Psychopharmacological Medication Use in Frontotemporal Dementia at the Time of Diagnosis: Comparison with Alzheimer's Disease.

BACKGROUND: Due to the significant presence of neuropsychiatric symptoms in patients with frontotemporal dementia (FTD) spectrum disorders, psychiatric misdiagnoses, diagnostic delay, and use of psychiatric treatments are common prior to the FTD diagnosis. Furthermore, treatment of diagnosed FTD patients mainly relies on off-label psychopharmacological approaches. Currently, limited real-world data are available regarding the actual use of psychopharmacological medications in FTD. OBJECTIVE: To evaluate psychopharmacological medication use at the time of FTD diagnosis. METHODS: Psychopharmacological medication use was evaluated in a Finnish FTD cohort containing 222 FTD patients, including the major clinical disease phenotypes (behavioral, language, and motor variants) and genetic patients carrying the C9orf72 repeat expansion. A cohort of 214 Alzheimer's disease (AD) patients was used as a neurodegenerative disease reference group. RESULTS: Active use of psychopharmacological medications at the time of diagnosis was significantly more common in FTD compared to AD, especially in the case of antidepressants (26.1% versus 15.0%, OR = 2.01, p = 0.008), antipsychotics (23.9% versus 9.3%, OR = 3.15, p < 0.001), and mood-stabilizers (6.3% versus 1.9%, OR = 2.93, p = 0.085; not statistically significant), whereas the use of cholinesterase inhibitors or memantine was nearly nonexistent in FTD patients. Female gender and behavioral variant of FTD phenotype alongside with depressive and psychotic symptoms were the most prominent factors associating with the use of these medications among the FTD spectrum patients. CONCLUSION: Use of off-label psychopharmacological medication and polypharmacy is substantially common at the time of FTD diagnosis. This likely reflects the challenges in using symptom-driven treatment approaches, especially prior to the eventual diagnosis.

Defining the presymptomatic phase of frontotemporal dementia.

PURPOSE OF REVIEW: Frontotemporal dementia (FTD) is a clinically, pathologically and genetically heterogeneous disorder. Whilst disease modifying therapy trials are mostly focused on the symptomatic phase, future studies will move earlier in the disease aiming to prevent symptom onset. This review summarizes the recent work to better understand this presymptomatic period. RECENT FINDINGS: The presymptomatic phase can be split into preclinical and prodromal stages. The onset of the preclinical phase is defined by the first presence of pathological inclusions of tau, TDP-43 or fused in sarcoma in the brain. Definitive biomarkers of these pathologies do not yet exist for FTD. The prodromal phase is defined by the onset of mild symptoms. Recent work has highlighted the wide phenotypic spectrum that occurs, with the concept of mild cognitive ± behavioural ± motor impairment (MCBMI) being put forward, and additions to scales such as the CDR plus NACC FTLD now incorporating neuropsychiatric and motor symptoms. SUMMARY: It will be important to better characterize the presymptomatic period moving forward and develop robust biomarkers that can be used both for stratification and outcome measures in prevention trials. The work of the FTD Prevention Initiative aims to facilitate this by bringing together data from natural history studies across the world.

A comprehensive perspective of autistic traits and catatonic symptoms in a patient with Fronto-Temporal Dementia and Bipolar Disorder: a case report.

BACKGROUND: Fronto-Temporal Dementia (FTD) is a neurodegenerative disorder featuring frontotemporal lobe atrophy which leads to profound changes in behavior and cognition in the affected subjects. Considering that the onset of this type of dementia is typically characterized by the development of affective symptoms, differential diagnosis between FTD and Bipolar Disorder (BD) is particularly difficult. An important overlapping feature between BD and FTD is the presence of catatonic symptoms: Catatonia is extremely frequent in FTD, and, on the other hand, BD is the psychiatric disease with the highest frequency of association with catatonic states. In this framework, it should be noted that also Autism Spectrum conditions have been reported to show high rates of comorbidity and overlapping features with BD. In addition, subjects with autistic traits were reported to show an increased vulnerability towards the development of mood and anxiety disorders, as well as increase the risk of mood episodes with mixed features, suicidal thoughts and catatonic symptoms. CASE PRESENTATION: We reported the case of a patient with a diagnosis of both BD and FTD who showed catatonic symptoms. OBJECTIVES: The aim of this case report is to evaluate the possible role of autistic traits in the illness trajectory of BD and FTD. CONCLUSION: This case confirms the presence of a continuum between psychiatric and neurological conditions, which should be considered as expressions of a same neurobiological system and further investigated in light of an integrative model.

Plasma inflammation for predicting phenotypic conversion and clinical progression of autosomal dominant frontotemporal lobar degeneration.

BACKGROUND: Measuring systemic inflammatory markers may improve clinical prognosis and help identify targetable pathways for treatment in patients with autosomal dominant forms of frontotemporal lobar degeneration (FTLD). METHODS: We measured plasma concentrations of IL-6, TNFα and YKL-40 in pathogenic variant carriers (MAPT, C9orf72, GRN) and non-carrier family members enrolled in the ARTFL-LEFFTDS Longitudinal Frontotemporal Lobar Degeneration consortium. We evaluated associations between baseline plasma inflammation and rate of clinical and neuroimaging changes (linear mixed effects models with standardised (z) outcomes). We compared inflammation between asymptomatic carriers who remained clinically normal ('asymptomatic non-converters') and those who became symptomatic ('asymptomatic converters') using area under the curve analyses. Discrimination accuracy was compared with that of plasma neurofilament light chain (NfL). RESULTS: We studied 394 participants (non-carriers=143, C9orf72=117, GRN=62, MAPT=72). In MAPT, higher TNFα was associated with faster functional decline (B=0.12 (0.02, 0.22), p=0.02) and temporal lobe atrophy. In C9orf72, higher TNFα was associated with faster functional decline (B=0.09 (0.03, 0.16), p=0.006) and cognitive decline (B=-0.16 (-0.22, -0.10), p<0.001), while higher IL-6 was associated with faster functional decline (B=0.12 (0.03, 0.21), p=0.01). TNFα was higher in asymptomatic converters than non-converters (ß=0.29 (0.09, 0.48), p=0.004) and improved discriminability compared with plasma NfL alone (ΔR2=0.16, p=0.007; NfL: OR=1.4 (1.03, 1.9), p=0.03; TNFα: OR=7.7 (1.7, 31.7), p=0.007). CONCLUSIONS: Systemic proinflammatory protein measurement, particularly TNFα, may improve clinical prognosis in autosomal dominant FTLD pathogenic variant carriers who are not yet exhibiting severe impairment. Integrating TNFα with markers of neuronal dysfunction like NfL could optimise detection of impending symptom conversion in asymptomatic pathogenic variant carriers and may help personalise therapeutic approaches.

Changing perspectives on frontotemporal dementia: A review.

This article examines the evolution in understanding of frontotemporal dementia (FTD) during the last four decades. A central theme is the recognition of heterogeneity. Originally construed as a disorder of behaviour and executive impairment, FTD is now known also to be associated with alterations in language, conceptual knowledge and praxis. An absence of neurological signs is the hallmark of many FTD patients, but there is also an established association with motor neurone disease (MND), progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). FTD is commonly defined as an early onset dementia, yet about a quarter of patients present after the age of 65. The underlying pathological protein is tau, TDP-43 or more rarely fused-in-sarcoma (FUS). Distinct genetic mutations have been identified in familial FTD. There are predictable relationships between clinical phenotype, pathological substrate and genetic mutation. For example, a circumscribed semantic disorder predicts TDP-43 pathology, and speech or limb apraxia tau pathology. The co-occurrence of MND predicts TDP-43 pathology, and PSP and CBD tau pathology. FUS pathology is associated with very youthful onset, stereotyped behaviours and caudate atrophy. Non-fluent aphasia is linked to progranulin (GRN) mutations and MND and psychosis to repeat expansions in the C9orf72 gene. Despite striking worldwide consensus in findings there remain some issues of contention, largely related to the classification of FTD and its sub-variants. Understanding the diverse nature of FTD is crucial for effective diagnosis, management and the development of targeted therapies.

Very early-onset behavioral variant frontotemporal dementia in a patient with a variant of uncertain significance of a FUS gene mutation.

The behavioral variant of Frontotemporal dementia (bvFTD) has typically a progressive course with cognitive and behavioral changes that manifests between 50 and 70 years. Very early-onset bvFTD with rapid progression is a rare syndrome under the frontotemporal lobar degeneration (FTLD) umbrella that has been associated with a variety of protein deposition and genetic mutations. We present a case of a 24-year-old man who developed behavioral symptoms and progressed with severe cognitive impairment and functional loss within months. Genetic testing identified a variant of uncertain significance (VUS) mutation in the FUS gene.

Relevance of plasma biomarkers to pathologies in Alzheimer's disease, Parkinson's disease and frontotemporal dementia.

Amyloid plaques and tau tangles are pathological hallmarks of Alzheimer's disease (AD). Parkinson's disease (PD) results from the accumulation of α-synuclein. TAR DNA-binding protein (TDP-43) and total tau protein (T-Tau) play roles in FTD pathology. All of the pathological evidence was found in the biopsy. However, it is impossible to perform stein examinations in clinical practice. Assays of biomarkers in plasma would be convenient. It would be better to investigate the combinations of various biomarkers in AD, PD and FTD. Ninety-one subjects without neurodegenerative diseases, 76 patients with amnesic mild cognitive impairment (aMCI) or AD dementia, combined as AD family, were enrolled. One hundred and nine PD patients with normal cognition (PD-NC) or dementia (PDD), combined as PD family, were enrolled. Twenty-five FTD patients were enrolled for assays of plasma amyloid ß 1-40 (Aß1-40), Aß1-42, T-Tau, α-synuclein and TDP-43 using immunomagnetic reduction (IMR). The results show that Aßs and T-Tau are major domains in AD family. α-synuclein is highly dominant in PD family. FTD is closely associated with TDP-43 and T-Tau. The dominant plasma biomarkers in AD family, PD family and FTD are consistent with pathology. This implies that plasma biomarkers are promising for precise and differential assessments of AD, PD and FTD in clinical practice.

A Young Man with Cognitive Impairment and a Heart Condition.

A 43-year-old came to our observation for progressive cognitive impairment, confirmed by the neuropsychological evaluation. A diagnosis of multidomain amnestic mild cognitive impairment, due to unknown reasons, was posited at the first assessment. The patient's neurological exam was otherwise completely normal. The patient's mother was clinically diagnosed with frontotemporal dementia in her forties. The patient underwent neuroimaging investigations and cerebrospinal fluid analysis. Our diagnostic work-up pointed toward a neurodegenerative etiology, but the presence of concurrent cardiomyopathy emerged in the meantime. Due to the patient's family history, a thorough genetic screening was performed. The results revealed a unique genetic asset, with heterozygotic variants of three amyloid-related genes (PSEN1, APP, and MYBPC3). PSEN1 and MYBPC3 mutations showed distinct pathogenic features and accounted for the patient's brain and cardiac amyloidosis, whereas the APP variant was of uncertain pathological implications.

Advances in Treatment of Frontotemporal Dementia.

In this review, the authors explored the clinical features of frontotemporal dementia (FTD), focusing on treatment. The clinical features of FTD are unique, with disinhibition, apathy, loss of empathy, and compulsions common. Motor changes occur later in the illness. The two major proteins that aggregate in the brain with FTD are tau and TDP-43, whereas a minority of patients aggregate FET proteins, primarily the FUS protein. Genetic causes include mutations in MAPT, GRN, and C9orf72. There are no medications that can slow FTD progression, although new therapies for the genetic forms of FTD are moving into clinical trials. Once a diagnosis is made, therapies should begin, focusing on the family and the patient. In the setting of FTD, families experience a severe burden associated with caregiving, and the clinician should focus on alleviating this burden. Advice around legal and financial issues is usually helpful. Careful consideration of environmental changes to cope with abnormal behaviors is essential. Most compounds that have been used to treat dementia of the Alzheimer's disease type are not effective in FTD, and cholinesterase inhibitors and memantine should be avoided. Although the data are scant, there is some evidence that antidepressants and second-generation antipsychotics may help individual patients.

Spanish version of the frontotemporal dementia knowledge scale: adaptation and validation / Versión en español de la escala de conocimiento sobre demencia frontotemporal: adaptación y validación

ABSTRACT Background: Frontotemporal dementia (FTD) is a neurodegenerative disease and is one of the most common causes of dementia in people under 65. There is often a significant diagnostic delay, as FTD can be confused with other psychiatric conditions. A lack of knowledge regarding FTD by health professionals is one possible cause for this diagnostic confusion. Objectives: The aim of this study was to adapt and validate the Frontotemporal Dementia Knowledge Scale (FTDKS) in Spanish. Methods: A translation was done, following cross-cultural adaptation guidelines, which consisted of forward translation, blind back translation, and an analysis by a committee of experts. For the present study, 134 professionals from different health areas responded the Spanish version of the FTDKS. The statistical analysis was performed using R version 4.0.0 "Arbor day" and the Psych, sjPlot packages. Results: The Spanish version of the FTDKS had good reliability and internal consistency (Cronbach alpha 0.74.). The sample's mean score was 19.78 (range = 4-32, SD 6.3) out of a maximum of 36 points. Conclusions: The results obtained show that the Spanish version has good psychometric properties. The FTDKS is applicable in our environment and can be a useful tool to evaluate the knowledge of health professionals regarding frontotemporal dementia.

RESUMEN Antecedentes: La demencia frontotemporal (DFT) es una enfermedad neurodegenerativa y es una de las causas más comunes de demencia en personas menores de 65 años. A menudo existe un retraso significativo en el diagnóstico, ya que la FTD puede confundirse con otras afecciones psiquiátricas. La falta de conocimientos sobre la DFT por parte de los profesionales de salud es una posible causa de esta confusión diagnóstica. Objetivos: El presente estudio describe nuestros esfuerzos para adaptar y validar la Escala de Conocimiento de la Demencia Frontotemporal (FTDKS) en español. Métodos: Se realizó una traducción, siguiendo las pautas de adaptación transcultural, que consistió en una traducción directa, una traducción inversa ciega y un análisis por parte de un comité de expertos. Para el presente estudio, 134 profesionales de diferentes áreas de la salud respondieron la versión en español del FTDKS. El análisis estadístico se realizó utilizando la versión 4.0.0 de R "Arbor day" y los paquetes Psych, sjPlot. Resultados: La versión en español del FTDKS tiene una buena fiabilidad y consistencia interna (alfa de Cronbach 0,74.). La puntuación media de la muestra fue de 19,78 (rango = 4-32, SD 6,3) sobre un máximo de 36 puntos. Conclusiones: Los resultados obtenidos muestran que la versión española tiene buenas propiedades psicométricas. El FTDKS es aplicable en nuestro medio y puede ser una herramienta útil para evaluar los conocimientos de los profesionales sanitarios sobre la demencia frontotemporal.

Demencia frontotemporal desde una mirada neuropsicológica / Frontotemporal dementia from a neuropsychological point of view

Introducción: La riqueza de las manifestaciones neuropsicológicas de la demencia frontotemporal, ha permitido la identificación de diferentes variantes de la enfermedad, sin embargo, existen pacientes en los que se entrelazan las características clínicas de más de una variante, lo que ha llevado a cuestionar lo relativo de las clasificaciones vigentes. Objetivo: Caracterizar el funcionamiento cognitivo de un paciente donde concomitan alteraciones conductuales y del lenguaje, típicas de la demencia frontotemporal. Caso clínico: Mujer diestra, de 50 años de edad, con cambios conductuales marcados, a los cuales, de forma progresiva, se sumaron alteraciones del lenguaje, en un periodo de evolución de aproximadamente un año y seis meses. Por imágenes de tomografía axial computarizada, se confirma atrofia cortical a predominio frontal. Se emplearon para la evaluación la batería neuropsicológica breve NEUROPSI, la escala Hasegawa y la batería de evaluación frontal de Litvan; se constata predominio de alteraciones en el lenguaje impresivo y expresivo, las funciones ejecutivas y en la memoria verbal. Conclusiones: Las alteraciones detectadas, confirman la coexistencia de manifestaciones de la variante conductual (con tendencia a la desinhibición) y la variante semántica de la demencia frontotemporal(AU)

Introduction: The richness of the neuropsychological manifestations of frontotemporal dementia has allowed the identification of different variants of the disease. However, there are patients in whom the clinical characteristics of more than one variant are intertwined, which has led to question the current classifications. Objective: To characterize the cognitive functioning of a patient with concomitant behavioral and language disorders, typical of frontotemporal dementia. Case presentation: Right-handed female, 50 years old, affected by marked behavioral changes, to which language alterations were progressively added in a period of evolution of approximately one year and six months. Images of Computerized Axial Tomography that confirm cortical atrophy mainly frontal. The Neuropsychological Battery abbreviated NEUROPSI, the Hasegawa Scale and the Litvan Frontal Evaluation Battery were used for the evaluation, with a predominance of alterations in printed and expressive language, executive functions and verbal memory. Conclusions: The alterations detected confirm the coexistence of manifestations of the behavioral variant (with a tendency to disinhibition) and the semantic variant of frontotemporal dementia(AU)

Odor Identification Testing Can Assist in the Clinical Distinction Between Psychiatric Disorders and Neurological/Neurodegenerative Disorders.

BACKGROUND/OBJECTIVES: The aim was to identify whether performance on olfactory identification can distinguish neurological/neurodegenerative disorders (NNDs) from primary psychiatric disorders (PPDs). METHODS: This is a cross-sectional retrospective study of inpatients assessed in Neuropsychiatry, Royal Melbourne Hospital. Data extracted from the admission records included: demographics, tobacco use, medical comorbidities, cognitive function using the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG), and odor identification using the Sniffin' Sticks Screening 12 test. The final diagnosis for patients was informed by established diagnostic criteria. RESULTS: A total 121 patients were included. Eighty-eight patients (73%) were diagnosed with neurological or neurodegenerative disease, including Alzheimers dementia, frontotemporal dementia, Lewy body parkinsonian-related dementias (Parkinson disease, multiple system atrophy, dementia with Lewy bodies) and other neurological causes of dementia; 33 patients (27%) were diagnosed with PPDs (including mood and psychotic disorders). Patients who scored ≤8 on the Sniffin' Sticks Screening 12 test were more likely to have NND than PPD, even after adjustment for age, sex and tobacco use (P=0.009, adjusted odds ratios=3.85, 95% confidence interval=1.40-10.62). Receiver operating characteristic curve analyses demonstrated that a score of ≤8 differentiated NND from PPD with sensitivity of 57% and specificity of 73% (receiver operating characteristic area under the curve of 0.67, P=0.004). CONCLUSIONS: Patients with neuropsychiatric difficulties who score 8 or less on Sniffin' Sticks are more likely to have a neurodegenerative illness. A cut-off score of 8 is potentially a "red flag" for clinicians faced with the diagnostic question of PPD versus NND.

The wide-ranging clinical and genetic features in Japanese families with valosin-containing protein proteinopathy.

Mutations in the valosin-containing protein (VCP) gene are known to cause various neurodegenerative disorders. Here, we report 8 Japanese patients [6 men, 2 women; median age at onset: 49.5 (range, 35-58) years] from 5 unrelated families with VCP missense mutations. Although 7 of 8 patients were diagnosed with either inclusion body myopathy or amyotrophic lateral sclerosis, 1 patient showed demyelinating polyneuropathy, which was confirmed by longitudinal nerve conduction studies. Sural nerve biopsy of the patient revealed intranuclear ubiquitin staining in Schwann cells. Three known pathogenic VCP mutations (p.Arg191Gln, p.Arg155Cys, and p.Ile126Phe) were detected. A novel mutation, c.293 A>T (p.Asp98Val), was also identified in a patient with amyotrophic lateral sclerosis and frontotemporal dementia. This mutation was predicted to be "deleterious" or "disease causing" using in silico mutation analyses. In conclusion, demyelinating polyneuropathy may be a novel phenotype caused by VCP mutations. The p.Asp98Val mutation was found to be a novel pathogenic mutation of VCP proteinopathy. We believe our cases represent a wide clinical spectrum of VCP mutations.

Frontotemporal dementia: Plasma metabolomic signature using gas chromatography-mass spectrometry.

Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairment in behavior, executive function, and language. The behavioral variant (bvFTD) is the most clinical common form and requires differential diagnosis with atypical Alzheimer's disease (AD) cases. This study aimed to investigate the plasma metabolite profile of patients with bvFTD compared to AD patients and cognitively healthy individuals using gas chromatography coupled to mass spectrometry (GCMS). This study included nine patients with bvFTD, 17 with AD and 15 cognitively healthy controls (training set), whose data were validated on a testing set (eight bvFTD, 14 AD and ten controls). The metabolites were detected by GCMS. A tendency towards a reduction in the levels of palmitoleic, oleic and lauric acids was found in the bvFTD group compared to the AD group; however, no significance after multiple comparison correction was observed. However, bvFTD group showed reduced levels of creatinine, glycine, tryptophan, uric acid, hypoxanthine, serine, valine, threonine, isoleucine, homoserine, methionine, glutamic acid, capric acid, tartronic acid, fumaric acid, and myo-inositol, metabolites related to glycine/serine/threonine, alanine/aspartate/glutamate pathways and aminoacyl-tRNA biosynthesis, when compared to controls. The data suggest that bvFTD patients may present an impairment of amino acid metabolism and the translation process. This pioneering study on bvFTD and its plasma metabolomic signature can be useful to provide new ideas about pathophysiological mechanisms, as well as guide more robust studies in search of possible biomarkers for the diagnosis of this important dementia.

Frontotemporal dementia: an unusual cause.

Intracerebral pneumocephalus is commonly associated with head and facial trauma, ear infection, tumors and surgical interventions. Osteomas are relatively common, benign tumors that occur mainly in the paranasal sinuses, the frontal sinus in particular. Pneumocephalus has been commonly reported with frontal osteoma but isolated presentation as frontotemporal dementia is uncommon. Patient was admitted with complaints of change of behavior and forgetfulness for the last one year. He had progressively become more apathetic and presented with behavioral abnormalities. General physical examinations were within normal limits including the motor and sensory system although neuropsychiatry assessments were below the average level, with features of dementia. Further, MRI brain revealed pneumocephalus in bilateral frontal lobe. CT cisternography revealed a well defined lobulated densely sclerotic lesion of approximate size 20 × 17 × 27mm transverse and cranio-caudal axis respectively arising from right ethmoid sinus. Clinically, the association of pneumocephalus and isolated presentation as frontotemporal dementia has not been described to the best of our knowledge. A single case has been described with ethmoid osteoma. Radiological features were suggestive of osteoid osteoma. The uniqueness of the case is the development of dementia with frontotemporal involvement and resemblance with Frontotemporal Dementia. This is the only case with dementia and pneumocephalus (secondary to osteoid osteoma) to best of our knowledge.

Transcranial magnetic stimulation and amyloid markers in mild cognitive impairment: impact on diagnostic confidence and diagnostic accuracy.

BACKGROUND: The development of diagnostic tools capable of accurately identifying the pathophysiology of mild cognitive impairment (MCI) has become a crucial target considering the claim that disease-modifying treatments should be administered as early as possible in the disease course. Transcranial magnetic stimulation (TMS) protocols have demonstrated analytical validity in discriminating different forms of dementia; however, its value in daily clinical practice in MCI subjects is still unknown. OBJECTIVE: To evaluate the clinical value of TMS compared to amyloid markers on diagnostic confidence and accuracy in MCI subjects, considering clinicians' expertise. METHODS: One hundred seven MCI subjects were included and classified as MCI-Alzheimer disease (MCI-AD), MCI-frontotemporal dementia (MCI-FTD), MCI-dementia with Lewy bodies (MCI-DLB), or MCI-other in a three-step process based on (i) demographic, clinical, and neuropsychological evaluation (clinical work-up); (ii) clinical work-up PLUS amyloidosis markers or clinical work-up PLUS TMS measures; and (iii) clinical work-up PLUS both markers. Two blinded neurologists with different clinical expertise were asked to express a diagnostic confidence for each MCI subgroup, and ROC curve analyses were performed at each step. RESULTS: The addition of TMS markers to clinical work-up significantly increased the diagnostic confidence for MCI-AD (p = 0.003), MCI-FTD (p = 0.044), and MCI-DLB (p = 0.033) compared to clinical work-up alone, but not for MCI-other (p > 0.05). No significant differences between the add-on effect of TMS and the add-on effect of amyloid markers to clinical work-up were observed (p > 0.732), while the diagnostic confidence further increased when both markers were available. The greater the clinical expertise, the greater the flexibility in considering alternative diagnosis, and the greater the ability to modify diagnostic confidence with TMS and amyloid markers. CONCLUSIONS: TMS in addition to routine clinical assessment in MCI subjects has a significant effect on diagnostic accuracy and confidence, comparable to well-established biomarkers of amyloidosis.

Implementation of an antibody characterization procedure and application to the major ALS/FTD disease gene C9ORF72.

Antibodies are a key resource in biomedical research yet there are no community-accepted standards to rigorously characterize their quality. Here we develop a procedure to validate pre-existing antibodies. Human cell lines with high expression of a target, determined through a proteomics database, are modified with CRISPR/Cas9 to knockout (KO) the corresponding gene. Commercial antibodies against the target are purchased and tested by immunoblot comparing parental and KO. Validated antibodies are used to definitively identify the most highly expressing cell lines, new KOs are generated if needed, and the lines are screened by immunoprecipitation and immunofluorescence. Selected antibodies are used for more intensive procedures such as immunohistochemistry. The pipeline is easy to implement and scalable. Application to the major ALS disease gene C9ORF72 identified high-quality antibodies revealing C9ORF72 localization to phagosomes/lysosomes. Antibodies that do not recognize C9ORF72 have been used in highly cited papers, raising concern over previously reported C9ORF72 properties.