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Resumen Actualmente, los estudios en torno a la organización de los procesos de entrenamiento mediante las tareas se han convertido en una de las líneas emergentes en las ciencias del deporte. Por ello, el objetivo del presente trabajo fue analizar el modo de actuación de un cuerpo técnico de un equipo de fútbol en edad escolar, sub-12, así como conocer la asociación del medio de iniciación al entrenamiento y las variables pedagógicas, de carga externa y organizativas que influyen en el diseño de las tareas. Para ello, se examinó un total de 177 tareas de entrenamiento enmarcadas durante cinco meses competitivos. Con miras a la categorización de dichas tareas, se utilizó la herramienta Sistema Integral para el Análisis de las Tareas de Entrenamiento, con la finalidad de estudiar las variables identificadas por el cuerpo técnico. Se realizó un análisis descriptivo y de diferencias entre las variables planteadas en la investigación, con base en el medio de iniciación al entrenamiento. Los resultados demostraron la existencia de asociaciones entre el medio de iniciación al entrenamiento y las variables situación de juego, fase de juego, tipo de contenido, contenido específico (pedagógicas). Estas asociaciones también fueron encontradas en las variables: densidad, número de ejecutantes simultáneos, carga competitiva, espacio de juego e implicación cognitiva (de carga externa), y la variable participación (organizativa). Por tanto, tales resultados evidencian la importancia de conocer las restricciones relacionadas con la carga de trabajo de las tareas de entrenamiento. Además, proporcionan al cuerpo técnico información sobre una herramienta fácil, asequible e informativa para cuantificar la carga de trabajo. Este método debe considerarse como un complemento de los dispositivos inerciales para el entrenamiento del control de la carga y monitoreo en deportes de invasión.

Abstract Currently, studies around the organization of training processes through tasks have become one of the emerging lines in Sports Sciences. Therefore, the present paperwork aimed to analyze the way of acting of a technical body of a soccer team in school age, U12, as well as to know the relationship of the means of initiation to training and the pedagogical, external load, and organizational variables that influence the design of homework. For this, a total of 177 training tasks framed during five competitive months were examined. In order to categorize the tasks, the Comprehensive System for the Analysis of Training Tasks was used to study the variables identified by the technical staff. A descriptive and difference analysis was conducted of the variables proposed in the study with the training initiation medium. The results demonstrated the existence of associations between the training initiation medium and the variables game situation, game phase, content-type, specific content (pedagogical). Associations were also identified/found in the variables density, number of simultaneous performers, competitive load, game space, and cognitive involvement (external load), and the participation variable (organizational). Associations were also found in the variables density, number of simultaneous performers, competitive load, game space, and cognitive involvement (external load), and the participation variable (organizational). Therefore, these results show the importance of knowing the restrictions related to the workload of training tasks. In addition, they provide the technical body with information on an easy, affordable, and informative tool to quantify workload. This method should be considered as a complement to portable devices for training load control and monitoring in invasion sports.

Resumo Atualmente, estudos sobre a organização de processos de treinamento por meio da tarefa de casa, se tornaram uma das linhas emergentes na ciência do esporte. Portanto, o objetivo deste trabalho foi analisar o modo de atuação de uma equipe técnica de um time de futebol em idade escolar, sub-12, bem como conhecer a associação dos meios de iniciação ao treinamento e as variáveis pedagógica, carga externa e organizacional que influenciam no desenho das tarefas. Para isso, um total de 177 tarefas de treinamento enquadradas durante cinco meses competitivos foram examinados. Com o objetivo de categorizar essas tarefas, a ferramenta utilizada foi o Sistema abrangente para a análise de tarefas de treinamento, a fim de estudar as variáveis identificadas pelo corpo técnico. Foi realizada uma análise descritiva e de diferença entre as variáveis propostas na pesquisa, com base nos meios de iniciação ao treinamento. Os resultados demonstraram a existência de associações entre os meios de iniciação ao treinamento e as variáveis situação do jogo, fase do jogo, tipo de conteúdo, conteúdo específico (pedagógico). Estas associações foram também encontradas nas variáveis densidade, número de artistas simultâneos, carga competitiva, espaço de jogo e envolvimento cognitivo (a partir de carga externa), e a variável participação (organizacional). Portanto, esses resultados mostram a importância de conhecer as restrições relacionadas à carga horária das tarefas de treinamento. Além disso, fornecem à equipe técnica informações sobre uma ferramenta fácil, acessível e informativa para quantificar a carga de trabalho. Este método deve ser considerado um complemento aos dispositivos inerciais para treinamento e monitoramento de controle de carga em esportes de invasão.

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The K+/Cl- cotransporter KCC2 (SLC12A5) allows mature neurons in the CNS to maintain low intracellular Cl- levels that are critical in mediating fast hyperpolarizing synaptic inhibition via type A γ-aminobutyric acid receptors (GABAARs). In accordance with this, compromised KCC2 activity results in seizures, but whether such deficits directly contribute to the subsequent changes in neuronal structure and viability that lead to epileptogenesis remains to be assessed. Canonical hyperpolarizing GABAAR currents develop postnatally, which reflect a progressive increase in KCC2 expression levels and activity. To investigate the role that KCC2 plays in regulating neuronal viability and architecture, we have conditionally ablated KCC2 expression in developing and mature neurons. Decreasing KCC2 expression in mature neurons resulted in the rapid activation of the extrinsic apoptotic pathway. Intriguingly, direct pharmacological inhibition of KCC2 in mature neurons was sufficient to rapidly induce apoptosis, an effect that was not abrogated via blockade of neuronal depolarization using tetrodotoxin (TTX). In contrast, ablating KCC2 expression in immature neurons had no discernable effects on their subsequent development, arborization, or dendritic structure. However, removing KCC2 in immature neurons was sufficient to ablate the subsequent postnatal development of hyperpolarizing GABAAR currents. Collectively, our results demonstrate that KCC2 plays a critical role in neuronal survival by limiting apoptosis, and mature neurons are highly sensitive to the loss of KCC2 function. In contrast, KCC2 appears to play a minimal role in mediating neuronal development or architecture.

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Kcc2 plays a critical role in determining the efficacy of synaptic inhibition, however, the cellular mechanisms neurons use to regulate its membrane trafficking, stability and activity are ill-defined. To address these issues, we used affinity purification to isolate stable multi-protein complexes of K-Cl Co-transporter 2 (Kcc2) from the plasma membrane of murine forebrain. We resolved these using blue-native polyacrylamide gel electrophoresis (BN-PAGE) coupled to LC-MS/MS and label-free quantification. Data are available via ProteomeXchange with identifier PXD021368. Purified Kcc2 migrated as distinct molecular species of 300, 600, and 800 kDa following BN-PAGE. In excess of 90% coverage of the soluble N- and C-termini of Kcc2 was obtained. In total we identified 246 proteins significantly associated with Kcc2. The 300 kDa species largely contained Kcc2, which is consistent with a dimeric quaternary structure for this transporter. The 600 and 800 kDa species represented stable multi-protein complexes of Kcc2. We identified a set of novel structural, ion transporting, immune related and signaling protein interactors, that are present at both excitatory and inhibitory synapses, consistent with the proposed localization of Kcc2. These included spectrins, C1qa/b/c and the IP3 receptor. We also identified interactors more directly associated with phosphorylation; Akap5, Akap13, and Lmtk3. Finally, we used LC-MS/MS on the same purified endogenous plasma membrane Kcc2 to detect phosphorylation sites. We detected 11 sites with high confidence, including known and novel sites. Collectively our experiments demonstrate that Kcc2 is associated with components of the neuronal cytoskeleton and signaling molecules that may act to regulate transporter membrane trafficking, stability, and activity.

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An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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The fidelity of inhibitory neurotransmission is dependent on the accumulation of γ-aminobutyric acid type A receptors (GABAARs) at the appropriate synaptic sites. Synaptic GABAARs are constructed from α(1-3), ß(1-3), and γ2 subunits, and neurons can target these subtypes to specific synapses. Here, we identify a 15-amino acid inhibitory synapse targeting motif (ISTM) within the α2 subunit that promotes the association between GABAARs and the inhibitory scaffold proteins collybistin and gephyrin. Using mice in which the ISTM has been introduced into the α1 subunit (Gabra1-2 mice), we show that the ISTM is critical for axo-axonic synapse formation, the efficacy of GABAergic neurotransmission, and seizure sensitivity. The Gabra1-2 mutation rescues seizure-induced lethality in Gabra2-1 mice, which lack axo-axonic synapses due to the deletion of the ISTM from the α2 subunit. Taken together, our data demonstrate that the ISTM plays a critical role in promoting inhibitory synapse formation, both in the axonic and somatodendritic compartments.

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Objetivo: Describir el crecimiento físico de niños con hiperplasia suprarrenal congénita (HSC) perdedora de sal durante los dos primeros años de vida, evaluados en el Servicio de Endocrinología del Instituto Nacional de Salud del Niño (INSN), Lima-Perú. Materiales y métodos: Es un estudio observacional, descriptivo y retrospectivo. Se incluyeron 55 niños con HSC que tuvieron seguimiento en el Servicio de Endocrinología del INSN del 2000 al 2016; se recopilaron datos como peso y talla al nacer y cada 6 meses, edad al diagnóstico, dosis de hidrocortisona y fludrocortisona y velocidad de crecimiento. Resultados: Se analizaron 55 niños con HSC perdedora de sal siendo el diagnóstico más precoz en mujeres (mediana: 21 días) que en varones (mediana: 52 días). Al nacimiento, su longitud promedio fue 0,07 + 0,75 DE; a los 6 meses fue -1,67 + 1,33 DE con mayor compromiso en varones (-2,29 + 1,18 DE; p=0,022); a los 12 meses fue -1,84 + 1,27 DE, con recuperación a los 24 meses (-1,51 + 1,10 DE). La velocidad de crecimiento fue -1,03 + 1,62 DE y -0,89 + 1,06 DE en el en el primer y segundo año, respectivamente. Conclusiones: Los niños con HSC perdedora de sal que tuvieron seguimiento en el INSN, tuvieron menor longitud a los 6 y 12 meses de edad y lograron recuperarse a los 24 meses.

Objective: To describe physical growth features in children with salt-wasting congenital adrenal hyperplasia (CAH) during their first two years of life, in the Endocrinology Service of the Peruvian National Children's Health Institute (CHI) in Lima, Peru. Materials and Methods: This is a retrospective, observational, and descriptive study. Fifty-five children with CAH underwent follow-up in the Endocrinology Service of the CHI from 2000 to 2016; data such as body weight and height were collected at birth time and every six months, as well as age at diagnosis, hydrocortisone and fludrocortisone doses, and growth velocity. Results: Fifty-five children with salt-wasting CAH were assessed, the diagnosis was more promptly made in females (median: 21 days) compared to males (median: 52 days). At birth, their average length was 0.07 ± 0.75 SD; at 6 months it was -1.67 ± 1.33 SD, and male subjects were more affected (-2.29 ± 1.18 SD; p= 0.022); at 12 months, this parameter was -1.84 ± 1.27 SD, and recovery was observed at 24 months (-1.51 ± 1.10 SD). Growth velocity values were -1.03 ± 1.62 SD and -0.89 ± 1.06 SD in the first and second years of life, respectively. Conclusions: Children with salt-wasting CAH who were followed-up at CHI had shorter length at 6- and 12- months of age, and their recovered at 24-monbths.

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Visual impairment is common in people living with dementia and regular ophthalmological exams may improve their quality of life. We evaluated visual function in a cohort of elderly individuals and analyzed its association with their degree of cognitive impairment. Participants underwent neurological and neuropsychological exams, neuro-ophthalmological assessment (visual acuity, intraocular pressure, rates of past ophthalmological pathologies, use of ocular correction, treatments and surgeries) and optical coherence tomography (OCT) scan. We analyzed differences in ophthalmological characteristics among diagnostic groups. The final sample of 1746 study participants aged ≥ 50 comprised 229 individuals with Subjective Cognitive Decline (SCD), 695 with mild cognitive impairment (MCI) and 833 with Dementia (Alzheimer disease: n = 660; vascular dementia: n = 92, Lewy body dementia: n = 34; frontotemporal dementia: n = 19 and other: n = 28). Age, gender and education were used as covariates. Patients with Dementia, compared to those with SCD and MCI, presented worse visual acuity (p < 0.001), used less visual correction (p = 0.02 and p < 0.001, respectively) and fewer ophthalmological treatments (p = 0.004 and p < 0.001, respectively) and underwent fewer ocular surgeries (p = 0.009 and p < 0.001, respectively). OCT image quality worsened in parallel to cognitive decline (Dementia vs SCD: p = 0.008; Dementia vs MCI: p < 0.001). No group differences in past ophthalmological disorders or abnormal OCT findings were detected. Efforts should be made to ensure dementia patients undergo regular ophthalmological assessments to correct their visual function in order to improve their quality of life.

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BACKGROUND: We investigated a sample of cognitively healthy subjects with normal Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarker levels to identify the earliest variables related to longitudinal memory changes. OBJECTIVE: Employing a new highly demanding learning and memory test (the Ancient Farming Equipment Test; AFE-T), we aimed to investigate whether a biomarker related to neurodegeneration (i.e., CSF tau) was associated with longitudinal memory decline. METHODS: Thirty-two cognitively and biologically normal (CBN) subjects underwent MRI, neuropsychological assessment, and the AFE-T at baseline and 18 months later. To explore the relationship between cognitive performance and relevant factors, a linear model was set up. For a secondary analysis that further explore the effect of tau, the subjects were divided into CBN-Tau↓ (tau < 228.64 pg/ml; n = 16) and CBN-Tau↑ (tau > 228.64 pg/ml; n = 16). We also performed voxel-based morphometry (VBM) to identify regions of grey matter volume that would predict both baseline and longitudinal cognitive performance. RESULTS: Our main finding was an association between CSF tau and longitudinal memory decline measured with AFE-T (B = -0.17, p < 0.05; r = -0.414; p < 0.01), and further analyses showed different evolvement between subgroups, with an accelerated decline in individuals with higher tau (F(1,31) = 8.37; p < 0.01). VBM results suggested that AFE-T performance is related to grey matter volume in a medial temporal, middle frontal, and posterior cerebellar network at baseline, and that there are strategic brain areas driving the longitudinal cognitive changes. CONCLUSIONS: The present findings provide evidence for structural and biological markers linked to cognitive aging by highlighting the role of tau, a marker of neurodegeneration, which can be related with the earliest memory changes in healthy subjects.

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In most, if not all health systems, dementia is underdiagnosed, and when diagnosis occurs, it is typically at a relatively late stage in the disease process despite mounting evidence showing that a timely diagnosis would result in numerous benefits for patients, families, and society. Moving toward earlier diagnoses in Alzheimer's disease (AD) requires a conscientious and collective effort to implement a global strategy addressing the multiple causes hindering patient engagement at different levels of society. This article describes the design of the Models of Patient Engagement for Alzheimer's Disease project, an ongoing EU-funded public-private multinational initiative that will compare four innovative patient engagement strategies across five European countries regarding their ability to identify individuals with prodromal AD and mild AD dementia, which are "hidden" in their communities and traditionally not found in the typical memory clinic setting. The strategies include an online AD citizen science platform, an open house initiative at the memory clinics, and patient engagement at primary care and diabetologist clinics.

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Objective: Behavioral variant frontotemporal dementia (bvFTD), is commonly considered the cognitive presentation of the frontotemporal dementia-motor neuron disease (FTD-MND) spectrum disorder. We evaluated the prevalence of primary progressive aphasia in a series of pathologically confirmed cases of FTD-MND spectrum. Methods: Pathologically confirmed cases of frontotemporal lobar degeneration-motor neuron disease (FTLD-MND) were obtained from the UCSF brain bank. Cases were analyzed for presence of language impairment via retrospective chart review of research visits that include neurologic exam, in-depth cognitive testing and magnetic resonance imaging (MRI) imaging. Forty one cases were included. Thirty two were diagnosed with FTD-MND, while nine cases were diagnosed as MND-only from clinical evaluation. Results: Ten FTLD-MND cases (31%) presented with prominent or isolated language involvement consistent with a diagnosis of primary progressive aphasia (PPA), which we called progressive aphasia with motor neuron disease (PA-MND). Of these, three cases that mirrored the non-fluent variant of PPA (nfvPPA) were named nfvPA-MND. The imaging pattern of these nfvPA-MND showed atrophy strictly confined to the frontal and anterior temporal language cortical areas. Another group of seven cases that resembled patients with the semantic variant PPA (svPPA) were named svPA-MND. The group of svPPA-MND on imaging analysis showed selective atrophy of the temporal lobe and orbitofrontal cortex. Conclusions: Language impairment was a frequent phenotype of FTD-MND associated with focal atrophy patterns within the language networks. This data suggest patients with FTD-MND can present quite often with language phenotype of nfvPPA and svPPA, as opposed to exclusive bvFTD symptoms.

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The role of genetic risk markers for Alzheimer's disease (AD) in mediating the neurocognitive endophenotypes (NEs) of subjects with mild cognitive impairment (MCI) has rarely been studied. The aim of the present study was to investigate the relationship between well-known AD-associated single-nucleotide polymorphisms (SNPs) and individual NEs routinely evaluated during diagnosis of MCI, AD, and other dementias. The Fundació ACE (ACE) dataset, comprising information from 1245 patients with MCI, was analyzed, including the total sample, amnestic MCI (aMCI) (n = 811), and non-amnestic MCI (naMCI) (n = 434). As probable-MCI (Pr-MCI) patients with memory impairment have a higher risk of AD, which could influence the statistical power to detect genetic associations, the MCI phenotype was also stratified into four related conditions: Pr-aMCI (n = 262), Pr-naMCI (n = 76), possible (Pss)-aMCI (n = 549), and Pss-naMCI (n = 358). Validation analyses were performed using data from the German study on Aging, Cognition, and Dementia in primary care patients (AgeCoDe), and the German Dementia Competence Network (DCN). SNP associations with NEs were calculated in PLINK using multivariate linear regression analysis adjusted for age, gender, and education. In the total MCI sample, APOE-ε4 was significantly associated with the memory function NEs "delayed recall (DR)" (ß = -0.76, p = 4.1 × 10-10), "learning" (ß = -1.35, p = 2.91 × 10-6), and "recognition memory" (ß = -0.58, p = 9.67 × 10-5); and with "DR" in the aMCI group (ß = -0.36, p = 2.96 × 10-5). These results were confirmed by validation in the AgeCoDe (n = 503) and DCN (n = 583) datasets. APOE-ε4 was also significantly associated with the NE "learning" in individuals classified as having Pss-aMCI (ß = -1.37, p = 5.82 × 10-5). Moreover, there was a near study-wide significant association between the HS3ST1 locus (rs6448799) and the "backward digits" working memory NE (ß = 0.52, p = 7.57 × 10-5) among individuals with Pr-aMCI, while the AP2A2 locus (rs10751667) was significantly associated with the language NE "repetition" (ß = -0.19, p = 5.34 × 10-6). Overall, our findings support specific associations of established AD-associated SNPs with MCI NEs.

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The use of optical coherence tomography (OCT) has been suggested as a potential biomarker for Alzheimer's Disease based on previously reported thinning of the retinal nerve fiber layer (RNFL) in Alzheimer's disease's (AD) and Mild Cognitive Impairment (MCI). However, other studies have not shown such results. 930 individuals (414 cognitively healthy individuals, 192 probable amnestic MCI and 324 probable AD) attending a memory clinic were consecutively included and underwent spectral domain OCT (Maestro, Topcon) examinations to assess differences in peripapillary RNFL thickness, using a design of high ecological validity. Adjustment by age, education, sex and OCT image quality was performed. We found a non-significant decrease in mean RNFL thickness as follows: control group: 100,20 ± 14,60 µm, MCI group: 98,54 ± 14,43 µm and AD group: 96,61 ± 15,27 µm. The multivariate adjusted analysis revealed no significant differences in mean overall (p = 0.352), temporal (p = 0,119), nasal (p = 0,151), superior (p = 0,435) or inferior (p = 0,825) quadrants between AD, MCI and control groups. These results do not support the usefulness of peripapillary RNFL analysis as a marker of cognitive impairment or in discriminating between cognitive groups. The analysis of other OCT measurements in other retinal areas and layers as biomarkers for AD should be tested further.

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Non-fluent/agrammatic primary progressive aphasia (nfvPPA) is caused by neurodegeneration within the left fronto-insular speech and language production network (SPN). Graph theory is a branch of mathematics that studies network architecture (topology) by quantifying features based on its elements (nodes and connections). This approach has been recently applied to neuroimaging data to explore the complex architecture of the brain connectome, though few studies have exploited this technique in PPA. Here, we used graph theory on functional MRI resting state data from a group of 20 nfvPPA patients and 20 matched controls to investigate topological changes in response to focal neurodegeneration. We hypothesized that changes in the network architecture would be specific to the affected SPN in nfvPPA, while preserved in the spared default mode network (DMN). Topological configuration was quantified by hub location and global network metrics. Our findings showed a less efficiently wired and less optimally clustered SPN, while no changes were detected in the DMN. The SPN in the nfvPPA group showed a loss of hubs in the left fronto-parietal-temporal area and new critical nodes in the anterior left inferior-frontal and right frontal regions. Behaviorally, speech production score and rule violation errors correlated with the strength of functional connectivity of the left (lost) and right (new) regions respectively. This study shows that focal neurodegeneration within the SPN in nfvPPA is associated with network-specific topological alterations, with the loss and gain of crucial hubs and decreased global efficiency that were better accounted for through functional rather than structural changes. These findings support the hypothesis of selective network vulnerability in nfvPPA and may offer biomarkers for future behavioral intervention.

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Recentemente cresceu o número de pesquisas sobre o exercício de força (EF) de baixa intensidade (20-50% de 1RM) combinado à restrição do fluxo sanguíneo (RFS), mostrando adaptações semelhantes ao EF de alta intensidade. Entretanto, muitas questões sobre essa metodologia necessitam ser investigadas. O objetivo desse estudo foi analisar a resposta aguda da pressão arterial em repouso e durante o EF combinado à RFS. Dezesseis jovens (22±2 anos de idade), ativos e de ambos os sexos, realizaram o EF em duas diferentes condições, separadas por um intervalo de 48h: 1) Exercício isolado (EF) e 2) Exercício combinado à RFS (EF+RFS, 100 mmHg, porção proximal da coxa, mantida durante o exercício). Ambos realizaram 3 séries no exercício leg press com o membro dominante, à 30% de 1RM, 1 minuto de descanso, duração de 90 segundos cada série e cadência de 2 segundos, totalizando 22 repetições para a fase concêntrica e 23 para a fase excêntrica do movimento. Foram avaliadas a pressão arterial sistólica (PAS), diastólica (PAD), frequência cardíaca (FC), duplo produto (DP) e lactato sanguíneo nos momentos: repouso e imediatamente após o exercício. Foi observado apenas aumento significativo da PAS e do DP em repouso e da PAS durante o EF+RFS. O lactato sanguíneo não se alterou em nenhuma condição avaliada. Concluindo que o exercício de força com restrição de fluxo sanguíneo apresentou maiores respostas de pressão arterial sistólica em repouso e durante o exercício em sujeitos jovens ativos...(AU)

Recently, the number of researches about the strength exercise (SE) of low intensity (20- 50% of 1RM) combined to the blood flow restriction (BFR) increased, showing similar adaptations to the high-intensity SE. However, many questions about this methodology need be investigated. The purpose of this study was to analyze the acute response of blood pressure at rest and during SE combined with BFR. Sixteen young subjects (22 ± 2 years old), actives and of both sexs, underwent SE in two different conditions, separated by an interval of 48h: 1) isolated strength exercise (SE) and 2) strength exercise combined to BFR (SE+BFR, 100 mmHg, proximal portion of the thigh, maintained throughout the exercise session). Both conditions performed 3 sets on the leg press exercise with the dominant leg, with 30% of 1RM, 1 minute of rest, each series with 90 seconds of the duration and movement cadence of the 2 seconds, totaling 22 repetitions in the concentric phase and 23 in the eccentric phase of movement. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), double product (DP) and blood lactate were evaluated on rest and immediately after exercise moments. It was observed only significant increase in SBP and DP at rest and SBP during SE+BFR condition. Blood lactate did not change in any condition evaluated. Concluding that strength exercise with blood flow restriction showed higher responses of systolic blood pressure at rest and during exercise in active young subjects...(AU)

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OBJECTIVE: To estimate the prevalence of amyloid positivity, defined by positron emission tomography (PET)/cerebrospinal fluid (CSF) biomarkers and/or neuropathological examination, in primary progressive aphasia (PPA) variants. METHODS: We conducted a meta-analysis with individual participant data from 1,251 patients diagnosed with PPA (including logopenic [lvPPA, n = 443], nonfluent [nfvPPA, n = 333], semantic [svPPA, n = 401], and mixed/unclassifiable [n = 74] variants of PPA) from 36 centers, with a measure of amyloid-ß pathology (CSF [n = 600], PET [n = 366], and/or autopsy [n = 378]) available. The estimated prevalence of amyloid positivity according to PPA variant, age, and apolipoprotein E (ApoE) ε4 status was determined using generalized estimating equation models. RESULTS: Amyloid-ß positivity was more prevalent in lvPPA (86%) than in nfvPPA (20%) or svPPA (16%; p < 0.001). Prevalence of amyloid-ß positivity increased with age in nfvPPA (from 10% at age 50 years to 27% at age 80 years, p < 0.01) and svPPA (from 6% at age 50 years to 32% at age 80 years, p < 0.001), but not in lvPPA (p = 0.94). Across PPA variants, ApoE ε4 carriers were more often amyloid-ß positive (58.0%) than noncarriers (35.0%, p < 0.001). Autopsy data revealed Alzheimer disease pathology as the most common pathologic diagnosis in lvPPA (76%), frontotemporal lobar degeneration-TDP-43 in svPPA (80%), and frontotemporal lobar degeneration-TDP-43/tau in nfvPPA (64%). INTERPRETATION: This study shows that the current PPA classification system helps to predict underlying pathology across different cohorts and clinical settings, and suggests that age and ApoE genotype should be considered when interpreting amyloid-ß biomarkers in PPA patients. Ann Neurol 2018;84:737-748.

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Importance: Increased prevalence of language-based learning disabilities (LDs) has been previously reported in patients with primary progressive aphasia (PPA). This study hypothesized that patients with focal neurodegenerative syndromes outside the language network, such as posterior cortical atrophy (PCA), would have a higher rate of nonlanguage LDs, congruent with their mainly visuospatial presentation. Objective: To investigate the prevalence and type of LD (language and/or mathematical and visuospatial) in a large cohort of patients with PCA compared with patients with logopenic variant PPA (lvPPA) and amnestic Alzheimer disease (AD). Design, Setting, and Participants: This case-control study reviewed 279 medical records from a university-based clinic and research center for patients with neurodegenerative diseases for LD history, including patients with PCA (n = 95), patients with lvPPA (n = 84), and a matched cohort with amnestic AD (n = 100). No records were excluded. The study compared cognitive and neuroimaging features of patients with PCA with and without LDs. A review of the records of patients presenting from March 1, 1999, to August 31, 2014, revealed 95 PCA cases and 84 lvPPA cases. Then 100 patients with amnestic AD from this same period were chosen for comparison, matching against the groups for age, sex, and disease severity. Data analysis was performed from September 8, 2013, to November 6, 2017. Main Outcomes and Measures: Prevalence of total LD history and prevalence of language and mathematical or visuospatial LD history across all cohorts. Results: A total of 179 atypical AD cases (95 with PCA and 84 with lvPPA) and 100 disease control cases (amnestic AD) were included in the study. The groups were not statistically different for mean (SD) age at first visit (PCA, 61.9 [7.0] years; lvPPA, 65.1 [8.7] years; amnestic AD, 64.0 [12.6] years; P = .08), mean (SD) age at first symptom (PCA, 57.5 [7.0] years; lvPPA, 61.1 [9.0] years; amnestic AD, 59.6 [13.7] years; P = .06), or sex (PCA, 66.3% female; lvPPA, 56.0% female; amnestic AD, 57.0% female; P = .30) but differed on non-right-hand preference (PCA, 18.3%; lvPPA, 20.2%; amnestic AD, 7.7%; P = .04), race/ethnicity (PCA, 88.3% white; lvPPA, 99.0% white; amnestic AD, 80.0% white; P < .001), and mean (SD) educational level (PCA, 15.7 [3.2] years; lvPPA, 16.2 [3.3] years; amnestic AD, 14.8 [3.5] years; P = .02). A total of 18 of the 95 patients with PCA (18.9%) reported a history of LD, which is greater than the 3 of 100 patients (3.0%) in the amnestic AD cohort (P < .001) and the 10.0% expected rate in the general population (P = .007). In the PCA cohort, 13 of 95 patients (13.7%) had a nonlanguage mathematical and/or visuospatial LD; this rate was greater than that in the amnestic AD (1 of 100 [1.0%]; P < .001) and lvPPA (2 of 84 [2.4%]; P = .006) cohorts and greater than the 6.0% expected general population rate of mathematical LD (P = .003). Compared with the patients with PCA without LDs, the group with LDs had greater preservation of global cognition and a more right-lateralized pattern of atrophy. Conclusions and Relevance: Nonlanguage mathematical and visuospatial LDs were associated with focal, visuospatial predominant neurodegenerative clinical syndromes. This finding supports the hypothesis that neurodevelopmental differences in specific brain networks are associated with phenotypic manifestation of later-life neurodegenerative disease.

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Alzheimer's disease (AD) research is at a critical time. The global society is increasingly aware of the frightening rate of growth of the human and financial burden caused by this condition and of the urgent need to halt its progression. Consequently, the scientific community holds great responsibility to quickly put in place and optimize the machinery necessary for testing new treatments or interventions. In this context demand for participants for AD research is at an all-time high. In this review, we will focus on a methodological factor that is increasingly recognized as a key factor that shapes trial populations and affects validity of results in clinical trials: patient engagement, recruitment, and retention. We outline specific problems relevant to patient engagement in AD including recruiting enough participants, difficulties in participant retention, ensuring the recruited sample is representative of the general AD population, the burden of screening failures, and new challenges related to recruiting in preclinical disease. To address the urgent need for more research studying the applicability and cost-effectiveness of different recruitment strategies across different settings and nationalities, we describe the Models of Patient Engagement for Alzheimer's Disease (MOPEAD) project, a public-private partnership promoted by the Innovative Medicine Initiative (IMI), which will provide a large multinational quantitative analysis comparing different innovative recruitment models. We also discuss strategies that address each problem and draw on the experience of Fundació ACE to argue that focusing resources on comprehensive AD centers that offer coordinated clinical and social care and participate in basic and clinical research, is an effective and efficient way of implementing many of the discussed strategies.

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Importance: The ability to predict the pathology underlying different neurodegenerative syndromes is of critical importance owing to the advent of molecule-specific therapies. Objective: To determine the rates of positron emission tomography (PET) amyloid positivity in the main clinical variants of primary progressive aphasia (PPA). Design, Setting, and Participants: This prospective clinical-pathologic case series was conducted at a tertiary research clinic specialized in cognitive disorders. Patients were evaluated as part of a prospective, longitudinal research study between January 2002 and December 2015. Inclusion criteria included clinical diagnosis of PPA; availability of complete speech, language, and cognitive testing; magnetic resonance imaging performed within 6 months of the cognitive evaluation; and PET carbon 11-labeled Pittsburgh Compound-B or florbetapir F 18 brain scan results. Of 109 patients referred for evaluation of language symptoms who underwent amyloid brain imaging, 3 were excluded because of incomplete language evaluations, 5 for absence of significant aphasia, and 12 for presenting with significant initial symptoms outside of the language domain, leaving a cohort of 89 patients with PPA. Main Outcomes and Measures: Clinical, cognitive, neuroimaging, and pathology results. Results: Twenty-eight cases were classified as imaging-supported semantic variant PPA (11 women [39.3%]; mean [SD] age, 64 [7] years), 31 nonfluent/agrammatic variant PPA (22 women [71.0%]; mean [SD] age, 68 [7] years), 26 logopenic variant PPA (17 women [65.4%]; mean [SD] age, 63 [8] years), and 4 mixed PPA cases. Twenty-four of 28 patients with semantic variant PPA (86%) and 28 of 31 patients with nonfluent/agrammatic variant PPA (90%) had negative amyloid PET scan results, while 25 of 26 patients with logopenic variant PPA (96%) and 3 of 4 mixed PPA cases (75%) had positive scan results. The amyloid positive semantic variant PPA and nonfluent/agrammatic variant PPA cases with available autopsy data (2 of 4 and 2 of 3, respectively) all had a primary frontotemporal lobar degeneration and secondary Alzheimer disease pathologic diagnoses, whereas autopsy of 2 patients with amyloid PET-positive logopenic variant PPA confirmed Alzheimer disease. One mixed PPA patient with a negative amyloid PET scan had Pick disease at autopsy. Conclusions and Relevance: Primary progressive aphasia variant diagnosis according to the current classification scheme is associated with Alzheimer disease biomarker status, with the logopenic variant being associated with carbon 11-labeled Pittsburgh Compound-B positivity in more than 95% of cases. Furthermore, in the presence of a clinical syndrome highly predictive of frontotemporal lobar degeneration pathology, biomarker positivity for Alzheimer disease may be associated more with mixed pathology rather than primary Alzheimer disease.

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OBJECTIVES: The aim of this study was to identify whether the three main primary progressive aphasia (PPA) variants would show differential profiles on measures of visuospatial cognition. We hypothesized that the logopenic variant would have the most difficulty across tasks requiring visuospatial and visual memory abilities. METHODS: PPA patients (n=156), diagnosed using current criteria, and controls were tested on a battery of tests tapping different aspects of visuospatial cognition. We compared the groups on an overall visuospatial factor; construction, immediate recall, delayed recall, and executive functioning composites; and on individual tests. Cross-sectional and longitudinal comparisons were made, adjusted for disease severity, age, and education. RESULTS: The logopenic variant had significantly lower scores on the visuospatial factor and the most impaired scores on all composites. The nonfluent variant had significant difficulty on all visuospatial composites except the delayed recall, which differentiated them from the logopenic variant. In contrast, the semantic variants performed poorly only on delayed recall of visual information. The logopenic and nonfluent variants showed decline in figure copying performance over time, whereas in the semantic variant, this skill was remarkably preserved. CONCLUSIONS: This extensive examination of performance on visuospatial tasks in the PPA variants solidifies some previous findings, for example, delayed recall of visual stimuli adds value in differential diagnosis between logopenic variant PPA and nonfluent variant PPA variants, and illuminates the possibility of common mechanisms that underlie both linguistic and non-linguistic deficits in the variants. Furthermore, this is the first study that has investigated visuospatial functioning over time in the PPA variants. (JINS, 2018, 24, 259-268).

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OBJECTIVE: To characterize in vivo signatures of pathological diagnosis in a large cohort of patients with primary progressive aphasia (PPA) variants defined by current diagnostic classification. METHODS: Extensive clinical, cognitive, neuroimaging, and neuropathological data were collected from 69 patients with sporadic PPA, divided into 29 semantic (svPPA), 25 nonfluent (nfvPPA), 11 logopenic (lvPPA), and 4 mixed PPA. Patterns of gray matter (GM) and white matter (WM) atrophy at presentation were assessed and tested as predictors of pathological diagnosis using support vector machine (SVM) algorithms. RESULTS: A clinical diagnosis of PPA was associated with frontotemporal lobar degeneration (FTLD) with transactive response DNA-binding protein (TDP) inclusions in 40.5%, FTLD-tau in 40.5%, and Alzheimer disease (AD) pathology in 19% of cases. Each variant was associated with 1 typical pathology; 24 of 29 (83%) svPPA showed FTLD-TDP type C, 22 of 25 (88%) nfvPPA showed FTLD-tau, and all 11 lvPPA had AD. Within FTLD-tau, 4R-tau pathology was commonly associated with nfvPPA, whereas Pick disease was observed in a minority of subjects across all variants except for lvPPA. Compared with pathologically typical cases, svPPA-tau showed significant extrapyramidal signs, greater executive impairment, and severe striatal and frontal GM and WM atrophy. nfvPPA-TDP patients lacked general motor symptoms or significant WM atrophy. Combining GM and WM volumes, SVM analysis showed 92.7% accuracy to distinguish FTLD-tau and FTLD-TDP pathologies across variants. INTERPRETATION: Each PPA clinical variant is associated with a typical and most frequent cognitive, neuroimaging, and neuropathological profile. Specific clinical and early anatomical features may suggest rare and atypical pathological diagnosis in vivo. Ann Neurol 2017;81:430-443.

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