups: 15 pre-HD1 with a Total Motor Score (TMS) ≤4 (far from onset) and 15 pre-HD2 with a 5 ≤ TMS≤9 (near to onset and Diagnostic Confidence Level (DCL) still<4). Two different tasks were performed in rapid and random succession, so that the task was either changed from one trial to the next one (switch trials) or repeated (repetition trials). Switch trials are usually slower than repetitions, causing a so-called Switch Cost (SC).

RESULTS

Pre-HD subjects had worse performance than HC in the switch and repetition trials, as indicated by increased SC and reaction times. In particular, pre-HD2 showed impaired switching abilities with reaction times slower than pre-HD1 and HC.

CONCLUSIONS

Our study highlighted a task-switching impairment since HD was still at a pre-manifest stage. Such abnormalities worsen when pre-HD subjects start to show subtle motor manifestations, still nonspecific and insufficient to define the clinical diagnosis of HD (DCL<4). Considering that such abilities have obvious implications for activities of daily living, early cognitive rehabilitation programs addressing such deficits might be useful in the premanifest stage of the disease.

Social Cognition and Oxytocin in Huntington's Disease: New Insights

This study is aimed at relating social cognition in Huntington's Disease (HD) to plasma levels of the social hormone oxytocin (OT). Indeed, HD patients commonly display reduced social skills and OT is involved in bonding behavior and improved recognition of facial emotions. Twelve mild-symptomatic HD patients (stage II Shoulson &amp; Fahn) and 11 gender/age matched controls (healthy controls, HC), without concurrent psychiatric disorders, were investigated at baseline (T₀) for OT plasma levels and social cognition through an extensive battery of neuropsychological tests. Social cognition was also re-examined after two years (T1) in 8 of the 12 patients. Results showed a trend for reduced T₀-OT levels in HD vs. HC, mean ± stardard deviation: 6.5 ± 2.4 vs. 9.9 ± 7.2 pg/mL, without reaching statistical significance. At T₀, patients showed significantly lower performances than controls at the "Faux-Pas" and "Strange Stories" tests (p < 0.05; p < 0.01); a reduced perception of visual emotions (p < 0.01) and verbal stimuli (p < 0.01) was also reported, involving anger, fear, and sadness (p < 0.05; p < 0.01). Additionally, in the HD population, OT concentrations positively correlated with T1-performances at Neutral\Faux-Pas test (p < 0.05), whereas the cognitive Montreal Cognitive Assessment (MoCA) and Mini Mental State Examination (MMSE) scores positively correlated with psychosocial perception at the "Strange Stories" and Karolinska Directed Emotional Faces (KDEF) tests (p < 0.05). This study, despite its limitations, supports correlations between OT and HD social cognition, suggesting a possible therapeutic use of this hormone. More subjects and additional body tissues/fluids, such as cerebrospinal fluid, should be investigated to confirm this hypothesis.

The Neuropsychology of Huntington's Disease

Huntington's disease is an inherited, degenerative brain disease, characterized by involuntary movements, cognitive disorder and neuropsychiatric change. Men and women are affected equally. Symptoms emerge at around 40 years, although there is wide variation. A rare juvenile form has onset in childhood or adolescence. The evolution of disease is insidious and structural and functional brain changes may be present more than a decade before symptoms and signs become manifest. The earliest site of pathology is the striatum and neuroimaging measures of striatal change correlate with neurological and cognitive markers of disease. Chorea and other aspects of the movement disorder are the most visible aspect of the disease. However, non-motor features have greatest affect on functional independence and quality of life, so require recognition and management. The evidence-base for non-pharmacological treatments in Huntington's disease is currently limited, but recent intervention studies are encouraging.

The visual cortex and visual cognition in Huntington's disease: An overview of current literature

The processing of visual stimuli from retina to higher cortical areas has been extensively studied in the human brain. In Huntington's disease (HD), an inherited neurodegenerative disorder, it is suggested that visual processing deficits are present in addition to more characteristic signs such as motor disturbances, cognitive dysfunction, and behavioral changes. Visual deficits are clinically important because they influence overall cognitive performance and have implications for daily functioning. The aim of this review is to summarize current literature on clinical visual deficits, visual cognitive impairment, and underlying visual cortical changes in HD patients. A literature search was conducted using the electronic database of PubMed/Medline. This review shows that changes of the visual system in patients with HD were not the primary focus of currently published studies. Still, early atrophy and alterations of the posterior cerebral cortex was frequently observed, primarily in the associative visual cortical areas such as the lingual and fusiform gyri, and lateral occipital cortex. Changes were even present in the premanifest phase, before clinical onset of motor symptoms, suggesting a primary region for cortical degeneration in HD. Although impairments in visuospatial processing and visual perception were reported in early disease stages, heterogeneous cognitive batteries were used, making a direct comparison between studies difficult. The use of a standardized battery of visual cognitive tasks might therefore provide more detailed information regarding the extent of impairments in specific visual domains. Further research could provide more insight into clinical, functional, and pathophysiological changes of the visual pathway in HD.

The Alteration of Emotion Regulation Precedes the Deficits in Interval Timing in the BACHD Rat Model for Huntington Disease

Huntington disease (HD) is an autosomal dominantly inherited, progressive neurodegenerative disorder which is accompanied by executive dysfunctions and emotional alteration. The aim of the present study was to assess the impact of emotion/stress on on-going highly demanding cognitive tasks, i.e., temporal processing, as a function of age in BACHD rats (a “full length” model of HD). Middle-aged (4–6 months) and old (10–12 months) rats were first trained on a 2 vs. 8-s temporal discrimination task, and then exposed to a series of bisection tests under normal and stressful (10 mild unpredictable foot-shocks) conditions. The animals were then trained on a peak interval task, in which reinforced fixed-interval (FI) 30-s trials were randomly intermixed with non-reinforced probe trials. After training, the effect of stress upon time perception was again assessed. Sensitivity to foot-shocks was also assessed independently. The results show effects of both age and genotype, with largely greater effects in old BACHD animals. The older BACHD animals had impaired learning in both tasks, but reached equivalent levels of performance as WT animals at the end of training in the temporal discrimination task, while remaining impaired in the peak interval task. Whereas sensitivity to foot-shock did not differ between BACHD and WT rats, delivery of foot-shocks during the test sessions had a disruptive impact on temporal behavior in WT animals, an effect which increased with age. In contrast, BACHD rats, independent of age, did not show any significant disruption under stress. In conclusion, BACHD rats showed a disruption in temporal learning in late symptomatic animals. Age-related modification in stress-induced impairment of temporal control of behavior was also observed, an effect which was greatly reduced in BACHD animals, thus confirming previous results suggesting reduced emotional reactivity in HD animals. The results suggest a staggered onset in cognitive and emotional alterations in HD, with emotional alteration being the earliest, possibly related to different time courses of degeneration in cortico-striatal and amygdala circuits.

Emotion Recognition Correlates With Social-Neuropsychiatric Dysfunction in Huntington's Disease

OBJECTIVES

People with Huntington's disease (HD) experience poor social quality of life, relationship breakdown, and social withdrawal, which are mediated to some extent by socially debilitating neuropsychiatric symptoms, such as apathy and disinhibition. Social cognitive symptoms, such as impaired emotion recognition, also occur in HD, however, the extent of their association with these socially debilitating neuropsychiatric symptoms is unknown. Our study examined the relationship between emotion recognition and symptom ratings of apathy and disinhibition in HD.

METHODS

Thirty-two people with premanifest or symptomatic-HD completed Part 1 of The Awareness of Social Inference Test (TASIT), which is a facial emotion recognition task. In addition, we obtained severity ratings for apathy and disinhibition on the Frontal Systems Behavior Scale (FrSBe) from a close family member. Our analyses used motor symptom severity as a proxy for disease progression.

RESULTS

Emotion recognition performance was significantly associated with family-ratings of apathy, above and beyond their shared association with disease severity. We found a similar pattern for disinhibition ratings, which fell short of statistical significance. As expected, worse emotion recognition performance was correlated with higher severity in FrSBe symptom ratings.

CONCLUSIONS

Our findings suggest that emotion recognition abilities relate to key socially debilitating neuropsychiatric symptoms in HD. Our results help to understand the functional significance of emotion recognition impairments in HD, and may have implications for the development of remediation programs aimed at improving patients' social quality of life. (JINS, 2018, 24, 417-423).

Whole-Brain Connectivity in a Large Study of Huntington's Disease Gene Mutation Carriers and Healthy Controls

Huntington's disease (HD) is an inherited brain disorder characterized by progressive motor, cognitive, and behavioral dysfunctions. It is caused by abnormally large trinucleotide cytosine-adenine-guanine (CAG) repeat expansions on exon 1 of the Huntingtin gene. CAG repeat length (CAG-RL) inversely correlates with an earlier age of onset. Region-based studies have shown that HD gene mutation carrier (HDgmc) individuals (CAG-RL ≥36) present functional connectivity alterations in subcortical (SC) and default mode networks. In this analysis, we expand on previous HD studies by investigating associations between CAG-RL and connectivity in the whole brain, as well as between CAG-dependent connectivity and motor and cognitive performances. We used group-independent component analysis on resting-state functional magnetic resonance imaging scans of 261 individuals (183 HDgmc and 78 healthy controls) from the PREDICT-HD study, to obtain whole-brain resting state networks (RSNs). Regression analysis was applied within and between RSNs connectivity (functional network connectivity [FNC]) to identify CAG-RL associations. Connectivity within the putamen RSN is negatively correlated with CAG-RL. The FNC between putamen and insula decreases with increasing CAG-RL, and also shows significant associations with motor and cognitive measures. The FNC between calcarine and middle frontal gyri increased with CAG-RL. In contrast, FNC in other visual (VIS) networks declined with increasing CAG-RL. In addition to observed effects in SC areas known to be related to HD, our study identifies a strong presence of alterations in VIS regions less commonly observed in previous reports and provides a step forward in understanding FNC dysfunction in HDgmc.

Exploring emotion regulation and emotion recognition in people with presymptomatic Huntington's disease: The role of emotional awareness

Interest in the role of both emotion regulation and recognition in our understanding of mental health has been steadily increasing, especially in people with chronic illness who also have psychological difficulties. One illness which belongs to this category is Huntington's disease. Huntington's disease (HD) is a chronic neurodegenerative disorder that can cause a number of cognitive and psychological difficulties, including emotion recognition deficits, even before the onset of the symptoms required to make a formal diagnosis. Despite the lack of definite evidence, recent studies have suggested that deficits of emotion regulation and recognition may be expected to play a pivotal role in the early cognitive manifestations of HD. In this study, we hypothesised that the ability to regulate emotions can be impaired in people with presymptomatic HD, and that such impairment may be associated with a deficit of emotion recognition. To test this, an online survey was carried out with 117 English and Italian-speaking people with presymptomatic HD, compared to 217 controls matched for age and education. The results suggest that, in presymptomatic participants, emotion regulation and emotion recognition are generally not significantly impaired, and no significant relationships between performances on the two constructs were observed. However, a specific impairment in emotional awareness (a subscale on the Difficulties in Emotion Regulation Scale, DERS) was observed, which appears to be enhanced by the co-occurrence of depressive symptoms, even at a subclinical level. Consequently, it is suggested that difficulties in emotional awareness may represent a precursor of more general emotion recognition impairments, which only become apparent as the disease reaches a more symptomatic level. Clinical implications of the findings are discussed and directions for future research are proposed.

Emotion Evaluation and Social Inference Impairments in Huntington's Disease

BACKGROUND

Huntington's disease (HD) is an inherited neurodegenerative disorder characterised by motor, cognitive and neuropsychiatric symptoms. Recent research has established that individuals with HD display reduced discrimination of emotional facial expressions and impaired higher-order social cognitive skills, including 'theory of mind'.

OBJECTIVE

This study aimed to further characterise the emotion evaluation and theory of mind deficits in HD in an ecologically-valid context, and determine their impact on socially-relevant functional abilities.

METHODS

A sample of 17 HD participants and 24 healthy controls were assessed using The Awareness of Social Inference Test (TASIT), together with additional self- and informant rated measures of cognition, social communication, empathy and neuropsychiatric symptoms.

RESULTS

Participants with HD showed significant difficulties in evaluating negative emotions, and understanding sincere, sarcastic and 'paradoxical sarcastic' statements, compared with controls. The ability to evaluate positive emotions was negatively correlated with behavioural problems, but no other clinical, behavioural or communication measures correlated significantly with TASIT subscales.

CONCLUSIONS

These findings suggest that social cognitive difficulties in symptomatic HD may be underpinned by more generalised impairments, related to deciphering social exchanges, as opposed to a selective theory of mind deficit. Such difficulties have the potential to place significant strain on interpersonal relationships, and thus warrant thorough clinical assessment, using ecologically-valid tools, to promote early detection and development of person-centred interventions.

Gray matter asymmetries in aging and neurodegeneration: A review and meta-analysis

Inter-hemispheric asymmetries are a common phenomenon of the human brain. Some evidence suggests that neurodegeneration related to aging and disease may preferentially affect the left-usually language- and motor-dominant-hemisphere. Here, we used activation likelihood estimation meta-analysis to assess gray matter (GM) loss and its lateralization in healthy aging and in neurodegeneration, namely, mild cognitive impairment (MCI), Alzheimer's dementia (AD), Parkinson's disease (PD), and Huntington's disease (HD). This meta-analysis, comprising 159 voxel-based morphometry publications (enrolling 4,469 patients and 4,307 controls), revealed that GM decline appeared to be asymmetric at trend levels but provided no evidence for increased left-hemisphere vulnerability. Regions with asymmetric GM decline were located in areas primarily affected by neurodegeneration. In HD, the left putamen showed converging evidence for more pronounced atrophy, while no consistent pattern was found in PD. In MCI, the right hippocampus was more atrophic than its left counterpart, a pattern that reversed in AD. The stability of these findings was confirmed using permutation tests. However, due to the lenient threshold used in the asymmetry analysis, further work is needed to confirm our results and to provide a better understanding of the functional role of GM asymmetries, for instance in the context of cognitive reserve and compensation. Hum Brain Mapp 38:5890-5904, 2017. © 2017 Wiley Periodicals, Inc.

Putamen Volume is Negatively Correlated with the Ability to Recognize Fearful Facial Expressions

Findings of previous functional magnetic resonance imaging (MRI) and neuropsychological studies have suggested that specific aspects of the basal ganglia, particularly the putamen, are involved in the recognition of emotional facial expressions. However, it remains unknown whether variations in putamen structure reflect individual differences in the ability to recognize facial expressions. Thus, the present study assessed the putamen volumes and shapes of 50 healthy Japanese adults using structural MRI scans and evaluated the ability of participants to recognize facial expressions associated with six basic emotions: anger, disgust, fear, happiness, sadness, and surprise. The volume of the bilateral putamen was negatively associated with the recognition of fearful faces, and the local shapes of both the anterior and posterior subregions of the bilateral putamen, which are thought to support cognitive/affective and motor processing, respectively, exhibited similar negative relationships with the recognition of fearful expressions. These results suggest that individual differences in putamen structure can predict the ability to recognize fearful facial expressions in others. Additionally, these findings indicate that cognitive/affective and motor processing underlie this process.