Prolonged Visual Facial Grasp in Frontotemporal Dementia

BACKGROUND

Gaze and eye contact is a critical aspect of social interaction. Patients with behavioral variant frontotemporal dementia (bvFTD) may exhibit abnormally prolonged stare toward human faces.

OBJECTIVE

To study characteristics of social gaze in patients with bvFTD compared to age and education matched-patients with early-onset Alzheimer's disease (eAD) and healthy controls (HC).

METHOD

Fifty picture stimuli were presented to each participant (bvFTD = 12, eAD = 18, HC = 13). Each stimuli contained two properties: face (facial versus non-facial) and valence (positive, negative, and neutral). The "facial" stimuli contained human faces. The participants Visual Fixation Time (VFT) was measured for each picture stimuli of interest (per facial expressions on the Facial Action Coding System). A linear mixed-effects regression model with participant-level of random effects was used to compare VFTs between groups.

RESULTS

The patients with bvFTD showed significantly prolonged VFTs to faces than the patients with eAD and the HC, regardless of valence (all p < 0.01). There were no differences in VFTs for non-facial stimuli between patients with bvFTD and eAD. However, patients with bvFTD and eAD had significantly prolonged VFTs to negative non-facial stimuli than the HC (p = 0.006 and 0.019, respectively).

CONCLUSION

Patients with bvFTD exhibited a prolonged stare toward human faces. This prolonged visual facial grasp may contribute to the disturbed social interactions of patients with bvFTD and can help distinguish them from those with Alzheimer's disease and other conditions. Additionally, both dementia groups tended to stare at negative stimuli whether faces or non-faces.

Skin Conduction Levels Differentiate Frontotemporal Dementia From Alzheimer's Disease

Patients with behavioral variant frontotemporal dementia (bvFTD) and Alzheimer's disease (AD) differ in basic emotional tone. Skin conduction levels (SCLs), a measure of sympathetic tone, may be a sensitive test for discriminating these two dementias early in their course. Previous research has shown differences in resting SCLs between patients with bvFTD and AD, but no study has evaluated the discriminability of SCLs during different environmental conditions. The authors compared bvFTD patients (N=8), AD patients (N=10), and healthy control subjects (N=9) on SCL measures pertaining to real-life vignettes or scenarios differing in valence and emotional intensity. The SCLs among the bvFTD patients were decreased across all conditions, whereas the SCLs among the AD patients were increased compared with control participants. On analysis, the SCLs in response to emotional stimuli differentiated bvFTD from AD with an area under the receiver operator characteristic curve of 95.3%. At a cutoff ≤0.77 μS, emotional vignettes distinguished bvFTD from AD with a sensitivity of 86% and a specificity of 96%. These preliminary results indicate the potential utility of SCLs for differentiating bvFTD from AD early in their course, regardless of environmental condition.

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.

Approach to atypical Alzheimer's disease and case studies of the major subtypes

Alzheimer's disease (AD) has long been recognized as a heterogeneous illness, with a common clinical presentation of progressive amnesia and less common "atypical" clinical presentations, including syndromes dominated by visual, aphasic, "frontal," or apraxic symptoms. Our knowledge of atypical clinical phenotypes of AD comes from clinicopathologic studies, but with the growing use of in vivo molecular biomarkers of amyloid and tau pathology, we are beginning to recognize that these syndromes may not be as rare as once thought. When a clinician is evaluating a patient whose clinical phenotype is dominated by progressive aphasia, complex visual impairment, or other neuropsychiatric symptoms with relative sparing of memory, the differential diagnosis may be broader and a confident diagnosis of an atypical form of AD may require the use of molecular biomarkers. Despite the evolving sophistication in our diagnostic tools, and the acknowledgment of atypical AD syndromes in the 2011 revised diagnostic criteria for AD, the assessment of such patients still poses substantial challenges. We use a case-based approach to review the clinical and imaging phenotypes of a series of patients with typical and atypical AD, and discuss our current approach to their evaluation. One day, we hope that regardless of whether a patient exhibits typical or atypical symptoms of AD pathology, we will be able to identify the condition at a prodromal phase and institute a combination of symptomatic and disease-modifying therapies to support cognitive processes, function, and behavior, and slow or halt progression to dementia.

Diogenes Syndrome in Frontotemporal Dementia

Diogenes syndrome refers to the combination of extreme self-neglect and excessive collecting with clutter and squalor, which is often present in patients with dementia. Diogenes syndrome may be particularly common in behavioral variant frontotemporal dementia (bvFTD), and the investigation of these patients may help clarify the nature of this syndrome. We describe 5 patients with bvFTD who exhibited a decline in self-care accompanied by hoarding behaviors. These patients, and a review of the literature, suggest a combination of frontal lobe disturbances: loss of insight or self-awareness with a failure to clean up or discard, a general compulsive drive, and an innate impulse to take environmental items. This impulse may be part of the environmental dependency syndrome in frontal disease, with specific involvement of a right frontolimbic-striatal system. Further investigation of the similarities and mechanisms of these symptoms in bvFTD could help in understanding Diogenes syndrome and lead to potential treatment options.

An advanced white matter tract analysis in frontotemporal dementia and early-onset Alzheimer's disease

Cortical and subcortical nuclei degenerate in the dementias, but less is known about changes in the white matter tracts that connect them. To better understand white matter changes in behavioral variant frontotemporal dementia (bvFTD) and early-onset Alzheimer’s disease (EOAD), we used a novel approach to extract full 3D profiles of fiber bundles from diffusion-weighted MRI (DWI) and map white matter abnormalities onto detailed models of each pathway. The result is a spatially complex picture of tract-by-tract microstructural changes. Our atlas of tracts for each disease consists of 21 anatomically clustered and recognizable white matter tracts generated from whole-brain tractography in 20 patients with bvFTD, 23 with age-matched EOAD, and 33 healthy elderly controls. To analyze the landscape of white matter abnormalities, we used a point-wise tract correspondence method along the 3D profiles of the tracts and quantified the pathway disruptions using common diffusion metrics – fractional anisotropy, mean, radial, and axial diffusivity. We tested the hypothesis that bvFTD and EOAD are associated with preferential degeneration in specific neural networks. We mapped axonal tract damage that was best detected with mean and radial diffusivity metrics, supporting our network hypothesis, highly statistically significant and more sensitive than widely studied fractional anisotropy reductions. From white matter diffusivity, we identified abnormalities in bvFTD in all 21 tracts of interest but especially in the bilateral uncinate fasciculus, frontal callosum, anterior thalamic radiations, cingulum bundles and left superior longitudinal fasciculus. This network of white matter alterations extends beyond the most commonly studied tracts, showing greater white matter abnormalities in bvFTD versus controls and EOAD patients. In EOAD, network alterations involved more posterior white matter – the parietal sector of the corpus callosum and parahipoccampal cingulum bilaterally. Widespread but distinctive white matter alterations are a key feature of the pathophysiology of these two forms of dementia.

A Neurology of the Conservative-Liberal Dimension of Political Ideology

Differences in political ideology are a major source of human disagreement and conflict. There is increasing evidence that neurobiological mechanisms mediate individual differences in political ideology through effects on a conservative-liberal axis. This review summarizes personality, evolutionary and genetic, cognitive, neuroimaging, and neurological studies of conservatism-liberalism and discusses how they might affect political ideology. What emerges from this highly variable literature is evidence for a normal right-sided "conservative-complex" involving structures sensitive to negativity bias, threat, disgust, and avoidance. This conservative-complex may be damaged with brain disease, sometimes leading to a pathological "liberal shift" or a reduced tendency to conservatism in political ideology. Although not deterministic, these findings recommend further research on politics and the brain.

Psychotic-Like Speech in Frontotemporal Dementia

Behavioral variant frontotemporal dementia (bvFTD) may result in psychotic-like speech without other psychotic features. The authors identified a bvFTD subgroup with pressure of speech, tangentiality, derailment, clanging/rhyming, and punning associated with the right anterior temporal atrophy and sparing of the left frontal lobe.

What is the Relationship of Traumatic Brain Injury to Dementia?

There is a long history linking traumatic brain injury (TBI) with the development of dementia. Despite significant reservations, such as recall bias or concluding causality for TBI, a summary of recent research points to several conclusions on the TBI-dementia relationship. 1) Increasing severity of a single moderate-to-severe TBI increases the risk of subsequent Alzheimer's disease (AD), the most common type of dementia. 2) Repetitive, often subconcussive, mild TBIs increases the risk for chronic traumatic encephalopathy (CTE), a degenerative neuropathology. 3) TBI may be a risk factor for other neurodegenerative disorders that can be associated with dementia. 4) TBI appears to lower the age of onset of TBI-related neurocognitive syndromes, potentially adding "TBI cognitive-behavioral features". The literature further indicates several specific risk factors for TBI-associated dementia: 5) any blast or blunt physical force to the head as long as there is violent head displacement; 6) decreased cognitive and/or neuronal reserve and the related variable of older age at TBI; and 7) the presence of apolipoprotein E ɛ4 alleles, a genetic risk factor for AD. Finally, there are neuropathological features relating TBI with neurocognitive syndromes: 8) acute TBI results in amyloid pathology and other neurodegenerative proteinopathies; 9) CTE shares features with neurodegenerative dementias; and 10) TBI results in white matter tract and neural network disruptions. Although further research is needed, these ten findings suggest that dose-dependent effects of violent head displacement in vulnerable brains predispose to dementia; among several potential mechanisms is the propagation of abnormal proteins along damaged white matter networks.

Non-Neurogenic Language Disorders: A Preliminary Classification

BACKGROUND

Few publications deal with non-neurogenic language disorders (NNLDs), distinct from psychogenic speech disorders such as psychogenic dysphonia or stuttering. NNLDs are alterations in language owing to psychosomatic preoccupations, conversion disorder, psychiatric disorders, or other psychological reasons.

OBJECTIVE

To identify and classify the range of NNLDs and their characteristics.

METHODS

This review summarizes the literature on disturbances in language, broadly defined as the use of symbols for communication, which may have a psychogenic or psychiatric etiology.

RESULTS

The literature suggests a classification for NNLDs that includes psychogenic aphasia with dysgrammatism; psychogenic "lalias" including oxylalia and agitolalia, palilalia and echolalia, xenolalia, glossolalia, and coprolalia; psychologically-mediated word usage; psychotic language; and psychogenic forms of the foreign accent syndrome.

CONCLUSIONS

Clinicians and researchers have insufficiently emphasized the presence of NNLDs, their characteristics, and their identification. Yet, these disorders may be the first or predominant manifestation of a psychologically-mediated illness. There are 2 steps to recognition. The first is to know how to distinguish NNLDs from the manifestations of neurogenic language impairments after a neurological evaluation. The second step is awareness of specific associated and examination features that suggest the presence of a NNLD.

Consensus classification of posterior cortical atrophy

INTRODUCTION

A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition of the syndrome in a variety of research settings.

METHODS

Consensus statements about PCA were developed through a detailed literature review, the formation of an international multidisciplinary working party which convened on four occasions, and a Web-based quantitative survey regarding symptom frequency and the conceptualization of PCA.

RESULTS

A three-level classification framework for PCA is described comprising both syndrome- and disease-level descriptions. Classification level 1 (PCA) defines the core clinical, cognitive, and neuroimaging features and exclusion criteria of the clinico-radiological syndrome. Classification level 2 (PCA-pure, PCA-plus) establishes whether, in addition to the core PCA syndrome, the core features of any other neurodegenerative syndromes are present. Classification level 3 (PCA attributable to AD [PCA-AD], Lewy body disease [PCA-LBD], corticobasal degeneration [PCA-CBD], prion disease [PCA-prion]) provides a more formal determination of the underlying cause of the PCA syndrome, based on available pathophysiological biomarker evidence. The issue of additional syndrome-level descriptors is discussed in relation to the challenges of defining stages of syndrome severity and characterizing phenotypic heterogeneity within the PCA spectrum.

DISCUSSION

There was strong agreement regarding the definition of the core clinico-radiological syndrome, meaning that the current consensus statement should be regarded as a refinement, development, and extension of previous single-center PCA criteria rather than any wholesale alteration or redescription of the syndrome. The framework and terminology may facilitate the interpretation of research data across studies, be applicable across a broad range of research scenarios (e.g., behavioral interventions, pharmacological trials), and provide a foundation for future collaborative work.

Pavlov's Orienting Response in Frontotemporal Dementia

Behavioral variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder with initial disturbances in socioemotional behavior in the absence of a sensitive diagnostic test. This study evaluated Pavlov's "orienting response" (OR) or "what is it?" reflex as a measure of their ability to refocus attention on socioemotional stimuli and as a potentially distinguishing measure for bvFTD. Ten patients with bvFTD were compared with 18 normal controls (NC) on ORs (defined as initial heart rate [HR] deceleration) to different pictures based on social and emotional (valence) differences from the International Affective Picture Stimuli. HR was measured while participants viewed pleasant-nonsocial (e.g., food), unpleasant-nonsocial (e.g., garbage), pleasant-social (e.g., babies), and unpleasant-social (e.g., violence) pictures. Participants watched each picture for 6 seconds, and the study examined HR changes during the first 2-second OR interval. The results showed significant differences in valence (pleasant-unpleasant) and valence-group interactions, but no effects of nonsocial-social. Whereas the NCs showed the expected HR deceleration (OR) to unpleasant stimuli, the bvFTD patients showed increased HRs without an initial refocusing. Decreased HR slowing to stimuli among the bvFTD patients correlated with increased scores on an emotional blunting scale. These findings suggest that decreased socioemotional behavior in bvFTD may be associated with decreased appreciation of emotional aspects of stimuli as evidenced by decreased ORs to emotional stimuli, regardless of social content. These findings also suggest further investigation of the OR in bvFTD as an early diagnostic measure for this disorder.

Early-Onset Alzheimer Disease

Early-onset Alzheimer disease (EOAD), with onset in individuals younger than 65 years, although overshadowed by the more common late-onset AD (LOAD), differs significantly from LOAD. EOAD comprises approximately 5% of AD and is associated with delays in diagnosis, aggressive course, and age-related psychosocial needs. One source of confusion is that a substantial percentage of EOAD are phenotypic variants that differ from the usual memory-disordered presentation of typical AD. The management of EOAD is similar to that for LOAD, but special emphasis should be placed on targeting the specific cognitive areas involved and more age-appropriate psychosocial support and education.

The attribution of animacy and agency in frontotemporal dementia versus Alzheimer's disease

Impaired attribution of animacy (state of living or being sentient) and of agency (capability of intrinsically-driven action) may underlie social behavior disturbances in behavioral variant frontotemporal dementia (bvFTD). We presented the Heider and Simmel film of moving geometric shapes to 11 bvFTD patients, 11 Alzheimer's disease (AD) patients, and 12 healthy controls (HCs) and rated their recorded verbal responses for animacy attribution and agency attribution. All participants had skin conductance (SC) continuously recorded while viewing the film, and all dementia participants underwent magnetic resonance imaging (MRI) for regions of interest. The bvFTD patients, but not the AD patients, were impaired in animacy attribution, compared to the HCs. In contrast, both bvFTD and AD groups were impaired in agency attribution, compared to the HCs, and only the HCs had increasing SC responsiveness during viewing of the film. On MRI analysis of cortical thicknesses, animacy scores significantly correlated across groups with the right pars orbitalis and opercularis; agency scores with the left inferior and superior parietal cortices and the supramarginal gyrus; and both scores with the left cingulate isthmus involved in visuospatial context. These findings suggest that bvFTD is specifically associated with impaired animacy attribution from right inferior frontal atrophy. In contrast, both dementias may have impaired agency attribution from left parietal cortical atrophy and absent SC increases during the film, a sympathetic indicator of attribution of a social "story" to the moving shapes. These findings clarify disease-related changes in social attribution and corroborate the neuroanatomical origins of animacy and agency.

Patient and caregiver reactions to clinical amyloid imaging

INTRODUCTION

Amyloid imaging is a tool that has recently become available to dementia specialists evaluating patients with possible Alzheimer's disease. Studies have assessed the impact of amyloid imaging on diagnostic and treatment decisions, but patient and family perspectives have received less attention.

METHODS

To examine how amyloid imaging affects the diagnostic experience of patients and families, we interviewed members of 26 patient-caregiver dyads with whom a neurologist discussed the option of amyloid positron emission tomography.

RESULTS

Most participants who chose to undergo amyloid imaging would choose to do so again. Regardless of the scan outcome, patients and caregivers commonly expressed relief on learning the scan results. Some participants expressed expectations that were beyond scan capabilities.

DISCUSSION

Amyloid imaging may provide information that patients and their families find useful. Clinicians must set correct expectations and ensure that families understand the limitations of amyloid imaging.

Executive Dysfunction and Behavioral Symptoms Are Associated with Deficits in Instrumental Activities of Daily Living in Frontotemporal Dementia

BACKGROUND

Deficits in instrumental activities of daily living (ADLs) may be more prominent in behavioral variant frontotemporal dementia (bvFTD) than in nonfluent/agrammatic variant primary progressive aphasia (nfvPPA) or semantic variant primary progressive aphasia (svPPA). It is uncertain whether frontotemporal dementia (FTD) subgroups exhibit different patterns and/or predictors of functional impairment.

METHODS

We examined data from participants diagnosed with bvFTD (n = 607), svPPA (n = 132), and nfvPPA (n = 155) who were included in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) and assessed with the Functional Activities Questionnaire (FAQ). Stepwise multiple linear regression analyses were performed to identify associations between FAQ scores and cognitive/behavioral deficits using the NACC UDS neuropsychological testing battery and the Neuropsychiatric Inventory Questionnaire.

RESULTS

FAQ scores were higher in bvFTD than svPPA or nfvPPA. Functional deficits across FTD subtypes differed in severity, but not pattern, and were driven by executive dysfunction and behavioral symptoms.

CONCLUSION

Executive dysfunction and behavioral symptoms underlie instrumental ADL deficits in FTD, which are most prominent in bvFTD.