Behavioral disorders in the frontal and temporal variants of frontotemporal dementia

Neuropsychological differentiation of progressive aphasic disorders

The differentiation of subtypes of primary progressive aphasia (PPA) remains challenging. We aimed to identify optimum neuropsychological measures for characterizing PPA, to examine the relationship between behavioural change and subtypes of PPA and to determine whether characteristic profiles of language, working memory, and behavioural changes occur in PPA. Forty‐seven patients with PPA and multi‐domain Alzheimer's disease (AD) together with 19 age‐matched controls underwent a large battery of working memory and language tests. We found that simple tasks of sentence ordering, narrative production, and buccofacial praxis were particularly useful in differentiating non‐fluent/agrammatic variant PPA (nfvPPA) from other PPA subtypes, whereas a test of single word comprehension was useful in detecting semantic dementia (SD). No individual tests were discriminating for logopenic variant PPA (lvPPA) relative to nfvPPA. LvPPA and multidomain AD exhibited similar language profiles. A principal components analysis revealed that characteristic PPA profiles extended beyond the realms of language, in particular, the presence of apraxia in nfvPPA, behavioural changes in SD, and working memory deficits in lvPPA. These findings suggest that not all tests are equally discriminatory for PPA and highlight the importance of a test profile in differentiating PPA. These results also support the view that lvPPA is a focal form of AD and emphasize the difficulties classifying lvPPA.

A Case of Fronto-Temporal Dementia (FTD) Masquerading as Mood Disorder

A 56-year old Chinese female was referred to an academic medical center with atypical, treatment-resistant depression that continued for approximately 3 years after her sister's death. Comprehensive evaluation including neurocognitive testing, EEG, spinal tap, HIV testing and brain MRI revealed behavioral variant of fronto-temporal dementia (bvFTD) with significant frontal and temporal lobe atrophy.This patient's unusual clinical presentation emphasizes the overlap between depression and bvFTD, and underlines the importance of prompt, accurate diagnosis to minimize often-ineffective pharmacological interventions and caregiver burnout.

Asymmetry of post-mortem neuropathology in behavioural-variant frontotemporal dementia

Antemortem behavioural and anatomic abnormalities have largely been associated with right hemisphere disease in behavioural-variant frontotemporal dementia, but post-mortem neuropathological examination of bilateral hemispheres remains to be defined. Here we measured the severity of post-mortem pathology in both grey and white matter using a validated digital image analysis method in four cortical regions sampled from each hemisphere in 26 patients with behavioural-variant frontotemporal dementia, including those with frontotemporal degeneration (i.e. tau = 9, TDP-43 = 14, or FUS = 1 proteinopathy) or Alzheimer's pathology (n = 2). We calculated an asymmetry index based on the difference in measured pathology from each left-right sample pair. Analysis of the absolute value of the asymmetry index (i.e. degree of asymmetry independent of direction) revealed asymmetric pathology for both grey and white matter in all four regions sampled in frontototemporal degeneration patients with tau or TDP-43 pathology (P ≤ 0.01). Direct interhemispheric comparisons of regional pathology measurements within-subjects in the combined tauopathy and TDP-43 proteinopathy group found higher pathology in the right orbitofrontal grey matter compared to the left (P < 0.01) and increased pathology in ventrolateral temporal lobe grey matter of the left hemisphere compared to the right (P < 0.02). Preliminary group-wise comparisons between tauopathy and TDP-43 proteinopathy groups found differences in patterns of interhemispheric burden of grey and white matter regional pathology, with greater relative white matter pathology in tauopathies. To test the association of pathology measurement with ante-mortem observations, we performed exploratory analyses in the subset of patients with imaging data (n = 15) and found a direct association for increasing pathologic burden with decreasing cortical thickness in frontotemporal regions on ante-mortem imaging in tauopathy (P = 0.001) and a trend for TDP-43 proteinopathy (P = 0.06). Exploratory clinicopathological correlations demonstrated an association of socially-inappropriate behaviours with asymmetric right orbitofrontal grey matter pathology, and reduced semantically-guided category naming fluency was associated asymmetric white matter pathology in the left ventrolateral temporal region. We conclude that pathologic disease burden is distributed asymmetrically in behavioural-variant frontotemporal dementia, although not universally in the right hemisphere, and this asymmetry contributes to the clinical heterogeneity of the disorder. The basis for this asymmetric profile is enigmatic but may reflect distinct species or strains of tau and TDP-43 pathologies with propensities to spread by distinct cell- and region-specific mechanisms. Patterns of region-specific pathology in the right hemisphere as well as the left hemisphere may play a role in antemortem clinical observations, and these observations may contribute to antemortem identification of molecular pathology in frontotemporal degeneration.

Manic behavior and asymmetric right frontotemporal dementia from a novel progranulin mutation

Studies suggest a relationship of manic behavior and bipolar disorder (BD) with behavioral variant frontotemporal dementia (bvFTD). The nature of this relationship is unclear. This report presents a patient with initial manic behavior as the main manifestation of familial bvFTD from a novel progranulin (GRN) mutation. In contrast, there are other reports of a long background of BD preceding a diagnosis of bvFTD. A review of the literature and this patient suggest that manic symptoms result from damage to right frontotemporal neural structures from longstanding BD, as well as from bvFTD and other focal neurological disorders. In addition, there is a subgroup of patients with a probable genetic predisposition to both BD and bvFTD.

[Emotional, affective and behavioral disorders in a behavioral variant of frontotemporal dementia]

AIM

To determine the prevalence and severity of non-cognitive nervous and psychiatric disorders (NNPD) in a behavioral variant of frontotemporal dementia.

MATERIAL AND METHODS

Twenty-nine patients with BVFTD, aged from 41 to 73 years (mean 60.7±8.1 years), were studied. All patients underwent neurological and neuropsychological examinations. NNPD were assessed using the Neuropsychiatric Inventory (J. Cummings et al). Twenty-seven patients underwent brain MRI with T1, T2 and FLAIR sequences.

RESULTS

The most clinically significant symptoms of NNPD were apathy, behavioral disinhibition, eating disorders, abnormal motor activity and euphoria. Irritability, sleep disorders and excitement were less frequent. Anxiety and depression were identified in 13.8 and 20.7% of the patients, respectively. The severity of NNPD can increase and their spectrum can be qualitatively changed with the disease progression that indicates the spread of the neurodegenerative process.

CONCLUSION

Patients with BVFTD had all NNPD with the exception of delusion and hallucinations. The character and degree of severity of some emotional, affective and behavioral disorders are associated with the predominant localization of the pathological process in frontal and temporal brain regions.

Longitudinal white matter change in frontotemporal dementia subtypes and sporadic late onset Alzheimer's disease

Background

Degradation of white matter microstructure has been demonstrated in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD). In preparation for clinical trials, ongoing studies are investigating the utility of longitudinal brain imaging for quantification of disease progression. To date only one study has examined sample size calculations based on longitudinal changes in white matter integrity in FTLD.

Objective

To quantify longitudinal changes in white matter microstructural integrity in the three canonical subtypes of frontotemporal dementia (FTD) and AD using diffusion tensor imaging (DTI).

Methods

60 patients with clinical diagnoses of FTD, including 27 with behavioral variant frontotemporal dementia (bvFTD), 14 with non-fluent variant primary progressive aphasia (nfvPPA), and 19 with semantic variant PPA (svPPA), as well as 19 patients with AD and 69 healthy controls were studied. We used a voxel-wise approach to calculate annual rate of change in fractional anisotropy (FA) and mean diffusivity (MD) in each group using two time points approximately one year apart. Mean rates of change in FA and MD in 48 atlas-based regions-of-interest, as well as global measures of cognitive function were used to calculate sample sizes for clinical trials (80% power, alpha of 5%).

Results

All FTD groups showed statistically significant baseline and longitudinal white matter degeneration, with predominant involvement of frontal tracts in the bvFTD group, frontal and temporal tracts in the PPA groups and posterior tracts in the AD group. Longitudinal change in MD yielded a larger number of regions with sample sizes below 100 participants per therapeutic arm in comparison with FA. SvPPA had the smallest sample size based on change in MD in the fornix (n = 41 participants per study arm to detect a 40% effect of drug), and nfvPPA and AD had their smallest sample sizes based on rate of change in MD within the left superior longitudinal fasciculus (n = 49 for nfvPPA, and n = 23 for AD). BvFTD generally showed the largest sample size estimates (minimum n = 140 based on MD in the corpus callosum). The corpus callosum appeared to be the best region for a potential study that would include all FTD subtypes. Change in global measure of functional status (CDR box score) yielded the smallest sample size for bvFTD (n = 71), but clinical measures were inferior to white matter change for the other groups.

Conclusions

All three of the canonical subtypes of FTD are associated with significant change in white matter integrity over one year. These changes are consistent enough that drug effects in future clinical trials could be detected with relatively small numbers of participants. While there are some differences in regions of change across groups, the genu of the corpus callosum is a region that could be used to track progression in studies that include all subtypes.

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We show longitudinal change in white matter in frontotemporal lobar degeneration (FTLD) and Alzheimer’s disease (AD).

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We use diffusion tensor imaging (DTI) to quantify rate of white matter degeneration in FTLD and AD.

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In preparation for clinical trials, utility of longitudinal DTI as surrogate marker of therapeutic efficacy is investigated.

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We produce sample sizes based on rate of change in DTI metrics in the three canonical subtypes of FTLD and AD.

Sleep Disturbances in Frontotemporal Dementia

Sleep disorders appear to be frequent comorbidities in patients with frontotemporal dementia (FTD). Insomnia and excessive daytime sleepiness commonly occur in patients with FTD and significantly contribute to caregiver burden and burnout. Sleep is severely fragmented in FTD patients, likely secondary to behavioral disturbances, other primary sleep disorders such as sleep disordered breathing and restless leg syndrome, and neurodegeneration of nuclei involved in sleep and wakefulness. Treatment of primary sleep disorders may improve excessive daytime sleepiness and sleep quality and may improve daytime cognitive functioning. Rapid eye movement (REM) sleep behavior disorder is rare in FTD and may be confused with excessive nocturnal activity due to disturbed circadian rhythm. The relationship between FTD, sleep quality, and sleep disorders requires further study to better understand the contribution of disturbed sleep to daytime neurocognitive functioning and quality of life in FTD. Further, future studies should focus on comparing sleep disturbances between different FTD syndromes, especially behavioral variant FTD and primary progressive aphasia. Comorbid sleep disorders should be promptly sought and treated in patients with FTD to improve patient and caregiver quality of life.

Frontotemporal lobar degeneration and social behaviour: Dissociation between the knowledge of its consequences and its conceptual meaning

Inappropriate social behaviour is an early symptom of frontotemporal lobar degeneration (FTLD) in both behavioural variant frontotemporal dementia (bvFTD) and semantic dementia (SD) subtypes. Knowledge of social behaviour is essential for appropriate social conduct. The superior anterior temporal lobe (ATL) has been identified as one key neural component for the conceptual knowledge of social behaviour, but it is unknown whether this is dissociable from knowledge of the consequences of social behaviour. Here, we used a newly-developed test of knowledge about long-term and short-term consequences of social behaviour to investigate its impairment in patients with FTLD relative to a previously-developed test of social conceptual knowledge. We included 19 healthy elderly control participants and 19 consecutive patients with features of bvFTD or SD and defined dissociations as performance differences between tasks for each patient (Bonferroni-corrected p < .05). Knowledge of long-term consequences was selectively impaired relative to short-term consequences in five patients and the reverse dissociation occurred in one patient. Six patients showed a selective impairment of social concepts relative to long-term consequences with the reverse dissociation occurring in one patient. These results corroborate the hypothesis that knowledge of long-term consequences of social behaviour is dissociable from knowledge of short-term consequences, as well as of social conceptual knowledge. Confirming our hypothesis, we found that patients with more marked grey matter (GM) volume loss in frontopolar relative to right superior ATL regions of interest exhibited poorer knowledge of the long-term consequences of social behaviour relative to the knowledge of its conceptual meaning and vice versa (n = 15). These findings support the hypothesis that frontopolar and ATL regions represent distinct aspects of social knowledge. This suggests that rather than being unable to suppress urges to behave inappropriately, FTLD patients often lose the knowledge of what appropriate social behaviour is and can therefore not be expected to behave accordingly.

Pharmacological Management of Psychiatric Symptoms in Frontotemporal Dementia: A Systematic Review

Psychiatric symptoms in patients with frontotemporal dementia (FTD) are highly prevalent and may complicate clinical management of these patients. Purpose of the present article is to present and discuss available data about the pharmacological treatment of psychiatric symptoms in patients with FTD. A research in the main database sources has been conducted to obtain an overview of the pharmacological management of psychiatric symptoms in patients with FTD. The search strategy included the following terms-"FTD and psychiatry," "FTD and behavioural disturbances," and "FTD and treatment". Pathophysiology of psychiatric symptoms in FTD is different from other types of dementia. Although drugs for Alzheimer disease appear to be ineffective for the treatment of psychiatric symptoms of FTD, preliminary evidence supports a possible usefulness of serotonergic antidepressants for these patients. Data are too scanty to draw definitive conclusions, but antidepressant treatment, particularly with serotonergic compounds, may improve psychiatric symptoms in patients with FTD. Large observational studies are needed to confirm this preliminary evidence, and a lot of effort and collaboration between neurologists and psychiatrists will be definitely crucial for future research of effective treatments for FTD.

Deconstructing empathy: Neuroanatomical dissociations between affect sharing and prosocial motivation using a patient lesion model

Affect sharing and prosocial motivation are integral parts of empathy that are conceptually and mechanistically distinct. We used a neurodegenerative disease (NDG) lesion model to examine the neural correlates of these two aspects of real-world empathic responding. The study enrolled 275 participants, including 44 healthy older controls and 231 patients diagnosed with one of five neurodegenerative diseases (75 Alzheimer's disease, 58 behavioral variant frontotemporal dementia (bvFTD), 42 semantic variant primary progressive aphasia (svPPA), 28 progressive supranuclear palsy, and 28 non-fluent variant primary progressive aphasia (nfvPPA). Informants completed the Revised Self-Monitoring Scale's Sensitivity to the Expressive Behavior of Others (RSMS-EX) subscale and the Interpersonal Reactivity Index's Empathic Concern (IRI-EC) subscale describing the typical empathic behavior of the participants in daily life. Using regression modeling of the voxel based morphometry of T1 brain scans prepared using SPM8 DARTEL-based preprocessing, we isolated the variance independently contributed by the affect sharing and the prosocial motivation elements of empathy as differentially measured by the two scales. We found that the affect sharing component uniquely correlated with volume in right>left medial and lateral temporal lobe structures, including the amygdala and insula, that support emotion recognition, emotion generation, and emotional awareness. Prosocial motivation, in contrast, involved structures such as the nucleus accumbens (NaCC), caudate head, and inferior frontal gyrus (IFG), which suggests that an individual must maintain the capacity to experience reward, to resolve ambiguity, and to inhibit their own emotional experience in order to effectively engage in spontaneous altruism as a component of their empathic response to others.

The effectiveness and unique contribution of neuropsychological tests and the δ latent phenotype in the differential diagnosis of dementia in the uniform data set

OBJECTIVE

Two main approaches to the interpretation of cognitive test performance have been utilized for the characterization of disease: evaluating shared variance across tests, as with measures of severity, and evaluating the unique variance across tests, as with pattern and error analysis. Both methods provide necessary information, but the unique contributions of each are rarely considered. This study compares the 2 approaches on their ability to differentially diagnose with accuracy, while controlling for the influence of other relevant demographic and risk variables.

METHOD

Archival data requested from the NACC provided clinical diagnostic groups that were paired to 1 another through a genetic matching procedure. For each diagnostic pairing, 2 separate logistic regression models predicting clinical diagnosis were performed and compared on their predictive ability. The shared variance approach was represented through the latent phenotype δ, which served as the lone predictor in 1 set of models. The unique variance approach was represented through raw score values for the 12 neuropsychological test variables comprising δ, which served as the set of predictors in the second group of models.

RESULTS

Examining the unique patterns of neuropsychological test performance across a battery of tests was the superior method of differentiating between competing diagnoses, and it accounted for 16-30% of the variance in diagnostic decision making.

CONCLUSION

Implications for clinical practice are discussed, including test selection and interpretation. (PsycINFO Database Record

Functional dissociation between anterior temporal lobe and inferior frontal gyrus in the processing of dynamic body expressions: Insights from behavioral variant frontotemporal dementia

Several brain regions are involved in the processing of emotional stimuli, however, the contribution of specific regions to emotion perception is still under debate. To investigate this issue, we combined behavioral testing, structural and resting state imaging in patients diagnosed with behavioral variant frontotemporal dementia (bvFTD) and age matched controls, with task-based functional imaging in young, healthy volunteers. As expected, bvFTD patients were impaired in emotion detection as well as emotion categorization tasks, testing dynamic emotional body expressions as stimuli. Interestingly, their performance in the two tasks correlated with gray matter volume in two distinct brain regions, the left anterior temporal lobe for emotion detection and the left inferior frontal gyrus (IFG) for emotion categorization. Confirming this observation, multivoxel pattern analysis in healthy volunteers demonstrated that both ROIs contained information for emotion detection, but that emotion categorization was only possible from the pattern in the IFG. Furthermore, functional connectivity analysis showed reduced connectivity between the two regions in bvFTD patients. Our results illustrate that the mentalizing network and the action observation network perform distinct tasks during emotion processing. In bvFTD, communication between the networks is reduced, indicating one possible cause underlying the behavioral symptoms. Hum Brain Mapp 37:4472-4486, 2016. © 2016 Wiley Periodicals, Inc.

You stole my food! Eating alterations in frontotemporal dementia

Patients with different types of dementia may exhibit pathological eating habits, including food fads, hyperphagia, or even ingestion of inanimate objects. Several findings reveal that such eating alterations are more common in patients with frontotemporal dementia (FTD) than other types of dementia. Moreover, eating alterations may differ between the two variants of the disease, namely the behavioral variant and semantic dementia (SD). In this review, we summarized evidences regarding four areas: eating and body weight alterations in FTD, the most common assessment methods, anatomical correlates of eating disorders, and finally, proposed underlying mechanisms. An increasing understanding of the factors that contribute to eating abnormalities may allow first, a better comprehension of the clinical features of the disease and second, shed light on the mechanism underlying eating behaviors in the normal population.

Longitudinal change in everyday function and behavioral symptoms in frontotemporal dementia

Background:

The relationship between behavioral changes and functional decline in frontotemporal dementia (FTD) is not well understood.

Methods:

Thirty-nine patients (21 behavioral variant FTD [bvFTD], 18 semantic variant primary progressive aphasia [svPPA]) were followed up longitudinally (2–4 years follow-up). Functional (Disability Assessment for Dementia) and behavioral (Cambridge Behavioural Inventory Revised) assessments were included for between-group (pairwise comparisons, mixed model analysis) and within-group analyses (bivariate correlations).

Results:

Functionally, patients with bvFTD were more impaired than patients with svPPA at baseline and continued to be at follow-up, despite similar disease duration. By contrast, behavioral impairments differed between patient groups at baseline and at follow-up. At baseline, patients with bvFTD exhibited higher levels of apathy and changes in eating than patients with svPPA; disinhibited and stereotypical behaviors were similar. Over the years, patients with bvFTD showed reduction in disinhibition and stereotypical behavior while apathy and eating changes increased. By contrast, all measured behaviors increased in patients with svPPA over time. Finally, only apathy made longitudinal contributions to functional disability in patients with svPPA, whereas apathy and stereotypical behavior were associated with increased disability in patients with bvFTD.

Conclusions:

Despite shared overlapping baseline behavioral symptoms, patients with bvFTD are more functionally impaired than patients with svPPA. Apathy has a strong role in disability for both bvFTD and svPPA, but stereotypical behaviors only contributed to functional deficits in patients with bvFTD. Our findings suggest that rigid/compulsive behaviors may in fact support activity engagement in patients with svPPA. Taken together, our results indicate that interventions to reduce disability in the FTD spectrum require an alternative rationale in comparison to Alzheimer disease dementia, and should carefully weigh the interaction of behavioral symptoms and functional status.

Co-Occurrence of Language and Behavioural Change in Frontotemporal Lobar Degeneration

Background/Objectives

We aimed to evaluate the co-occurrence of language and behavioural impairment in patients with frontotemporal lobar degeneration (FTLD) spectrum pathology.

Methods

Eighty-one dementia patients with pathological confirmation of FTLD were identified. Anonymized clinical records from patients' first assessment were rated for language and behavioural features from frontotemporal dementia consensus criteria, primary progressive aphasia (PPA) criteria and 1998 FTLD criteria.

Results

Over 90% of patients with FTLD pathology exhibited a combination of at least one behavioural and one language feature. Changes in language, in particular, were commonly accompanied by behavioural change. Notably, the majority of patients who displayed language features characteristic of semantic variant PPA exhibited ‘early perseverative, stereotyped or compulsive/ritualistic behaviour’. Moreover, ‘executive/generation deficits with relative sparing of memory and visuospatial functions’ occurred in most patients with core features of non-fluent variant PPA.

Conclusion

Behavioural and language symptoms frequently co-occur in patients with FTLD pathology. Current classifications, which separate behavioural and language syndromes, do not reflect this co-occurrence.

Mania secondary to focal brain lesions: implications for understanding the functional neuroanatomy of bipolar disorder

OBJECTIVES

Approximately 3.5 million Americans will experience a manic episode during their lifetimes. The most common causes are psychiatric illnesses such as bipolar I disorder and schizoaffective disorder, but mania can also occur secondary to neurological illnesses, brain injury, or neurosurgical procedures.

METHODS

For this narrative review, we searched Medline for articles on the association of mania with stroke, brain tumors, traumatic brain injury, multiple sclerosis, neurodegenerative disorders, epilepsy, and neurosurgical interventions. We discuss the epidemiology, features, and treatment of these cases. We also review the anatomy of the lesions, in light of what is known about the neurobiology of bipolar disorder.

RESULTS

The prevalence of mania in patients with brain lesions varies widely by condition, from <2% in stroke to 31% in basal ganglia calcification. Mania occurs most commonly with lesions affecting frontal, temporal, and subcortical limbic brain areas. Right-sided lesions causing hypo-functionality or disconnection (e.g., stroke; neoplasms) and left-sided excitatory lesions (e.g., epileptogenic foci) are frequently observed.

CONCLUSIONS

Secondary mania should be suspected in patients with neurological deficits, histories atypical for classic bipolar disorder, and first manic episodes after the age of 40 years. Treatment with antimanic medications, along with specific treatment for the underlying neurologic condition, is typically required. Typical lesion locations fit with current models of bipolar disorder, which implicate hyperactivity of left-hemisphere reward-processing brain areas and hypoactivity of bilateral prefrontal emotion-modulating regions. Lesion studies complement these models by suggesting that right-hemisphere limbic-brain hypoactivity, or a left/right imbalance, may be relevant to the pathophysiology of mania.

Hemispheric Specialization within the Superior Anterior Temporal Cortex for Social and Nonsocial Concepts

Studies of semantic dementia, imaging, and repetitive TMS have suggested that the bilateral anterior temporal lobes (ATLs) underpin a modality-invariant representational hub within the semantic system. Questions remain, however, regarding functional specialization across a variety of knowledge domains within the ATL region. We investigated direct evidence for the functional relevance of the superior ATL in processing social concepts. Using converging evidence from noninvasive brain stimulation and neuropsychology, we demonstrate graded differentiation of right and left superior anterior temporal areas in social cognition. Whereas the left superior ATL is necessary for processing both social and nonsocial abstract concepts, social conceptual processing predominates in the right superior ATL. This graded hemispheric specialization is mirrored in the patient results. Our data shed new light on the classic debate about hemispheric differences in semantic and social cognition. These results are considered in the context of models of semantic representation and the emerging data on connectivity for left and right ATL regions.

Amyotrophic lateral sclerosis and frontotemporal dementia: distinct and overlapping changes in eating behaviour and metabolism

Metabolic changes incorporating fluctuations in weight, insulin resistance, and cholesterol concentrations have been identified in several neurodegenerative disorders. Whether these changes result from the neurodegenerative process affecting brain regions necessary for metabolic regulation or whether they drive the degenerative process is unknown. Emerging evidence from epidemiological, clinical, pathological, and experimental studies emphasises a range of changes in eating behaviours and metabolism in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In ALS, metabolic changes have been linked to disease progression and prognosis. Furthermore, changes in eating behaviour that affect metabolism have been incorporated into the diagnostic criteria for FTD, which has some clinical and pathological overlap with ALS. Whether the distinct and shared metabolic and eating changes represent a component of the proposed spectrum of the two diseases is an intriguing possibility. Moreover, future research should aim to unravel the complex connections between eating, metabolism, and neurodegeneration in ALS and FTD, and aim to understand the potential for targeting modifiable risk factors in disease development and progression.

Comparing the driving behaviours of individuals with frontotemporal lobar degeneration and those with Alzheimer's disease

BACKGROUND

Assessing driving aptitude in dementia patients is critically important for both patient and public safety. However, there have been only a few reports on the driving behaviours and accident risk of patients with dementia, especially frontotemporal lobar degeneration (FTLD). Therefore, we compared the characteristics of driving behaviours in patients with FTLD and those with Alzheimer's disease (AD).

METHODS

The subjects were 28 FTLD and 67 AD patients who visited the Department of Psychiatry, Kochi Medical School Hospital. We conducted semi-structured interviews with their families and caregivers about traffic accident history and changes in patient driving behaviours after dementia onset and then compared the findings between the two groups.

RESULTS

Overall changes in driving behaviours were reported in 89% (25/28) and 76% (51/67) of the FTLD and AD patients, respectively (P = 0.17). In the FTLD group, difficulty in judging inter-vehicle distances, ignoring road signs and traffic signals, and distraction were reported in 50% (14/28), 61% (17/28), and 50% (14/28) of patients, respectively, and 75% (21/28) patients had caused a traffic accident after dementia onset. The risk of causing an accident was higher in the FTLD group than in the AD group (odds ratio = 10.4, 95% confidence interval = 3.7-29.1). In addition, the mean duration between dementia onset and a traffic accident was 1.35 years in the FTLD group compared with 3.0 years in the AD group (P < 0.01).

CONCLUSIONS

Patients with FTLD were more likely to show dangerous driving behaviours than those with AD, and the risk of causing a traffic accident may be higher in patients with FTLD from an early disease stage.

The prevalence of depressive symptoms in frontotemporal dementia: a meta-analysis

BACKGROUND

Depression is common in Alzheimer's and vascular dementia and is associated with poorer outcomes; however, less is known about the impact of depression on frontotemporal dementia (FTD). Here, we conducted a meta-analysis of diagnostic methods and the prevalence of depressive symptoms in FTD.

METHODS

PubMed, EMBASE and PsychINFO were queried for 'depression' and/or 'depressive mood' in behavioral- and language-variant FTD. The prevalence and diagnosis of depressive symptoms were extracted from relevant studies and the results pooled using a random-effects model.

RESULTS

We included 29 studies in this meta-analysis, with sample sizes ranging from 3 to 73 (n = 870). The omnibus estimated event rate of depressed mood was 0.334 (33%; 95% CI: 0.268-0.407). Symptoms were most commonly assessed via standardized neuropsychiatric rating scales, with other methods including subjective caregiver reports and chart reviews. The study results were heterogeneous due to the variability in diagnostic methods.

CONCLUSIONS

Depressive symptoms similar to those in other dementias are commonly detected in FTD. However, the diagnostic methods are heterogeneous, and symptoms of depression often overlap with manifestations of FTD. Having a standardized diagnostic approach to depression in FTD will greatly facilitate future research in this area.

Neuroanatomical correlates of emotional blunting in behavioral variant frontotemporal dementia and early-onset Alzheimer's disease

BACKGROUND

Emotional blunting is a characteristic feature of behavioral variant frontotemporal dementia (bvFTD) and can help discriminate between patients with bvFTD and other forms of younger-onset dementia.

OBJECTIVE

We compared the presence of emotional blunting symptoms in patients with bvFTD and early-onset Alzheimer's disease (AD), and investigated the neuroanatomical associations between emotional blunting and regional brain volume.

METHODS

Twenty-five individuals with bvFTD (n = 11) and early-onset AD (n = 14) underwent magnetic resonance imaging (MRI) and were rated on symptoms of emotional blunting using the Scale for Emotional Blunting (SEB). The two groups were compared on SEB ratings and MRI-derived brain volume using tensor-based morphometry. Voxel-wise linear regression was performed to determine neuroanatomical correlates of SEB scores.

RESULTS

The bvFTD group had significantly higher SEB scores compared to the AD group. On MRI, bvFTD patients had smaller bilateral frontal lobe volume compared to AD patients, while AD patients had smaller bilateral temporal and left parietal volume than bvFTD patients. In bvFTD, SEB ratings were strongly correlated with right anterior temporal volume, while the association between SEB and the right orbitofrontal cortex was non-significant.

CONCLUSIONS

Symptoms of emotional blunting were more prevalent in bvFTD than early-onset AD patients. These symptoms were particularly associated with right-sided atrophy, with significant involvement of the right anterior temporal region. Based on these findings, the SEB appears to measure symptoms of emotional blunting that are localized to the right anterior temporal lobe.

Neural basis of motivational approach and withdrawal behaviors in neurodegenerative disease

INTRODUCTION

The Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS) have been theorized as neural systems that regulate approach/withdrawal behaviors. Behavioral activation/inhibition balance may change in neurodegenerative disease based on underlying alterations in systems supporting motivation and approach/withdrawal behaviors, which may in turn be reflected in neuropsychiatric symptoms.

METHOD

A total of 187 participants (31 patients diagnosed with behavioral variant of FTD [bvFTD], 13 semantic variant of primary progressive aphasia [svPPA], 14 right temporal variant FTD [rtFTD], 54 Alzheimer's disease [AD], and 75 older healthy controls [NCs]) were included in this study. Changes in behavioral inhibition/activation were measured using the BIS/BAS scale. We analyzed the correlation between regional atrophy pattern and BIS/BAS score, using voxel-based morphometry (VBM).

RESULTS

ADs had significantly higher BIS scores than bvFTDs and NCs. bvFTDs activation-reward response (BAS-RR) was significantly lower than ADs and NCs, though their activation-drive (BAS-D) was significantly higher than in ADs. Both AD and rtFTD patients had abnormally low activation fun-seeking (BAS-FS) scores. BIS score correlated positively with right anterior cingulate and middle frontal gyrus volume, as well as volume in the right precentral gyrus and left insula/operculum.

CONCLUSIONS

AD, bvFTD, and rtFTD patients show divergent patterns of change in approach/withdrawal reactivity. High BIS scores correlated with preservation of right-predominant structures involved in task control and self-protective avoidance of potentially negative reinforcers. Damage to these regions in bvFTD may create a punishment insensitivity that underlies patients' lack of self-consciousness in social contexts.

Data-driven regions of interest for longitudinal change in frontotemporal lobar degeneration

Current research is investigating the potential utility of longitudinal measurement of brain structure as a marker of drug effect in clinical trials for neurodegenerative disease. Recent studies in Alzheimer's disease (AD) have shown that measurement of change in empirically derived regions of interest (ROIs) allows more reliable measurement of change over time compared with regions chosen a-priori based on known effects of AD on brain anatomy. Frontotemporal lobar degeneration (FTLD) is a devastating neurodegenerative disorder for which there are no approved treatments. The goal of this study was to identify an empirical ROI that maximizes the effect size for the annual rate of brain atrophy in FTLD compared with healthy age matched controls, and to estimate the effect size and associated power estimates for a theoretical study that would use change within this ROI as an outcome measure. Eighty six patients with FTLD were studied, including 43 who were imaged twice at 1.5 T and 43 at 3 T, along with 105 controls (37 imaged at 1.5 T and 67 at 3 T). Empirically-derived maps of change were generated separately for each field strength and included the bilateral insula, dorsolateral, medial and orbital frontal, basal ganglia and lateral and inferior temporal regions. The extent of regions included in the 3 T map was larger than that in the 1.5 T map. At both field strengths, the effect sizes for imaging were larger than for any clinical measures. At 3 T, the effect size for longitudinal change measured within the empirically derived ROI was larger than the effect sizes derived from frontal lobe, temporal lobe or whole brain ROIs. The effect size derived from the data-driven 1.5 T map was smaller than at 3 T, and was not larger than the effect size derived from a-priori ROIs. It was estimated that measurement of longitudinal change using 1.5 T MR systems requires approximately a 3-fold increase in sample size to obtain effect sizes equivalent to those seen at 3 T. While the results should be confirmed in additional datasets, these results indicate that empirically derived ROIs can reduce the number of subjects needed for a longitudinal study of drug effects in FTLD compared with a-priori ROIs. Field strength may have a significant impact on the utility of imaging for measuring longitudinal change.

Neuropsychiatric symptoms as early manifestations of emergent dementia: Provisional diagnostic criteria for mild behavioral impairment

Neuropsychiatric symptoms (NPS) are common in dementia and in predementia syndromes such as mild cognitive impairment (MCI). NPS in MCI confer a greater risk for conversion to dementia in comparison to MCI patients without NPS. NPS in older adults with normal cognition also confers a greater risk of cognitive decline in comparison to older adults without NPS. Mild behavioral impairment (MBI) has been proposed as a diagnostic construct aimed to identify patients with an increased risk of developing dementia, but who may or may not have cognitive symptoms. We propose criteria that include MCI in the MBI framework, in contrast to prior definitions of MBI. Although MBI and MCI can co-occur, we suggest that they are different and that both portend a higher risk of dementia. These MBI criteria extend the previous literature in this area and will serve as a template for validation of the MBI construct from epidemiologic, neurobiological, treatment, and prevention perspectives.

Enhancing caregivers' understanding of dementia and tailoring activities in frontotemporal dementia: two case studies

PURPOSE

The purpose of this study is to describe the intervention process and results of the Tailored Activities Program (TAP) in two people diagnosed with Frontotemporal Dementia (FTD).

METHOD

TAP is an occupational therapy (OT) community-based intervention program that prescribes personalised activities to reduce difficult behaviours of dementia. The OT works with carers over a 4-month period (assessment, activity prescription and generalisation of strategies). Study measures were collected (blind researcher) pre- and post-intervention: cognition, functional disability, behavioural symptoms and Caregiver Confidence and Vigilance.

RESULTS

A 51-year-old woman with behavioural-variant FTD could consistently engage in more activities post-intervention, with scores indicating improvements to behaviour, function and caregiver confidence. A 63-year-old man with semantic variant FTD engaged well in the prescribed activities, with scores reflecting reduced carer distress regarding challenging behaviours and improved caregiver vigilance.

CONCLUSIONS

TAP is efficacious in FTD, allowing for differences in approach for FTD subtype, where behavioural symptoms are very severe and pervasive.

IMPLICATIONS FOR REHABILITATION

The Tailored Activities Program is an intervention which can be tailored to account for unique behavioural and language profiles inherent across frontotemporal dementia (FTD) subtypes. Maintaining a flexible approach when applying an intervention in FTD allows for tailoring to individual case variability within FTD subtypes.

White matter disease contributes to apathy and disinhibition in behavioral variant frontotemporal dementia

OBJECTIVE

To relate changes in fractional anisotropy associated with behavioral variant frontotemporal dementia to measures of apathy and disinhibition.

BACKGROUND

Apathy and disinhibition are the 2 most common behavioral features of behavioral variant frontotemporal dementia, and these symptoms are associated with accelerated patient decline and caregiver stress. However, little is known about how white matter disease contributes to these symptoms.

METHODS

We collected neuropsychiatric data, volumetric magnetic resonance imaging, and diffusion-weighted imaging in 11 patients who met published criteria for behavioral variant frontotemporal dementia and had an autopsy-validated cerebrospinal fluid profile consistent with frontotemporal lobar degeneration. We also collected imaging data on 34 healthy seniors for analyses defining regions of disease in the patients. We calculated and analyzed fractional anisotropy with a white matter tract-specific method. This approach uses anatomically guided data reduction to increase sensitivity, and localizes results within canonically defined tracts. We used nonparametric, cluster-based statistical analysis to relate fractional anisotropy to neuropsychiatric measures of apathy and disinhibition.

RESULTS

The patients with behavioral variant frontotemporal dementia had widespread reductions in fractional anisotropy in anterior portions of frontal and temporal white matter, compared to the controls. Fractional anisotropy correlated with apathy in the left uncinate fasciculus and with disinhibition in the right corona radiata.

CONCLUSIONS

In patients with behavioral variant frontotemporal dementia, apathy and disinhibition are associated with distinct regions of white matter disease. The implicated fiber tracts likely support frontotemporal networks that are involved in goal-directed behavior.

Paranoid personality masking an atypical case of frontotemporal dementia

Frontotemporal dementia (FTD) is a debilitating disease that is well described in the “Diagnostic and statistical manual of mental disorders, fifth edition (DSM-5)”, and typically presents with memory impairment, progressive decline in cortical functioning, and behavioral changes. Age of onset is generally in the late fifties, and usually the first presentation involves a change in behavior and emotional blunting. Treatment of FTD involves management of any neurobehavioral symptoms while trials of atypical antipsychotics are ongoing but suggest some efficacy. We present a case of a patient who first presented with severe paranoid personality traits and frank persecutory delusions. This atypical presentation of our patient first led to her incorrect diagnosis of a psychotic disorder and paranoid personality disorder. As a result of this diagnosis, she was treated unsuccessfully. A subsequent magnetic resonance imaging (MRI) then showed atrophy of frontal and temporal lobes bilaterally (left more prominent than right) which confirmed the diagnosis of FTD. The importance of this case involves the atypical presentation of paranoia and delusions, and our patient’s incorrect diagnosis based on her clinical presentation led to a trial of unsuccessful treatment. Only after performing an MRI, which showed atrophy, was the patient appropriately treated and deemed medically stable. This case report illustrates the importance of considering a rare presentation of frontotemporal lobe dementia with patients who are in the typical age range and present with paranoia and delusions.

Divergent CSF τ alterations in two common tauopathies: Alzheimer's disease and progressive supranuclear palsy

BACKGROUND

Elevated CSF τ is considered a biomarker of neuronal injury in newly developed Alzheimer's disease (AD) and mild cognitive impairment (MCI) criteria. However, previous studies have failed to detect alterations of τ species in other primary tauopathies. We assessed CSF τ protein abnormalities in AD, a tauopathy with prominent Aβ pathology, and progressive supranuclear palsy (PSP), a primary tauopathy characterised by deposition of four microtubule-binding repeat (4R) τ with minimal Aβ pathology.

METHODS

26 normal control (NC), 37 AD, and 24 patients with PSP participated in the study. AD and PSP were matched for severity using the clinical dementia rating sum of boxes (CDR-sb) scores. The INNO BIA AlzBio3 multiplex immunoassay was used to measure CSF Aβ, total τ, and ptau181. Additional, novel ELISAs targeting different N-terminal and central τ epitopes were developed to examine CSF τ components and to investigate interactions between diagnostic group, demographics and genetic variables.

RESULTS

PSP had lower CSF N-terminal and C-terminal τ concentrations than NC and AD measured with the novel τ ELISAs and the standard AlzBio3 τ and ptau assays. AD had higher total τ and ptau levels than NC and PSP. There was a gender by diagnosis interaction in AD and PSP for most τ species, with lower concentrations for male compared to female patients.

CONCLUSIONS

CSF τ fragment concentrations are different in PSP compared with AD despite the presence of severe τ pathology and neuronal injury in both disorders. CSF τ concentration likely reflects multiple factors in addition to the degree of neuronal injury.

Anosognosia in people with cognitive impairment: association with cognitive deficits and behavioral disturbances

AIMS

To investigate, in a group of subjects at an early stage of cognitive impairment, the relationship between anosognosia and both cognitive and behavioral symptoms by exploring the various domains of insight.

METHODS

One hundred and eight subjects affected by cognitive impairment were consecutively enrolled. The level of awareness was evaluated by means of the Clinical Insight Rating Scale (CIRS). Psychiatric symptoms were evaluated using the Italian version of the Neuropsychiatric Inventory (NPI), whereas memory (memory index, MI) and executive (executive index, EI) functions were explored using a battery of neuropsychological tests and qualified by means of a single composite cognitive index score for each function.

RESULTS

A significant positive correlation between the total NPI score and global anosognosia score was found. Furthermore, both the MI and EI scores were lower in subjects with anosognosia than in those without anosognosia (p < 0.001 and p < 0.007, respectively). When the single domains of the CIRS were considered, anosognosia of reason of visit correlated with the EI score (r = -0.327, p = 0.01) and night-time behavioral disturbances (r = 0.225; p = 0.021); anosognosia of cognitive deficit correlated with depression (r = -0.193; p = 0.049) and the MI score (r = -0.201; p = 0.040); anosognosia of functional deficit correlated with the MI score (r = -0.257; p = 0.008), delusions (r = 0.232; p = 0.015) and aberrant motor behavior (r = 0.289; p = 0.003); anosognosia of disease progression correlated with the MI score (r = -0.236; p = 0.015), agitation (r = 0.247; p = 0.011), aberrant motor behavior (r = 0.351; p = 0.001) and night-time behavioral disturbances (r = 0.216; p = 0.027).

CONCLUSIONS

Our study suggests that, in the early stage of cognitive impairment, anosognosia is associated with both cognitive deficits and behavioral disorders according to the specific functional anatomy of the symptoms.

Integrating Neuropsychology and Brain Imaging for a Referral of Possible Pseudodementia: A Case Report

The study aimed to highlight the importance of interdisciplinary collaboration and the value for combining normative neuropsychological and neuroradiological measures for clinical purposes. We present the case of "CL," a 65-year-old, right-handed, Caucasian female referred for a neuropsychological evaluation of memory difficulties and depression with the rule-out of pseudodementia. A brain magnetic resonance imaging (MRI) scan was conducted within 24 hours of the neuropsychology exam. Mood measures showed elevated depression and apathy symptoms. The neuropsychological profile showed variable effort, intact comprehension but compromised confrontation naming and verbal memory deficits. Using normative references from 20 female age- and education-matched healthy control peers, CL showed significantly reduced temporal cortex thickness with reduced bilateral hippocampal, right amygdala, and right caudate volumes. Combined data were supportive of a diagnosis of semantic dementia. Examining neuropsychological profiles in combination with neuroimaging standardized metrics relative to peers improved case conceptualization. Standard measures of effort and malingering examined alone and without MRI for the diagnosis of pseudodementia have questionable validity and rationale. We additionally discuss the advantages and limitations/challenges for integrating neuropsychological assessments with normative based MRI brain metrics.

Altered network connectivity in frontotemporal dementia with C9orf72 hexanucleotide repeat expansion

Hexanucleotide repeat expansion in C9orf72 represents the most common genetic cause of familial and sporadic behavioural variant frontotemporal dementia. Previous studies show that some C9orf72 carriers with behavioural variant frontotemporal dementia exhibit distinctive atrophy patterns whereas others show mild or undetectable atrophy despite severe behavioural impairment. To explore this observation, we examined intrinsic connectivity network integrity in patients with or without the C9orf72 expansion. We studied 28 patients with behavioural variant frontotemporal dementia, including 14 C9orf72 mutation carriers (age 58.3 ± 7.7 years, four females) and 14 non-carriers (age 60.8 ± 6.9 years, four females), and 14 age- and sex-matched healthy controls. Both patient groups included five patients with comorbid motor neuron disease. Neuropsychological data, structural brain magnetic resonance imaging, and task-free functional magnetic resonance imaging were obtained. Voxel-based morphometry delineated atrophy patterns, and seed-based intrinsic connectivity analyses enabled group comparisons of the salience, sensorimotor, and default mode networks. Single-patient analyses were used to explore network imaging as a potential biomarker. Despite contrasting atrophy patterns in C9orf72 carriers versus non-carriers, patient groups showed topographically similar connectivity reductions in the salience and sensorimotor networks. Patients without C9orf72 expansions exhibited increases in default mode network connectivity compared to controls and mutation carriers. Across all patients, behavioural symptom severity correlated with diminished salience network connectivity and heightened default mode network connectivity. In C9orf72 carriers, salience network connectivity reduction correlated with atrophy in the left medial pulvinar thalamic nucleus, and this region further showed diminished connectivity with key salience network hubs. Single-patient analyses revealed salience network disruption and default mode network connectivity enhancement in C9orf72 carriers with early-stage or slowly progressive symptoms. The findings suggest that patients with behavioural variant frontotemporal dementia with or without the C9orf72 expansion show convergent large-scale network breakdowns despite distinctive atrophy patterns. Medial pulvinar degeneration may contribute to the behavioural variant frontotemporal dementia syndrome in C9orf72 carriers by disrupting salience network connectivity. Task-free functional magnetic resonance imaging shows promise in detecting early-stage disease in C9orf72 carriers and may provide a unifying biomarker across diverse anatomical variants.

Tau overexpression impacts a neuroinflammation gene expression network perturbed in Alzheimer's disease

Filamentous inclusions of the microtubule-associated protein, tau, define a variety of neurodegenerative diseases known as tauopathies, including Alzheimer's disease (AD). To better understand the role of tau-mediated effects on pathophysiology and global central nervous system function, we extensively characterized gene expression, pathology and behavior of the rTg4510 mouse model, which overexpresses a mutant form of human tau that causes Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). We found that the most predominantly altered gene expression pathways in rTg4510 mice were in inflammatory processes. These results closely matched the causal immune function and microglial gene-regulatory network recently identified in AD. We identified additional gene expression changes by laser microdissecting specific regions of the hippocampus, which highlighted alterations in neuronal network activity. Expression of inflammatory genes and markers of neuronal activity changed as a function of age in rTg4510 mice and coincided with behavioral deficits. Inflammatory changes were tau-dependent, as they were reversed by suppression of the tau transgene. Our results suggest that the alterations in microglial phenotypes that appear to contribute to the pathogenesis of Alzheimer's disease may be driven by tau dysfunction, in addition to the direct effects of beta-amyloid.

Atrophy in distinct corticolimbic networks in frontotemporal dementia relates to social impairments measured using the Social Impairment Rating Scale

Patients with frontotemporal dementia (FTD) often exhibit prominent, early and progressive impairments in social behaviour. We developed the Social Impairment Rating Scale (SIRS), rated by a clinician after a structured interview, which grades the types and severity of social behavioural symptoms in seven domains. In 20 FTD patients, we used the SIRS to study the anatomic basis of social impairments. In support of hypotheses generated from a prior study of healthy adults, we found that the relative magnitude of brain atrophy in three partially dissociable corticolimbic networks anchored in the amygdala predicted the severity of distinct social impairments measured using the SIRS. Patients with the greatest atrophy in a mesolimbic, reward-related (affiliation) network exhibited the most severe socioemotional detachment, whereas patients with the greatest atrophy in an interoceptive, pain-related (aversion) network exhibited the most severe lack of social apprehension. Patients with the greatest atrophy in a perceptual network exhibited the most severe lack of awareness or understanding of others' social and emotional behaviour. Our findings underscore observations that FTD is associated with heterogeneous social symptoms that can be understood in a refined manner by measuring impairments in component processes subserved by dissociable neural networks. Furthermore, these findings support the validity of the SIRS as an instrument to measure the social symptoms of patients with FTD. Ultimately, we hope it will be useful as a longitudinal outcome measure in natural history studies and in clinical trials of putative interventions to improve social functioning.

Sequential distribution of pTDP-43 pathology in behavioral variant frontotemporal dementia (bvFTD)

We examined regional distribution patterns of phosphorylated 43-kDa TAR DNA-binding protein (pTDP-43) intraneuronal inclusions in frontotemporal lobar degeneration (FTLD). Immunohistochemistry was performed on 70 μm sections from FTLD-TDP autopsy cases (n = 39) presenting with behavioral variant frontotemporal dementia. Two main types of cortical pTDP-43 pathology emerged, characterized by either predominantly perikaryal pTDP-43 inclusions (cytoplasmic type, cFTLD) or long aggregates in dendrites (neuritic type, nFTLD). Cortical involvement in nFTLD was extensive and frequently reached occipital areas, whereas cases with cFTLD often involved bulbar somatomotor neurons and the spinal cord. We observed four patterns indicative of potentially sequential dissemination of pTDP-43: cases with the lowest burden of pathology (pattern I) were characterized by widespread pTDP-43 lesions in the orbital gyri, gyrus rectus, and amygdala. With increasing burden of pathology (pattern II) pTDP-43 lesions emerged in the middle frontal and anterior cingulate gyrus as well as in anteromedial temporal lobe areas, the superior and medial temporal gyri, striatum, red nucleus, thalamus, and precerebellar nuclei. More advanced cases showed a third pattern (III) with involvement of the motor cortex, bulbar somatomotor neurons, and the spinal cord anterior horn, whereas cases with the highest burden of pathology (pattern IV) were characterized by pTDP-43 lesions in the visual cortex. We interpret the four neuropathological patterns in bvFTD to be consistent with the hypothesis that pTDP-43 pathology can spread sequentially and may propagate along axonal pathways.

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.

Emotional and behavioral symptoms in neurodegenerative disease: a model for studying the neural bases of psychopathology

Disruptions in emotional, cognitive, and social behavior are common in neurodegenerative disease and in many forms of psychopathology. Because neurodegenerative diseases have patterns of brain atrophy that are much clearer than those of psychiatric disorders, they may provide a window into the neural bases of common emotional and behavioral symptoms. We discuss five common symptoms that occur in both neurodegenerative disease and psychopathology (i.e., anxiety, dysphoric mood, apathy, disinhibition, and euphoric mood) and their associated neural circuitry. We focus on two neurodegenerative diseases (i.e., Alzheimer's disease and frontotemporal dementia) that are common and well characterized in terms of emotion, cognition, and social behavior and in patterns of associated atrophy. Neurodegenerative diseases provide a powerful model system for studying the neural correlates of psychopathological symptoms; this is supported by evidence indicating convergence with psychiatric syndromes (e.g., symptoms of disinhibition associated with dysfunction in orbitofrontal cortex in both frontotemporal dementia and bipolar disorder). We conclude that neurodegenerative diseases can play an important role in future approaches to the assessment, prevention, and treatment of mental illness.

A case report of anxiety disorder preceding frontotemporal dementia with asymmetric right temporal lobe atrophy

Behavioral variant frontotemporal dementia presents with progressive loss of social skills and cognition and is usually associated with asymmetric frontal or temporal lobe involvement. This article reports about a patient with a long history of anxiety disorder who later proceeded to develop behavioral variant frontotemporal dementia. Further discussion about selective specific network vulnerability and a possible link between these two conditions is provided.

Behavioral symptoms related to cognitive impairment

Neuropsychiatric symptoms (NPS) are core features of Alzheimer's disease and related dementias. On one hand, behavioral symptoms in patients with mild cognitive impairment (MCI) can indicate an increased risk of progressing to dementia. On the other hand, mild behavioral impairment (MBI) in patients who usually have normal cognition indicates an increased risk of developing dementia. Whatever the cause, all dementias carry a high rate of NPI. These symptoms can be observed at any stage of the disease, may fluctuate over its course, are a leading cause of stress and overload for caregivers, and increase rates of hospitalization and early institutionalization for patients with dementia. The clinician should be able to promptly recognize NPI through the use of instruments capable of measuring their frequency and severity to support diagnosis, and to help monitor the treatment of behavioral symptoms. The aims of this review are to describe and update the construct 'MBI' and to revise the reported NPS related to prodromal stages of dementia (MCI and MBI) and dementia stages of Alzheimer's disease and frontotemporal lobar degeneration.

Reduced orexin-A levels in frontotemporal dementia: possible association with sleep disturbance

Sleep disturbances including excessive daytime sleepiness (EDS) are encountered in frontotemporal dementia (FTD). To investigate the relationship between the plasma orexin-A levels and sleep disturbance patterns, we measured the plasma orexin-A levels and performed sleep studies in patients with FTD. The orexin-A levels were measured in 10 consecutive patients with FTD and controls by enzyme-linked immunosorbent assay. Nocturnal polysomnography (PSG) and Multiple Sleep Latency Test (MSLT) were performed in 2 patients with FTD. The orexin-A levels were significantly lower in patients with FTD compared to controls. The PSG revealed increased rapid eye movement (REM) latency in patients, whether or not they reported EDS. Mean sleep latency in MSLT was less than 10 minutes in both the patients, being shorter in patient without EDS, but none of them had REM sleep onset. Some patients with FTD may develop narcolepsy-like involuntary sleep attacks, even without complaining of EDS. Involvement of hypothalamus and a subsequent alteration in the orexin levels might be one of the determining factors in this sleep disturbance.