Browsing by Author "Laske, Christoph"
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Item Association of BDNF Val66Met With Tau Hyperphosphorylation and Cognition in Dominantly Inherited Alzheimer Disease(American Medical Association, 2022-03-01) Lim, Yen Ying; Maruff, Paul; Barthélemy, Nicolas R.; Goate, Alison; Hassenstab, Jason; Sato, Chihiro; Fagan, Anne M.; Benzinger, Tammie L. S.; Xiong, Chengjie; Cruchaga, Carlos; Levin, Johannes; Farlow, Martin R.; Graff-Radford, Neill R.; Laske, Christoph; Masters, Colin L.; Salloway, Stephen; Schofield, Peter R.; Morris, John C.; Bateman, Randall J.; McDade, Eric; Dominantly Inherited Alzheimer Network; Neurology, School of MedicineImportance: Allelic variation in the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism moderates increases in cerebrospinal fluid (CSF) levels of tau and phosphorylated tau 181 (p-tau181), measured using immunoassay, and cognitive decline in presymptomatic dominantly inherited Alzheimer disease (DIAD). Advances in mass spectrometry show that CSF tau phosphorylation occupancy at threonine 181 and 217 (p-tau181/tau181, p-tau217/tau217) increases with initial β-amyloid (Aβ) aggregation, while phosphorylation occupancy at threonine 205 (p-tau205/tau205) and level of total tau increase when brain atrophy and clinical symptoms become evident. Objective: To determine whether site-specific tau phosphorylation occupancy (ratio of phosphorylated to unphosphorylated tau) is associated with BDNF Val66Met in presymptomatic and symptomatic DIAD. Design, setting, and participants: This cross-sectional cohort study included participants from the Dominantly Inherited Alzheimer Network (DIAN) and Aβ-positive cognitively normal older adults in the Alzheimer's Disease Neuroimaging Initiative (ADNI). Data were collected from 2009 through 2018 at multicenter clinical sites in the United States, United Kingdom, and Australia, with no follow-up. DIAN participants provided a CSF sample and completed clinical and cognitive assessments. Data analysis was conducted between March 2020 and March 2021. Main outcomes and measures: Mass spectrometry analysis was used to determine site-specific tau phosphorylation level; tau levels were also measured using immunoassay. Episodic memory and global cognitive composites were computed. Results: Of 374 study participants, 144 were mutation noncarriers, 156 were presymptomatic mutation carriers, and 74 were symptomatic carriers. Of the 527 participants in the network, 153 were excluded because their CSF sample, BDNF status, or both were unavailable. Also included were 125 Aβ-positive cognitively normal older adults in the ADNI. The mean (SD) age of DIAD participants was 38.7 (10.9) years; 43% were women. The mean (SD) age of participants with preclinical sporadic AD was 74.8 (5.6) years; 52% were women. In presymptomatic mutation carriers, compared with Val66 homozygotes, Met66 carriers showed significantly poorer episodic memory (d = 0.62; 95% CI, 0.28-0.95), lower hippocampal volume (d = 0.40; 95% CI, 0.09-0.71), and higher p-tau217/tau217 (d = 0.64; 95% CI, 0.30-0.97), p-tau181/tau181 (d = 0.65; 95% CI, 0.32-0.99), and mass spectrometry total tau (d = 0.43; 95% CI, 0.10-0.76). In symptomatic mutation carriers, Met66 carriers showed significantly poorer global cognition (d = 1.17; 95% CI, 0.65-1.66) and higher p-tau217/tau217 (d = 0.53; 95% CI, 0.05-1.01), mass spectrometry total tau (d = 0.78; 95% CI, 0.28-1.25), and p-tau205/tau205 (d = 0.97; 95% CI, 0.46-1.45), when compared with Val66 homozygotes. In preclinical sporadic AD, Met66 carriers showed poorer episodic memory (d = 0.39; 95% CI, 0.00-0.77) and higher total tau (d = 0.45; 95% CI, 0.07-0.84) and p-tau181 (d = 0.46; 95% CI, 0.07-0.85). Conclusions and relevance: In DIAD, clinical disease stage and BDNF Met66 were associated with cognitive impairment and levels of site-specific tau phosphorylation. This suggests that pharmacological strategies designed to increase neurotrophic support in the presymptomatic stages of AD may be beneficial.Item Axonal damage and inflammation response are biological correlates of decline in small-world values: a cohort study in autosomal dominant Alzheimer's disease(Oxford University Press, 2024-10-09) Vermunt, Lisa; Sutphen, Courtney L.; Dicks, Ellen; de Leeuw, Diederick M.; Allegri, Ricardo F.; Berman, Sarah B.; Cash, David M.; Chhatwal, Jasmeer P.; Cruchaga, Carlos; Day, Gregory S.; Ewers, Michael; Farlow, Martin R.; Fox, Nick C.; Ghetti, Bernardino; Graff-Radford, Neill R.; Hassenstab, Jason; Jucker, Mathias; Karch, Celeste M.; Kuhle, Jens; Laske, Christoph; Levin, Johannes; Masters, Colin L.; McDade, Eric; Mori, Hiroshi; Morris, John C.; Perrin, Richard J.; Preische, Oliver; Schofield, Peter R.; Suárez-Calvet, Marc; Xiong, Chengjie; Scheltens, Philip; Teunissen, Charlotte E.; Visser, Pieter Jelle; Bateman, Randall J.; Benzinger, Tammie L. S.; Fagan, Anne M.; Gordon, Brian A.; Tijms, Betty M.; Pathology and Laboratory Medicine, School of MedicineThe grey matter of the brain develops and declines in coordinated patterns during the lifespan. Such covariation patterns of grey matter structure can be quantified as grey matter networks, which can be measured with magnetic resonance imaging. In Alzheimer's disease, the global organization of grey matter networks becomes more random, which is captured by a decline in the small-world coefficient. Such decline in the small-world value has been robustly associated with cognitive decline across clinical stages of Alzheimer's disease. The biological mechanisms causing this decline in small-world values remain unknown. Cerebrospinal fluid (CSF) protein biomarkers are available for studying diverse pathological mechanisms in humans and can provide insight into decline. We investigated the relationships between 10 CSF proteins and small-world coefficient in mutation carriers (N = 219) and non-carriers (N = 136) of the Dominantly Inherited Alzheimer Network Observational study. Abnormalities in Amyloid beta, Tau, synaptic (Synaptosome associated protein-25, Neurogranin) and neuronal calcium-sensor protein (Visinin-like protein-1) preceded loss of small-world coefficient by several years, while increased levels in CSF markers for inflammation (Chitinase-3-like protein 1) and axonal injury (Neurofilament light) co-occurred with decreasing small-world values. This suggests that axonal loss and inflammation play a role in structural grey matter network changes.Item BDNF Val66Met moderates memory impairment, hippocampal function and tau in preclinical autosomal dominant Alzheimer’s disease(Oxford, 2016-10) Lim, Yen Ying; Hassenstab, Jason; Cruchaga, Carlos; Goate, Alison; Fagan, Anne M.; Benzinger, Tammie L. S.; Maruff, Paul; Snyder, Peter J.; Masters, Colin L.; Allegri, Ricardo; Chhatwal, Jasmeer; Farlow, Martin R.; Graff-Radford, Neill R.; Laske, Christoph; Levin, Johannes; McDade, Eric; Ringman, John M.; Rossor, Martin N.; Salloway, Stephen; Schofield, Peter R.; Holtzman, David M.; Morris, John C.; Bateman, Randall J.; Department of Neurology, IU School of MedicineThe brain-derived neurotrophic factor ( BDNF ) Val66Met polymorphism is implicated in synaptic excitation and neuronal integrity, and has previously been shown to moderate amyloid-β-related memory decline and hippocampal atrophy in preclinical sporadic Alzheimer’s disease. However, the effect of BDNF in autosomal dominant Alzheimer’s disease is unknown. We aimed to determine the effect of BDNF Val66Met on cognitive function, hippocampal function, tau and amyloid-β in preclinical autosomal dominant Alzheimer’s disease. We explored effects of apolipoprotein E ( APOE ) ε4 on these relationships. The Dominantly Inherited Alzheimer Network conducted clinical, neuropsychological, genetic, biomarker and neuroimaging measures at baseline in 131 mutation non-carriers and 143 preclinical autosomal dominant Alzheimer’s disease mutation carriers on average 12 years before clinical symptom onset. BDNF genotype data were obtained for mutation carriers (95 Val 66 homozygotes, 48 Met 66 carriers). Among preclinical mutation carriers, Met 66 carriers had worse memory performance, lower hippocampal glucose metabolism and increased levels of cerebrospinal fluid tau and phosphorylated tau (p-tau) than Val 66 homozygotes. Cortical amyloid-β and cerebrospinal fluid amyloid-β 42 levels were significantly different from non-carriers but did not differ between preclinical mutation carrier Val 66 homozygotes and Met 66 carriers. There was an effect of APOE on amyloid-β levels, but not cognitive function, glucose metabolism or tau. As in sporadic Alzheimer’s disease, the deleterious effects of amyloid-β on memory, hippocampal function, and tau in preclinical autosomal dominant Alzheimer’s disease mutation carriers are greater in Met 66 carriers. To date, this is the only genetic factor found to moderate downstream effects of amyloid-β in autosomal dominant Alzheimer’s disease.Item Decreased body mass index in the preclinical stage of autosomal dominant Alzheimer's disease(SpringerNature, 2017-04-27) Müller, Stephan; Preische, Oliver; Sohrabi, Hamid R.; Gräber, Susanne; Jucker, Mathias; Dietzsch, Janko; Ringman, Ralph N.; Martins, Ralph N.; McDade, Eric; Schofield, Peter R.; Ghetti, Bernardino; Rossor, Martin; Graff-Radford, Neill R.; Levin, Johannes; Galasko, Douglas; Quaid, Kimberly A.; Salloway, Stephen; Xiong, Chengjie; Benzinger, Tammie; Buckles, Virginia; Masters, Colin L.; Sperling, Reisa; Bateman, Randall J.; Morris, John C.; Laske, Christoph; Department of Pathology and Laboratory Medicine, School of MedicineThe relationship between body-mass index (BMI) and Alzheimer´s disease (AD) has been extensively investigated. However, BMI alterations in preclinical individuals with autosomal dominant AD (ADAD) have not yet been investigated. We analyzed cross-sectional data from 230 asymptomatic members of families with ADAD participating in the Dominantly Inherited Alzheimer Network (DIAN) study including 120 preclinical mutation carriers (MCs) and 110 asymptomatic non-carriers (NCs). Differences in BMI and their relation with cerebral amyloid load and episodic memory as a function of estimated years to symptom onset (EYO) were analyzed. Preclinical MCs showed significantly lower BMIs compared to NCs, starting 11.2 years before expected symptom onset. However, the BMI curves begun to diverge already at 17.8 years before expected symptom onset. Lower BMI in preclinical MCs was significantly associated with less years before estimated symptom onset, higher global Aβ brain burden, and with lower delayed total recall scores in the logical memory test. The study provides cross-sectional evidence that weight loss starts one to two decades before expected symptom onset of ADAD. Our findings point toward a link between the pathophysiology of ADAD and disturbance of weight control mechanisms. Longitudinal follow-up studies are warranted to investigate BMI changes over time.Item Diagnostic Value of Subjective Memory Complaints Assessed with a Single Item in Dominantly Inherited Alzheimer’s Disease: Results of the DIAN Study(Hindawi, 2015) Laske, Christoph; Sohrabi, Hamid R.; Jasielec, Mateusz S.; Müller, Stephan; Koehler, Niklas K.; Gräber, Susanne; Förster, Stefan; Drzezga, Alexander; Mueller-Sarnowski, Felix; Danek, Adrian; Jucker, Mathias; Bateman, Randall J.; Buckles, Virginia; Saykin, Andrew J.; Martins, Ralph N.; Morris, John C.; Indiana Alzheimer Disease Center, Indiana University School of MedicineObjective. We examined the diagnostic value of subjective memory complaints (SMCs) assessed with a single item in a large cross-sectional cohort consisting of families with autosomal dominant Alzheimer’s disease (ADAD) participating in the Dominantly Inherited Alzheimer Network (DIAN). Methods. The baseline sample of 183 mutation carriers (MCs) and 117 noncarriers (NCs) was divided according to Clinical Dementia Rating (CDR) scale into preclinical (CDR 0; MCs: ; NCs: ), early symptomatic (CDR 0.5; MCs: ; NCs: ), and dementia stage (CDR ≥ 1; MCs: ; NCs: ). These groups were subdivided by the presence or absence of SMCs. Results. At CDR 0, SMCs were present in 12.1% of MCs and 9.2% of NCs . At CDR 0.5, SMCs were present in 66.7% of MCs and 62.5% of NCs . At CDR ≥ 1, SMCs were present in 96.4% of MCs. SMCs in MCs were significantly associated with CDR, logical memory scores, Geriatric Depression Scale, education, and estimated years to onset. Conclusions. The present study shows that SMCs assessed by a single-item scale have no diagnostic value to identify preclinical ADAD in asymptomatic individuals. These results demonstrate the need of further improvement of SMC measures that should be examined in large clinical trials.Item Effect of BDNFVal66Met on disease markers in dominantly inherited Alzheimer's disease(Wiley, 2018-09) Lim, Yen Ying; Hassenstab, Jason; Goate, Alison; Fagan, Anne M.; Benzinger, Tammie L.S.; Cruchaga, Carlos; McDade, Eric; Chhatwal, Jasmeer; Levin, Johannes; Farlow, Martin R.; GraffRadford, Neill R.; Laske, Christoph; Masters, Colin L; Salloway, Stephen; Schofield, Peter; Morris, John C.; Maruff, Paul; Bateman, Randall J.; Neurology, School of MedicineOBJECTIVE: Previous studies suggest that the brain-derived neurotrophic factor (BDNF) Val66Met (rs6265) polymorphism may influence symptom onset in Alzheimer's disease (AD). Our recent cross-sectional findings suggest that Met66 may influence clinical expression in dominantly inherited AD (DIAD) through its effects on tau. However, it remains unclear whether carriage of Met66 in DIAD results in faster increases in cerebrospinal fluid (CSF) tau and ptau181 , and whether these increases are associated with accelerated brain volume loss and memory decline. METHODS: A total of 211 subjects (101 mutation noncarriers, 110 mutation carriers), who were cognitively normal, as defined by a Clinical Dementia Rating global score of 0, completed assessments of cognitive function, neuroimaging, and CSF sampling over 3.5 years as part of the Dominantly Inherited Alzheimer's Network. RESULTS: In mutation carriers, Met66 carriers showed faster memory decline (4×), hippocampal volume loss (16×), and CSF tau and ptau181 increases (6×) than Val66 homozygotes. BDNF did not influence rates of cortical β-amyloid accumulation or change in CSF Aβ42 levels in mutation carriers. In mutation noncarriers, BDNF genotype had no effect on change in cognition, brain volume, cortical β-amyloid accumulation, or change in any CSF measures of tau, ptau181 , and CSF Aβ42 . INTERPRETATION: As in sporadic AD, the deleterious effects of β-amyloid on cognitive function, brain volume loss, and CSF tau in DIAD mutation carriers are less in Val66 homozygotes. The BDNF Val66Met polymorphism should be considered as a potential moderator of clinical trial outcomes in current treatment and prevention trials in DIAD and sporadic AD. Ann Neurol 2018;84:424-435.Item Guidelines for the standardization of preanalytic variables for blood-based biomarker studies in Alzheimer's disease research(Elsevier, 2015-05) O’Bryant, Sid E.; Gupta, Veer; Henriksen, Kim; Edwards, Melissa; Jeromin, Andreas; Lista, Simone; Bazenet, Chantal; Soares, Holly; Lovestone, Simon; Hampel, Harald; Montine, Thomas; Blennow, Kaj; Foroud, Tatiana; Carrillo, Maria; Graff-Radford, Neill; Laske, Christoph; Breteler, Monique; Shaw, Leslie; Trojanowski, John Q.; Schupf, Nicole; Rissman, Robert A.; Fagan, Anne M.; Oberoi, Pankaj; Umek, Robert; Weiner, Michael W.; Grammas, Paul; Posner, Holly; Martins, Ralph; Department of Medical & Molecular Genetics, IU School of MedicineThe lack of readily available biomarkers is a significant hindrance towards progressing to effective therapeutic and preventative strategies for Alzheimer’s disease (AD). Blood-based biomarkers have potential to overcome access and cost barriers and greatly facilitate advanced neuroimaging and cerebrospinal fluid biomarker approaches. Despite the fact that preanalytical processing is the largest source of variability in laboratory testing, there are no currently available standardized preanalytical guidelines. The current international working group provides the initial starting point for such guidelines for standardized operating procedures (SOPs). It is anticipated that these guidelines will be updated as additional research findings become available. The statement provides (1) a synopsis of selected preanalytical methods utilized in many international AD cohort studies, (2) initial draft guidelines/SOPs for preanalytical methods, and (3) a list of required methodological information and protocols to be made available for publications in the field in order to foster cross-validation across cohorts and laboratories.Item Longitudinal Accumulation of Cerebral Microhemorrhages in Dominantly Inherited Alzheimer Disease(American Academy of Neurology, 2021-03-23) Joseph-Mathurin, Nelly; Wang, Guoqiao; Kantarci, Kejal; Jack, Clifford R., Jr.; McDade, Eric; Hassenstab, Jason; Blazey, Tyler M.; Gordon, Brian A.; Su, Yi; Chen, Gengsheng; Massoumzadeh, Parinaz; Hornbeck, Russ C.; Allegri, Ricardo F.; Ances, Beau M.; Berman, Sarah B.; Brickman, Adam M.; Brooks, William S.; Cash, David M.; Chhatwal, Jasmeer P.; Chui, Helena C.; Correia, Stephen; Cruchaga, Carlos; Farlow, Martin R.; Fox, Nick C.; Fulham, Michael; Ghetti, Bernardino; Graff-Radford, Neill R.; Johnson, Keith A.; Karch, Celeste M.; Laske, Christoph; Lee, Athene K.W.; Levin, Johannes; Masters, Colin L.; Noble, James M.; O’Connor, Antoinette; Perrin, Richard J.; Preboske, Gregory M.; Ringman, John M.; Rowe, Christopher C.; Salloway, Stephen; Saykin, Andrew J.; Schofield, Peter R.; Shimada, Hiroyuki; Shoji, Mikio; Suzuki, Kazushi; Villemagne, Victor L.; Xiong, Chengjie; Yakushev, Igor; Morris, John C.; Bateman, Randall J.; Benzinger, Tammie L.S.; Pathology and Laboratory Medicine, School of MedicineObjective: To investigate the inherent clinical risks associated with the presence of cerebral microhemorrhages (CMHs) or cerebral microbleeds and characterize individuals at high risk for developing hemorrhagic amyloid-related imaging abnormality (ARIA-H), we longitudinally evaluated families with dominantly inherited Alzheimer disease (DIAD). Methods: Mutation carriers (n = 310) and noncarriers (n = 201) underwent neuroimaging, including gradient echo MRI sequences to detect CMHs, and neuropsychological and clinical assessments. Cross-sectional and longitudinal analyses evaluated relationships between CMHs and neuroimaging and clinical markers of disease. Results: Three percent of noncarriers and 8% of carriers developed CMHs primarily located in lobar areas. Carriers with CMHs were older, had higher diastolic blood pressure and Hachinski ischemic scores, and more clinical, cognitive, and motor impairments than those without CMHs. APOE ε4 status was not associated with the prevalence or incidence of CMHs. Prevalent or incident CMHs predicted faster change in Clinical Dementia Rating although not composite cognitive measure, cortical thickness, hippocampal volume, or white matter lesions. Critically, the presence of 2 or more CMHs was associated with a significant risk for development of additional CMHs over time (8.95 ± 10.04 per year). Conclusion: Our study highlights factors associated with the development of CMHs in individuals with DIAD. CMHs are a part of the underlying disease process in DIAD and are significantly associated with dementia. This highlights that in participants in treatment trials exposed to drugs, which carry the risk of ARIA-H as a complication, it may be challenging to separate natural incidence of CMHs from drug-related CMHs.Item Pattern and implications of neurological examination findings in autosomal dominant Alzheimer disease(Wiley, 2023) Vöglein, Jonathan; Franzmeier, Nicolai; Morris, John C.; Dieterich, Marianne; McDade, Eric; Simons, Mikael; Preische, Oliver; Hofmann, Anna; Hassenstab, Jason; Benzinger, Tammie L.; Fagan, Anne; Noble, James M.; Berman, Sarah B.; Graff-Radford, Neill R.; Ghetti, Bernardino; Farlow, Martin R.; Chhatwal, Jasmeer P.; Salloway, Stephen; Xiong, Chengjie; Karch, Celeste M.; Cairns, Nigel; Perrin, Richard J.; Day, Gregory; Martins, Ralph; Sanchez-Valle, Raquel; Mori, Hiroshi; Shimada, Hiroyuki; Ikeuchi, Takeshi; Suzuki, Kazushi; Schofield, Peter R.; Masters, Colin L.; Goate, Alison; Buckles, Virginia; Fox, Nick C.; Chrem, Patricio; Allegri, Ricardo; Ringman, John M.; Yakushev, Igor; Laske, Christoph; Jucker, Mathias; Höglinger, Günter; Bateman, Randall J.; Danek, Adrian; Levin, Johannes; Dominantly Inherited Alzheimer Network; Pathology and Laboratory Medicine, School of MedicineIntroduction: As knowledge about neurological examination findings in autosomal dominant Alzheimer disease (ADAD) is incomplete, we aimed to determine the frequency and significance of neurological examination findings in ADAD. Methods: Frequencies of neurological examination findings were compared between symptomatic mutation carriers and non mutation carriers from the Dominantly Inherited Alzheimer Network (DIAN) to define AD neurological examination findings. AD neurological examination findings were analyzed regarding frequency, association with and predictive value regarding cognitive decline, and association with brain atrophy in symptomatic mutation carriers. Results: AD neurological examination findings included abnormal deep tendon reflexes, gait disturbance, pathological cranial nerve examination findings, tremor, abnormal finger to nose and heel to shin testing, and compromised motor strength. The frequency of AD neurological examination findings was 65.1%. Cross-sectionally, mutation carriers with AD neurological examination findings showed a more than two-fold faster cognitive decline and had greater parieto-temporal atrophy, including hippocampal atrophy. Longitudinally, AD neurological examination findings predicted a significantly greater decline over time. Discussion: ADAD features a distinct pattern of neurological examination findings that is useful to estimate prognosis and may inform clinical care and therapeutic trial designs.Item Preferential degradation of cognitive networks differentiates Alzheimer's disease from ageing(Oxford University Press, 2018-05-01) Chhatwal, Jasmeer P.; Schultz, Aaron P.; Johnson, Keith A.; Hedden, Trey; Jaimes, Sehily; Benzinger, Tammie L S.; Jack, Clifford; Ances, Beau M.; Ringman, John M.; Marcus, Daniel S.; Ghetti, Bernardino; Farlow, Martin R.; Danek, Adrian; Levin, Johannes; Yakushev, Igor; Laske, Christoph; Koeppe, Robert A.; Galasko, Douglas R.; Xiong, Chengjie; Masters, Colin L.; Schofield, Peter R.; Kinnunen, Kirsi M.; Salloway, Stephen; Martins, Ralph N.; McDade, Eric; Cairns, Nigel J.; Buckles, Virginia D.; Morris, John C.; Bateman, Randall; Sperling, Reisa A.; Pathology and Laboratory Medicine, School of MedicineConverging evidence from structural, metabolic and functional connectivity MRI suggests that neurodegenerative diseases, such as Alzheimer's disease, target specific neural networks. However, age-related network changes commonly co-occur with neuropathological cascades, limiting efforts to disentangle disease-specific alterations in network function from those associated with normal ageing. Here we elucidate the differential effects of ageing and Alzheimer's disease pathology through simultaneous analyses of two functional connectivity MRI datasets: (i) young participants harbouring highly-penetrant mutations leading to autosomal-dominant Alzheimer's disease from the Dominantly Inherited Alzheimer's Network (DIAN), an Alzheimer's disease cohort in which age-related comorbidities are minimal and likelihood of progression along an Alzheimer's disease trajectory is extremely high; and (ii) young and elderly participants from the Harvard Aging Brain Study, a cohort in which imaging biomarkers of amyloid burden and neurodegeneration can be used to disambiguate ageing alone from preclinical Alzheimer's disease. Consonant with prior reports, we observed the preferential degradation of cognitive (especially the default and dorsal attention networks) over motor and sensory networks in early autosomal-dominant Alzheimer's disease, and found that this distinctive degradation pattern was magnified in more advanced stages of disease. Importantly, a nascent form of the pattern observed across the autosomal-dominant Alzheimer's disease spectrum was also detectable in clinically normal elderly with clear biomarker evidence of Alzheimer's disease pathology (preclinical Alzheimer's disease). At the more granular level of individual connections between node pairs, we observed that connections within cognitive networks were preferentially targeted in Alzheimer's disease (with between network connections relatively spared), and that connections between positively coupled nodes (correlations) were preferentially degraded as compared to connections between negatively coupled nodes (anti-correlations). In contrast, ageing in the absence of Alzheimer's disease biomarkers was characterized by a far less network-specific degradation across cognitive and sensory networks, of between- and within-network connections, and of connections between positively and negatively coupled nodes. We go on to demonstrate that formalizing the differential patterns of network degradation in ageing and Alzheimer's disease may have the practical benefit of yielding connectivity measurements that highlight early Alzheimer's disease-related connectivity changes over those due to age-related processes. Together, the contrasting patterns of connectivity in Alzheimer's disease and ageing add to prior work arguing against Alzheimer's disease as a form of accelerated ageing, and suggest multi-network composite functional connectivity MRI metrics may be useful in the detection of early Alzheimer's disease-specific alterations co-occurring with age-related connectivity changes. More broadly, our findings are consistent with a specific pattern of network degradation associated with the spreading of Alzheimer's disease pathology within targeted neural networks.