Clinical applicability of diagnostic biomarkers in early-onset cognitive impairment.

BACKGROUND AND PURPOSE: Several diagnostic biomarkers are currently available for clinical use in early-onset cognitive impairment. The decision on which biomarker is used in each patient depends on several factors such as its predictive value or tolerability. METHODS: There were a total of 40 subjects with early-onset cognitive complaints (<65 years of age): 26 with Alzheimer's disease (AD), five with frontotemporal dementia and nine with diagnostic suspicion of non-neurodegenerative disorder. Clinical and neuropsychological evaluation, lumbar puncture for cerebrospinal fluid (CSF) AD core biochemical marker determination, medial temporal atrophy evaluation on magnetic resonance imaging, amyloid-positron emission tomography (PET) and 18 F-fluorodeoxyglucose-PET were performed. Neurologists provided pre- and post-biomarker diagnosis, together with diagnostic confidence and clinical/therapeutic management. Patients scored the tolerability of each procedure. RESULTS: Cerebrospinal fluid biomarkers and amyloid-PET increased diagnostic confidence in AD (77.4%-86.2% after CSF, 92.4% after amyloid-PET, P < 0.01) and non-neurodegenerative conditions (53.6%-75% after CSF, 95% after amyloid-PET, P < 0.05). Biomarker results led to diagnostic (32.5%) and treatment (32.5%) changes. All tests were well tolerated. CONCLUSIONS: Biomarker procedures are well tolerated and have an important diagnostic/therapeutic impact on early-onset cognitive impairment.

Adaptation and validation of a Spanish-language version of the Frontotemporal Dementia Rating Scale (FTD-FRS). / Adaptación y validación de la Frontotemporal Dementia Rating Scale (FTD-FRS) al castellano.

INTRODUCTION: The Frontotemporal Dementia Rating Scale (FTD-FRS) is a tool designed to aid with clinical staging and assessment of the progression of frontotemporal dementia (FTD-FRS). OBJECTIVE: Present a multicentre adaptation and validation study of a Spanish version of the FRS. METHODOLOGY: The adapted version was created using 2 translation-back translation processes (English to Spanish, Spanish to English) and verified by the scale's original authors. We validated the adapted version in a sample of consecutive patients diagnosed with FTD. The procedure included evaluating internal consistency, testing unidimensionality with the Rasch model, analysing construct validity and discriminant validity, and calculating the degree of agreement between the Clinical Dementia Rating scale (CDR) and FTD-FRS for FTD cases. RESULTS: The study included 60 patients with DFT. The mean score on the FRS was 12.1 points (SD=6.5; range, 2-25) with inter-group differences (F=120.3; df=3; P<.001). Cronbach's alpha was 0.897 and principal component analysis of residuals delivered an acceptable eigenvalue for 5 contrasts (1.6-2.7) and 36.1% raw variance. FRS was correlated with the Mini-mental State Examination (r=0.572; P<.001) and functional capacity (DAD; r=0.790; P<.001). FTD-FRS also showed a significant correlation with CDR (r=-0.641; P<.001), but we did observe variability in the severity levels; cases appeared to be less severe according to the CDR than when measured with the FTD-FRS (kappa=0.055). CONCLUSIONS: This process of validating the Spanish translation of the FTD-FRS yielded satisfactory results for validity and unidimensionality (severity) in the assessment of patients with FTD.

Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU): Trial Satisfaction and Attitudes towards Future Clinical Trials.

BACKGROUND: Clinical trial satisfaction is increasingly important for future trial designs and is associated with treatment adherence and willingness to enroll in future research studies or to recommend trial participation. In this post-trial survey, we examined participant satisfaction and attitudes toward future clinical trials in the Dominantly Inherited Alzheimer Network Trials Unit (DIAN-TU). METHODS: We developed an anonymous, participant satisfaction survey tailored to participants enrolled in the DIAN-TU-001 double-blind clinical trial of solanezumab or gantenerumab and requested that all study sites share the survey with their trial participants. A total of 194 participants enrolled in the trial at 24 study sites. We utilized regression analysis to explore the link between participants' clinical trial experiences, their satisfaction, and their willingness to participate in upcoming trials. RESULTS: Survey responses were received over a sixteen-month window during 2020-2021 from 58 participants representing 15 study sites. Notably, 96.5% of the survey respondents expressed high levels of satisfaction with the trial, 91.4% would recommend trial participation, and 96.5% were willing to enroll again. Age, gender, and education did not influence satisfaction levels. Participants reported enhanced medical care (70.7%) and pride in contributing to the DIAN-TU trial (84.5%). Satisfaction with personnel and procedures was high (98.3%). Respondents had a mean age of 48.7 years, with most being from North America and Western Europe, matching the trial's demographic distribution. Participants' decisions to learn their genetic status increased during the trial, and most participants endorsed considering future trial participation regardless of the DIAN-TU-001 trial outcome. CONCLUSION: Results suggest that DIAN-TU-001 participants who responded to the survey exhibited high motivation to participate in research, overall satisfaction with the clinical trial, and willingness to participate in research in the future, despite a long trial duration of 4-7 years with detailed annual clinical, cognitive, PET, MRI, and lumbar puncture assessments. Implementation of features that alleviate barriers and challenges to trial participation is like to have a high impact on trial satisfaction and reduce participant burden.

Decreased striatal dopamine transporter uptake in the non-fluent/agrammatic variant of primary progressive aphasia.

BACKGROUND AND PURPOSE: Patients with the non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) may develop atypical parkinsonian syndromes. However, there is no current biomarker to assess which patients are at high risk of developing parkinsonism. 123I-2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane (123I-FP-CIT)-SPECT detects striatal dopamine dysfunction in vivo. The objective of the present study was to study whether non-fluent/agrammatic patients without parkinsonism at baseline present decreased striatal 123I-FP-CIT uptake. METHODS: Visual and semi-quantitative assessments of the striatal 123I-FP-CIT uptake ratio were carried out in 15 patients with nfvPPA, eight patients with the logopenic variant of PPA (lvPPA) and 18 controls. To rule out progranulin mutations or underlying Alzheimer's disease (AD), serum progranulin levels and cerebrospinal fluid (CSF) biomarkers of AD (Aß42 , total-tau, phosphorylated-tau181 ) were determined. A second 123I-FP-CIT-SPECT analysis in the biomarker-enriched groups was also carried out. RESULTS: Patients with nfvPPA presented reduced striatal 123I-FP-CIT binding, especially in the left hemisphere (P = 0.002), compared with controls. All lvPPA patients had normal striatal 123I-FP-CIT uptake. 123I-FP-CIT striatal binding in nfvPPA patients with normal progranulin and CSF biomarker levels (nfvPPA/bio-) was also significantly reduced (P < 0.05) compared with lvPPA patients with positive AD biomarkers. Sixty-four per cent (9/14) of nfvPPA patients and 80% of nfvPPA/bio- patients (8/10) showed a diminished individual left striatal 123I-FP-CIT uptake ratio. On follow-up, seven nfvPPA/bio- patients developed parkinsonism (median 1.9 years; range 1.2-2.9), six of them with baseline reduced 123I-FP-CIT uptake. CONCLUSIONS: Reduced striatal tracer uptake in nfvPPA patients prior to clinical parkinsonism can be detected by 123I-FP-CIT-SPECT, especially in those with nfvPPA/bio-, suggesting subclinical nigrostriatal degeneration. Decreased striatal 123I-FP-CIT binding might identify PPA patients at increased risk of developing atypical parkinsonian syndromes, probably related to tau-pathology.

Neuroimaging and biochemical markers in the three variants of primary progressive aphasia.

BACKGROUND/AIM: To investigate in variants of primary progressive aphasia (PPA) the association between current clinical and neuroimaging criteria and biochemical/genetic markers at the individual level. METHODS: Thirty-two PPA patients were classified as non-fluent/agrammatic (nfvPPA), semantic (svPPA), or logopenic variant (lvPPA) or as unclassifiable (uPPA). In all patients, we evaluated the neuroimaging criteria (magnetic resonance imaging and/or single photon emission computed tomography/positron emission tomography) of each variant and studied serum progranulin levels, APOE genotype and Alzheimer's disease (AD)-cerebrospinal fluid (CSF) biomarkers. Cases with a first-degree family history of early-onset dementia were genetically tested. RESULTS: Ten of 15 (66%) nfvPPA, 5/5 (100%) svPPA and 7/7 (100%) lvPPA patients showed at least one positive neuroimaging-supported diagnostic criterion. All lvPPA and 3/5 (60%) uPPA patients presented AD-CSF biomarkers, which were absent in nfvPPA and svPPA cases. Four (27%) nfvPPA patients had dementia-causing mutations: 2 carried a GRN mutation and 2 the C9ORF72 hexanucleotide expansion. CONCLUSIONS: There was an excellent association between clinical criteria and neuroimaging-supported biomarkers in svPPA and lvPPA, as well as with AD-CSF biochemical markers in the lvPPA. Neuroimaging, biochemical and genetic findings in nfvPPA were heterogeneous. Incorporating biochemical/genetic markers into the PPA clinical diagnosis would allow clinicians to improve their predictions of PPA neuropathology, especially in nfvPPA and uPPA cases.

Hirano body-rich subtypes of Creutzfeldt-Jakob disease.

BACKGROUND: In definite Creutzfeldt-Jakob disease (CJD), morphological and immunohistochemical patterns are useful to identify molecular subtypes. Severe cerebellar pathology and hippocampal involvement helps to identify VV subtypes. The rare VV1 variant (<1%), more frequent in young individuals, is additionally characterized by the presence of ballooned neurones in affected areas. In 1985, Cartier et al. described a family cluster of three individuals with an ataxic CJD form, showing, in addition to severe cerebellar and hippocampal involvement, the presence of frequent Hirano bodies (HB) in CA1 pyramidal neurones. HB are frequently found in aged individuals with Alzheimer pathology although they are not a specific finding. AIMS AND METHODS: In this study, we evaluated the presence of HB in hippocampi of 54 genetically and molecularly characterized CJD cases, aiming to elucidate whether additional morphological features could be helpful to point to molecular subtypes. RESULTS: We identified nine cases (four VV1, one out of three MV2K, three out of six MV2K+2C and one MV carrying a 96-base pair insertion) with abundant, partly bizarre and clustered HB in CA1 sector, not observed in other subtypes. The presence of HB was independent of hippocampal involvement by the disease itself. CONCLUSIONS: Clusters of abundant HB might be found in rare CJD subtypes such as VV1, MV2K/MV2K+2C and some genetic cases. In addition to histopathological and PrP immunohistochemical deposition patterns, their presence might be a useful additional morphologic feature that could point to the molecular subtype, especially when genetic and/or Western blot analyses are not available.

Barcelona scale for buccophonatory apraxia: Quantitative assessment tool.

INTRODUCTION: Currently there is no tool to quantify buccophonatory apraxia to stratify, compare and monitor patients longitudinally in an objective manner. Our aim in this study is to create a quantitative scale for buccophonatory apraxia and evaluate it in patients with the non-fluent/grammatical variant of primary progressive aphasia (nfvPPA) and other neurodegenerative diseases that occur with speech and/or language problems. METHODS: The scale was designed based on useful elements in the assessment of buccophonatory apraxia and the total was quantified in seconds. The scale was administered to 64 participants with diagnoses of: nfvPPA, semantic variant of primary progressive aphasia (svPPA), logopenic variant of primary progressive aphasia (lvPPA), Huntington's disease, Parkinson's disease, as well as a group of healthy controls. RESULTS: Patients showed a significantly higher score compared to controls. The nfvPPA group had the highest mean score on the scale (429 seconds ± 278). The scale was useful to differentiate vnfPPA from svPPA and Parkinson's disease (area under curve [AUC] of 0.956 and 0.989, respectively), but less to differentiate it from Huntington's disease (AUC = 0.67) and lvPPA. There was a statistically significant relationship between total score and disease severity in nfvPPA (P < .029). CONCLUSIONS: The Barcelona scale for buccophonatory apraxia could be useful to quantitatively evaluate buccophonatory apraxia in different neurodegenerative diseases, and compare patients, especially in nfvPPA.

PICOGEN: five years experience with a genetic counselling program for dementia.

INTRODUCTION: We describe the 5 year experience of a genetic counselling program for familial dementias (the PICOGEN program). METHODS: The neurologist selected the candidates for genetic testing in the screening visit based on family history and phenotype (Alzheimer disease-AD, frontotemporal lobar degeneration-FTLD, or prion disease). Asymptomatic subjects who decided to know their genetic status were evaluated within a structured protocol by the psychiatrist and psychologist prior to entering the program and followed up afterwards. RESULTS: A total of 87 patients from 72 families were candidates for the genetic study, 20 of the 72 families had a family history of autosomal dominant early-onset dementia (ADEOD). A pathogenic mutation was found in 22 patients (8 PSEN1, 1 PSEN2, 1 APP, 4 MAPT, 8 PRNP), 5 of which had not been previously described. All positive cases, except for 1 PSEN1 (12.5%) and 4 PRNP (50%) showed ADEOD. In 3 ADEOD cases (15%) no pathogenic mutation was found. After individual genetic counselling, 24/54 asymptomatic subjects at risk decided to have the pre-symptomatic study, of whom 10 (42%) were carriers of the pathogenic mutation. In the follow up, no major psychiatric complication was observed. CONCLUSIONS: In our series, family history of ADEOD was a sensitive criterion for the detection of pathogenic mutations in AD and FTLD but not in prion diseases. No genetic anomalies were detected in 15% of the ADEOD cases using conventional diagnostic procedures, and 43% of pre-symptomatic subjects at risk who received individual genetic counselling decided to have the study. The pre-symptomatic diagnosis proved to be safe under these conditions.

A novel PSEN1 mutation (K239N) associated with Alzheimer's disease with wide range age of onset and slow progression.

OBJECTIVE: To describe a novel mutation (K239N) in the PSEN1 associated with familial Alzheimer's disease (AD). METHODS AND RESULTS: The proband was a man who developed cognitive decline with marked behavioural abnormalities at age 57. At age 70, he was admitted into a psychiatric facility because of aggressiveness and a suicide attempt. Family history was consistent with autosomal dominant AD. One of the two other family members studied presented also with prominent behavioural symptoms at age 42 and has also been forced into a psychiatric facility because of aggressiveness at age 56. The remainder patient has presented a prototypical AD, but starting at age 71. Direct sequencing of PSEN1 in the three living affected members disclosed a heterozygous G to C transition in exon 7 of PSEN1 leading to the K239N mutation. CONCLUSION: The K239N mutation is associated with autosomal dominant AD with a wide range of age of onset and incomplete penetrance at the age of 65, prominent behavioural features and slow progression.

Naming is associated with left temporal pole metabolite levels in neurodegenerative diseases.

AIM: To investigate the relationship between performance in language tests and levels of brain metabolites in two selected left temporal lobe regions. METHODS: Ninety-five subjects were included: 26 controls, 30 amnestic mild cognitive impairment subjects, 27 Alzheimer's disease and 12 frontotemporal lobar degeneration (FTLD) patients. Language was assessed by a naming test: Boston Naming Test (BNT) and by a semantic verbal fluency test. Other cognitive functions: verbal and visual memory, visual perception, attention and executive function, and praxis were also assessed. Single voxel magnetic resonance spectroscopy was obtained in the left temporal pole (L-TPOLE), and in the left posterior temporoparietal region (L-TPAR). RESULTS: BNT scores were significantly associated with N-acetylaspartate/creatine ratios (r = 0.45; p < 0.001) and choline/creatine ratios (r = 0.33; p < 0.005) in the L-TPOLE. No significant associations were found between BNT and metabolite levels in the L-TPAR. No significant associations were found between the semantic verbal fluency test and other cognitive tests and metabolite levels either in the L-TPOLE or in the L-TPAR. CONCLUSION: Naming performance is related to metabolite levels in the anterior L-TPOLE.

MAPT gene duplications are not a cause of frontotemporal lobar degeneration.

Recurrent deletions of the 17q21.31 region encompassing the microtubule-associated protein tau (MAPT) gene have recently been described in patients with mental retardation. This region is flanked by segmental duplications that make it prone to inversions, deletions and duplications. Since gain-of-function mutations of the MAPT gene cause frontotemporal lobar degeneration (FTLD) characterized by deposition of tau protein, we hypothesize that MAPT duplication affecting gene dosage could also lead to disease. Gene dosage alterations have already been found to be involved in the etiology of neurodegenerative disorders caused by protein or peptide accumulation, such as Alzheimer's and Parkinson's diseases. To determine whether MAPT gene copy number variation is involved in FTLD, 70 patients with clinical diagnosis of FTLD and no MAPT mutation (including 12 patients with pathologically proven tau-positive FTLD) were screened by using multiplex ligation probe amplification (MLPA) with specific oligonucleotide probes. No copy number variation in the MAPT gene was observed in cases. Although our study was limited by the relatively small number of patients, it does not support the theory that chromosomal rearrangements in this region are a cause of FTLD.

A novel mutation in the PSEN1 gene (L286P) associated with familial early-onset dementia of Alzheimer type and lobar haematomas.

The aim of this study was to describe a novel mutation in exon 8 of the presenilin gene (L286P) associated with early-onset autosomal dominant Alzheimer's disease (AD) and lobar haematomas. The proband was a woman who developed cognitive decline with predominant memory loss at the age of 35 years. The patient died at the age of 54 years and the neuropathological examination confirmed the diagnosis of AD. Three of her four siblings, one parent and one sibling of her parent had suffered from cognitive decline at ages between 35 and 42 years. Three of them also presented lobar haematomas. The neuropathological examination, available in one of them, disclosed the presence of severe amyloid angiopathy as the cause of the haematoma. The study of PSEN1 gene with single strand conformation polymorphism technique failed to show abnormalities suggestive of mutations. Direct sequencing disclosed the presence of a missense mutation in codon 286 (L286P) in the proband and her already affected descendent, which was absent in the healthy sibling. L286P is a novel mutation in PSEN1 that causes familial early-onset AD and brain haematomas related to amyloid angiopathy.

CSF analysis in patients with sporadic CJD and other transmissible spongiform encephalopathies.

Patients with suspected Creutzfeldt-Jakob disease (CJD) often have routine cerebrospinal fluid (CSF) analysis performed to exclude treatable inflammatory conditions; however, little information is available about the range of results obtained for CSF tests in patients with sporadic CJD and other transmissible spongiform encephalopathies (TSE). Data from 450 patients with sporadic CJD and 47 patients with other TSEs were collected as part of an EC-supported multinational study. Raised white cell counts of >5 cells/microl were found in three of 298 patients with sporadic CJD, with two cell counts of 7 cells/microl and one of 20 cells/microl. Total protein concentrations of >0.9 g/l were found in five of 438 patients with sporadic CJD, although none had a concentration of >1 g/l. CSF oligoclonal IgG was detected in eight of 182 sporadic CJD patients. Of the patients with other TSEs, six had elevated cell counts ranging from 6 to 14 cells/microl but none had total protein concentrations of >0.9 g/l and one patient had detectable oligoclonal IgG. None of the patients with sporadic CJD or other TSEs had abnormalities in all three tests.

14-3-3 protein in the CSF as prognostic marker in early multiple sclerosis.

Axonal damage probably occurs early in the evolution of MS. Five of 38 (13%) patients had a positive assay for the neuronal 14-3-3 protein in the CSF obtained at the first clinically isolated syndrome suggestive of MS. A positive 14-3-3 assay was the only independent predictor for a shorter time to conversion to clinical definite MS (risk ratio 4.1; 95% CI 1.1 to 15) and to reach an Expanded Disability Status Scale (EDSS) > or =2 at the end of follow-up (odds ratio 14.8; 95% CI 2.86 to 76.8). The detection of the 14-3-3 protein in the CSF at the first neurologic event suggestive of MS may be a useful predictor of short-term evolution.

Clinical features and APOE genotype of pathologically proven early-onset Alzheimer disease.

OBJECTIVES: Early-onset Alzheimer disease (EOAD) diagnosis often represents a challenge because of the high frequency of atypical presentations. Our aim was to describe the clinical features, APOE genotype, and its pathologic correlations of neuropathologic confirmed EOAD. METHODS: Retrospective review of clinical data (age at onset, family history, clinical presentation, diagnostic delay, diagnosis) and APOE genotype of patients with neuropathologically confirmed EOAD (<60 years). RESULTS: Forty cases were selected. Mean age at onset was 54.5 years (range 46-60). The mean disease duration was 11 years with a mean diagnostic delay of 3.1 years. A total of 37.5% had a nonmemory presentation. Behavioral/executive dysfunction was the most prevalent atypical presentation. Incorrect initial clinical diagnoses were common (53%) in patients with atypical presentations, but rare when anterograde amnesia was the presenting symptom (4%). The incorrect initial clinical diagnoses were 2 behavioral variant frontotemporal lobar degeneration, 2 normal pressure hydrocephalus, 1 semantic dementia, 1 primary progressive aphasia, 1 corticobasal degeneration, 1 pseudodementia with depression, and 1 unclassifiable dementia. APOE genotype was ε3/ε3 in 59%, with no significant differences between typical and atypical presentations. APOE ε4 was 3.3 times more frequent in subjects with family history of AD. A total of 97.5% of the cases presented advanced neurofibrillary pathology. A total of 45% of the patients had concomitant Lewy body pathology although localized in most cases and without a significant clinical correlate. CONCLUSION: One third of patients with pathologic confirmed EOAD presented with atypical symptoms. Patients with EOAD with nonamnestic presentations often receive incorrect clinical diagnoses.

The memory alteration test (M@T) discriminates between subjective memory complaints, mild cognitive impairment and Alzheimer's disease.

This work aimed at establishing the memory alteration test (M@T), which is a memory screening test, capable for discriminating between subjects with subjective memory complaints (SMC) (without objective memory impairment) and patients with amnestic mild cognitive impairment (A-MCI) and with mild Alzheimer's disease (AD). The discriminative validity was assessed in a sample of 37 subjects with SMC, 50 patients with A-MCI according to the Petersen-criteria, and 66 patients with mild AD (global deterioration scale: 4 stage) according to the NINCDS-ADRDA criteria. M@T mean scores were significantly different among groups: 39.7 + or - 5.1 (+ or - S.D.) in the SMC group, 31.5 + or - 3.9 in the A-MCI group, and 21.8 + or - 4.9 in mild AD. A cut-off score of 37 points had a sensitivity of 96% and a specificity of 70% to differentiate A-MCI from SMC (ABC = 0.88). A cut-off score of 33 points had a sensitivity of 100% and a specificity of 86% to differentiate mild AD from SMC sample (AUC = 0.99). We conclude that the M@T provides efficient and valid discrimination between SMC subjects and A-MCI, and between SMC subjects and mild AD.