Assessment of Mendelian and risk-factor genes in Alzheimer disease: A prospective nationwide clinical utility study and recommendations for genetic screening.

Purpose: To assess the likely pathogenic/pathogenic (LP/P) variants rates in Mendelian dementia genes and the moderate-to-strong risk factors rates in patients with Alzheimer disease (AD).

Methods: We included 700 patients in a prospective study and performed exome sequencing. A panel of 28 Mendelian and 6 risk-factor genes was interpreted and returned to patients.

Comparative diagnosis interest of NfL and pNfH in CSF and plasma in a context of FTD-ALS spectrum.

Objective: The 'Frontotemporal dementia-Amyotrophic lateral sclerosis Spectrum' (FAS) encompasses different phenotypes, including cognitive disorders (frontotemporal dementia, FTD) and/or motor impairments (amyotrophic lateral sclerosis, ALS). The aim of this study was to apprehend the specific uses of neurofilaments light chain (NfL) and phosphorylated neurofilaments heavy chain (pNfH) in a context of FAS.

Methods: First, NfL and pNfH were measured in 39 paired cerebrospinal fluid (CSF) and plasma samples of FAS and primary psychiatric disorders (PPD) patients, considered as controls.

A trial of gantenerumab or solanezumab in dominantly inherited Alzheimer's disease.

Dominantly inherited Alzheimer's disease (DIAD) causes predictable biological changes decades before the onset of clinical symptoms, enabling testing of interventions in the asymptomatic and symptomatic stages to delay or slow disease progression. We conducted a randomized, placebo-controlled, multi-arm trial of gantenerumab or solanezumab in participants with DIAD across asymptomatic and symptomatic disease stages. Mutation carriers were assigned 3:1 to either drug or placebo and received treatment for 4-7 years.

Core cerebrospinal fluid biomarker profile in anti-LGI1 encephalitis.

Objective: To compare CSF biomarkers' levels in patients suffering from anti-Leucine-rich Glioma-Inactivated 1 (LGI1) encephalitis to neurodegenerative [Alzheimer's disease (AD), Creutzfeldt-Jakob's disease (CJD)] and primary psychiatric (PSY) disorders.

Methods: Patients with LGI1 encephalitis were retrospectively selected from the French Reference Centre database between 2010 and 2019 and enrolled if CSF was available for biomarkers analysis including total tau (T-tau), phosphorylated tau (P-tau), amyloid-beta Aβ1-42, and neurofilaments light chains (Nf L). Samples sent for biomarker determination as part of routine practice, and formally diagnosed as AD, CJD, and PSY, were used as comparators.

Improving the Diagnosis of the Frontal Variant of Alzheimer's Disease with the DAPHNE Scale.

Background: The frontal variant of Alzheimer's disease (fAD) is poorly understood and poorly defined. The diagnosis remains challenging. The main differential diagnosis is the behavioral variant of frontotemporal degeneration (bvFTD).

A Spatial Decision Eye-Tracking Task in Patients with Prodromal and Mild Alzheimer's Disease.

Background/objective: Performances on spatial decision eye-tracking tasks are known to be impaired in patients with moderate Alzheimer's disease (AD), but the clinical relevance of this deficit during earlier stages of AD remains unclear.

Methods: This study recruited patients with amnestic mild cognitive impairment (aMCI, prodromal AD), patients with mild AD, and age-matched controls from three French memory clinics. Participants' ability to make spatial judgments and decisions was assessed with an eye-tracking system, and cognitive performance on conventional neuropsychological tests was evaluated.

Causative Mutations and Genetic Risk Factors in Sporadic Early Onset Alzheimer's Disease Before 51 Years.

Background: Pathogenic variants in the autosomal dominant genes PSEN1, PSEN2, or APP, APOE4 alleles, and rare variants within TREM2, SORL1, and ABCA7 contribute to early-onset Alzheimer's disease (EOAD). However, sporadic EOAD patients have been insufficiently studied to define the probability of being a carrier of one of these variants.

Objective: To describe the proportion of each genetic variation among patients with very young-onset sporadic AD.

C9orf72 Protein Plasmatic Concentrations Are Similar between C9ORF72 Expansion Carriers and Noncarriers in Frontotemporal Dementia.

Background/aims: The aim of the study was to assess the theory of haploinsufficiency in C9ORF72 expansion carriers, the most frequent causative gene of frontotemporal dementia.

Methods: Plasmatic concentrations of C9orf72 protein were measured in 33 patients suspected of familial frontotemporal dementia using an enzyme-linked immunosorbent assay.

Results: No difference was observed between C9ORF72 expansion carriers (21.

Prodromal Alzheimer's Disease Demonstrates Increased Errors at a Simple and Automated Anti-Saccade Task.

Saccade alterations are potential early signs of Alzheimer's disease. However, uncertainty persists in how early and reliably automated saccade recording systems detect impairments. This multicenter pathophysiological case-control transversal study explored saccade execution in carefully diagnosed amnestic mild cognitive impairment patients fulfilling research criteria for prodromal Alzheimer's disease (n = 29), as compared to both aged-matched mild Alzheimer's disease patients (n = 23) and controls (n = 27).

APP, PSEN1, and PSEN2 mutations in early-onset Alzheimer disease: A genetic screening study of familial and sporadic cases.

Background: Amyloid protein precursor (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2) mutations cause autosomal dominant forms of early-onset Alzheimer disease (AD-EOAD). Although these genes were identified in the 1990s, variant classification remains a challenge, highlighting the need to colligate mutations from large series.

Methods And Findings: We report here a novel update (2012-2016) of the genetic screening of the large AD-EOAD series ascertained across 28 French hospitals from 1993 onwards, bringing the total number of families with identified mutations to n = 170.

Characteristics in limbic encephalitis with anti-adenylate kinase 5 autoantibodies.

Objective: To report 10 patients with limbic encephalitis (LE) and adenylate kinase 5 autoantibodies (AK5-Abs).

Methods: We conducted a retrospective study in a cohort of 50 patients with LE with uncharacterized autoantibodies and identified a specific target using immunohistochemistry, Western blotting, immunoprecipitation, mass spectrometry, and cell-based assay.

Results: AK5 (a known autoantigen of LE) was identified as the target of antibodies in the CSFs and sera of 10 patients with LE (median age 64 years; range 57-80), which was characterized by subacute anterograde amnesia without seizure and sometimes preceded by a prodromal phase of asthenia or mood disturbances.

Seizures in dominantly inherited Alzheimer disease.

Objective: To assess seizure frequency in a large French cohort of autosomal dominant early-onset Alzheimer disease (ADEOAD) and to determine possible correlations with causative mutations.

Methods: A national multicentric study was performed in patients with ADEOAD harboring a pathogenic mutation within PSEN1, PSEN2, APP, or a duplication of APP, and a minimal follow-up of 5 years. Clinical, EEG, and imaging data were systematically recorded.

Pseudotumoral presentation of cerebral amyloid angiopathy-related inflammation.

Objective: To identify the clinical and radiologic features that should raise suspicion for the pseudotumoral presentation of cerebral amyloid angiopathy-related inflammation (CAA-I).

Methods: We retrospectively reviewed the characteristics of 5 newly diagnosed and 23 previously reported patients in whom the CAA-I imaging findings were initially interpreted as CNS neoplasms.

Results: Most cases (85%) occurred in patients >60 years old.

Increased cerebrospinal fluid tau levels in logopenic variant of Alzheimer's disease.

Background: Patients with logopenic variant of primary progressive aphasia (lvPPA) display neuropathological differences from typical amnestic Alzheimer's disease (AD).

Objective: The aim of the study was to compare cerebrospinal fluid (CSF) biomarker levels between patients with lvPPA due to AD (lvPPA-AD), non-logopenic forms of AD (nlAD), and amnestic mild cognitive impairment due to AD (aMCI-AD).

Methods: CSF biomarker concentrations were assessed in 124 patients divided into three groups matched for age, level of education, center, and disease duration: lvPPA-AD (n = 30), nlAD (n = 67).

In vivo demonstration of amyloid burden in posterior cortical atrophy: a case series with PET and CSF findings.

Our objective was to evaluate amyloid deposition in posterior cortical atrophy (PCA), using both cerebrospinal fluid (CSF) biomarker analysis and amyloid imaging. Five PCA patients, selected based on their neuropsychological profile and atrophic changes in posterior regions on MRI, underwent CSF analysis. CSF amyloid-beta 1-42, total tau, and phosphorylated tau at threonine 181 levels were determined.