Objective
C9orf72 hexanucleotide repeats expansions account for almost half of familial amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) cases. Recent imaging studies in ...asymptomatic C9orf72 carriers have demonstrated cerebral white (WM) and gray matter (GM) degeneration before the age of 40 years. The objective of this study was to characterize cervical spinal cord (SC) changes in asymptomatic C9orf72 hexanucleotide carriers.
Methods
Seventy‐two asymptomatic individuals were enrolled in a prospective study of first‐degree relatives of ALS and FTD patients carrying the c9orf72 hexanucleotide expansion. Forty of them carried the pathogenic mutation (C9+). Each subject underwent quantitative cervical cord imaging. Structural GM and WM metrics and diffusivity parameters were evaluated at baseline and 18 months later. Data were analyzed in C9+ and C9− subgroups, and C9+ subjects were further stratified by age.
Results
At baseline, significant WM atrophy was detected at each cervical vertebral level in C9+ subjects older than 40 years without associated changes in GM and diffusion tensor imaging parameters. At 18‐month follow‐up, WM atrophy was accompanied by significant corticospinal tract (CST) fractional anisotropy (FA) reductions. Intriguingly, asymptomatic C9+ subjects older than 40 years with family history of ALS (as opposed to FTD) also exhibited significant CST FA reduction at baseline.
Interpretation
Cervical SC imaging detects WM atrophy exclusively in C9+ subjects older than 40 years, and progressive CST FA reductions can be identified on 18‐month follow‐up. Cervical SC magnetic resonance imaging readily captures presymptomatic pathological changes and disease propagation in c9orf72‐associated conditions. ANN NEUROL 2019;86:158–167
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Frontotemporal dementia and amyotrophic lateral sclerosis are rare neurodegenerative diseases with no effective treatment. The development of biomarkers allowing an accurate assessment of disease ...progression is crucial for evaluating new therapies. Concretely, neuroimaging and transcriptomic (microRNA) data have been shown useful in tracking their progression. However, no single biomarker can accurately measure progression in these complex diseases. Additionally, large samples are not available for such rare disorders. It is thus essential to develop methods that can model disease progression by combining multiple biomarkers from small samples. In this paper, we propose a new framework for computing a disease progression score (DPS) from cross-sectional multimodal data. Specifically, we introduce a supervised multimodal variational autoencoder that can infer a meaningful latent space, where latent representations are placed along a disease trajectory. A score is computed by orthogonal projections onto this path. We evaluate our framework with multiple synthetic datasets and with a real dataset containing 14 patients, 40 presymptomatic genetic mutation carriers and 37 controls from the PREV-DEMALS study. There is no ground truth for the DPS in real-world scenarios, therefore we use the area under the ROC curve (AUC) as a proxy metric. Results with the synthetic datasets support this choice, since the higher the AUC, the more accurate the predicted simulated DPS. Experiments with the real dataset demonstrate better performance in comparison with state-of-the-art approaches. The proposed framework thus leverages cross-sectional multimodal datasets with small sample sizes to objectively measure disease progression, with potential application in clinical trials.
As gene-based therapies may soon arise for patients with spinocerebellar ataxia (SCA), there is a critical need to identify biomarkers of disease progression with effect sizes greater than clinical ...scores, enabling trials with smaller sample sizes.
We enrolled a unique cohort of patients with SCA1 (n = 15), SCA2 (n = 12), SCA3 (n = 20) and SCA7 (n = 10) and 24 healthy controls of similar age, sex and body mass index. We collected longitudinal clinical and imaging data at baseline and follow-up (mean interval of 24 months). We performed both manual and automated volumetric analyses. Diffusion tensor imaging (DTI) and a novel tractography method, called fixel-based analysis (FBA), were assessed at follow-up. Effect sizes were calculated for clinical scores and imaging parameters.
Clinical scores worsened as atrophy increased over time (p < 0.05). However, atrophy of cerebellum and pons showed very large effect sizes (>1.2) compared to clinical scores (<0.8). FBA, applied for the first time to SCA, was sensitive to microstructural cross-sectional differences that were not captured by conventional DTI metrics, especially in the less studied SCA7 group. FBA also showed larger effect sizes than DTI metrics.
This study showed that volumetry outperformed clinical scores to measure disease progression in SCA1, SCA2, SCA3 and SCA7. Therefore, we advocate the use of volumetric biomarkers in therapeutic trials of autosomal dominant ataxias. In addition, FBA showed larger effect size than DTI to detect cross-sectional microstructural alterations in patients relative to controls.
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•Biomarkers are needed to test upcoming therapies for spinocerebellar ataxia.•As spinocerebellar ataxias are rare, biomarkers with high effect sizes are needed.•We identified imaging biomarkers with higher effect sizes than clinical scores.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Valosin-containing protein (VCP) mutations are rare causes of autosomal dominant frontotemporal dementias associated with Paget's disease of bone, inclusion body myopathy, and amyotrophic lateral ...sclerosis. We analyzed the VCP gene in a cohort of 199 patients with frontotemporal dementia and identified 7 heterozygous mutations in unrelated families, including 3 novel mutations segregating with dementia. This expands the VCP mutation spectrum and suggests that although VCP mutations are rare (3.5% in this study), the gene should be analyzed even in absence of the full syndromic complex. Reporting genetic variants with convincing arguments for pathogenicity is important considering the large amount of data generated by next-generation sequencing and the growing difficulties to interpret rare genetic variants identified in isolated cases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Objective
MicroRNAs are promising biomarkers of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS), but discrepant results between studies have so far hampered their use in ...clinical trials. We aim to assess all previously identified circulating microRNA signatures as potential biomarkers of genetic FTD and/or ALS, using homogeneous, independent validation cohorts of C9orf72 and GRN mutation carriers.
Methods
104 individuals carrying a C9orf72 or a GRN mutation, along with 31 controls, were recruited through the French research network on FTD/ALS. All subjects underwent blood sampling, from which circulating microRNAs were extracted. We measured differences in the expression levels of 65 microRNAs, selected from 15 published studies about FTD or ALS, between 31 controls, 17 C9orf72 presymptomatic subjects, and 29 C9orf72 patients. We also assessed differences in the expression levels of 30 microRNAs, selected from five studies about FTD, between 31 controls, 30 GRN presymptomatic subjects, and 28 GRN patients.
Results
More than half (35/65) of the selected microRNAs were differentially expressed in the C9orf72 cohort, while only a small proportion (5/30) of microRNAs were differentially expressed in the GRN cohort. In multivariate analyses, only individuals in the C9orf72 cohort could be adequately classified (ROC AUC up to 0.98 for controls versus presymptomatic subjects, 0.94 for controls versus patients, and 0.77 for presymptomatic subjects versus patients) with some of the signatures.
Interpretation
Our results suggest that previously identified microRNAs using sporadic or mixed cohorts of FTD and ALS patients could potentially serve as biomarkers of C9orf72‐associated disease, but not GRN‐associated disease.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
...Lewy bodies and 1C2-positive inclusions in substantia nigra, pontine nuclei and cerebellum, described in few parkinsonian patients 9, were absent in our case. ...the phenotype might be directly ...impacted by the modification of RNA secondary structure of ATXN2 transcripts including one or more CAA. ...our patient showed a rather unique lesional pattern, characterized by FTLD-TDP type A, distinct both from pure or interrupted expansions and intermediate alleles, that expands neuropathological hallmarks associated with ATXN2 expansions (Additional file 1: (DOCX 17641 kb) Authors’ Affiliations (1) Institut du Cerveau et la Moelle épinière (ICM), Sorbonne Université, UPMC Univ Paris 06, Inserm U1127, CNRS UMR 7225, Hôpital Pitié-Salpêtrière, Paris, France (2) Ecole Pratique des Hautes Etudes – EPHE, PSL research University, Paris, France (3) Département de médecine gériatrique, Centre hospitalier Rives de Seine, Courbevoie, France (4) Neurological Tissue Bank of the Biobanc-Hospital Clinic-IDIBAPS, Barcelona, Spain (5) Laboratoire de Neuropathologie Escourolle, AP-HP - Hôpital Pitié-Salpêtrière, Paris, France (6) Department of Neurology, AP-HP - Hopital Pitié-Salpêtrière, Reference center for rare or early dementias, Institute of Memory and Alzheimer’s Disease (IM2A), Paris, France (7) Alzheimer disease and other Cognitive Disorders Unit, Department of Neurology, Hospital Clinic, Barcelona, Spain (8) Reference center for neurogenetics, Departement of Genetics, APHP, Hôpital Pitié-Salpêtrière, Paris, France Dürr A, Smadja D, Cancel G, Lezin A, Stevanin G, Mikol J et al (1995) Autosomal dominant cerebellar ataxia type I in Martinique (French West Indies).
Based on our previous work in Huntington disease (HD) showing improved energy metabolism in muscle by providing substrates to the Krebs cycle, we wished to obtain a proof-of-concept of the ...therapeutic benefit of triheptanoin using a functional biomarker of brain energy metabolism validated in HD.
We performed an open-label study using (31)P brain magnetic resonance spectroscopy (MRS) to measure the levels of phosphocreatine (PCr) and inorganic phosphate (Pi) before (rest), during (activation), and after (recovery) a visual stimulus. We performed (31)P brain MRS in 10 patients at an early stage of HD and 13 controls. Patients with HD were then treated for 1 month with triheptanoin after which they returned for follow-up including (31)P brain MRS scan.
At baseline, we confirmed an increase in Pi/PCr ratio during brain activation in controls-reflecting increased adenosine triphosphate synthesis-followed by a return to baseline levels during recovery (p = 0.013). In patients with HD, we validated the existence of an abnormal brain energy profile as previously reported. After 1 month, this profile remained abnormal in patients with HD who did not receive treatment. Conversely, the MRS profile was improved in patients with HD treated with triheptanoin for 1 month with the restoration of an increased Pi/PCr ratio during visual stimulation (p = 0.005).
This study suggests that triheptanoin is able to correct the bioenergetic profile in the brain of patients with HD at an early stage of the disease.
This study provides Class III evidence that, for patients with HD, treatment with triheptanoin for 1 month restores an increased MRS Pi/PCr ratio during visual stimulation.
IMPORTANCE: Presymptomatic carriers of chromosome 9 open reading frame 72 (C9orf72) mutation, the most frequent genetic cause of frontotemporal lobar degeneration and amyotrophic lateral sclerosis, ...represent the optimal target population for the development of disease-modifying drugs. Preclinical biomarkers are needed to monitor the effect of therapeutic interventions in this population. OBJECTIVES: To assess the occurrence of cognitive, structural, and microstructural changes in presymptomatic C9orf72 carriers. DESIGN, SETTING, AND PARTICIPANTS: The PREV-DEMALS study is a prospective, multicenter, observational study of first-degree relatives of individuals carrying the C9orf72 mutation. Eighty-four participants entered the study between October 2015 and April 2017; 80 (95%) were included in cross-sectional analyses of baseline data. All participants underwent neuropsychological testing and magnetic resonance imaging; 63 (79%) underwent diffusion tensor magnetic resonance imaging. Gray matter volumes and diffusion tensor imaging metrics were calculated within regions of interest. Anatomical and microstructural differences between individuals who carried the C9orf72 mutation (C9+) and those who did not carry the C9orf72 mutation (C9−) were assessed using linear mixed-effects models. Data were analyzed from October 2015 to April 2017. MAIN OUTCOMES AND MEASURES: Differences in neuropsychological scores, gray matter volume, and white matter integrity between C9+ and C9− individuals. RESULTS: Of the 80 included participants, there were 41 C9+ individuals (24 59% female; mean SD age, 39.8 11.1 years) and 39 C9− individuals (24 62% female; mean SD age, 45.2 13.9 years). Compared with C9− individuals, C9+ individuals had lower mean (SD) praxis scores (163.4 6.1 vs 165.3 5.9; P = .01) and intransitive gesture scores (34.9 1.6 vs 35.7 1.5; P = .004), atrophy in 8 cortical regions of interest and in the right thalamus, and white matter alterations in 8 tracts. When restricting the analyses to participants younger than 40 years, compared with C9− individuals, C9+ individuals had lower praxis scores and intransitive gesture scores, atrophy in 4 cortical regions of interest and in the right thalamus, and white matter alterations in 2 tracts. CONCLUSIONS AND RELEVANCE: Cognitive, structural, and microstructural alterations are detectable in young C9+ individuals. Early and subtle praxis alterations, underpinned by focal atrophy of the left supramarginal gyrus, may represent an early and nonevolving phenotype related to neurodevelopmental effects of C9orf72 mutation. White matter alterations reflect the future phenotype of frontotemporal lobar degeneration/amyotrophic lateral sclerosis, while atrophy appears more diffuse. Our results contribute to a better understanding of the preclinical phase of C9orf72 disease and of the respective contribution of magnetic resonance biomarkers. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02590276
To identify potential biomarkers of preclinical and clinical progression in chromosome 9 open reading frame 72 gene (
-associated disease by assessing the expression levels of plasma microRNAs ...(miRNAs) in
patients and presymptomatic carriers.
The PREV-DEMALS study is a prospective study including 22
patients, 45 presymptomatic
mutation carriers and 43 controls. We assessed the expression levels of 2576 miRNAs, among which 589 were above noise level, in plasma samples of all participants using RNA sequencing. The expression levels of the differentially expressed miRNAs between patients, presymptomatic carriers and controls were further used to build logistic regression classifiers.
Four miRNAs were differentially expressed between patients and controls: miR-34a-5p and miR-345-5p were overexpressed, while miR-200c-3p and miR-10a-3p were underexpressed in patients. MiR-34a-5p was also overexpressed in presymptomatic carriers compared with healthy controls, suggesting that miR-34a-5p expression is deregulated in cases with
mutation. Moreover, miR-345-5p was also overexpressed in patients compared with presymptomatic carriers, which supports the correlation of miR-345-5p expression with the progression of
-associated disease. Together, miR-200c-3p and miR-10a-3p underexpression might be associated with full-blown disease. Four presymptomatic subjects in transitional/prodromal stage, close to the disease conversion, exhibited a stronger similarity with the expression levels of patients.
We identified a signature of four miRNAs differentially expressed in plasma between clinical conditions that have potential to represent progression biomarkers for
-associated frontotemporal dementia and amyotrophic lateral sclerosis. This study suggests that dysregulation of miRNAs is dynamically altered throughout neurodegenerative diseases progression, and can be detectable even long before clinical onset.
NCT02590276.
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