Frontotemporal dementia due to C9ORF72 mutations: clinical and imaging features.

Objective: To describe the phenotype of patients with C9FTD/ALS (C9ORF72) hexanucleotide repeat expansion.

Methods: A total of 648 patients with frontotemporal dementia (FTD)-related clinical diagnoses and Alzheimer disease (AD) dementia were tested for C9ORF72 expansion and 31 carried expanded repeats (C9+). Clinical and neuroimaging data were compared between C9+ (15 behavioral variant FTD [bvFTD], 11 FTD-motor neuron disease [MND], 5 amyotrophic lateral sclerosis [ALS]) and sporadic noncarriers (48 bvFTD, 19 FTD-MND, 6 ALS).

Evidence for a role of the rare p.A152T variant in MAPT in increasing the risk for FTD-spectrum and Alzheimer's diseases.

Rare mutations in the gene encoding for tau (MAPT, microtubule-associated protein tau) cause frontotemporal dementia-spectrum (FTD-s) disorders, including FTD, progressive supranuclear palsy (PSP) and corticobasal syndrome, and a common extended haplotype spanning across the MAPT locus is associated with increased risk of PSP and Parkinson's disease. We identified a rare tau variant (p.A152T) in a patient with a clinical diagnosis of PSP and assessed its frequency in multiple independent series of patients with neurodegenerative conditions and controls, in a total of 15 369 subjects.

Saccade abnormalities in autopsy-confirmed frontotemporal lobar degeneration and Alzheimer disease.

Background: Deficits in the generation and control of saccades have been described in clinically defined frontotemporal dementia (FTD) and Alzheimer disease (AD).

Objective: To determine the saccade abnormalities associated with autopsy-defined cases of frontotemporal lobar degeneration (FTLD) and of AD, because clinical FTD syndromes can correspond to a number of different underlying neuropathologic FTD and non-FTD diagnoses.

Design: An infrared eye tracker was used to record visually guided saccades to 10° targets and antisaccades in subjects with autopsy-confirmed FTD and subjects with autopsy-confirmed AD, a mean (SE) of 35.

Atypical, slowly progressive behavioural variant frontotemporal dementia associated with C9ORF72 hexanucleotide expansion.

Background: Some patients meeting behavioural variant frontotemporal dementia (bvFTD) diagnostic criteria progress slowly and plateau at mild symptom severity. Such patients have mild neuropsychological and functional impairments, lack characteristic bvFTD brain atrophy and have thus been referred to as bvFTD 'phenocopies' or slowly progressive (bvFTD-SP). The few patients with bvFTD-SP that have been studied at autopsy have demonstrated no evidence of FTD pathology, suggesting that bvFTD-SP is neuropathologically distinct from other forms of FTD.

Patterns of striatal degeneration in frontotemporal dementia.

Behavioral variant frontotemporal dementia and semantic dementia have been associated with striatal degeneration, but few studies have delineated striatal subregion volumes in vivo or related them to the clinical phenotype. We traced caudate, putamen, and nucleus accumbens on magnetic resonance images to quantify volumes of these structures in behavioral variant frontotemporal dementia, semantic dementia, Alzheimer disease, and healthy controls (n=12 per group). We further related these striatal volumes to clinical deficits and neuropathologic findings in a subset of patients.

Expanded GGGGCC hexanucleotide repeat in noncoding region of C9ORF72 causes chromosome 9p-linked FTD and ALS.

Several families have been reported with autosomal-dominant frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), genetically linked to chromosome 9p21. Here, we report an expansion of a noncoding GGGGCC hexanucleotide repeat in the gene C9ORF72 that is strongly associated with disease in a large FTD/ALS kindred, previously reported to be conclusively linked to chromosome 9p. This same repeat expansion was identified in the majority of our families with a combined FTD/ALS phenotype and TDP-43-based pathology.

Chromosome 9 ALS and FTD locus is probably derived from a single founder.

We and others have recently reported an association between amyotrophic lateral sclerosis (ALS) and single nucleotide polymorphisms on chromosome 9p21 in several populations. Here we show that the associated haplotype is the same in all populations and that several families previously shown to have genetic linkage to this region also share this haplotype. The most parsimonious explanation of these data are that there is a single founder for this form of disease.

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

Patients with corticobasal degeneration (CBD) pathology present with diverse clinical syndromes also associated with other neuropathologies, including corticobasal syndrome, progressive nonfluent aphasia, and an Alzheimer's-type dementia. Some present with behavioral variant frontotemporal dementia (bvFTD), though this subtype still requires more detailed clinical characterization. All patients with CBD pathology and clinical assessment were reviewed (N = 17) and selected if they initially met criteria for bvFTD [bvFTD(CBD), N = 5].

Clinicopathological correlations in corticobasal degeneration.

Objective: To characterize cognitive and behavioral features, physical findings, and brain atrophy patterns in pathology-proven corticobasal degeneration (CBD) and corticobasal syndrome (CBS) with known histopathology.

Methods: We reviewed clinical and magnetic resonance imaging data in all patients evaluated at our center with either an autopsy diagnosis of CBD (n = 18) or clinical CBS at first presentation with known histopathology (n = 40). Atrophy patterns were compared using voxel-based morphometry.

Anti-saccade performance predicts executive function and brain structure in normal elders.

Objective: To assess the neuropsychological and anatomical correlates of anti-saccade (AS) task performance in normal elders.

Background: The AS task correlates with neuropsychological measures of executive function and frontal lobe volume in neurological diseases, but has not been studied in a well-characterized normal elderly population. Because executive dysfunction can indicate an increased risk for cognitive decline in cognitively normal elders, we hypothesized that AS performance might be a sensitive test of age-related processes that impair cognition.

Visual search patterns in semantic dementia show paradoxical facilitation of binding processes.

While patients with Alzheimer's disease (AD) show deficits in attention, manifested by inefficient performance on visual search, new visual talents can emerge in patients with frontotemporal lobar degeneration (FTLD), suggesting that, at least in some of the patients, visual attention is spared, if not enhanced. To investigate the underlying mechanisms for visual talent in FTLD (behavioral variant FTD [bvFTD] and semantic dementia [SD]) patients, we measured performance on a visual search paradigm that includes both feature and conjunction search, while simultaneously monitoring saccadic eye movements. AD patients were impaired relative to healthy controls (NC) and FTLD patients on both feature and conjunction search.

Baseline predictors of clinical progression among patients with dysexecutive mild cognitive impairment.

Background/aims: There are few studies that evaluate the clinical outcomes of individuals with non-amnestic mild cognitive impairment (MCI). The purpose of this study was to evaluate baseline predictors of clinical progression after 2 years for patients with dysexecutive MCI (dMCI), a single-domain non-amnestic MCI subgroup.

Methods: We evaluated clinical progression in a sample of 31 older adults with dMCI.

Mutual gaze in Alzheimer's disease, frontotemporal and semantic dementia couples.

Alzheimer's disease (AD), frontotemporal dementia (FTD) and semantic dementia (SD) are neurodegenerative diseases that differ in their socioemotional presentations. Mutual gaze (i.e.

Clinical, neuroimaging and neuropathological features of a new chromosome 9p-linked FTD-ALS family.

Background: Frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS) is a heritable form of FTD, but the gene(s) responsible for the majority of autosomal dominant FTD-ALS cases have yet to be found. Previous studies have identified a region on chromosome 9p that is associated with FTD and ALS.

Methods: The authors report the clinical, volumetric MRI, neuropathological and genetic features of a new chromosome 9p-linked FTD-ALS family, VSM-20.

Bapineuzumab.

Importance Of The Field: Alzheimer's disease is the leading cause of dementia in the elderly, and there is no disease-modifying therapy yet available. Immunotherapy directed against the beta-amyloid peptide may be capable of slowing the rate of disease progression. Bapineuzumab, an anti-beta-amyloid monoclonal antibody, will be the first such agent to emerge from Phase III clinical trials.

Gray matter correlates of set-shifting among neurodegenerative disease, mild cognitive impairment, and healthy older adults.

There is increasing recognition that set-shifting, a form of cognitive control, is mediated by different neural structures. However, these regions have not yet been carefully identified as many studies do not account for the influence of component processes (e.g.

Off-label medication use in frontotemporal dementia.

Objective: There are no Food and Drug Administration (FDA)-approved medications indicated for the treatment of frontotemporal dementia (FTD). We sought to determine the most commonly used drugs used to treat behavioral variant FTD (bvFTD) in specialized dementia clinics.

Methods: Medication and demographic data from the Alzheimer's Disease Research Centers of California (ARCC) and a multicenter FTD natural history study (NHS) data set were compared in bvFTD and Alzheimer's disease (AD), and effects of demographic variables were assessed using logistic regression.

An open-label study of memantine treatment in 3 subtypes of frontotemporal lobar degeneration.

There are currently no Food and Drug Administration-approved treatments for frontotemporal lobar degeneration (FTLD). The objectives of this study were to explore the tolerability of memantine treatment in FTLD and to monitor for possible effects on behavior, cognition, and function. Forty-three individuals who met clinical criteria for FTLD [21 with frontotemporal dementia (FTD), 13 with semantic dementia (SD), and 9 with progressive nonfluent aphasia (PA)] received 26 weeks of open-label treatment with memantine at a target dose of 20 mg daily.

Apolipoprotein E epsilon4 is associated with disease-specific effects on brain atrophy in Alzheimer's disease and frontotemporal dementia.

Apolipoprotein epsilon4 (apoE4) has been strongly linked with Alzheimer's disease (AD) and contributes to several other neurological disorders. We investigated the influence of epsilon4 allele carrier status on the pattern of gray matter atrophy and disease severity in 51 patients with probable AD and 31 patients with behavioral variant frontotemporal dementia (bvFTD), compared with 56 healthy controls. Voxel-based morphometry was performed by using statistical parametric mapping.

Oculomotor function in frontotemporal lobar degeneration, related disorders and Alzheimer's disease.

Frontotemporal lobar degeneration (FTLD) often overlaps clinically with corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP), both of which have prominent eye movement abnormalities. To investigate the ability of oculomotor performance to differentiate between FTLD, Alzheimer's disease, CBS and PSP, saccades and smooth pursuit were measured in three FTLD subtypes, including 24 individuals with frontotemporal dementia (FTD), 19 with semantic dementia (SD) and six with progressive non-fluent aphasia (PA), as compared to 28 individuals with Alzheimer's disease, 15 with CBS, 10 with PSP and 27 control subjects. Different combinations of oculomotor abnormalities were identified in all clinical syndromes except for SD, which had oculomotor performance that was indistinguishable from age-matched controls.

Frontotemporal dementia treatment: current symptomatic therapies and implications of recent genetic, biochemical, and neuroimaging studies.

Frontotemporal dementia (FTD) is a common cause of dementia that encompasses 3 clinical subtypes: a behavioral/dysexecutive (frontal) variant and 2 variants with prominent language impairments. There are currently no Food and Drug Administration-approved medications for FTD although symptomatic treatments such as selective serotonin reuptake inhibitors and atypical antipsychotic agents are frequently used to manage behavioral abnormalities associated with this disorder. Evidence for the use of currently available symptomatic treatments in each FTD clinical subtype is reviewed.

Deformation-based morphometry reveals brain atrophy in frontotemporal dementia.

Objective: To compare deformation-based maps of local anatomical size between subjects with frontotemporal dementia (FTD) and healthy subjects to identify regions of the brain involved in FTD.

Design: Structural magnetic resonance images were obtained from 22 subjects with FTD and 22 cognitively normal, age-matched controls. We applied deformation-based morphometry and compared anatomy between groups using an analysis of covariance model that included a categorical variable denoting group membership and covaried for head size.

Medial versus lateral frontal lobe contributions to voluntary saccade control as revealed by the study of patients with frontal lobe degeneration.

Deficits in the ability to suppress automatic behaviors lead to impaired decision making, aberrant motor behavior, and impaired social function in humans with frontal lobe neurodegeneration. We have studied patients with different patterns of frontal lobe dysfunction resulting from frontotemporal lobar degeneration or Alzheimer's disease, investigating their ability to perform visually guided saccades and smooth pursuit eye movements and to suppress visually guided saccades on the antisaccade task. Patients with clinical syndromes associated with dorsal frontal lobe damage had normal visually guided saccades but were impaired relative to other patients and control subjects in smooth pursuit eye movements and on the antisaccade task.

Patterns of brain atrophy that differentiate corticobasal degeneration syndrome from progressive supranuclear palsy.

Background: Progressive brain atrophy is associated with the corticobasal degeneration syndrome (CBDS) and progressive supranuclear palsy (PSP). Regional differences in brain atrophy may reflect the clinical features of disease.

Objective: To quantify the structural neuroanatomical differences between CBDS and PSP.

Clinical features of frontotemporal dementia.

What was once called Pick's disease has three major anatomic variants. With all three, frontotemporal brain is selectively injured whereas posterior cortical regions are spared. These three clinical patterns include a bifrontal, slightly asymmetric subtype with more involvement of the right frontotemporal region called frontotemporal dementia or the frontal variant of FTD (fvFTD), a temporal-predominant subtype called the temporal variant of FTD or semantic dementia (SD), and a left frontal-predominant subtype called progressive nonfluent aphasia (PNFA).