Relationship between antisocial behavior and regional cerebral blood flow in frontotemporal dementia

Measuring Antisocial Behaviors in Behavioral Variant Frontotemporal Dementia With a Novel Informant-Based Questionnaire

OBJECTIVE

Antisocial behaviors are common and problematic among patients with behavioral variant frontotemporal dementia (bvFTD). In the present study, the investigators aimed to validate an informant-based questionnaire developed to measure the extent and severity of antisocial behaviors among patients with dementia.

METHODS

The Social Behavior Questionnaire (SBQ) was developed to measure 26 antisocial behaviors on a scale from absent (0) to very severe (5). It was administered to 23 patients with bvFTD, 19 patients with Alzheimer's disease, and 14 patients with other frontotemporal lobar degeneration syndromes. Group-level differences in the presence and severity of antisocial behaviors were measured. Psychometric properties of the SBQ were assessed by using Cronbach's alpha, exploratory factor analysis, and comparisons with a psychopathy questionnaire. Cluster analysis was used to determine whether the SBQ identifies different subgroups of patients.

RESULTS

Antisocial behaviors identified by using the SBQ were common and severe among patients with bvFTD, with at least one such behavior endorsed for 21 of 23 (91%) patients. Antisocial behaviors were more severe among patients with bvFTD, including the subsets of patients with milder cognitive impairment and milder disease severity, than among patients in the other groups. The SBQ was internally consistent (Cronbach's α=0.81). Exploratory factor analysis supported separate factors for aggressive and nonaggressive behaviors. Among the patients with bvFTD, the factor scores for aggressive behavior on the SBQ were correlated with those for antisocial behavior measured on the psychopathy scale, but the nonaggressive scores were not correlated with psychopathy scale measures. The k-means clustering analysis identified a subset of patients with severe antisocial behaviors.

CONCLUSIONS

The SBQ is a useful tool to identify, characterize, and measure the severity of antisocial behaviors among patients with dementia.

Network localization of antisocial behavior in neurological patients: Evidence and implications

Antisocial behavior may develop in otherwise normal persons as a result of neurological diseases, including patients with focal brain lesions, frontotemporal dementia, and Parkinson Disease patients taking dopamine agonist medications. Evidence from these neurological patients demonstrates that antisocial behaviors relate to dysfunction in several different brain regions that form a specific brain network, rather than any single location alone. This network associated with acquired antisocial behavior is involved in social decision-making (measured using moral decision-making tasks) and value-based decision-making (measured using neuroeconomic and reward-based tasks). Collectively, this work supports the hypothesis that antisocial behavior across different neurological diseases results from dysfunction within a common network of brain regions associated with social valuation and decision-making, providing insight into the neural mechanisms leading to acquired antisocial behavior. These findings have important implications, but also important limitations, for understanding criminal behavior in patients with psychopathy, for rehabilitation in criminals, for ethical discussions regarding moral and legal responsibility, and for forensic neurological evaluations in persons accused of crimes.

A transdiagnostic review of neuroimaging studies of apathy and disinhibition in dementia

Apathy and disinhibition are common and highly distressing neuropsychiatric symptoms associated with negative outcomes in persons with dementia. This paper is a critical review of functional and structural neuroimaging studies of these symptoms transdiagnostically in dementia of the Alzheimer type, which is characterized by prominent amnesia early in the disease course, and behavioural variant frontotemporal dementia, characterized by early social-comportmental deficits. We describe the prevalence and clinical correlates of these symptoms and describe methodological issues, including difficulties with symptom definition and different measurement instruments. We highlight the heterogeneity of findings, noting however, a striking similarity of the set of brain regions implicated across clinical diagnoses and symptoms. These regions involve several key nodes of the salience network, and we describe the functions and anatomical connectivity of these brain areas, as well as present a new theoretical account of disinhibition in dementia. Future avenues for research are discussed, including the importance of transdiagnostic studies, measuring subdomains of apathy and disinhibition, and examining different units of analysis for deepening our understanding of the networks and mechanisms underlying these extremely distressing symptoms.

Fronto-Striatal Atrophy in Behavioral Variant Frontotemporal Dementia and Alzheimer's Disease

Behavioral variant frontotemporal dementia (bvFTD) has only recently been associated with significant striatal atrophy, whereas the striatum appears to be relatively preserved in Alzheimer’s disease (AD). Considering the critical role the striatum has in cognition and behavior, striatal degeneration, together with frontal atrophy, could be responsible of some characteristic symptoms in bvFTD and emerges therefore as promising novel diagnostic biomarker to distinguish bvFTD and AD. Previous studies have, however, only taken either cortical or striatal atrophy into account when comparing the two diseases. In this study, we establish for the first time a profile of fronto-striatal atrophy in 23 bvFTD and 29 AD patients at presentation, based on the structural connectivity of striatal and cortical regions. Patients are compared to 50 healthy controls by using a novel probabilistic connectivity atlas, which defines striatal regions by their cortical white-matter connectivity, allowing us to explore the degeneration of the frontal and striatal regions that are functionally linked. Comparisons with controls revealed that bvFTD showed substantial fronto-striatal atrophy affecting the ventral as well as anterior and posterior dorso-lateral prefrontal cortices and the related striatal subregions. In contrast, AD showed few fronto-striatal atrophy, despite having significant posterior dorso-lateral prefrontal degeneration. Direct comparison between bvFTD and AD revealed significantly more atrophy in the ventral striatal–ventromedial prefrontal cortex regions in bvFTD. Consequently, deficits in ventral fronto-striatal regions emerge as promising novel and efficient diagnosis biomarker for bvFTD. Future investigations into the contributions of these fronto-striatal loops on bvFTD symptomology are needed to develop simple diagnostic and disease tracking algorithms.

Sensitivity and specificity of ventromedial prefrontal cortex tests in behavioral variant frontotemporal dementia

BACKGROUND

Behavioral variant frontotemporal dementia (bvFTD) is characterized by early and substantial ventromedial prefrontal cortex (VMPFC) dysfunction. To date, however, there is no consensus regarding which tests are most sensitive and specific to assess VMPFC dysfunction in this condition.

METHODS

In this study we compared the sensitivity and specificity of four common VMPFC specific tests (Mini-SEA, Go/No-Go Subtest of the Frontal Assessment Battery, Reversal-Learning Test, and Iowa Gambling Task) at first clinic presentation in two neurodegenerative cohorts (bvFTD, Alzheimer's disease) and age-matched, healthy controls.

RESULTS

We found that the Mini-SEA, evaluating theory of mind and emotion processes, emerged as the most sensitive and specific of the VMPFC tests employed. The Mini-SEA alone successfully distinguished bvFTD and Alzheimer's disease (AD) in >82% of subjects at first presentation. Similarly, the FAB Go/No-Go and Reversal-Learning Tests also showed very good discrimination power, but to a lesser degree. The Iowa Gambling Task, one of the most common measures of VMPFC function, was the least specific of these tests.

CONCLUSION

Sensitivity to detect VMPFC dysfunction was high across all test employed, but specificity varied considerably. The Mini-SEA emerged as the most promising of the VMPFC-specific diagnostic tests. Clinicians should take into account the variable specificity of currently available VMPFC tests, which can complement current carer-based questionnaires and clinical evaluation to improve the diagnosis of behavioral dysfunctions due to VMPFC dysfunction.

Social Cognition and Emotional Assessment (SEA) is a marker of medial and orbital frontal functions: a voxel-based morphometry study in behavioral variant of frontotemporal degeneration

The aim of this study was to explore the cerebral correlates of functional deficits that occur in behavioral variant frontotemporal dementia (bvFTD). A specific neuropsychological battery, the Social cognition & Emotional Assessment (SEA; Funkiewiez et al., 2012), was used to assess impaired social and emotional functions in 20 bvFTD patients who also underwent structural MRI scanning. The SEA subscores of theory of mind, reversal-learning tests, facial emotion identification, and apathy evaluation were entered as covariates in a voxel-based morphometry analysis. The results revealed that the gray matter volume in the rostral part of the medial prefrontal cortex [mPFC, Brodmann area (BA) 10] was associated with scores on the theory of mind subtest, while gray matter volume within the orbitofrontal (OFC) and ventral mPFC (BA 11 and 47) was related to the scores observed in the reversal-learning subtest. Gray matter volume within BA 9 in the mPFC was correlated with scores on the emotion recognition subtest, and the severity of apathetic symptoms in the Apathy scale covaried with gray matter volume in the lateral PFC (BA 44/45). Among these regions, the mPFC and OFC cortices have been shown to be atrophied in the early stages of bvFTD. In addition, SEA and its abbreviated version (mini-SEA) have been demonstrated to be sensitive to early impairments in bvFTD (Bertoux et al., 2012). Taken together, these results suggest a differential involvement of orbital and medial prefrontal subregions in SEA subscores and support the use of the SEA to evaluate the integrity of these regions in the early stages of bvFTD.

Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, 'possible' behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). 'Probable' behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia 'with definite frontotemporal lobar degeneration' requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer's disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met 'possible' criteria, and 104 (76%) met criteria for 'probable' behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia

Based on the recent literature and collective experience, an international consortium developed revised guidelines for the diagnosis of behavioural variant frontotemporal dementia. The validation process retrospectively reviewed clinical records and compared the sensitivity of proposed and earlier criteria in a multi-site sample of patients with pathologically verified frontotemporal lobar degeneration. According to the revised criteria, 'possible' behavioural variant frontotemporal dementia requires three of six clinically discriminating features (disinhibition, apathy/inertia, loss of sympathy/empathy, perseverative/compulsive behaviours, hyperorality and dysexecutive neuropsychological profile). 'Probable' behavioural variant frontotemporal dementia adds functional disability and characteristic neuroimaging, while behavioural variant frontotemporal dementia 'with definite frontotemporal lobar degeneration' requires histopathological confirmation or a pathogenic mutation. Sixteen brain banks contributed cases meeting histopathological criteria for frontotemporal lobar degeneration and a clinical diagnosis of behavioural variant frontotemporal dementia, Alzheimer's disease, dementia with Lewy bodies or vascular dementia at presentation. Cases with predominant primary progressive aphasia or extra-pyramidal syndromes were excluded. In these autopsy-confirmed cases, an experienced neurologist or psychiatrist ascertained clinical features necessary for making a diagnosis according to previous and proposed criteria at presentation. Of 137 cases where features were available for both proposed and previously established criteria, 118 (86%) met 'possible' criteria, and 104 (76%) met criteria for 'probable' behavioural variant frontotemporal dementia. In contrast, 72 cases (53%) met previously established criteria for the syndrome (P < 0.001 for comparison with 'possible' and 'probable' criteria). Patients who failed to meet revised criteria were significantly older and most had atypical presentations with marked memory impairment. In conclusion, the revised criteria for behavioural variant frontotemporal dementia improve diagnostic accuracy compared with previously established criteria in a sample with known frontotemporal lobar degeneration. Greater sensitivity of the proposed criteria may reflect the optimized diagnostic features, less restrictive exclusion features and a flexible structure that accommodates different initial clinical presentations. Future studies will be needed to establish the reliability and specificity of these revised diagnostic guidelines.

Neuroimaging findings in frontotemporal lobar degeneration spectrum of disorders

Frontotemporal lobar degeneration (FTLD) is a clinically and pathologically heterogeneous spectrum of disorders. In the last few years, neuroimaging has contributed to the phenotypic characterisation of these patients. Complementary to the clinical and neuropsychological evaluations, structural magnetic resonance imaging (MRI) and functional techniques provide important pieces of information for the diagnosis of FTLD. They also appear to be useful in distinguishing FTLD from patients with Alzheimer's disease (AD). Preliminary studies in pathologically proven cases suggested that distinct patterns of tissue loss could assist in predicting in vivo the pathological subtype. Recent years have also witnessed impressive advances in the development of novel imaging approaches. Diffusion tensor MRI and functional MRI have improved our understanding of the pathophysiology of the disease, and this should lead to the identification of additional useful markers of disease progression. This reviews discusses comprehensively the state-of-the-art of neuroimaging in the study of FTLD spectrum of disorders, and attempts to envisage which will be new neuroimaging biomarkers that could serve as surrogate measures of the underlying pathology. This will be central in the design of treatment trials of experimental drugs, which are likely to emerge in the near future, to target the pathological processes associated with this condition.

Neuropsychiatric symptoms of progressive supranuclear palsy in a dementia clinic

BACKGROUND

Progressive supranuclear palsy (PSP) is a neurodegenerative disease characterized by supranuclear gaze palsy, postural instability, akinesia and other parkinsonism. Recently, the relationship between PSP and frontotemporal dementia (FTD) has been recognized, which includes clinical, pathological, biochemical and genetic features. However, there have been few studies that directly compared neuropsychiatric symptoms between PSP and FTD. The aim of the present study was to investigate comprehensive psychiatric and behavioural symptoms in PSP and compared them with those in FTD.

METHODS

Patients with PSP (n = 10) and FTD (n = 13) were selected on the basis of inclusion/exclusion criteria from a consecutive series in the dementia clinic of Kumamoto University Hospital. We assessed their comprehensive neuropsychiatric features by using the Neuropsychiatric Inventory (NPI), the Stereotypy Rating Inventory (SRI) and a specific antisocial behaviour checklist.

RESULTS

There were no significant differences in the total NPI and NPI subscale scores between the two groups. Both groups showed quite a similar pattern in the features of neuropsychiatric symptoms: apathy showed the highest score, followed by aberrant motor behaviour and disinhibition. The PSP group was significantly lower in the total SRI and eating and cooking behaviour scores than those in the FTD group. The prevalence of antisocial behaviours in PSP (50%) was equal to those in the FTD group (46%).

CONCLUSIONS

In a dementia clinic, the neuropsychiatric profile in patients with PSP closely resembled those in the FTD group. The present results suggest that PSP should be considered as not only a movement disorder, but also a disorder with a wide range of neuropsychiatric symptoms.

Executive and behavioral deficits share common neural substrates in frontotemporal lobar degeneration - a pilot FDG-PET study

Behavioral and executive dysfunctions are typical symptoms of frontotemporal lobar degeneration, associated with its subtypes frontotemporal and semantic dementia. Although both functions depend on the frontal lobes, no study has yet compared their neural correlates in frontotemporal lobar degeneration. Accordingly, we correlated clinical scores of behavioral and executive deficits with glucose utilization as measured by [(18)F]fluorodeoxyglucose positron emission tomography in 17 patients with frontotemporal lobar degeneration and 9 age- and sex-matched control subjects. Impairment in executive functions was measured by the Behavioral Assessment of the Dysexecutive Syndrome, a modified Stroop paradigm and/or the Tower of Toronto Test. Behavioral deficits were examined with the Neuropsychiatric Inventory. Executive dysfunction was correlated with diminished glucose utilization in frontomedial and frontolateral cortices. Brain regions included the anterior cingulate and midcingulate gyri, anterior medial frontal cortex, and left frontolateral cortex. Behavioral deficits were associated with mainly frontomedial networks, particularly the anterior medial frontal cortex, gyrus rectus, and area subcallosa. Our pilot study reveals partially overlapping neural correlates of executive and behavioral dysfunction in frontotemporal lobar degeneration. The results suggest that some behavioral deficits, namely disinhibition and appetite and eating abnormalities, are particularly related to executive dysfunction. This hypothesis might be further explored in studies involving larger patient groups.

Theory of mind ability in the behavioural variant of frontotemporal dementia: an analysis of the neural, cognitive, and social levels

The paper reviews convergent evidence on the ability to attribute mental states to one's self and to others (i.e., theory of mind, ToM) in patients affected by the behavioural variant of frontotemporal dementia (bv-FTD). This disease represents a particular challenge for researchers and clinicians, due to its insidious onset and ambiguous clinical features, which frequently render difficult a precise and timely diagnosis. The paper proposes a way to shed new light on the hypothesis that the neuropsychiatric profile of individuals with bv-FTD can be at least partially explained by a deficit in ToM ability. We examined both neuroimaging data on the neural correlates of ToM ability in healthy participants and studies investigating the progressive cerebral atrophy in patients with bv-FTD. Our findings suggest a link between the progressive degeneration of the anterior regions of medial frontal structures characterising the early stages of the bv-FTD and the ToM deficit these patients show. They also suggest the importance of using ToM tests during the diagnostic process of bv-FTD.

A case with Hodgkin lymphoma and fronto-temporal lobular degeneration (FTLD)-like dementia facilitated by chemotherapy

We report a case of a 39-year-old man with Hodgkin lymphoma who developed depressive symptoms after starting adriamycin, bleomycin, vinblastine and dacarbazine chemotherapy and later exhibited sexual disinhibition in addition to cognitive dysfunction (mainly executive dysfunction). Seven months after the start of adriamycin, bleomycin, vinblastine and dacarbazine chemotherapy, he was finally diagnosed as having fronto-temporal lobular degeneration-like dementia facilitated by adriamycin, bleomycin, vinblastine and dacarbazine chemotherapy. At the time of writing, the patient's condition has persisted for more than 6 months after the discontinuation of adriamycin, bleomycin, vinblastine and dacarbazine chemotherapy, and the changes in brain function brought on by the adriamycin, bleomycin, vinblastine and dacarbazine chemotherapy may now be irreversible. This case points to the importance of being attentive to the appearance of neuropsychiatric symptoms and evaluating brain functions properly when performing anti-cancer chemotherapy.

Prefrontal structural and functional brain imaging findings in antisocial, violent, and psychopathic individuals: a meta-analysis

Brain-imaging studies suggest that antisocial and violent behavior is associated with structural and functional deficits in the prefrontal cortex, but there is heterogeneity in findings and it is unclear whether findings apply to psychopaths, non-violent offenders, community-based samples, and studies employing psychiatric controls. A meta-analysis was conducted on 43 structural and functional imaging studies, and the results show significantly reduced prefrontal structure and function in antisocial individuals. Effect sizes were significant for both structural and functional studies. With minor exceptions, no statistically significant moderating effects of sample characteristics and methodological variables were observed. Findings were localized to the right orbitofrontal cortex, right anterior cingulate cortex, and left dorsolateral prefrontal cortex. Findings confirm the replicability of prefrontal structural and functional impairments in antisocial populations and highlight the involvement of orbitofrontal, dorsolateral frontal, and anterior cingulate cortex in antisocial behavior.

Understanding social dysfunction in the behavioural variant of frontotemporal dementia: the role of emotion and sarcasm processing

Social interaction is profoundly affected in the behavioural form of frontotemporal dementia (bvFTD) yet there are few means of objectively assessing this. Diagnosis of bvFTD is based on informant report, however a number of individuals with a clinical profile consistent with the disease have no imaging abnormality and seem to remain stable, with doubt about the presence of underlying neurodegenerative pathology. We aimed to quantify aspects of the behavioural disorder and link it to the underlying level of atrophy in socially relevant brain regions. We tested individuals with either bvFTD (N = 26) or Alzheimer's disease (N = 9) and 16 controls using The Awareness of Social Inference Test (TASIT) to assess their ability to identify emotion and sarcasm in video vignettes. A subset of bvFTD patients (N = 21) and controls (N = 12) were scanned using MRI within 6 months of assessment. There was marked impairment in the ability of bvFTD patients whose scans showed abnormalities to recognize sarcastic, but not sincere statements. Their capacity to interpret negative emotion was also impaired, and this appeared to be a major factor underlying the deficit in sarcasm recognition. Clinically diagnosed bvFTD patients whose scans were normal, Alzheimer's disease patients and controls had no difficulty in appreciating both types of statement. In a multivariate imaging analysis it was shown that the sarcasm (and emotion recognition) deficit was dependent on a circuit involving the lateral orbitofrontal cortex, insula, amygdala and temporal pole, particularly on the right. Performance on a more global test of cognitive function, the Addenbrooke's Cognitive Examination did not have a unique association with these regions. The TASIT is an objective test of social dysfunction in bvFTD which indexes the frontotemporal volume loss in bvFTD patients and provides an objective measure for separating behavioural patients who are likely to decline from those who may remain stable. These results provide additional evidence for the role of the orbitofrontal cortex and related structures in the processing of socially relevant signals, particularly those where negative emotion recognition is important.

Postulated role of vasoactive neuropeptide-related immunopathology of the blood brain barrier and Virchow-Robin spaces in the aetiology of neurological-related conditions

Vasoactive neuropeptides (VNs) such as pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) have critical roles as neurotransmitters, vasodilators including perfusion and hypoxia regulators, as well as immune and nociception modulators. They have key roles in blood vessels in the central nervous system (CNS) including maintaining functional integrity of the blood brain barrier (BBB) and blood spinal barrier (BSB). VNs are potent activators of adenylate cyclase and thus also have a key role in cyclic AMP production affecting regulatory T cell and other immune functions. Virchow-Robin spaces (VRSs) are perivascular compartments surrounding small vessels within the CNS and contain VNs. Autoimmunity of VNs or VN receptors may affect BBB and VRS function and, therefore, may contribute to the aetiology of neurological-related conditions including multiple sclerosis, Parkinson's disease, and amyotrophic lateral sclerosis. VN autoimmunity will likely affect CNS and immunological homeostasis. Various pharmacological and immunological treatments including phosphodiesterase inhibitors and plasmapheresis may be indicated.

Multivariate and univariate neuroimaging biomarkers of Alzheimer's disease

We performed univariate and multivariate discriminant analysis of FDG-PET scans to evaluate their ability to identify Alzheimer's disease (AD). FDG-PET scans came from two sources: 17 AD patients and 33 healthy elderly controls were scanned at the University of Michigan; 102 early AD patients and 20 healthy elderly controls were scanned at the Technical University of Munich, Germany. We selected a derivation sample of 20 AD patients and 20 healthy controls matched on age with the remainder divided into 5 replication samples. The sensitivity and specificity of diagnostic AD-markers and threshold criteria from the derivation sample were determined in the replication samples. Although both univariate and multivariate analyses produced markers with high classification accuracy in the derivation sample, the multivariate marker's diagnostic performance in the replication samples was superior. Further, supplementary analysis showed its performance to be unaffected by the loss of key regions. Multivariate measures of AD utilize the covariance structure of imaging data and provide complementary, clinically relevant information that may be superior to univariate measures.

The effects of HIV on P300 are moderated by familial risk for substance dependence: implications for a theory of brain reserve

BACKGROUND

The goal of the study was to test the validity of additive versus synergistic versus underadditive versions of brain reserve theory within the context of HIV/AIDS. In addition, it tested the convergent validity of 2 operational definitions of premorbid reserve: verbal IQ (VIQ) and a family history (FH) of substance abuse or dependence.

METHODS

Seventy HIV-1 seronegative and 115 HIV-1 seropositive male and female volunteers were assigned to 4 subgroups defined by the crossing of a VIQ score < versus > or = 90 with the presence versus absence of a paternal history of alcohol, cocaine, or opiate abuse or dependence. The principal dependent measure was the P300 event related brain potential elicited during the Stroop color-word interference task.

RESULTS

The principal finding was an underadditive effect of FH plus HIV/AIDS on P300 area over the frontal region: FH reduced frontal scalp P300 to such a degree that the additional effects of HIV/AIDS were blunted. The alternate operational definition of brain reserve, VIQ, had no effect on P300 and did not alter the effects of HIV/AIDS.

CONCLUSIONS

Familial risk for substance dependence and low VIQ compromise different aspects of brain structure and/or function and therefore differ in their relationship to HIV/AIDS and P300. Genetic differences associated with familial risk may reduce brain reserve to such a degree that the neurophysiological effects of HIV/AIDS can no longer be measured.

Diagnostic criteria for the behavioral variant of frontotemporal dementia (bvFTD): current limitations and future directions

The most widely established diagnostic criteria for the behavioral variant of frontotemporal dementia have now been in use for almost a decade. Although consensus criteria have provided a much needed standard for frontotemporal dementia research, a growing body of evidence suggests that revisions are needed to improve their applicability. In this article, we discuss the limitations of current diagnostic criteria and propose the establishment of an international consortium to revise diagnostic and research criteria for the behavioral variant of frontotemporal dementia.

Evaluation of brain perfusion SPECT using an easy Z-score imaging system (eZIS) as an adjunct to early-diagnosis of neurodegenerative diseases

The eZIS allows computer-assisted statistical analysis of brain perfusion SPECT images. We evaluated the diagnostic value of brain perfusion SPECT using eZIS in patients with various neurodegenerative diseases at a very early stage, within one year from onset.

METHODS

SPECT using eZIS was performed for patients with Alzheimer disease (AD), dementia with Lewy bodies (DLB), frontotemporal dementia (FTD,), idiopathic Parkinson disease (PD) and vascular Parkinsonism (VP), multiple systemic atrophy of the cerebellar type (MSA-C), cortical cerebellar atrophy (CCA) and amyotrophic lateral sclerosis (ALS).

RESULTS

Decreased rCBF was observed in the posterior cingulate cortex, precuneus and parietal cortex in AD; in the frontal gyrus and insula in FTD; in the occipital lobe, precuneus gyrus and posterior cingulate cortex in DLB; in the striatum and the thalamus in VP; in the cerebellum in CCA; in the cerebellum and pons in MSA-C and in the frontal cortex including the central sulcus in ALS. Increased rCBF in the striatum, thalamus and cerebellar dentate nuclei were observed in PD.

CONCLUSIONS

A specific rCBF pattern was observed for each disease using eZIS analysis, consistent with previous reports. Our results showed eZIS can be easily used as an adjunct to early-diagnosis of neurodegenerative diseases in any hospital.

Towards a nosology for frontotemporal lobar degenerations—A meta-analysis involving 267 subjects

Frontotemporal lobar degeneration is the second most common diagnosis of dementia in individuals younger than 65 years. We conducted a systematic and quantitative meta-analysis to examine neural correlates of frontotemporal lobar degeneration and its subtypes and to place the disease in a framework of cognitive neuropsychiatry. MedLine and Current Contents search engines were used to identify functional and anatomical imaging studies investigating frontotemporal lobar degeneration between 1980 and 2005. Studies were included, if they were peer-reviewed, applied internationally recognized diagnostic criteria, were original studies, and had results normalized to a stereotactic space. 19 studies were identified reporting either atrophy or decreases in glucose utilization. Finally, the analysis involved 267 subjects suffering from frontotemporal lobar degeneration and 351 control subjects. A quantitative meta-analysis was performed. Maxima of the studies resulted in activation likelihood estimates. The meta-analysis revealed specific neural networks for each of the three clinically defined subtypes of frontotemporal lobar degeneration, namely frontotemporal dementia, semantic dementia, and progressive non-fluent aphasia. Networks did not overlap as shown by a conjunction analysis, and they corresponded to clinical characteristics. The study relates the clinical features of each subtype of frontotemporal lobar degeneration specifically to its neural substrate. By 'triple dissociating' frontotemporal lobar degenerations into three clinicoanatomical prototypes, the study contributes to placing these disorders in cognitive neuropsychiatry and suggests a respective nosology.

Neural networks in frontotemporal dementia--a meta-analysis

OBJECTIVE

Frontotemporal dementia is the most common form of frontotemporal lobar degeneration. It is characterized by deep alterations in behavior and personality. We conducted a systematic and quantitative meta-analysis to examine its neural correlates and place the disease in a framework of cognitive neuropsychiatry.

METHODS

MedLine and Current Contents search engines were used to identify imaging studies investigating frontotemporal dementia between 1980 and 2005. Nine studies were identified reporting either atrophy or decreases in glucose utilization. Finally, the analysis involved 132 patients and 166 controls. A quantitative meta-analysis was performed. Maxima of the studies resulted in activation likelihood estimates.

RESULTS

The meta-analysis revealed a particularly frontomedian network impaired in frontotemporal dementia. Additionally, right anterior insula, and medial thalamus were identified.

CONCLUSIONS

Our study specifies frontotemporal dementia as the frontomedian variant of frontotemporal lobar degeneration. The disease affects neural networks enabling self-monitoring, theory of mind capabilities, processing/evaluation of internal mental states, perception of pain and emotions, and sustaining personality and self. Our study contributes to placing frontotemporal dementia in cognitive neuropsychiatry.