Demographic, neurological and behavioural characteristics and brain perfusion SPECT in frontal variant of frontotemporal dementia

Progranulin haploinsufficiency causes biphasic social dominance abnormalities in the tube test

Loss-of-function mutations in progranulin (GRN) are a major autosomal dominant cause of frontotemporal dementia (FTD), a neurodegenerative disorder in which social behavior is disrupted. Progranulin-insufficient mice, both Grn(+/-) and Grn(-/-) , are used as models of FTD due to GRN mutations, with Grn(+/-) mice mimicking the progranulin haploinsufficiency of FTD patients with GRN mutations. Grn(+/-) mice have increased social dominance in the tube test at 6 months of age, although this phenotype has not been reported in Grn(-/-) mice. In this study, we investigated how the tube test phenotype of progranulin-insufficient mice changes with age, determined its robustness under several testing conditions, and explored the associated cellular mechanisms. We observed biphasic social dominance abnormalities in Grn(+/-) mice: at 6-8 months, Grn(+/-) mice were more dominant than wild-type littermates, while after 9 months of age, Grn(+/-) mice were less dominant. In contrast, Grn(-/-) mice did not exhibit abnormal social dominance, suggesting that progranulin haploinsufficiency has distinct effects from complete progranulin deficiency. The biphasic tube test phenotype of Grn(+/-) mice was associated with abnormal cellular signaling and neuronal morphology in the amygdala and prefrontal cortex. At 6-9 months, Grn(+/-) mice exhibited increased mTORC2/Akt signaling in the amygdala and enhanced dendritic arbors in the basomedial amygdala, and at 9-16 months Grn(+/-) mice exhibited diminished basal dendritic arbors in the prelimbic cortex. These data show a progressive change in tube test dominance in Grn(+/-) mice and highlight potential underlying mechanisms by which progranulin insufficiency may disrupt social behavior.

Frontotemporal lobar degeneration: Pathogenesis, pathology and pathways to phenotype

Frontotemporal Lobar Degeneration (FTLD) is a clinically, pathologically and genetically heterogeneous group of disorders that affect principally the frontal and temporal lobes of the brain. There are three major associated clinical syndromes, behavioral variant frontotemporal dementia (bvFTD), semantic dementia (SD) and progressive non-fluent aphasia (PNFA); three principal histologies, involving tau, TDP-43 and FUS proteins; and mutations in three major genes, MAPT, GRN and C9orf72, along with several other less common gene mutations. All three clinical syndromes can exist separately or in combination with Amyotrophic Lateral Sclerosis (ALS). SD is exclusively a TDP-43 proteinopathy, and PNFA may be so, with both showing tight clinical, histological and genetic inter-relationships. bvFTD is more of a challenge with overlapping histological and genetic features, involvement of any of the three aggregating proteins, and changes in any of the three major genes. However, when ALS is present, all cases show a clear histological phenotype with TDP-43 aggregated proteins, and familial forms are associated with expansions in C9orf72. TDP-43 and FUS are nuclear carrier proteins involved in the regulation of RNA metabolism, whereas tau protein - the product of MAPT - is responsible for the assembly/disassembly of microtubules, which are vital for intracellular transport. Mutations in TDP-43 and FUS genes are linked to clinical ALS rather than FTLD (with or without ALS), suggesting that clinical ALS may be a disorder of RNA metabolism. Conversely, the protein products of GRN and C9orf72, along with those of the other minor genes, appear to form part of the cellular protein degradation machinery. It is possible therefore that FTLD is a reflection of dysfunction within lysosomal/proteasomal systems resulting in failure to remove potentially neurotoxic (TDP-43 and tau) aggregates, which ultimately overwhelm capacity to function. Spread of aggregates along distinct pathways may account for the different clinical phenotypes, and patterns of progression of disease.

Psychosis in behavioral variant frontotemporal dementia

BACKGROUND

Dementia is generally characterized by cognitive impairment that can be accompanied by psychotic symptoms; for example, visual hallucinations are a core feature of dementia with Lewy bodies, and delusions are often seen in Alzheimer's disease. However, for behavioral variant of frontotemporal dementia (bvFTD), studies on the broad spectrum of psychotic symptoms are still lacking. The aim of this study was to systematically and prospectively subtype the wide spectrum of psychotic symptoms in probable and definite bvFTD.

METHODS

In this study, a commonly used and validated clinical scale that quantifies the broad spectrum of psychotic symptoms (Positive and Negative Symptom Scale) was used in patients with probable and definite bvFTD (n=22) and with a primary psychiatric disorder (n=35) in a late-onset frontal lobe cohort. Median symptom duration was 2.8 years, and the patients were prospectively followed for 2 years.

RESULTS

In total, 22.7% of bvFTD patients suffered from delusions, hallucinatory behavior, and suspiciousness, although the majority of the patients exhibited negative psychotic symptoms such as social and emotional withdrawal and blunted affect (95.5%) and formal thought disorders (81.8%). "Difficulty in abstract thinking" and "stereotypical thinking" (formal thought disorders) differentiated bvFTD from psychiatric disorders. The combined predictors difficulty in abstract thinking, stereotypical thinking, "anxiety", "guilt feelings," and "tension" explained 75.4% of variance in the diagnosis of bvFTD versus psychiatric diagnoses (P<0.001).

CONCLUSION

Delusions, hallucinatory behavior, and suspiciousness were present in one-fifth of bvFTD patients, whereas negative psychotic symptoms such as social and emotional withdrawal, blunted affect, and formal thought disorders were more frequently present. This suggests that negative psychotic symptoms and formal thought disorders have an important role in the psychiatric misdiagnosis in bvFTD; misdiagnosis in bvFTD might be reduced by systematically exploring the broad spectrum of psychiatric symptoms.

Eating Behaviors and Dietary Changes in Patients With Dementia

BACKGROUND

Eating problems and dietary changes have been reported in patients with dementia.

OBJECTIVES

The aim of this article is to explore the generalized problems with nutrition, diet, feeding, and eating reported among patients with dementia.

METHODS

Medline and Google Scholar searches were conducted for relevant articles, chapters, and books published before 2016. Search terms used included behavioral and psychological symptoms of dementia, dementia, dietary changes, eating behavior. Publications found through this indexed search were reviewed for further relevant references.

RESULTS

Abnormal eating behaviors, eating problems, and dietary changes are present in most people with dementia, especially in the later stages of the condition.

CONCLUSION

Individuals with dementia frequently develop serious feeding difficulties and changes in eating and dietary habits. The changes may be secondary to cognitive impairment or apraxia, or the result of insufficient caregiving, or the consequence of metabolic or neurochemical abnormalities occurring as part of the dementing process.

A Clinical Guide to Frontotemporal Dementias

The term frontotemporal dementia (FTD) describes a diverse group of clinical syndromes, including behavioral-variant FTD (bvFTD), nonfluent/agrammatic-variant primary progressive aphasia (nfvPPA), semantic-variant primary progressive aphasia (svPPA), FTD motor neuron disease (FTD-MND), progressive supranuclear palsy syndrome (PSP-S), and corticobasal syndrome (CBS). Although each of these syndromes may be distinguished by their respective disturbances in behavior, language, or motor function and characteristic imaging findings, they may present a diagnostic dilemma when encountered clinically. In this article, we review the clinical features, diagnostic criteria, pathology, genetics, and therapeutic interventions for FTD spectrum disorders.

Survival in Frontotemporal Dementia Phenotypes: A Meta-Analysis

BACKGROUND

Survival in frontotemporal dementia (FTD) is not well understood. We conducted a mixed effects meta-analysis of survival in FTD to examine phenotype differences and contributory factors.

METHODS

The PubMed, Medline, EMBASE, CINAHL, PsycINFO and Cochrane databases were searched for studies describing survival or natural history of behavioral variant FTD (bvFTD), progressive non-fluent aphasia (PNFA), semantic dementia (SD), FTD with amyotrophic lateral sclerosis (FTD-ALS), progressive supranuclear palsy and corticobasal degeneration. There were no language restrictions.

RESULTS

We included 27 studies (2,462 subjects). Aggregate mean and median survival were derived for each phenotype and, for comparison, Alzheimer's disease (AD) (using data from the selected studies). Survival was shortest in FTD-ALS (2.5 years). Mean survival was longest in bvFTD and PNFA (8 years) and median survival in SD (12 years). AD was comparable in survival to all except FTD-ALS. Age and sex did not affect survival; the education effect was equivocal. Heterogeneity in FTD survival was largely, but not wholly, explained by phenotypes.

CONCLUSIONS

Survival differs for FTD phenotypes but, except for FTD-ALS, compares well to AD survival. Elucidating the potential causes of within-phenotype heterogeneity in survival (such as complicating features and comorbidities) may open up opportunities for tailored interventions.

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.

Amnesia in frontotemporal dementia: shedding light on the Geneva historical data

Recent accumulated evidence indicates that episodic memory impairments could be part of the initial clinical expression of frontotemporal dementia (FTD). An early study on this issue was carried out by Constantinidis and colleagues in 1974, but it was subsequently overlooked for a long period of time. The scope of the present research was: (a) to explore the presence of early episodic memory impairments in the entire population of neuropathologically confirmed FTD patients from the Geneva brain collection; and (b) to expand the present insight on the association between the initial symptomatology and various characteristics, namely gender, age at onset, disease duration, and presence of Pick body neuropathology. A careful review of the records of 50 FTD patients hospitalized at the Department of Psychiatry of the Bel-Air Hospital, Geneva, Switzerland, from 1929 to 1999, was conducted. Further in-depth neuropathological analysis with novel immunohistological methods was carried out in 37 of the cases. The data showed that memory impairments were the first clinical symptom in several of the patients. In addition, this specific phenotypic expression of FTD was associated with the female gender, advanced age, and positive Pick body neuropathology. The current findings give the opportunity to historically vindicate the early work of Constantinidis and colleagues. In addition, the novel observations about the association of episodic memory impairments with the female gender and positive Pick body neuropathology add to the existing knowledge about this phenotypic expression of FTD.

Frontotemporal dementia

Frontotemporal dementia is an umbrella clinical term that encompasses a group of neurodegenerative diseases characterised by progressive deficits in behaviour, executive function, or language. Frontotemporal dementia is a common type of dementia, particularly in patients younger than 65 years. The disease can mimic many psychiatric disorders because of the prominent behavioural features. Various underlying neuropathological entities lead to the frontotemporal dementia clinical phenotype, all of which are characterised by the selective degeneration of the frontal and temporal cortices. Genetics is an important risk factor for frontotemporal dementia. Advances in clinical, imaging, and molecular characterisation have increased the accuracy of frontotemporal dementia diagnosis, thus allowing for the accurate differentiation of these syndromes from psychiatric disorders. As the understanding of the molecular basis for frontotemporal dementia improves, rational therapies are beginning to emerge.

Key emerging issues in frontotemporal dementia

Frontotemporal dementia (FTD) encompasses the syndromes of behavioural variant FTD (bvFTD) and primary progressive aphasia (PPA) and refers to those neurodegenerative diseases characterised by predominant pathological involvement of the frontal and temporal lobes. Recent years have witnessed major advances in the clinical characterisation of FTD, reflected in the publication of updated diagnostic criteria for bvFTD and PPA, and the discovery of new pathogenic mutations has added to the understanding of genotype-phenotype interactions and of disease mechanisms. Emerging results from longitudinal studies of familial FTD show that imaging and cognitive changes occur years before symptom onset and such studies may yield biomarkers of early disease that in turn will facilitate earlier diagnosis. The hope and (guarded) expectation is that these advances may together herald the beginning of the end of the chapter in which FTD is considered an inexorably progressive and untreatable condition.

Trajectories of Behavioural Disturbances Across Dementia Types

OBJECTIVE

To replicate a previous finding that the trajectory of the Neuropsychiatric Inventory (NPI) shifts in the sixth year of behavioural variant frontotemporal dementia (bvFTD). We evaluated longitudinal tracking with both the Frontal Behavioural Inventory (FBI) and NPI, comparing bvFTD against other dementias.

METHODS

Chart reviews over two to five years for patients with bvFTD (n=30), primary progressive aphasia (PPA, n=13) and Alzheimer's disease (AD, n=118) at an urban Canadian tertiary clinic specializing in dementia. Linear regressions of the longitudinal data tested predictors of annualized rates of change (ROC) in NPI and FBI total and subscales for apathy and disinhibition among dementia groups.

RESULTS

The mode of the overall sample for the most advanced duration of illness observed was 5 years, with the median at 7 years. We did not find a crescendo-decrescendo pattern in scores although, for bvFTD and AD, high initial scores correlated with ensuing downward ROCs on the NPI and FBI. Educational level showed an influence on disinhibition ROCs. The FBI was no more revealing than the NPI for apathy and disinhibition scores in these dementias.

CONCLUSIONS

A cognitive reserve effect on behavioural disturbance was supported but it may take longer than our 4 years of observing the clinical sample to record inflection points in the behavioural and psychiatric symptoms seen in bvFTD. The current data only imply that both apathy and disinhibition will diminish over the course of dementia.

Regional cerebral blood flow single photon emission computed tomography for detection of Frontotemporal dementia in people with suspected dementia

BACKGROUND

In the UK, dementia affects 5% of the population aged over 65 years and 25% of those over 85 years. Frontotemporal dementia (FTD) represents one subtype and is thought to account for up to 16% of all degenerative dementias. Although the core of the diagnostic process in dementia rests firmly on clinical and cognitive assessments, a wide range of investigations are available to aid diagnosis.Regional cerebral blood flow (rCBF) single-photon emission computed tomography (SPECT) is an established clinical tool that uses an intravenously injected radiolabelled tracer to map blood flow in the brain. In FTD the characteristic pattern seen is hypoperfusion of the frontal and anterior temporal lobes. This pattern of blood flow is different to patterns seen in other subtypes of dementia and so can be used to differentiate FTD.It has been proposed that a diagnosis of FTD, (particularly early stage), should be made not only on the basis of clinical criteria but using a combination of other diagnostic findings, including rCBF SPECT. However, more extensive testing comes at a financial cost, and with a potential risk to patient safety and comfort.

OBJECTIVES

To determine the diagnostic accuracy of rCBF SPECT for diagnosing FTD in populations with suspected dementia in secondary/tertiary healthcare settings and in the differential diagnosis of FTD from other dementia subtypes.

SEARCH METHODS

Our search strategy used two concepts: (a) the index test and (b) the condition of interest. We searched citation databases, including MEDLINE (Ovid SP), EMBASE (Ovid SP), BIOSIS (Ovid SP), Web of Science Core Collection (ISI Web of Science), PsycINFO (Ovid SP), CINAHL (EBSCOhost) and LILACS (Bireme), using structured search strategies appropriate for each database. In addition we searched specialised sources of diagnostic test accuracy studies and reviews including: MEDION (Universities of Maastricht and Leuven), DARE (Database of Abstracts of Reviews of Effects) and HTA (Health Technology Assessment) database.We requested a search of the Cochrane Register of Diagnostic Test Accuracy Studies and used the related articles feature in PubMed to search for additional studies. We tracked key studies in citation databases such as Science Citation Index and Scopus to ascertain any further relevant studies. We identified 'grey' literature, mainly in the form of conference abstracts, through the Web of Science Core Collection, including Conference Proceedings Citation Index and Embase. The most recent search for this review was run on the 1 June 2013.Following title and abstract screening of the search results, full-text papers were obtained for each potentially eligible study. These papers were then independently evaluated for inclusion or exclusion.

SELECTION CRITERIA

We included both case-control and cohort (delayed verification of diagnosis) studies. Where studies used a case-control design we included all participants who had a clinical diagnosis of FTD or other dementia subtype using standard clinical diagnostic criteria. For cohort studies, we included studies where all participants with suspected dementia were administered rCBF SPECT at baseline. We excluded studies of participants from selected populations (e.g. post-stroke) and studies of participants with a secondary cause of cognitive impairment.

DATA COLLECTION AND ANALYSIS

Two review authors extracted information on study characteristics and data for the assessment of methodological quality and the investigation of heterogeneity. We assessed the methodological quality of each study using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool. We produced a narrative summary describing numbers of studies that were found to have high/low/unclear risk of bias as well as concerns regarding applicability. To produce 2 x 2 tables, we dichotomised the rCBF SPECT results (scan positive or negative for FTD) and cross-tabulated them against the results for the reference standard. These tables were then used to calculate the sensitivity and specificity of the index test. Meta-analysis was not performed due to the considerable between-study variation in clinical and methodological characteristics.

MAIN RESULTS

Eleven studies (1117 participants) met our inclusion criteria. These consisted of six case-control studies, two retrospective cohort studies and three prospective cohort studies. Three studies used single-headed camera SPECT while the remaining eight used multiple-headed camera SPECT. Study design and methods varied widely. Overall, participant selection was not well described and the studies were judged as having either high or unclear risk of bias. Often the threshold used to define a positive SPECT result was not predefined and the results were reported with knowledge of the reference standard. Concerns regarding applicability of the studies to the review question were generally low across all three domains (participant selection, index test and reference standard).Sensitivities and specificities for differentiating FTD from non-FTD ranged from 0.73 to 1.00 and from 0.80 to 1.00, respectively, for the three multiple-headed camera studies. Sensitivities were lower for the two single-headed camera studies; one reported a sensitivity and specificity of 0.40 (95% confidence interval (CI) 0.05 to 0.85) and 0.95 (95% CI 0.90 to 0.98), respectively, and the other a sensitivity and specificity of 0.36 (95% CI 0.24 to 0.50) and 0.92 (95% CI 0.88 to 0.95), respectively.Eight of the 11 studies which used SPECT to differentiate FTD from Alzheimer's disease used multiple-headed camera SPECT. Of these studies, five used a case-control design and reported sensitivities of between 0.52 and 1.00, and specificities of between 0.41 and 0.86. The remaining three studies used a cohort design and reported sensitivities of between 0.73 and 1.00, and specificities of between 0.94 and 1.00. The three studies that used single-headed camera SPECT reported sensitivities of between 0.40 and 0.80, and specificities of between 0.61 and 0.97.

AUTHORS' CONCLUSIONS

At present, we would not recommend the routine use of rCBF SPECT in clinical practice because there is insufficient evidence from the available literature to support this.Further research into the use of rCBF SPECT for differentiating FTD from other dementias is required. In particular, protocols should be standardised, study populations should be well described, the threshold for 'abnormal' scans predefined and clear details given on how scans are analysed. More prospective cohort studies that verify the presence or absence of FTD during a period of follow up should be undertaken.

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.

Differentiating subtypes of apathy to improve person-centered care in frontotemporal degeneration

Apathy, a reduction in goal-directed behavior (GDB), affects 90% of individuals with behavioral variant frontotemporal degeneration, which is a common cause of early onset neurodegenerative disease. The cognitive and neural impairments associated with apathy make it difficult to initiate, plan, and self-motivate activities toward a specific goal, such as dressing or bathing. These impairments are associated with significant decline in functional ability, caregiver burden, and increased cost of care due to early institutionalization. The current article reviews the evidence suggesting that apathy arises from the interruption of one or any combination of three GDB processes: initiation, planning, and motivation. From this perspective, three subtypes of apathy related to dysfunction at the level of GDB and the corresponding neuroanatomy are explored. Further research is required to confirm and measure these subtypes of apathy for use in clinical and research settings. A more precise classification of apathy by subtype will allow implementation of the most appropriate person-centered, individualized therapy.

Heritability in frontotemporal dementia: more missing pieces?

Frontotemporal dementia (FTD) is reportedly highly heritable, even though a recognized genetic cause is often absent. To explain this contradiction, we explored the "strength" of family history in FTD, Alzheimer's disease (AD), and controls. Clinical syndromes associated with heritability of FTD and AD were also examined. FTD and AD patients were recruited from an FTD-specific research clinic, and patients were further sub-classified into FTD or AD phenotypes. The strength of family history was graded using the Goldman score (GS), and GS of 1-3 was regarded as a "strong" family history. A subset of FTD patients underwent screening for the main genetic causes of FTD. In total, 307 participants were included (122 FTD, 98 AD, and 87 controls). Although reported positive family history did not differ between groups, a strong family history was more common in FTD (FTD 17.2 %, AD 5.1 %, controls 2.3 %, P < 0.001). The bvFTD and FTD-ALS groups drove heritability, but 12.2 % of atypical AD patients also had a strong family history. A pathogenic mutation was identified in 16 FTD patients (10 C9ORF72 repeat expansion, 5 GRN, 1 MAPT), but more than half of FTD patients with a strong family history had no mutation detected. FTD is a highly heritable disease, even more than AD, and patients with bvFTD and FTD-ALS drive this heritability. Atypical AD also appears to be more heritable than typical AD. These results suggest that further genetic influences await discovery in FTD.

Myelin oligodendrocyte basic protein and prognosis in behavioral-variant frontotemporal dementia

OBJECTIVE

To determine the prognostic utility of tauopathy-associated single nucleotide polymorphisms (SNPs) in sporadic behavioral-variant frontotemporal dementia (bvFTD).

METHODS

Eighty-one patients with sporadic bvFTD were genotyped for tauopathy-associated SNPs at rs8070723 (microtubule-associated protein tau [MAPT]) and rs1768208 (myelin-associated oligodendrocyte basic protein [MOBP]). We performed a retrospective case-control study comparing age at onset and disease duration between carriers of ≥1 polymorphism allele and noncarriers for these SNPs. Subanalyses were performed for autopsied subgroups with tauopathy (n = 20) and TDP-43 proteinopathy (n = 12). To identify a potential biological basis for disease duration, neuroimaging measures of white matter integrity were evaluated (n = 37).

RESULTS

Carriers of risk allele (T) in rs1768208 (i.e., MOBP RA+) had a shorter median disease duration (TC/TT = 5.5 years, CC = 9.5 years; p = 0.02). This was also found in the subset of cases with autopsy-confirmed tauopathies (p = 0.04) but not with TDP-43 proteinopathies (p > 0.1). By comparison, polymorphisms at rs8070723 (MAPT) had no effect on disease duration (p > 0.1), although carriers of protective allele (G) in rs8070723 had a younger median age at onset (AG/GG = 54.5 years, AA = 58 years; p < 0.01). MOBP RA+ patients had increased radial diffusivity in the superior corona radiata and midbrain, and reduced fractional anisotropy in the superior corona radiata as well as superior and inferior longitudinal fasciculi compared with noncarriers (p < 0.01).

CONCLUSIONS

The rs1768208 risk polymorphism in MOBP may have prognostic value in bvFTD. MOBP RA+ patients have more severe white matter degeneration in bvFTD that may contribute to shorter disease duration. Future studies are needed to help confirm these findings.

SQSTM1 mutations in French patients with frontotemporal dementia or frontotemporal dementia with amyotrophic lateral sclerosis

IMPORTANCE

Mutations in the SQSTM1 gene, coding for p62, are a cause of Paget disease of bone and amyotrophic lateral sclerosis (ALS). Recently, SQSTM1 mutations were confirmed in ALS, and mutations were also identified in 3 patients with frontotemporal dementia (FTD), suggesting a role for SQSTM1 in FTD.

OBJECTIVE

To evaluate the exact contribution of SQSTM1 to FTD and FTD with ALS (FTD-ALS) in an independent cohort of patients.

DESIGN

A SQSTM1 mutation was first identified in a multiplex family with FTD by use of whole-exome sequencing. To evaluate the frequency of SQSTM1 mutations, we sequenced this gene in a cohort of patients with FTD or FTD-ALS, with no mutations in known FTD and ALS genes.

SETTING

Primary care or referral center.

PARTICIPANTS

An overall cohort of 188 French patients, including 132 probands with FTD and 56 probands with FTD-ALS.

MAIN OUTCOMES AND MEASURES

Frequency of SQSTM1 mutations in patients with FTD or FTD-ALS; description of associated phenotypes.

RESULTS

We identified 4 heterozygous missense mutations in 4 unrelated families with FTD; only 1 family had clinical symptoms of Paget disease of bone, and only 1 family had clinical symptoms of FTD-ALS, possibly owing to the low penetrance of some of the clinical manifestations.

CONCLUSIONS AND RELEVANCE

Although the frequency of the mutations is low in our series (4 of 188 patients [2%]), our results, similar to those already reported, support a direct pathogenic role of p62 in different types of FTD.

Are frontal cognitive and atrophy patterns different in PSP and bvFTD? A comparative neuropsychological and VBM study

Progressive supranuclear palsy (PSP) and frontotemporal lobar degeneration (FTD) are two clinicohistological entities that share a severe prefrontal syndrome. To what extent do the cognitive syndrome and the location of the underlying brain atrophy unify or segregate these entities? Here, we examined the clinical and radiological patterns of frontal involvement and the neural bases of the cognitive dysfunctions observed in the Richardson form of PSP and the behavioral variant of FTD (bvFTD). The cognitive profile and grey and white matter volume of PSP (n = 19) and bvFTD (n = 16) patients and control participants (n = 18) were compared using a standard battery of neuropsychological tests and voxel-based morphometry (VBM), respectively. Analyses of correlations between neuropsychological and morphometric data were additionally performed. The severity and qualitative pattern of cognitive dysfunction was globally similar between the two patient groups. Grey matter volume was decreased in widespread frontal areas and in the temporal uncus in bvFTD, while it was decreased in the frontal and temporal lobes as well as in the thalamus in PSP. We also found an unexpected involvement of the frontal rectal gyrus in PSP patients compared to controls. Correlation analyses yielded different results in the two groups, with no area showing significant correlations in PSP patients, while several frontal and some temporal areas did so in bvFTD patients. In spite of minor neuropsychological and morphological differences, this study shows that the patterns of cognitive dysfunction and atrophy are very similar in PSP and bvFTD. However, executive dysfunction in these diseases may stem from partially divergent cortical and subcortical neural circuits.

Vascular factors are associated with the severity of the neuropsychiatric symptoms in Alzheimer's disease

INTRODUCTION

The purpose of this study is to determine whether vascular risk factors are associated with severity of neuropsychiatric symptoms (NPS) in patients of Alzheimer's dementia.

METHODS

We reviewed medical records of 162 patients with Alzheimer's dementia. The NPS were assessed using the Neuropsychiatric Inventory (NPI). Hypertension and cardiovascular events were detected through detailed history taking. Diabetes mellitus and hyperlipidemia were uncovered through laboratory test. The asymptomatic stroke and white matter hyperintensities (WMH) were defined by magnetic resonance imaging. Partial correlation analysis was used.

RESULTS

Hypertension was correlated with the severity of apathy (r = 0.231, p = 0.015). The asymptomatic stroke was related to the severity of depression (r = 0.255, p = 0.007). The remaining vascular factors were not significant.

CONCLUSION

Presence of hypertension and asymptomatic stroke are related with the severity of apathy and depression in Alzheimer's dementia.

A critical role for the hippocampus in the valuation of imagined outcomes

Converging evidence from neuroimaging and clinical data demonstrates the important involvement of the hippocampus in finding the motivation to pursue goals that we need to imagine because they are not within sight.

Many choice situations require imagining potential outcomes, a capacity that was shown to involve memory brain regions such as the hippocampus. We reasoned that the quality of hippocampus-mediated simulation might therefore condition the subjective value assigned to imagined outcomes. We developed a novel paradigm to assess the impact of hippocampus structure and function on the propensity to favor imagined outcomes in the context of intertemporal choices. The ecological condition opposed immediate options presented as pictures (hence directly observable) to delayed options presented as texts (hence requiring mental stimulation). To avoid confounding simulation process with delay discounting, we compared this ecological condition to control conditions using the same temporal labels while keeping constant the presentation mode. Behavioral data showed that participants who imagined future options with greater details rated them as more likeable. Functional MRI data confirmed that hippocampus activity could account for subjects assigning higher values to simulated options. Structural MRI data suggested that grey matter density was a significant predictor of hippocampus activation, and therefore of the propensity to favor simulated options. Conversely, patients with hippocampus atrophy due to Alzheimer's disease, but not patients with Fronto-Temporal Dementia, were less inclined to favor options that required mental simulation. We conclude that hippocampus-mediated simulation plays a critical role in providing the motivation to pursue goals that are not present to our senses.

Economic theory assumes that we assign some sort of value to options that are presented to us in order to choose between them. In neuroscience, evidence suggests that memory brain regions, such as the hippocampus, are involved in imagining novel situations. We therefore hypothesized that the hippocampus might be critical for evaluating outcomes that we need to imagine. This is typically the case in intertemporal choices, where immediate rewards are considered against future gratifications (e.g., a beer now or a bottle of champagne a week from now). Previous investigations have implicated the dorsal prefrontal cortex brain region in resisting immediate rewards. Here we manipulated the mode of presentation (text or picture), such that options were represented either in simulation or in perception systems. Functional neuroimaging data confirmed that hippocampal activity lends a preference to choosing simulated options (irrespective of time), whereas dorsal prefrontal cortex brain activity supports the preference for delayed options (irrespective of presentation mode). Structural neuroimaging in healthy subjects and in patients with brain atrophy, due to Alzheimer's disease (with hippocampal damage) or Fronto-Temporal Dementia (with damage to the prefrontal cortex), further demonstrated the critical implication of the hippocampus. Individuals with higher neuronal density in the hippocampus, but not in the dorsal prefrontal cortex, were more likely to choose future rewards that have to be mentally simulated.

Using the revised diagnostic criteria for frontotemporal dementia in India: evidence of an advanced and florid disease

BACKGROUND

The International Consortium (FTDC) that revised the diagnostic criteria for behavioural variant frontotemporal dementia (bvFTD) did not have an Asian representation. Whether the revised criteria are equally useful in the early detection of Asian bvFTD patients therefore remains largely unexplored. Earlier studies have indicated differences in clinical manifestations in Indian and other Asian bvFTD patients when compared to western groups. There is an urgent need for clarification, given the projected exponential rise in dementia in these countries and the imminent clinical trials on bvFTD.

OBJECTIVE

To assess how Indian bvFTD patients fulfil the FTDC criteria, hypothesizing that our patients might present differently early in the illness.

METHOD

In a hospital-based retrospective observational study, we assessed 48 probable bvFTD patients, diagnosed according to the FTDC criteria, for the speed with which these criteria were fulfilled, the frequency of individual symptoms and their order of appearance during the illness.

RESULTS

Most of our patients presented with moderate to severe dementia, in spite of having relatively short onset to diagnosis times. Patients on average took 1.4 years from onset to meet the FTDC criteria, with 90% of them presenting with four or more symptoms at diagnosis. Disinhibition was the commonest symptom and the first symptom in most patients.

CONCLUSION

With most patients presenting with advanced and florid disease, the FTDC criteria have little additional impact in early identification of bvFTD in India. Modifying the criteria further could allow detection of Indian patients early enough for their inclusion in future clinical trials.

Distinct patterns of medial temporal impairment in degenerative dementia: a brain SPECT perfusion study in Alzheimer's disease and frontotemporal dementia

PURPOSE

Medial temporal impairment can be detected clinically and by morphological imaging during Alzheimer's disease (AD), but the existence of a functional impairment in this area seems to be less well established. Yet such functional impairment is classically found in other degenerative cortical dementias, such as the frontal variant of frontotemporal dementia (fv-FTD). The aim of this study was to characterize and compare brain SPECT perfusion of the medial temporal lobe in AD and fv-FTD.

METHODS

Voxel-based comparisons were performed using SPM8 between cerebral SPECT images from 85 AD patients, 25 fv-FTD patients and 12 healthy controls at the whole-brain level and the medial temporal lobe level using a region of interest approach (p < 0.001, corrected for the cluster).

RESULTS

In the free and cued selective reminding test, used to evaluate medial temporal memory function, AD patients had significantly lower scores than the fv-FTD patients (p < 0.005). AD and fv-FTD patients showed hypoperfused medial temporal structures in comparison to normal controls. However, fv-FTD patients had more pronounced hypoperfusion in this area, with a different topography, more anterior and more parahippocampal.

CONCLUSION

These results show that medial temporal hypoperfusion can be detected in degenerative dementias by SPECT. Paradoxically, the hypoperfusion is more severe in fv-FTD than in AD patients, even though the mnesic profile of AD is more altered, suggesting the existence of inefficient compensatory mechanisms.

The overlap of symptomatic dimensions between frontotemporal dementia and several psychiatric disorders that appear in late adulthood

Several factors make diagnosis of a possible behavioural variant of frontotemporal dementia (bvFTD) particularly challenging, especially the overlap of certain symptomatic dimensions such as apathy, disinhibition, depression, anhedonia, stereotyped behaviour, and psychosis between bvFTD and several psychiatric disorders that appear in late adulthood. We discuss the most frequent psychiatric conditions that can simulate early bvFTD symptoms, including late onset bipolar disorder, late onset schizophrenia-like psychosis, late onset depression, and attention deficit hyperactivity disorder in middle and older age.

Schizophrenia and frontotemporal dementia: shared causation?

The relationship between specific genes and particular diseases in neuropsychiatry is unclear, and newer studies focus on shared domains of neurobiological and cognitive pathology across different disorders. This paper reviews the evidence for an association between schizophrenia and frontotemporal dementia, including symptom similarity, familial co-morbidity, and neuroanatomical changes. Genetic as well as epigenetic findings from both schizophrenia and frontotemporal dementia are also discussed. As a result, we introduce the hypothesis of a shared susceptibility for certain subgroups of schizophrenia and frontotemporal dementia. This common causation may involve the same gene(s) at different stages of life: early in schizophrenia and late in frontotemporal dementia. Additionally, we provide a rationale for future research that should emphasize both genetic and cognitive parallels between certain forms of schizophrenia and frontotemporal dementia in a synergistic, coordinated way, placing both in the context of aberrant lateralization patterns.

Dissociating behavioral disorders in early dementia-An FDG-PET study

Behavioral impairments occur frequently in dementia. Studies with magnetic resonance imaging, measuring atrophy, have systematically investigated their neural correlates. Such a systematic approach has not yet been applied to imaging with [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET), although regional hypometabolism may precede and exceed atrophy in dementia. The present study related all behavioral disorders as assessed with the Neuropsychiatric Inventory to reductions in brain glucose utilization as measured by FDG-PET with Statistical Parametric Mapping (SPM5). It included 54 subjects mainly with early Alzheimer's disease, frontotemporal lobar degeneration, and subjective cognitive impairment. Apathy, disinhibition and eating disorders - most frequent in frontotemporal lobar degeneration - correlated significantly with regional brain hypometabolism. Whereas a single regressor analysis and conjunction analysis revealed largely overlapping frontomedian regions that were associated with all three behavioral domains, a disjunction analysis identified three specific neural networks for each behavioral disorder, independent of dementia severity. Apathy was related to the ventral tegmental area, a component of the motivational dopaminergic network; disinhibition to both anterior temporal lobes including the anterior hippocampi and left amygdala, caudate head, orbitofrontal cortex and insulae; and eating disorders to the right lateral (orbito) frontal cortex/insula. Our study contributes to the understanding of behavioral deficits in early dementia and suggests specific diagnostic and therapeutic approaches.

[Diagnostic profile of young-onset dementia before 65 years. Experience of a French Memory Referral Center]

OBJECTIVE

The aim of the study was to compare the profiles of patients with young (age≤65 years) and late (age>65 years) onset of dementia in a memory clinic of a Memory Referral Center in Lyons (France), for the year 2008.

METHODS

A total of 746 demented patients were evaluated using clinical, neuropsychological and imaging information. For each patient, diagnoses of the dementing disorder used clinical criteria at the first visit. We examined the distribution of patients diagnosis and differences in sex and education between the young-onset dementia (YOD) and the late-onset dementia (LOD) groups.

RESULTS

From a total of 746 registered demented patients (300 men, 446 women), there were 91 patients (12.2%) with YOD (from 36.5 to 65 years) and 655 patients with LOD (from 66 to 92 years). Among the 91 YOD patients, the most frequent causes were Mild Cognitive Impairment (MCI) (18.7%), then Alzheimer's disease (AD), frontotemporal dementia and posterior cortical atrophy (14.3% each), followed by progressive aphasia (11.0%), dementia with Lewy bodies (DLD) (9.9%), semantic dementia (8.8%), other causes (3.3%), vascular dementia (2.2%), undetermined dementia (2.2%), AD+cerebrovascular disease (1.1%). Among the 655 LOD patients, AD was the most frequent cause of dementia (57.4%). Referred cases by a specialist doctor were 50.5% in the YOD group and 12.7% in the LOD group (P<0.0001). In the ACP group, 68.4% patients began before 65 years.

CONCLUSION

The number of YOD in our memory clinic was four-fold the number of expected patients in France. The characteristics of the Referral Center explain the high frequency of rare dementia such as progressive aphasia (5.2% of overall number), semantic dementia (3.6%) and posterior cortical atrophy (2.5%).

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.

Frontotemporal dementias: Recent advances and current controversies

Frontotemporal dementia (FTD) syndromes comprise a heterogeneous group of neurodegenerative conditions characterized by atrophy in the frontal and temporal lobes. Three main clinical variants are recognized: Behavioral variant (bv-FTD), Semantic dementia (SD), and Progressive nonfluent aphasia (PNFA). However, logopenic/phonological (LPA) variant has been recently described, showing a distinctive pattern of brain atrophy and often associated to Alzheimer's disease pathology. The diagnosis of FTD is challenging, since there is clinical, pathological, and genetic overlap between the variants and other neurodegenerative diseases, such as motoneuron disease (MND) and corticobasal degeneration (CBD). In addition, patients with gene mutations (tau and progranulin) display an inconsistent clinical phenotype and the correspondence between the clinical variant and its pathology is unpredictable. New cognitive tests based on social cognition and emotional recognition together with advances in molecular pathology and genetics have contributed to an improved understanding. There is now a real possibility of accurate biomarkers for early diagnosis. The present review concentrates on new insights and debates in FTD.

Imaging signatures of molecular pathology in behavioral variant frontotemporal dementia

Pathology underlying behavioral variant frontotemporal dementia (bvFTD) is heterogeneous, with the most common pathologies being Pick's disease (PiD), corticobasal degeneration (CBD), and FTLD-TDP type 1. Clinical features are unhelpful in differentiating these pathologies. We aimed to determine whether imaging atrophy patterns differ across these pathologies in bvFTD subjects. We identified 15 bvFTD subjects that had volumetric MRI during life and autopsy: five with PiD, five CBD, and five FTLD-TDP type 1. Voxel-based morphometry was used to assess atrophy patterns in each bvFTD group compared to 20 age- and gender-matched controls. All three pathological groups showed gray matter loss in frontal lobes, although specific patterns of atrophy differed across groups: PiD showed widespread loss in frontal lobes with additional involvement of anterior temporal lobes; CBD showed subtle patterns of loss involving posterior lateral and medial superior frontal lobe; and FTLD-TDP type 1 showed widespread loss in frontal, temporal, and parietal lobes. Greater parietal loss was observed in FTLD-TDP type 1 compared to both other groups, and greater anterior temporal and medial frontal loss was observed in PiD compared to CBD. Imaging patterns of atrophy in bvFTD vary according to pathological diagnosis and may therefore be helpful in predicting these pathologies in bvFTD.

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.

Neural correlates of cognitive impairment in posterior cortical atrophy

With the prospect of disease-modifying drugs that will target the physiopathological process of Alzheimer's disease, it is now crucial to increase the understanding of the atypical focal presentations of Alzheimer's disease, such as posterior cortical atrophy. This study aimed to (i) characterize the brain perfusion profile in posterior cortical atrophy using regions of interest and a voxel-based approach; (ii) study the influence of the disease duration on the clinical and imaging profiles; and (iii) explore the correlations between brain perfusion and cognitive deficits. Thirty-nine patients with posterior cortical atrophy underwent a specific battery of neuropsychological tests, mainly targeting visuospatial functions, and a brain perfusion scintigraphy with 99mTc-ethyl cysteinate dimer. The imaging analysis included a comparison with a group of 24 patients with Alzheimer's disease, matched for age, disease duration and Mini-Mental State Examination, and 24 healthy controls. The single-photon emission computed tomography profile in patients with posterior cortical atrophy was characterized by extensive and severe hypoperfusion in the occipital, parietal, posterior temporal cortices and in a smaller cortical area corresponding to the frontal eye fields (Brodmann areas 6/8). Compared with patients with Alzheimer's disease, the group with posterior cortical atrophy showed more severe occipitoparietal hypoperfusion and higher perfusion in the frontal, anterior cingulate and mesiotemporal regions. When considering the disease duration, the functional changes began and remained centred on the posterior lobes, even in the late stage. Correlation analyses of brain perfusion and neuropsychological scores in posterior cortical atrophy highlighted the prominent role of left inferior parietal damage in acalculia, Gerstmann's syndrome, left-right indistinction and limb apraxia, whereas damage to the bilateral dorsal occipitoparietal regions appeared to be involved in Bálint's syndrome. Our findings provide new insight into the natural history of functional changes according to disease duration and highlight the role of parietal and occipital cortices in the cognitive syndromes that characterize the posterior cortical atrophy.

Predicting functional decline in behavioural variant frontotemporal dementia

Behavioural variant frontotemporal dementia is characterized by a change in comportment. It is associated with considerable functional decline over the course of the illness albeit with sometimes dramatic variability among patients. It is unknown whether any baseline features, or combination of features, could predict rate of functional decline in behavioural variant frontotemporal dementia. The aim of this study was to investigate the effects of different baseline clinical, neuropsychological, neuropsychiatric, genetic and anatomic predictors on the rate of functional decline as measured by the Clinical Dementia Rating Sum of Boxes scale. We identified 86 subjects with behavioural variant frontotemporal dementia that had multiple serial Clinical Dementia Rating Sum of Boxes assessments (mean 4, range 2-18). Atlas-based parcellation was used to generate volumes for specific regions of interest at baseline. Volumes were utilized to classify subjects into different anatomical subtypes using the advanced statistical technique of cluster analysis and were assessed as predictor variables. Composite scores were generated for the neuropsychological domains of executive, language, memory and visuospatial function. Behaviours from the brief questionnaire form of the Neuropsychiatric Inventory were assessed. Linear mixed-effects regression modelling was used to determine which baseline features predict rate of future functional decline. Rates of functional decline differed across the anatomical subtypes of behavioural variant frontotemporal dementia, with faster rates observed in the frontal dominant and frontotemporal subtypes. In addition, subjects with poorer performance on neuropsychological tests of executive, language and visuospatial function, less disinhibition, agitation/aggression and night-time behaviours at presentation, and smaller medial, lateral and orbital frontal lobe volumes showed faster rates of decline. In many instances, the effect of the predictor variables observed across all subjects was also preserved within anatomical subtypes. Furthermore, some of the predictor variables improved our prediction of rate of functional decline after anatomical subtype was taken into account. In particular, age at onset was a highly significant predictor but only after adjusting for subtype. We also found that although some predictor variables, for example gender, Mini-Mental State Examination score, and apathy/indifference, did not affect the rate of functional decline; these variables were associated with the actual Clinical Dementia Rating Sum of Boxes score estimated for any given time-point. These findings suggest that in behavioural variant frontotemporal dementia, rate of functional decline is driven by the combination of anatomical pattern of atrophy, age at onset, and neuropsychiatric characteristics of the subject at baseline.

[Diagnosis contribution of biomarkers in Alzheimer disease: A case of frontotemporal dementia]

INTRODUCTION

Cerebrospinal fluid biomarkers are a fundamental contribution for the diagnosis of Alzheimer disease, in particular for young people.

CASE REPORT

We report a case of Alzheimer disease of a 51-years old man whose clinical presentation corresponded to frontotemporal behavioural criteria. The clinical evaluation noticed some troubles in verbal memory. Only the CSF biomarkers confirmed the diagnosis.

CONCLUSION

There are different phenotypes of presenile Alzheimer disease and among them we note frontotemporal dementia. It is very important to identify them to introduce a specific treatment.

Cholinergic imaging in corticobasal syndrome, progressive supranuclear palsy and frontotemporal dementia

Corticobasal syndrome, progressive supranuclear palsy and frontotemporal dementia are all part of a disease spectrum that includes common cognitive impairment and movement disorders. The aim of this study was to characterize brain cholinergic deficits in these disorders. We measured brain acetylcholinesterase activity by [11C] N-methylpiperidin-4-yl acetate and positron emission tomography in seven patients with corticobasal syndrome (67.6+/-5.9 years), 12 with progressive supranuclear palsy (68.5+/-4.1 years), eight with frontotemporal dementia (59.8+/-6.9 years) and 16 healthy controls (61.2+/-8.5 years). Two-tissue compartment three-parameter model and non-linear least squares analysis with arterial input function were performed. k3 value, an index of acetylcholinesterase activity, was calculated voxel-by-voxel in the brain of each subject. The k3 images in each disease group were compared with the control group by using Statistical Parametric Mapping 2. Volume of interest analysis was performed on spatially normalized k3 images. The corticobasal syndrome group showed decreased acetylcholinesterase activity (k3 values) in the paracentral region, frontal, parietal and occipital cortices (P<0.05, cluster corrected). The group with progressive supranuclear palsy had reduced acetylcholinesterase activity in the paracentral region and thalamus (P<0.05, cluster corrected). The frontotemporal dementia group showed no significant differences in acetylcholinesterase activity. Volume of interest analysis showed mean cortical acetylcholinesterase activity to be reduced by 17.5% in corticobasal syndrome (P<0.001), 9.4% in progressive supranuclear palsy (P<0.05) and 4.4% in frontotemporal dementia (non-significant), when compared with the control group. Thalamic acetylcholinesterase activity was reduced by 6.4% in corticobasal syndrome (non-significant), 24.0% in progressive supranuclear palsy (P<0.03) and increased by 3.3% in frontotemporal dementia (non-significant). Both corticobasal syndrome and progressive supranuclear palsy showed brain cholinergic deficits, but their distribution differed somewhat. Significant brain cholinergic deficits were not seen in frontotemporal dementia, which may explain the unresponsiveness of this condition to cholinergic modulation therapy.