Loss of insight in frontotemporal dementia, corticobasal degeneration and progressive supranuclear palsy

Social Cognition, Executive Functions and Self-Report of Psychological Distress in Huntington's Disease

Objective: Huntington’s disease (HD) is characterized by motor symptoms, psychiatric symptoms and cognitive impairment in, inter alia, executive functions and social cognition. The aim of this study was to investigate the relationship between subjective feeling of psychological distress using a self-report questionnaire and performances on tests of executive functions and social cognition in a large consecutive cohort of HD patients.

Method: 50 manifest HD patients were tested in social cognition and executive functions and each answered a self-report questionnaire about current status of perceived psychological distress (the Symptom Checklist-90-Revised (SCL-90-R)). Correlation analyses of test performance and SCL-90-R scores were made as well as stepwise linear regression analyses with the SCL-90-R GSI score and test performances as dependent variables.

Results: We found that less psychological distress was significantly associated with worse performances on social cognitive tests (mean absolute correlation .34) and that there were no significant correlations between perceived psychological distress and performance on tests of executive functions. The correlations between perceived psychological distress and performance on social cognitive tests remained significant after controlling for age, Unified Huntington’s Disease Rating Scale-99 total motor score and performance on tests of executive functions.

Conclusions: Based on previous findings that insight and apathy are closely connected and may be mediated by overlapping neuroanatomical networks involving the prefrontal cortex and frontostriatal circuits, we speculate that apathy/and or impaired insight may offer an explanation for the correlation between self-report of psychological distress and performance on social cognitive tests in this study.

Managing cognition in progressive supranuclear palsy

Cognitive impairment is integral to the syndrome of progressive supranuclear palsy. It is most commonly described as a frontal dysexecutive syndrome but other impairments include apathy, impulsivity, visuospatial and memory functions. Cognitive dysfunction may be exacerbated by mood disturbance, medication and communication problems. In this review we advocate an individualized approach to managing cognitive impairment in progressive supranuclear palsy with the education of caregivers as a central component. Specific cognitive and behavioral treatments are complemented by treatment of mood disturbances, rationalizing medications and a patient-centered approach to communication. This aims to improve patients’ quality of life, reduce carer burden and assist people with progressive supranuclear palsy in decisions about their life and health, including discussions of feeding and end-of-life issues.

Grey and White Matter Clinico-Anatomical Correlates of Disinhibition in Neurodegenerative Disease

Disinhibition is an important symptom in neurodegenerative diseases. However, the clinico-anatomical underpinnings remain controversial. We explored the anatomical correlates of disinhibition in neurodegenerative disease using the perspective of grey and white matter imaging. Disinhibition was assessed with a neuropsychological test and a caregiver information-based clinical rating scale in 21 patients with prefrontal syndromes due to behavioural variant frontotemporal dementia (n = 12) or progressive supranuclear palsy (n = 9), and healthy controls (n = 25). Cortical thickness was assessed using the Freesurfer software on 3T MRI data. The integrity of selected white matter tracts was determined by the fractional anisotropy (FA) from Diffusion Tensor Imaging. Disinhibition correlated with the cortical thickness of the right parahippocampal gyrus, right orbitofrontal cortex and right insula and the FA of the right uncinate fasciculus and right anterior cingulum. Notably, no relationship was seen with the thickness of ventromedial prefrontal cortex. Our results support an associative model of inhibitory control, distributed in a medial temporal lobe-insular-orbitofrontal network, connected by the intercommunicating white matter tracts. This reconciles some of the divergences among previous studies, but also questions the current conceptualisation of the “prefrontal” syndrome and the central role attributed to the ventromedial prefrontal cortex in inhibitory control.

The self-reference effect in dementia: Differential involvement of cortical midline structures in Alzheimer's disease and behavioural-variant frontotemporal dementia

Encoding information in reference to the self enhances subsequent memory for the source of this information. In healthy adults, self-referential processing has been proposed to be mediated by the cortical midline structures (CMS), with functional differentiation between anterior-ventral, anterior-dorsal and posterior regions. While both Alzheimer's disease (AD) and behavioural-variant frontotemporal dementia (bvFTD) patients show source memory impairment, it remains unclear whether they show a typical memory advantage for self-referenced materials. We also sought to identify the neural correlates of this so-called 'self-reference effect' (SRE) in these patient groups. The SRE paradigm was tested in AD (n = 16) and bvFTD (n = 22) patients and age-matched healthy controls (n = 17). In this task, participants studied pictures of common objects paired with one of two background scenes (sources) under self-reference or other-reference encoding instructions, followed by an item and source recognition memory test. Voxel-based morphometry was used to investigate correlations between SRE measures and regions of grey matter atrophy in the CMS. The behavioural results indicated that self-referential encoding did not ameliorate the significant source memory impairments in AD and bvFTD patients. Furthermore, the reduced benefit of self-referential relative to other-referential encoding was not related to general episodic memory deficits. Our imaging findings revealed that reductions in the SRE were associated with atrophy in the anterior-dorsal CMS across both patient groups, with additional involvement of the posterior CMS in AD and anterior-ventral CMS in bvFTD. These findings suggest that although the SRE is comparably reduced in AD and bvFTD, this arises due to impairments in different subcomponents of self-referential processing.

Neural correlates of reduced awareness in instrumental activities of daily living in frontotemporal dementia

A decline in instrumental activities of daily living has been described as the earliest functional deficit in patients with neurodegenerative disease. It embraces specific competencies such as: "recalling the date and telephone calls, orienting to new places, remembering the location of objects at home, understanding conversation and the plot of a movie, keeping belongings in order, doing mental calculations and handling money, remembering appointments and shopping lists and performing clerical work". Since changes in instrumental daily living activities are one of the descriptors of behavioural-variant frontotemporal dementia, we decided to investigate the neural correlates of a reduced awareness in this specific domain in twenty-three consecutive behavioural-variant frontotemporal dementia patients. Gray matter volume changes associated with a reduced awareness for the instrumental domain, assessed using a validated caregiver-patient discrepancy questionnaire, were examined. Interestingly, we found disabilities in instrumental daily living activities and a reduced awareness of these to be related to medial prefrontal cortex atrophy, where the mid-cingulate cortices, dorsal anterior insula and cuneous play an important role. Importantly, if the executive system does not function correctly, the comparator mechanism of action self-monitoring does not detect mismatches between the current and previous performance states stored in the personal database, and produces a reduced awareness for the instrumental domain.

C9ORF72 G4C2-repeat expansion and frontotemporal dementia first reported case in Argentina

We present a female patient aged 51 who developed behavioral disorders followed by cognitive impairment over 3 years. Neuropsychological, neuropsychiatric, and radiological features suggested a probable behavioral variant of frontotemporal dementia (bvFTD). A family history of amyotrophic lateral sclerosis and parkinsonism suggested the hexanucleotide repeat expansion G4C2 in C9ORF72 . We set up a two-step genotyping algorithm for the detection of the expansion using fragment-length analysis polymerase chain reaction (PCR) and repeat-primed PCR with fluorescent primers. We confirmed the presence of an expanded G4C2 allele in the patient. This represents the first documented case of bvFTD due to a C9ORF72 expansion in Argentina.

Factors predicting the presence of impaired clinical insight in liaison psychiatric patients assessed in the Emergency Room

OBJECTIVES

There are limited studies on the factors that can predict the presence of impaired clinical insight specifically in an Emergency Room (ER) psychiatric patient population. The objective of this study is to examine the factors that can predict the likelihood that a patient presenting to the ER will have impaired clinical insight.

METHODS

Nineteen independent demographic and clinical factors contained on data assessment tools for 337 patients assessed by the crisis team in the ER over 6 months were compiled and analysed using SPSS Version 20 with univariate analyses and logistic regression.

RESULTS

Patients who were unemployed or had a history of self-harm or had psychotic symptoms on mental state examination were about two, three and six times, respectively, more likely to have impaired clinical insight compared with those who were employed, had no history of self-harm or had no psychotic symptoms on mental state examination, controlling for other factors in the logistic regression model.

CONCLUSION

Patients who are unemployed, have a history of self-harm or have psychotic symptoms following as psychiatric assessment in the ER may benefit from an insight-oriented psychotherapy.

Right Limbic FDG-PET Hypometabolism Correlates with Emotion Recognition and Attribution in Probable Behavioral Variant of Frontotemporal Dementia Patients

The behavioural variant of frontotemporal dementia (bvFTD) is a rare disease mainly affecting the social brain. FDG-PET fronto-temporal hypometabolism is a supportive feature for the diagnosis. It may also provide specific functional metabolic signatures for altered socio-emotional processing. In this study, we evaluated the emotion recognition and attribution deficits and FDG-PET cerebral metabolic patterns at the group and individual levels in a sample of sporadic bvFTD patients, exploring the cognitive-functional correlations. Seventeen probable mild bvFTD patients (10 male and 7 female; age 67.8±9.9) were administered standardized and validated version of social cognition tasks assessing the recognition of basic emotions and the attribution of emotions and intentions (i.e., Ekman 60-Faces test-Ek60F and Story-based Empathy task-SET). FDG-PET was analysed using an optimized voxel-based SPM method at the single-subject and group levels. Severe deficits of emotion recognition and processing characterized the bvFTD condition. At the group level, metabolic dysfunction in the right amygdala, temporal pole, and middle cingulate cortex was highly correlated to the emotional recognition and attribution performances. At the single-subject level, however, heterogeneous impairments of social cognition tasks emerged, and different metabolic patterns, involving limbic structures and prefrontal cortices, were also observed. The derangement of a right limbic network is associated with altered socio-emotional processing in bvFTD patients, but different hypometabolic FDG-PET patterns and heterogeneous performances on social tasks at an individual level exist.

Connecting Self-Awareness and Error-Awareness in Patients with Traumatic Brain Injury

Impaired self-awareness after traumatic brain injury (TBI) is often seen in stark contrast to the observations of significant-others, who are acutely aware of the difficulties experienced by patients. Our objective was to investigate the relationship between metacognitive knowledge in daily life and emergent awareness of errors during laboratory tasks, since the breakdown of error detection mechanisms may impose limitations on the recovery of metacognitive knowledge after TBI. We also examined the extent to which these measures of awareness can predict dysexecutive behaviors. A sample of TBI patients (n=62) and their significant-others, provided reports of daily functioning post injury. In addition, patients underwent a neuropsychological assessment and were instructed to signal their errors during go/no-go tests. Interrelationships between metacognitive and emergent levels of awareness were examined, after controlling for the influence of secondary cognitive variables. Significant-other ratings correlated with errors made by the patients on neuropsychological tests but not with their premorbid function. Patients who under-reported daily life difficulties or over-reported their competency, compared to significant-other reports, were less likely to show awareness of laboratory errors. Emergent awareness was also identified as the sole predictor of performance on the modified six-element test, an ecologically valid test of multitasking. The online breakdown of error awareness after brain injury is related to difficulties with metacognitive awareness as reported in daily life, and is also predictive of dysexecutive behaviors. These findings are discussed in the context of multidimensional and neural models of awareness and error monitoring.

Connecting clinical and experimental investigations of awareness in traumatic brain injury

Questionnaire-based demonstrations of impaired self-awareness (SA) after traumatic brain injury (TBI) are not always supported by experimental studies of in-the-moment or online awareness. This chapter begins by describing the clinical phenomenon of impaired SA, how it is measured, and why its interdependency with mechanisms of online awareness may provide the scaffolding from which appraisals of cognitive functioning can be accurately revised following a brain injury. We review research that has measured unawareness of errors in routine action in TBI patients and propose more rigorous methodological approaches to studying the emergent properties of awareness with greater clarity in the laboratory. We discuss how neuropsychological and electrophysiologic studies are beginning to inform our understanding of impaired error processing in TBI patients and we highlight recent theory proposing that online metacognitive processes accumulate evidence of erroneous responses in a graded fashion. Neural signals with amplitudes that scale with the strength of accruing evidence and peak latencies that mark the threshold at which awareness emerges represent important neural mechanisms to examine the breakdown of error awareness after brain injury. We also discuss how errors can be investigated in relation to different sources of evidence that contribute to aware experiences after brain injury. Finally, we explore conditions beyond error signaling, and how different "objects of insight" that require retrospective and prospective judgments of confidence need to be examined in relation to the clinical phenomenon of impaired SA.

Unawareness of bipolar disorder: the role of the cingulate cortex

Reduced awareness of illness is a well-known phenomenon that has been understudied in remitted patients with bipolar disorder. In particular, the relationship between reduced awareness and executive dysfunction is an intriguing question that has yet to be resolved. The aim of the current study is to analyze the link between reduced awareness, brain dysfunction, and concomitant cognitive-behavioral disturbances from a neurocognitive perspective. In previous studies, we demonstrated the role of the anterior cingulate cortex (ACC) in the unawareness of distinct pathologies that exhibit overlapping symptoms in the context of overlapping circuit-specific dysfunction. Given the clinical importance of the results obtained, the present study considers six aware and four unaware remitted bipolar disorder patients. Cingulate functionality was assessed with functional magnetic resonance imaging while patients performed a go/no-go task. Patients were also studied on an overall cognitive task battery and with behavioral assessment of mood changes in terms of apathy and disinhibited behavior. Unaware patients showed frontoparietal hypo-perfusion, with a significant reduction of task-sensitive activity in the bilateral superior and middle frontal gyrus, putamen, insular, and ACCs.

Degradation of emotion processing ability in corticobasal syndrome and Alzheimer's disease

Disturbed emotion processing and difficulty with social interactions are present to variable degrees in dementia. They are characteristic features of frontotemporal dementia, whereas these deficits tend to be mild in Alzheimer's disease, reflecting the different patterns of neurodegeneration seen in these disorders. Corticobasal syndrome is an atypical parkinsonian disorder clinically and pathologically related to frontotemporal dementia. Corticobasal syndrome typically presents as a motor disturbance, although cognitive and behavioural changes are now recognized. Pathological changes are found in frontoparietal cortical regions and in the basal ganglia; regions that are heavily involved in emotion processing. Despite the overlap with frontotemporal dementia and the observed regions of brain atrophy, emotion processing has not been systematically explored in corticobasal syndrome. This study aimed to (i) comprehensively examine emotion processing in corticobasal syndrome in comparison to Alzheimer's disease, to determine whether emotion processing deficits exist in this syndrome, beyond those seen in Alzheimer's disease; and (ii) identify the neural correlates underlying emotion processing in corticobasal syndrome and Alzheimer's disease. Sixteen patients with corticobasal syndrome, 18 patients with Alzheimer's disease and 22 matched healthy control subjects were assessed on a comprehensive battery of face and emotion processing tasks. Behavioural analyses revealed deficits in both basic face processing and high-level emotion processing tasks in patients with corticobasal syndrome. Notably, the emotion processing disturbance persisted even after controlling for face processing deficits. In contrast, patients with Alzheimer's disease were impaired on high-level complex and cognitively demanding emotion recognition tasks (Ekman 60, The Awareness of Social Inference Test) only. Neuroimaging analyses using FreeSurfer revealed that emotion processing deficits in corticobasal syndrome were associated with basal ganglia volume loss as well as cortical thinning of the left paracentral gyrus/precuneus region. In Alzheimer's disease, however, emotion processing deficits were associated with atrophy in a different set of brain regions, including the right cingulate and the bilateral insulae, as well as the hippocampi, right amygdala and nucleus accumbens bilaterally. Our results demonstrate that patients with corticobasal syndrome experience widespread deficits in emotion processing, and these deficits are related to changes in brain regions known to be crucial for emotion processing. These findings have important clinical implications for the treatment and management of these patients.

Self-unawareness of levodopa induced dyskinesias in patients with Parkinson's disease

The study analyzes the presence of dyskinesias-reduced-self-awareness in forty-eight patients suffering from Parkinson's disease (PD). As the association with executive dysfunction is a matter of debate and we hypothesize it plays an important role in dyskinesias self-unawareness, we analyzed the role of dopaminergic treatment on the medial-prefrontal-ventral-striatal circuitry using a neurocognitive approach. Special attention was given to metacognitive abilities related to action-monitoring that represent a novel explanation of the phenomenon. PD patients were assessed using different rating scales that we devised to measure movement awareness disorders. In order to ascertain whether each variable measured at a cognitive-clinical level contributes to predicting the scores of the movement-disorder-awareness-scales, we conducted multiple logistic regression models using the latter as binary dependent variables. We used the Wisconsin Card Sorting Test-metacognitive-version to assess the executive functions of the prefrontal-ventral-striatal circuitry. Data showed that a reduction of self-awareness using the Dyskinesia rating scale was associated with global monitoring (p=.04), monitoring resolution (p=.04) and control sensitivity (p=.04). Patients failed to perceive their performance, distinguish between correct and incorrect sorts, be confident in their choice and consequently decide to gamble during the task. We did not find any association with executive functions using the hypo-bradykinesia rating scale. Our findings indicate that when the comparator mechanism for monitoring attentive performance is compromised at a prefrontal striatal level, patients lose the ability to recognize their motor disturbances that do not achieve conscious awareness.

Self-awareness in neurodegenerative disease relies on neural structures mediating reward-driven attention

Accurate self-awareness is essential for adapting one's tasks and goals to one's actual abilities. Patients with neurodegenerative diseases, particularly those with right frontal involvement, often present with poor self-awareness of their functional limitations that may exacerbate their already jeopardized decision-making and behaviour. We studied the structural neuroanatomical basis for impaired self-awareness among patients with neurodegenerative disease and healthy older adults. One hundred and twenty-four participants (78 patients with neurodegenerative diseases including Alzheimer's disease, behavioural variant frontotemporal dementia, right-temporal frontotemporal dementia, semantic variant and non-fluent variant primary progressive aphasia, and 46 healthy controls) described themselves on the Patient Competency Rating Scale, rating observable functioning across four domains (daily living activities, cognitive, emotional control, interpersonal). All participants underwent structural magnetic resonance imaging. Informants also described subjects' functioning on the same scale. Self-awareness was measured by comparing self and informant ratings. Group differences in discrepancy scores were analysed using general linear models, controlling for age, sex and disease severity. Compared with controls, patients with behavioural variant frontotemporal dementia overestimated their functioning in all domains, patients with Alzheimer's disease overestimated cognitive and emotional functioning, patients with right-temporal frontotemporal dementia overestimated interpersonal functioning, and patients with non-fluent aphasia overestimated emotional and interpersonal functioning. Patients with semantic variant aphasia did not overestimate functioning on any domain. To examine the neuroanatomic correlates of impaired self-awareness, discrepancy scores were correlated with brain volume using voxel-based morphometry. To identify the unique neural correlates of overlooking versus exaggerating deficits, overestimation and underestimation scores were analysed separately, controlling for age, sex, total intracranial volume and extent of actual functional decline. Atrophy related to overestimating one's functioning included bilateral, right greater than left frontal and subcortical regions, including dorsal superior and middle frontal gyri, lateral and medial orbitofrontal gyri, right anterior insula, putamen, thalamus, and caudate, and midbrain and pons. Thus, our patients' tendency to under-represent their functional decline was related to degeneration of domain-general dorsal frontal regions involved in attention, as well as orbitofrontal and subcortical regions likely involved in assigning a reward value to self-related processing and maintaining accurate self-knowledge. The anatomic correlates of underestimation (right rostral anterior cingulate cortex, uncorrected significance level) were distinct from overestimation and had a substantially smaller effect size. This suggests that underestimation or 'tarnishing' may be influenced by non-structural neurobiological and sociocultural factors, and should not be considered to be on a continuum with overestimation or 'polishing' of functional capacity, which appears to be more directly mediated by neural circuit dysfunction.

Measuring disease progression in corticobasal syndrome

Corticobasal syndrome (CBS) is a complex neurodegenerative disorder with marked clinical, neuropsychological, and pathological heterogeneity. Measurement of disease progression in CBS is complex and little understood. This study aimed to establish clinical and neuropsychological indicators of prognosis in CBS. Patients with CBS were retrospectively recruited from a frontotemporal dementia specific research clinic. All patients underwent detailed clinical and neuropsychological testing including the frontotemporal dementia rating scale (FRS). Using the differences in FRS logit scores over a period of 12 months, CBS patients were divided into rapid and slow progressor groups. Demographic, clinical and neuropsychological features were compared between the two groups. Sixteen participants who met defined criteria were included (9 males, 7 females; mean age 65.8 ± 22 years; median symptom duration 51.8 ± 22 years; mean duration of follow-up 11.4 ± 2.8 months). There were no significant differences between the rapid and slow progressors in age, gender, symptom duration, motor/cognitive presentation, and ACE-R scores at baseline. Clinically, slow progressors were significantly more likely to have a motor speech disorder, with a trend for more frequent dysgraphia, whereas rapid progressors were more likely to exhibit surface dyslexia. Rapid and slow progressor groups did not differ on neuropsychological performance. The presence of motor speech disorder, dysgraphia, and surface dyslexia may be useful in differentiating patients with rapid progression of CBS from those with a more indolent disease course.

Metacognition in the behavioral variant of frontotemporal dementia and Alzheimer's disease

OBJECTIVE

Impaired self-awareness is characteristic of nearly all dementias, including Alzheimer's disease (AD), but the deficit is most severe in the behavioral variant of frontotemporal dementia (bvFTD). The prominence of frontal pathology in bvFTD suggests that failure of online monitoring, the process by which individuals monitor their own cognitive processing in real time, is an important contributor. Metacognitive research offers several approaches to measure self-assessment, some more and others less sensitive to online monitoring. The goal of this study was to assess metacognition in bvFTD using several approaches, and to compare the results with those in AD.

METHOD

We examined metacognition in 12 patients with bvFTD, 14 with AD, and 35 healthy controls using feeling of knowing (FOK), ease of learning (EOL), judgment of learning (JOL), and retrospective confidence rating (CR) tasks, as well as response to feedback about performance.

RESULTS

BvFTD and AD were both impaired at FOK compared with controls, although AD showed some sparing. Both groups were similarly impaired at CR and neither group was impaired at JOL after accounting for memory performance. Most striking, bvFTD patients failed to appropriately adjust their predictions about future memory performance even after receiving explicit feedback that they had performed worse than they expected.

CONCLUSIONS

Both bvFTD and AD show deficits in online monitoring, although the deficit appears more severe in bvFTD. The insensitivity of bvFTD patients to overt feedback may point to unique mechanisms, possibly frontally mediated, that add to their severe lack of self-awareness.

Unawareness of deficits in ischemic injury: role of the cingulate cortex

Reduced awareness of illness is a well-known phenomenon that has been studied in patients with vascular disease, but the precise nature of their executive dysfunction is an intriguing question that still has to be resolved. It would be particularly interesting to study patients with reduced awareness of disease possibly related to vascular lesions of the prefrontal cortex. Due to the clinical importance of the case, here we present a patient with a selective right anterior cingulate ischemic injury and impaired awareness of deficits. We suggest that the cingulo-frontal area dysfunction may represent one of the corresponding neurobiological substrates of his persistent unawareness, which has not yet been evaluated in the literature on patients with acquired brain injury (ABI).

Inability to empathize: brain lesions that disrupt sharing and understanding another's emotions

Emotional empathy--the ability to recognize, share in, and make inferences about another person's emotional state--is critical for all social interactions. The neural mechanisms underlying emotional empathy have been widely studied with functional imaging of healthy participants. However, functional imaging studies reveal correlations between areas of activation and performance of a task, so that they can only reveal areas engaged in a task, rather than areas of the brain that are critical for the task. Lesion studies complement functional imaging, to identify areas necessary for a task. Impairments in emotional empathy have been mostly studied in neurological diseases with fairly diffuse injury, such as traumatic brain injury, autism and dementia. The classic 'focal lesion' is stroke. There have been scattered studies of patients with impaired empathy after stroke and other focal injury, but these studies have included small numbers of patients. This review will bring together data from these studies, to complement evidence from functional imaging. Here I review how focal lesions affect emotional empathy. I will show how lesion studies contribute to the understanding of the cognitive and neural mechanisms underlying emotional empathy, and how they contribute to the management of patients with impaired emotional empathy.

Deficits in self-awareness impact the diagnosis of asymptomatic neurocognitive impairment in HIV

A recent national survey of HIV(+) adults noted that nearly three-quarters of cognitively impaired individuals are categorized as having asymptomatic neurocognitive impairment (ANI), lacking documented compromise of everyday function. The clinical impact and long-term consequences of ANI are unknown and the importance of this asymptomatic diagnosis has raised concerns in clinical care settings where competing priorities often exist. In this study, we conducted structured tests of everyday functioning in a sample of HIV(+) subjects over 60 years of age and asked subjects to rate their performance relative to peers. We demonstrate that individuals with neuropsychological testing impairment often lack self-awareness of functional performance deficits. Specifically, ANI subjects rated functional performance similar to that of HIV-negative control subjects, despite noted deficits in objective measures of function. These findings have important implications for use of self-report of function in the diagnosis of HIV-associated neurocognitive disorders (HAND), likely underestimating symptomatic impairment.

Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind

Theory of Mind (ToM) is the ability to infer other people’s mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM.

Self-rated anosognosia score may be a sensitive and predictive indicator for progressive brain atrophy in amyotrophic lateral sclerosis: an X-ray computed tomographic study

We investigated whether a self-rated anosognosia score can be an indicator for progression of brain atrophy in patients with amyotrophic lateral sclerosis (ALS). Scores for 16 patients were compared with the ventricular areas of the bilateral anterior and inferior horns measured on x-ray computed tomography. Longitudinal enlargement was expressed as a monthly increase in size: (ventricular size at the initial scan - ventricular size at the follow-up scan)/scan interval (months). The anosognosia scores ranged from -4 to 3 and 3-18 in patients with and without frontotemporal lobar degeneration (FTLD), respectively (p = 0.0011). Anosognosia scores were significantly correlated with sizes of anterior (r = 0.704, p = 0.0016) and inferior (r = 0.898, p < 0.0001) horns. In non-demented patients for whom follow-up CT scans were available (n = 7), the scores were significantly correlated with the longitudinal increase in inferior horn size (r = 0.754, p = 0.0496), but not with that of anterior horn size (r = -0.166, p = 0.7111). In conclusion, anosognosia in ALS is associated with greater anterior and inferior horn sizes, reflecting frontotemporal lobar atrophy. Moreover, mild anosognosia in ALS patients without FTLD may predict impending inferior horn enlargement, reflecting medial temporal atrophy.

Sustaining attention to simple tasks: a meta-analytic review of the neural mechanisms of vigilant attention

Maintaining attention for more than a few seconds is essential for mastering everyday life. Yet, our ability to stay focused on a particular task is limited, resulting in well-known performance decrements with increasing time on task. Intriguingly, such decrements are even more likely if the task is cognitively simple and repetitive. The attentional function that enables our prolonged engagement in intellectually unchallenging, uninteresting activities has been termed vigilant attention. Here we synthesized what we have learned from functional neuroimaging about the mechanisms of this essential mental faculty. To this end, a quantitative meta-analysis of pertinent neuroimaging studies was performed, including supplementary analyses of moderating factors. Furthermore, we reviewed the available evidence on neural time-on-task effects, additionally considering information obtained from patients with focal brain damage. Integrating the results of both meta-analysis and review, we identified a set of mainly right-lateralized brain regions that may form the core network subserving vigilant attention in humans, including dorsomedial, mid- and ventrolateral prefrontal cortex, anterior insula, parietal areas (intraparietal sulcus, temporoparietal junction), and subcortical structures (cerebellar vermis, thalamus, putamen, midbrain). We discuss the potential functional roles of different nodes of this network as well as implications of our findings for a theoretical account of vigilant attention. It is conjectured that sustaining attention is a multicomponent, nonunitary mental faculty, involving a mixture of (a) sustained/recurrent processes subserving task-set/arousal maintenance and (b) transient processes subserving the target-driven reorienting of attention. Finally, limitations of previous studies are considered and suggestions for future research are provided.

Ventromedial-frontopolar prefrontal cortex atrophy correlates with insight loss in frontotemporal dementia and Alzheimer's disease

Loss in insight is a major feature of frontotemporal dementia (FTD) but has been investigated relatively little. More importantly, the neural basis of insight loss is still poorly understood. The current study investigated insight deficit profiles across a large cohort of neurodegenerative patients (n = 81), including FTD and Alzheimer's disease (AD) patients. We employed a novel insight questionnaire, which tapped into changes across different domains: social interaction, emotion, diagnosis/treatment, language, and motivation. FTD subtypes varied considerably for insight loss, with the behavioral variant worst and the progressive non-fluent variant least affected. All other subtypes and AD showed milder but consistent insight loss. Voxel-based morphometry analysis revealed that overall insight loss correlated with ventromedial and frontopolar prefrontal atrophy, with exception of social interaction and emotion insight loss, which additionally correlated with lateral temporal and amygdala atrophy, respectively. Our results show that patients with neurodegenerative conditions show variable loss of insight, with ventromedial and frontopolar cortex regions appearing to be particularly important for insight.

Failures of metacognition and lack of insight in neuropsychiatric disorders

Lack of insight or unawareness of illness are the hallmarks of many psychiatric disorders, especially schizophrenia (SCZ) and other psychoses and could be conceived of as a failure in metacognition. Research in this area in the mental health field h as burgeoned with the development and widespread use of standard assessment instruments and the mapping out of the clinical and neuropsychological correlates of insight and its loss. There has been a growing appreciation of the multi-faceted nature of the concept and of the different 'objects' of insight, such as the general awareness that one is ill, to more specific metacognitive awareness of individual symptoms, impairments and performance. This in turn has led to the notion that insight may show modularity and may fractionate across different domains and disorders, supported by work that directly compares metacognition of memory deficits and illness awareness in patients with SCZ, Alzheimer's disease and brain injury. The focus of this paper will be on the varieties of metacognitive failure in psychiatry, particularly the psychoses. We explore cognitive models based on self-reflectiveness and their possible social and neurological bases, including data from structural and functional MRI. The medial frontal cortex appears to play an important role in self-appraisal in health and disease.

Disturbance of emotion processing in frontotemporal dementia: a synthesis of cognitive and neuroimaging findings

Accurate processing of emotional information is a critical component of appropriate social interactions and interpersonal relationships. Disturbance of emotion processing is present in frontotemporal dementia (FTD) and is a clinical feature in two of the three subtypes: behavioural-variant FTD and semantic dementia. Emotion processing in progressive nonfluent aphasia, the third FTD subtype, is thought to be mostly preserved, although current evidence is scant. This paper reviews the literature on emotion recognition, reactivity and expression in FTD subtypes, although most studies focus on emotion recognition. The relationship between patterns of emotion processing deficits and patterns of neural atrophy are considered, by integrating evidence from recent neuroimaging studies. The review findings are discussed in the context of three contemporary theories of emotion processing: the limbic system model, the right hemisphere model and a multimodal system of emotion. Results across subtypes of FTD are most consistent with the multimodal system model, and support the presence of somewhat dissociable neural correlates for basic emotions, with strongest evidence for the emotions anger and sadness. Poor emotion processing is evident in all three subtypes, although deficits are more widespread than what would be predicted based on studies in healthy cohorts. Studies that include behavioural and imaging data are limited. Future investigations combining these approaches will help improve the understanding of the neural network underlying emotion processing. Presently, longitudinal investigations of emotion processing in FTD are lacking, and studies investigating emotion processing over time are critical to understand the clinical manifestations of disease progression in FTD.

Tracking emotional valence: the role of the orbitofrontal cortex

Successful navigation of the social world requires the ability to recognize and track emotions as they unfold and change dynamically. Neuroimaging and neurological studies of emotion recognition have primarily focused on the ability to identify the emotion shown in static photographs of facial expressions, showing correlations with the amygdala as well as temporal and frontal brain regions. In this study, we examined the neural correlates of continuously tracking dynamically changing emotions. Fifty-nine patients with diverse neurodegenerative diseases used a rating dial to track continuously how positive or how negative the character in a film clip felt. Tracking accuracy was determined by comparing participants' ratings with the ratings of 10 normal control participants. The relationship between tracking accuracy and regional brain tissue content was examined using voxel-based morphometry. Low tracking accuracy was primarily associated with gray matter loss in the right lateral orbitofrontal cortex (OFC). Our finding that the right OFC is critical to the ability to track dynamically changing emotions is consistent with previous research showing right OFC involvement in both socioemotional understanding and modifying responding in changing situations.

Theory of Mind in normal ageing and neurodegenerative pathologies

This paper reviews findings in three subcomponents of social cognition (i.e., Theory of Mind, facial emotion recognition, empathy) during ageing. Changes over time in social cognition were evaluated in normal ageing and in patients with various neurodegenerative pathologies, such as Alzheimer's disease, mild cognitive impairment, frontal and temporal variants of frontotemporal lobar degeneration and Parkinson's disease. Findings suggest a decline in social cognition with normal ageing, a decline that is at least partially independent of a more general cognitive or executive decline. The investigation of neurodegenerative pathologies showing specific deficits in Theory of Mind in relation to damage to specific cerebral regions led us to suggest a neural network involved in Theory of Mind processes, namely a fronto-subcortical loop linking the basal ganglia to the regions of the frontal lobes.

Theory of mind impairments in patients with semantic dementia

Semantic dementia is characterized by semantic deficits and behavioural abnormalities that occur in the wake of bilateral inferolateral and predominantly left-sided anterior temporal lobe atrophy. The temporal poles have been shown to be involved in theory of mind, namely the ability to ascribe cognitive and affective mental states to others that regulates social interactions by predicting and interpreting human behaviour. However, very few studies have examined theory of mind in semantic dementia. In this study, we investigated both cognitive and affective theory of mind in a group of patients with semantic dementia, using separate objective and subjective assessment tasks. Results provided objective evidence of an impact of semantic dementia on cognitive and affective theory of mind, consistent with the patients' atrophy in the left temporal lobe and hypometabolism in the temporal lobes and the medial frontal cortex. However, the subjective assessment of theory of mind suggested that awareness of the affective but not cognitive theory of mind deficit persists into the moderate stage of the disease.

Awareness of cognitive impairment in schizophrenia and its relationship to insight into illness

BACKGROUND

Patients with schizophrenia have been found to show unawareness of cognitive impairment. However, its frequency and its relationship to lack of insight into illness are uncertain.

METHOD

Forty-two patients with chronic schizophrenia were given tests of executive function and memory. Awareness of cognitive impairment was measured by means of discrepancy scores--differences between patient and psychologist ratings of memory and frontal/executive failures in daily life. Insight into illness was assessed using the Scale to Assess Unawareness of Mental Disorder (SUMD).

RESULTS

A majority of the patients were found to underestimate their cognitive impairment; however, some overestimated it. Unawareness of cognitive impairment and lack of clinical insight loaded on different factors in a factor analysis, but these two factors were themselves correlated.

CONCLUSIONS

The findings suggest that both unawareness and overestimation of cognitive impairment characterise patients with schizophrenia, although the former is more common. Awareness of cognitive impairment occurs independently of insight into illness at the clinical level, although the two phenomena may be linked at a deeper level.

Brain alterations and mini-mental state examination in patients with progressive supranuclear palsy: voxel-based investigations using f-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging

BACKGROUND/AIMS

The aim of this study was to compare differences in morphological and functional changes in brain regions in individual patients with progressive supranuclear palsy (PSP) and correlate their Mini-Mental State Examination (MMSE) score with anatomy and function using magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET).

METHODS

Sixteen PSP patients and 20 age-matched healthy volunteers underwent FDG-PET and 3-dimensional MRI. Gray matter, white matter and metabolic activity were compared between patients and normal controls. In addition, possible correlations between the MMSE score and brain function/anatomy were examined.

RESULTS

The PSP group had reduced cerebral glucose metabolism, and lower gray and white matter volumes in the frontal lobes and midbrain compared with normal controls. In PSP subjects, the metabolic changes observed in the PET scans were greater than the loss in gray and white matter observed in the MRI scans. The MMSE scores were positively correlated with volume and FDG uptake in the frontal lobe.

CONCLUSION

FDG-PET is a more effective tool in the diagnosis of PSP than MRI. Atrophy and hypometabolism in the frontal lobe are as important as in the basal midbrain for differentiating PSP patients who primarily exhibit cognitive dysfunction from normal controls.

Behavioral variant frontotemporal dementia with corticobasal degeneration pathology: phenotypic comparison to bvFTD with Pick's disease

Patients with corticobasal degeneration (CBD) pathology present with diverse clinical syndromes also associated with other neuropathologies, including corticobasal syndrome, progressive nonfluent aphasia, and an Alzheimer's-type dementia. Some present with behavioral variant frontotemporal dementia (bvFTD), though this subtype still requires more detailed clinical characterization. All patients with CBD pathology and clinical assessment were reviewed (N = 17) and selected if they initially met criteria for bvFTD [bvFTD(CBD), N = 5]. Available bvFTD patients with Pick's [bvFTD(Pick's), N = 5] were selected as controls. Patients were also compared to healthy older controls [N = 53] on neuropsychological and neuroimaging measures. At initial presentation, bvFTD(CBD) showed few neuropsychological or motor differences from bvFTD(Pick's). Neuropsychiatrically, they were predominantly apathetic with less florid social disinhibition and eating disturbances, and were more anxious than bvFTD(Pick's) patients. Voxel-based morphometry revealed similar patterns of predominantly frontal atrophy between bvFTD groups, though overall degree of atrophy was less severe in bvFTD(CBD), who also showed comparative preservation of the frontoinsular rim, with dorsal > ventral frontal atrophy, and sparing of temporal and parietal structures relative to bvFTD(Pick's) patients. Despite a remarkable overlap between the two patient types, bvFTD patients with underlying CBD pathology show subtle clinical features that may distinguish them from patients with Pick's disease neuropathology.

Loss of emotional insight in behavioral variant frontotemporal dementia or "frontal anosodiaphoria"

Loss of insight is a prominent clinical manifestation of behavioral variant frontotemporal dementia (bvFTD), but its characteristics are poorly understood. Twelve bvFTD patients were compared with 12 Alzheimer's disease (AD) patients on a structured insight interview of cognitive insight (awareness of having a disorder) and emotional insight (concern over having a disorder). Compared to the AD patients, the bvFTD patients were less aware and less concerned about their disorder, and they had less appreciation of its effects on themselves and on others. After corrective feedback ("updating"), the bvFTD patients were just as aware of their disorder as the AD patients but remained unconcerned and unappreciative of its effects. These findings suggest that lack of insight in bvFTD is not due to "anosognosia," or impaired cognitive and executive awareness of disease, but to "frontal anosodiaphoria," or lack of emotional concern over having bvFTD and its impact on themselves and others.

Differential diagnosis of behavioral variant of fronto-temporal dementia (bvFTD)

Background

The aim of the paper is the differential diagnosis of various types of Fronto-Temporal Dementia (FTD), with the focus on its behavioural variant (bvFTD).

Material/Method

Material and Method. Screening was done in order to assess the depth of dementia with the short version of MMSE, while evaluation of various variants of FTD was performed with the use of such neuropsychological tests as Newcomb and Chicago Fluency Tests, Wechsler Memory Scale - III (WMS-III), Western Aphasia Battery (WAB-R), and the Boston Naming Test (BNT). Behaviour was evaluated with a Polish version of the Frontal Behavioral Inventory (FBInv). The inventory consists of 24 questions which enable an evaluation of social behaviour disorders. The study included 112 patients - 68 men and 46 women treated in the Reintegrative -Training Centre of the Foundation for Persons with Brain Dysfunctions in Kraków and in the Clinic for Developmental Psychiatry, Psychotic Disorders and Old Age Psychiatry, of the Medical University at Gdańsk, who were suffering from various types of dementia.

Results

It was found that FTD patients scored the highest, while the VAD patients scored somewhat lower in the FBInv. At the same time the scores obtained by PPA patients were higher in comparison to the control groups, but not as high as in the case of patients with FTD. In the process of the neurotherapy of FTD patients we found a reduction of the behavioral disturbances, despite the progression of the illness.

Conclusions

The results obtained in the present study confirmed the diagnostic value of FBInv in the differential diagnosis of various types of FTD and in the evaluation of neurotherapy efficacy.

Anosognosia in neurodegenerative disease

Patients with neurological disorders are often partially or completely unaware of the deficits caused by their disease. This impairment is referred to as anosognosia, and it is very common in neurodegenerative disease, particularly in frontotemporal dementia. Anosognosia has significant impacts on function and quality of life for patients with neurodegenerative disease and their caregivers, but the phenomenon has received little formal study, especially in non-Alzheimer's (non-AD) dementias. Furthermore, few studies have attempted to systematically verify the potential role of specific cognitive impairments in producing anosognosia. As a result, the mechanisms underlying this phenomenon are poorly understood. Episodic memory likely plays an important role. In addition, the frontal lobe systems are important for intact self-awareness, but the most relevant frontal functions have not been identified. Motivation required to engage in self-monitoring and emotional activation marking errors as significant are often-overlooked aspects of performance monitoring that may underlie anosognosia in some patients. The present review offers a working model that incorporates these functions and stipulates specific processes that may be important for awareness of changes in one's abilities. Specification of the specific processes whose potential failure results in anosognosia can establish a roadmap for future studies.

Translating mouse vocalizations: prosody and frequency modulation

Mental illness can include impaired abilities to express emotions or respond to the emotions of others. Speech provides a mechanism for expressing emotions, by both what words are spoken and by the melody or intonation of speech (prosody). Through the perception of variations in prosody, an individual can detect changes in another's emotional state. Prosodic features of mouse ultrasonic vocalizations (USVs), indicated by changes in frequency and amplitude, also convey information. Dams retrieve pups that emit separation calls, females approach males emitting solicitous calls, and mice can become fearful of a cue associated with the vocalizations of a distressed conspecific. Because acoustic features of mouse USVs respond to drugs and genetic manipulations that influence reward circuits, USV analysis can be employed to examine how genes influence social motivation, affect regulation, and communication. The purpose of this review is to discuss how genetic and developmental factors influence aspects of the mouse vocal repertoire and how mice respond to the vocalizations of their conspecifics. To generate falsifiable hypotheses about the emotional content of particular calls, this review addresses USV analysis within the framework of affective neuroscience (e.g. measures of motivated behavior such as conditioned place preference tests, brain activity and systemic physiology). Suggested future studies include employment of an expanded array of physiological and statistical approaches to identify the salient acoustic features of mouse vocalizations. We are particularly interested in rearing environments that incorporate sufficient spatial and temporal complexity to familiarize developing mice with a broader array of affective states.

Anosognosia: clinical and ethical considerations

PURPOSE OF REVIEW

This review considers recent findings on classical forms of anosognosia and less dramatic disturbances in self-awareness observed in various brain disorders. It also addresses issues of clinical management and ethical treatment.

RECENT FINDINGS

The study of anosognosia for hemiplegia, Anton's syndrome, and less dramatic disturbances in self-awareness in conditions such as Alzheimer's disease, mild cognitive impairment, and severe traumatic brain injury suggests its 'multifactorial' nature. Lesions in various regions of the brain may contribute to different forms of anosognosia. Animal and human studies suggest that the insular cortex plays an important role in subjective awareness of feeling states, and may be implicated in various forms of anosognosia. Also, right frontal lobe lesions have been implicated, but typically in patients who have bilateral cerebral dysfunction. These patients require careful clinical management in light of their reduced awareness of their neurological and neuropsychological functions that impact daily activities.

SUMMARY

The study of anosognosia and disorders of self-awareness has expanded greatly over the past 20 years. Various patient groups may show different levels of impaired awareness or anosognosia. Guidelines for the clinical management and ethical treatment of these patients are needed, but beginning efforts have been made.

Anosognosia for behavioral disturbances in frontotemporal dementia and corticobasal syndrome: A voxel-based morphometry study

BACKGROUND

Patients with syndromes of the frontotemporal dementia spectrum are frequently unaware of their behavioral changes.

METHODS

Seventy patients with a clinical diagnosis of behavioral variant frontotemporal dementia (bv-FTD, n = 27), aphasic variant frontotemporal dementia (a-FTD, n = 12) and corticobasal syndrome (CBS, n = 31) participated in the study. Anosognosia for behavioral disturbances was measured as discrepancy between caregiver's and patient's ratings on the Frontal Systems Behavior Scale for present and premorbid behavioral symptoms. Voxel-based morphometry analysis of MRI data was performed to explore the association between anosognosia and gray matter loss.

RESULTS

Although behavioral symptoms were reported in all the groups, the comparison between present and premorbid anosognosia revealed that bv-FTD patients not only underestimated their present behavioral disturbances compared to their caregivers, but also overestimated their premorbid behavioral disturbances. Across all groups, the degree of anosognosia for present behavioral impairment correlated with gray matter atrophy in a posterior region of the right superior temporal sulcus (adjacent to the temporoparietal junction).

CONCLUSION

These results confirm the role of the right temporoparietal cortex in the genesis of anosognosia and suggest that, in clinical syndromes of the frontotemporal dementia spectrum, anosognosia is associated with the dysfunction of temporoparietal mechanisms of self versus others knowledge.

Standardised measurement of self-awareness deficits in FTD and AD

BACKGROUND

Diminished ability to perceive one's own impairments, whether cognitive or social, is common in dementia, in particular frontotemporal dementia (FTD), where 'lack of insight' is listed as a core diagnostic feature. Yet, there is no currently accepted method for measuring insight in dementia. The most commonly used methods, which involve comparing patients' opinions of their level of impairment with the opinions of care givers or close family members, are subjective and require the participation of a knowledgeable informant. Here, the authors introduce a new method that allows objective quantification of an individual's awareness of their cognitive abilities and relies upon objective bedside testing.

METHODS

The authors administered several tests of everyday, real-world functions to patients with FTD (n=10) and Alzheimer's disease (AD, n=10) and to control subjects (n=10). Prior to the tasks, participants were asked to predict their performance using a percentile-based rating system. They were also asked to estimate their performance after task completion. Differences between their self-rated and actual performances were calculated.

RESULTS

Whereas the control group showed very little discrepancy between pretest predictions, post-task estimates and actual performance (mean difference of 3.9 percentile points for prediction/3.0 percentile points for post-task estimate), both patient groups overpredicted and overestimated their performance, with a significantly greater discrepancy for FTD (49.0/54.3 percentile points) than AD (27.2/28.3 percentile points).

DISCUSSION

Failures of insight and self-awareness of cognitive dysfunction can be objectively measured in dementia without the assistance of an informant, which will facilitate further study of this key component of higher cognitive functioning.

Neuroanatomical correlates of cognitive self-appraisal in neurodegenerative disease

Self-appraisal is a critical cognitive function, which helps us to choose tasks based on an accurate assessment of our abilities. The neural mechanisms of self-appraisal are incompletely understood, although a growing body of literature suggests that several frontal and subcortical regions are important for self-related processing. Anosognosia, or lack of awareness of one's deficits, is common in neurodegenerative dementias, offering an important window onto the brain systems involved in self-appraisal. We examined the neuroanatomical basis of self-appraisal in a mixed group of 39 individuals, including 35 with cognitive impairment due to one of several probable neurodegenerative diseases, using voxel-based morphometry and an objective, neuropsychologically-based measure of self-appraisal accuracy. Self-appraisal accuracy was correlated with tissue content in the right ventromedial prefrontal cortex (vmPFC). We hypothesize that emotional/physiological processing carried out by vmPFC is an important factor mediating self-appraisal accuracy in dementia.