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1.
N Engl J Med ; 388(1): 9-21, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-36449413

RESUMEN

BACKGROUND: The accumulation of soluble and insoluble aggregated amyloid-beta (Aß) may initiate or potentiate pathologic processes in Alzheimer's disease. Lecanemab, a humanized IgG1 monoclonal antibody that binds with high affinity to Aß soluble protofibrils, is being tested in persons with early Alzheimer's disease. METHODS: We conducted an 18-month, multicenter, double-blind, phase 3 trial involving persons 50 to 90 years of age with early Alzheimer's disease (mild cognitive impairment or mild dementia due to Alzheimer's disease) with evidence of amyloid on positron-emission tomography (PET) or by cerebrospinal fluid testing. Participants were randomly assigned in a 1:1 ratio to receive intravenous lecanemab (10 mg per kilogram of body weight every 2 weeks) or placebo. The primary end point was the change from baseline at 18 months in the score on the Clinical Dementia Rating-Sum of Boxes (CDR-SB; range, 0 to 18, with higher scores indicating greater impairment). Key secondary end points were the change in amyloid burden on PET, the score on the 14-item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog14; range, 0 to 90; higher scores indicate greater impairment), the Alzheimer's Disease Composite Score (ADCOMS; range, 0 to 1.97; higher scores indicate greater impairment), and the score on the Alzheimer's Disease Cooperative Study-Activities of Daily Living Scale for Mild Cognitive Impairment (ADCS-MCI-ADL; range, 0 to 53; lower scores indicate greater impairment). RESULTS: A total of 1795 participants were enrolled, with 898 assigned to receive lecanemab and 897 to receive placebo. The mean CDR-SB score at baseline was approximately 3.2 in both groups. The adjusted least-squares mean change from baseline at 18 months was 1.21 with lecanemab and 1.66 with placebo (difference, -0.45; 95% confidence interval [CI], -0.67 to -0.23; P<0.001). In a substudy involving 698 participants, there were greater reductions in brain amyloid burden with lecanemab than with placebo (difference, -59.1 centiloids; 95% CI, -62.6 to -55.6). Other mean differences between the two groups in the change from baseline favoring lecanemab were as follows: for the ADAS-cog14 score, -1.44 (95% CI, -2.27 to -0.61; P<0.001); for the ADCOMS, -0.050 (95% CI, -0.074 to -0.027; P<0.001); and for the ADCS-MCI-ADL score, 2.0 (95% CI, 1.2 to 2.8; P<0.001). Lecanemab resulted in infusion-related reactions in 26.4% of the participants and amyloid-related imaging abnormalities with edema or effusions in 12.6%. CONCLUSIONS: Lecanemab reduced markers of amyloid in early Alzheimer's disease and resulted in moderately less decline on measures of cognition and function than placebo at 18 months but was associated with adverse events. Longer trials are warranted to determine the efficacy and safety of lecanemab in early Alzheimer's disease. (Funded by Eisai and Biogen; Clarity AD ClinicalTrials.gov number, NCT03887455.).


Asunto(s)
Enfermedad de Alzheimer , Anticuerpos Monoclonales Humanizados , Nootrópicos , Humanos , Actividades Cotidianas , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/líquido cefalorraquídeo , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Cognición/efectos de los fármacos , Método Doble Ciego , Nootrópicos/efectos adversos , Nootrópicos/farmacología , Nootrópicos/uso terapéutico
2.
Mov Disord ; 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38597193

RESUMEN

BACKGROUND: While preclinical studies have shown that alpha-synuclein can spread through cell-to-cell transmission whether it can be transmitted between humans is unknown. OBJECTIVES: The aim was to assess the presence of a synucleinopathy in autopsied conjugal couples. METHODS: Neuropathological findings in conjugal couples were categorized as Parkinson's disease (PD), dementia with Lewy bodies (DLB), Alzheimer's disease with Lewy bodies (ADLB), incidental Lewy body disease (ILBD), or no Lewy bodies. RESULTS: Ninety conjugal couples were included; the mean age of death was 88.3 years; 32 couples had no Lewy bodies; 42 couples had 1 spouse with a synucleinopathy: 10 PD, 3 DLB, 13 ADLB, and 16 ILBD; 16 couples had both spouses with a synucleinopathy: in 4 couples both spouses had PD, 1 couple had PD and DLB, 4 couples had PD and ADLB, 2 couples had PD and ILBD, 1 couple had DLB and ADLB, in 3 couples both had ADLB, and 1 couple had ADLB and ILBD. No couples had both spouses with ILBD. CONCLUSIONS: This large series of 90 autopsied conjugal couples found 16 conjugal couples with synucleinopathies, suggesting transmission of synucleinopathy between spouses is unlikely. © 2024 International Parkinson and Movement Disorder Society.

3.
Alzheimer Dis Assoc Disord ; 38(1): 8-13, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38277642

RESUMEN

OBJECTIVE: To assess the value of rescreening patients with Alzheimer's disease who do not meet the inclusion criteria for the Repeatable Battery for the Assessment of Neuropsychological Status Delayed Memory Index (RBANS DMI) at the initial assessment. PATIENTS AND METHODS: Participants (aged 50-85 years, without dementia, Mini-Mental State Examination score ≥22, valid Clinical Dementia Rating [CDR] global score, and amyloid status at baseline) were identified in the European Prevention of Alzheimer's Dementia database. Changes from baseline in RBANS DMI were estimated using a mixed model for repeated measurements. Logistic regressions were used to estimate the probability of participants with baseline RBANS DMI 86-95 having RBANS DMI ≤85, CDR global score ≥0.5, and amyloid positivity at 6 and 12 months. RESULTS: There was significant variability in the change in RBANS DMI scores over time (median change at 6 months: 2.0). An estimated 15% of participants with RBANS DMI 86-95 at baseline progressed to ≤85 at 6 months; 8% also achieved CDR global score ≥0.5 and 5% were also amyloid positive. CONCLUSIONS: The results from our analysis indicate that there is limited value in rescreening patients based on their initial RBANS DMI score.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Pruebas Neuropsicológicas , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/psicología , Proteínas Amiloidogénicas , Represión Psicológica
4.
Alzheimers Dement ; 20(1): 549-562, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37740924

RESUMEN

INTRODUCTION: The National Institute on Aging - Alzheimer's Association (NIA-AA) ATN research framework proposes to use biomarkers for amyloid (A), tau (T), and neurodegeneration (N) to stage individuals with AD pathological features and track changes longitudinally. The overall aim was to utilize this framework to characterize pre-mortem ATN status longitudinally in a clinically diagnosed cohort of dementia with Lewy bodies (DLB) and to correlate it with the post mortem diagnosis. METHODS: The cohort was subtyped by cerebrospinal fluid (CSF) ATN category. A subcohort had longitudinal data, and a subgroup was neuropathologically evaluated. RESULTS: We observed a significant difference in Aß42/40 after 12 months in the A+T- group. Post mortem neuropathologic analyses indicated that most of the p-Tau 181 positive (T+) cases also had a high Braak stage. DISCUSSION: This suggests that DLB patients who are A+ but T- may need to be monitored to determine whether they remain A+ or ever progress to T positivity. HIGHLIGHTS: Some A+T- DLB subjects transition from A+ to negative after 12-months. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Monitoring of the A+T- sub-type of DLB may be necessary.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad por Cuerpos de Lewy , Humanos , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad por Cuerpos de Lewy/diagnóstico , Enfermedad por Cuerpos de Lewy/líquido cefalorraquídeo , Péptidos beta-Amiloides/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Fragmentos de Péptidos/líquido cefalorraquídeo
5.
Expert Opin Emerg Drugs ; 28(4): 311-332, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38100555

RESUMEN

INTRODUCTION: Despite the recent full FDA approval of lecanemab, there is currently no disease modifying therapy (DMT) that can efficiently slow down the progression of Alzheimer's disease (AD) in the general population. This statement emphasizes the need to identify novel DMTs in the shortest time possible to prevent a global epidemic of AD cases as the world population experiences an increase in lifespan. AREAS COVERED: Here, we review several classes of anti-cancer drugs that have been or are being investigated in Phase II/III clinical trials for AD, including immunomodulatory drugs, RXR agonists, sex hormone therapies, tyrosine kinase inhibitors, and monoclonal antibodies. EXPERT OPINION: Given the overall course of brain pathologies during the progression of AD, we express a great enthusiasm for the repositioning of anti-cancer drugs as possible AD DMTs. We anticipate an increasing number of combinatorial therapy strategies to tackle AD symptoms and their underlying pathologies. However, we strongly encourage improvements in clinical trial study designs to better assess target engagement and possible efficacy over sufficient periods of drug exposure.


Asunto(s)
Enfermedad de Alzheimer , Antineoplásicos , Reposicionamiento de Medicamentos , Humanos , Enfermedad de Alzheimer/tratamiento farmacológico , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico
6.
Alzheimer Dis Assoc Disord ; 37(4): 290-295, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37695107

RESUMEN

BACKGROUND: A once-weekly donepezil transdermal delivery system (TDS; Adlarity; Corium, LLC) is indicated for the treatment of mild, moderate, and severe dementia of the Alzheimer type. METHODS: In this placebo-controlled, randomized, double-blind phase 1 trial, healthy volunteers aged 40 years or older were randomized to receive a placebo and donepezil TDS and were evaluated for the primary endpoints of skin irritation and sensitization potential. Skin irritation was scored. RESULTS: Two hundred fifty-six participants were randomized and received ≥1 dose of any treatment. After the first weekly TDS application, no skin irritation or minimal irritation was evident between donepezil and placebo TDSs. At the third weekly TDS application, for donepezil TDS, the average of the mean combined skin irritation score was 0.55 of a possible maximum of 7, indicating none to minimal skin irritation, and for placebo, the score was 0.19, indicating no skin irritation. Of 198 participants, 4 (2.0%) were considered potentially sensitized to donepezil TDS, and 0 were potentially sensitized to placebo TDS. CONCLUSION: Once-weekly 5-mg/d donepezil TDS demonstrated minimal skin irritation under conditions of use of 3 consecutive weekly patch applications to the same skin site and minimal sensitization potential.


Asunto(s)
Enfermedad de Alzheimer , Piel , Humanos , Donepezilo/uso terapéutico , Administración Cutánea , Método Doble Ciego , Voluntarios Sanos , Enfermedad de Alzheimer/tratamiento farmacológico , Inhibidores de la Colinesterasa/uso terapéutico
7.
Int J Psychiatry Clin Pract ; 27(1): 69-81, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35574992

RESUMEN

Dementia due to Parkinson's disease and Alzheimer's disease are associated with behavioural and psychological symptoms, including psychosis. Long-term management presents a challenge for health care providers and caregivers. Symptoms of psychosis include hallucinations and delusions; if untreated, these can lead to institutionalisation, decreased quality of life, and significant patient and caregiver distress. A critical step in the effective management of dementia-related psychosis (DRP) is the identification and diagnosis of affected patients. The lack of a standardised diagnostic approach presents a barrier to treatment and there are no consensus guidelines for DRP. Furthermore, there are no approved therapies for the treatment of DRP. Antipsychotic medications are often prescribed off-label, even though some are associated with an increased risk of adverse events or mortality. We present currently available screening tools and guidelines for the diagnosis and treatment of Parkinson's disease psychosis and DRP in the context of what is needed for effective management of psychosis.KEY POINTSWe present currently available screening tools and guidelines for Parkinson's disease psychosis and dementia-related psychosis, and discuss the unmet need for simple clinical diagnostic tools and treatment guidelines.The identification of psychosis is variable across different settings and specialties, without a unified approach to screening, definition, or diagnosis.Currently used tools for defining and assessing psychosis in a research setting are usually too cumbersome for everyday clinical practice.The development of a standardised set of diagnostic criteria would provide clinicians the opportunity to improve the detection, treatment, and quality of life of patients and their caregivers.


Asunto(s)
Enfermedad de Alzheimer , Antipsicóticos , Enfermedad de Parkinson , Trastornos Psicóticos , Humanos , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/terapia , Calidad de Vida , Piperidinas/efectos adversos , Urea/efectos adversos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/etiología , Trastornos Psicóticos/terapia , Enfermedad de Alzheimer/tratamiento farmacológico , Antipsicóticos/efectos adversos
8.
J Magn Reson Imaging ; 56(6): 1845-1862, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35319142

RESUMEN

BACKGROUND: Advanced diffusion-based MRI biomarkers may provide insight into microstructural and perfusion changes associated with neurodegeneration and cognitive decline. PURPOSE: To assess longitudinal microstructural and perfusion changes using apparent diffusion coefficient (ADC) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) parameters in cognitively impaired (CI) and healthy control (HC) groups. STUDY TYPE: Prospective/longitudinal. POPULATION: Twelve CI patients (75% female) and 13 HC subjects (69% female). FIELD STRENGTH/SEQUENCE: 3 T; Spin-Echo-IVIM-DWI. ASSESSMENT: Two MRI scans were performed with a 12-month interval. ADC and IVIM-DWI metrics (diffusion coefficient [D] and perfusion fraction [f]) were generated from monoexponential and biexponential fits, respectively. Additionally, voxel-based correlations were evaluated between change in Montreal Cognitive Assessment (ΔMoCA) and baseline imaging parameters. STATISTICAL TESTS: Analysis of covariance with sex and age as covariates was performed for main effects of group and time (false discovery rate [FDR] corrected) with post hoc comparisons using Bonferroni correction. Partial-η2 and Hedges' g were used for effect-size analysis. Spearman's correlations (FDR corrected) were used for the relationship between ΔMoCA score and imaging. P < 0.05 was considered statistically significant. RESULTS: Significant differences were found for the main effects of group (HC vs. CI) and time. For group effects, higher ADC, IVIM-D, and IVIM-f were observed in the CI group compared to HC (ADC: 1.23 ± 0.08. 10-3 vs. 1.09 ± 0.07. 10-3  mm2 /sec; IVIM-D: 0.82 ± 0.01. 10-3 vs. 0.73 ± 0.01. 10-3  mm2 /sec; and IVIM-f: 0.317 ± 0.008 vs. 0.253 ± 0.009). Significantly higher ADC, IVIM-D, and IVIM-f values were observed in the CI group after 12 months (ADC: 1.45 ± 0.05. 10-3 vs. 1.50 ± 0.07. 10-3  mm2 /sec; IVIM-D: 0.87 ± 0.01. 10-3 vs. 0.94 ± 0.02. 10-3  mm2 /sec; and IVIM-f: 0.303 ± 0.007 vs. 0.332 ± 0.008), but not in the HC group at large effect size. ADC, IVIM-D, and IVIM-f negatively correlated with ΔMoCA score (ρ = -0.49, -0.51, and -0.50, respectively). DATA CONCLUSION: These findings demonstrate that longitudinal differences between CI and HC cohorts can be measured using IVIM-based metrics. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.


Asunto(s)
Disfunción Cognitiva , Imagen de Difusión por Resonancia Magnética , Humanos , Femenino , Masculino , Estudios Prospectivos , Imagen de Difusión por Resonancia Magnética/métodos , Movimiento (Física) , Perfusión , Disfunción Cognitiva/diagnóstico por imagen
9.
Brain ; 144(9): 2837-2851, 2021 10 22.
Artículo en Inglés | MEDLINE | ID: mdl-33905474

RESUMEN

Because of its involvement in a wide variety of cardiovascular, metabolic and behavioural functions, the hypothalamus constitutes a potential target for neuromodulation in a number of treatment-refractory conditions. The precise neural substrates and circuitry subserving these responses, however, are poorly characterized to date. We sought to retrospectively explore the acute sequelae of hypothalamic region deep brain stimulation and characterize their neuroanatomical correlates. To this end we studied-at multiple international centres-58 patients (mean age: 68.5 ± 7.9 years, 26 females) suffering from mild Alzheimer's disease who underwent stimulation of the fornix region between 2007 and 2019. We catalogued the diverse spectrum of acutely induced clinical responses during electrical stimulation and interrogated their neural substrates using volume of tissue activated modelling, voxel-wise mapping, and supervised machine learning techniques. In total 627 acute clinical responses to stimulation-including tachycardia, hypertension, flushing, sweating, warmth, coldness, nausea, phosphenes, and fear-were recorded and catalogued across patients using standard descriptive methods. The most common manifestations during hypothalamic region stimulation were tachycardia (30.9%) and warmth (24.6%) followed by flushing (9.1%) and hypertension (6.9%). Voxel-wise mapping identified distinct, locally separable clusters for all sequelae that could be mapped to specific hypothalamic and extrahypothalamic grey and white matter structures. K-nearest neighbour classification further validated the clinico-anatomical correlates emphasizing the functional importance of identified neural substrates with area under the receiving operating characteristic curves between 0.67 and 0.91. Overall, we were able to localize acute effects of hypothalamic region stimulation to distinct tracts and nuclei within the hypothalamus and the wider diencephalon providing clinico-anatomical insights that may help to guide future neuromodulation work.


Asunto(s)
Afecto/fisiología , Sistema Nervioso Autónomo/diagnóstico por imagen , Mapeo Encefálico/métodos , Cognición/fisiología , Estimulación Encefálica Profunda/métodos , Hipotálamo/diagnóstico por imagen , Anciano , Sistema Nervioso Autónomo/fisiología , Temperatura Corporal/fisiología , Electrodos Implantados , Femenino , Humanos , Hipotálamo/fisiología , Hipotálamo/cirugía , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Taquicardia/diagnóstico por imagen , Taquicardia/fisiopatología
10.
Aging Clin Exp Res ; 34(11): 2905-2909, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36031683

RESUMEN

The Alzheimer's Questionnaire (AQ) is an informant-based screening tool with good diagnostic accuracy for Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI). The aim of this study is to validate the AQ with AD-associated neuritic plaque (NP) and neurofibrillary tangle (NFT) pathology. Data from 205 prospectively followed autopsy cases clinically classified as AD (n = 90), aMCI (n = 42), or cognitively unimpaired (CU, n = 73) were used. Semi-quantitative measures of NP and NFT pathology were correlated with the AQ, Clinical Dementia Rating Sum of Boxes (CDR-SOB), and the Mini-Mental State Exam (MMSE). The AQ correlated significantly (p < 0.001) with NP load (r = 0.37) and NFT load (r = 0.57). The MMSE and CDR-SOB showed similar correlations with NP load (r = - 0.37, r = 0.35, respectively) and NFT load (r = - 0.58, r = 0.55, respectively). The AQ correlates well with NP and NFT pathology of AD, which provides additional confidence to clinicians using the AQ to screen for AD-related cognitive impairment.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Enfermedad de Alzheimer/diagnóstico , Pruebas de Estado Mental y Demencia , Disfunción Cognitiva/diagnóstico , Autopsia , Encuestas y Cuestionarios
11.
Alzheimers Dement ; 18(8): 1569-1579, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35026040

RESUMEN

INTRODUCTION: Few resources address steps clinicians can take to help patients reduce their risk of dementia, despite growing recognition that brain health can be optimized and that risk reduction for cognitive decline can be accomplished by lifestyle modifications. METHODS: To address this gap, UsAgainstAlzheimer's convened a risk reduction workgroup (RRWG) to review existing evidence and develop recommendations for primary care clinicians discussing cognitive decline and risk reduction with their patients.  RESULTS: The RRWG produced 11 consensus-based recommendations and implementation strategies across six topics: neurovascular risk management, physical activity, sleep, nutrition, social isolation, and cognitive stimulation.  DISCUSSION: These recommendations are a first step for clinicians to address brain health with patients and potentially help them prevent cognitive decline. To ensure there is routine care for brain health, proper incentives and policies must be instituted and more education for consumers should be provided.


Asunto(s)
Disfunción Cognitiva , Disfunción Cognitiva/prevención & control , Ejercicio Físico , Humanos , Estilo de Vida , Prevención Primaria , Conducta de Reducción del Riesgo
13.
N Engl J Med ; 388(17): 1631-1632, 2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37099355
14.
Curr Neurol Neurosci Rep ; 21(8): 39, 2021 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-34110536

RESUMEN

PURPOSE OF REVIEW: According to the amyloid cascade hypothesis, removing amyloid beta (Aß) should cure Alzheimer's disease (AD). In the past three decades, many agents have been tested to try to lower Aß production, prevent Aß aggregation, and dissolve Aß deposits. However, the paucity in definitive preventative or curative properties of these agents in clinical trials has resulted in more avant-garde approaches to therapeutic investigations. Immunotherapy has become an area of focus for research on disease-modifying therapies for neurodegenerative diseases. In this review, we highlight the current clinical development landscape of monoclonal antibody (mAb) therapies that target Aß plaque formation and removal in AD. RECENT FINDINGS: Multiple potential disease-modifying therapeutics for AD are in active development. Targeting Aß with mAbs has the potential to treat various stages of AD: prodromal, prodromal to mild, mild, and mild to moderate. Monoclonal antibodies discussed here include aducanumab, lecanemab, solanezumab, crenezumab, donanemab, and gantenerumab. The final decision by the FDA regarding the approval of aducanumab will offer valuable insight into the trajectory of drug development for mAbs in AD and other neurodegenerative diseases. Future directions for improving the treatment of AD will include more inquiry into the efficacy of mAbs as disease-modifying agents that specifically target Aß peptides and/or multimers. In addition, a more robust trial design for AD immunotherapy agents should improve outcomes such that objective measures of clinical efficacy will eventually lead to higher chances of drug approval.


Asunto(s)
Enfermedad de Alzheimer , Enfermedad de Alzheimer/tratamiento farmacológico , Amiloide , Péptidos beta-Amiloides , Anticuerpos Monoclonales/uso terapéutico , Humanos , Inmunoterapia
15.
Alzheimers Dement ; 17(5): 777-787, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33480187

RESUMEN

INTRODUCTION: Fornix deep brain stimulation (fx-DBS) is under investigation for treatment of Alzheimer's disease (AD). We investigated the anatomic correlates of flashback phenomena that were reported previously during acute diencephalic stimulation. METHODS: Thirty-nine patients with mild AD who took part in a prior fx-DBS trial (NCT01608061) were studied. After localizing patients' implanted electrodes and modeling the volume of tissue activated (VTA) by DBS during systematic stimulation testing, we performed (1) voxel-wise VTA mapping to identify flashback-associated zones; (2) machine learning-based prediction of flashback occurrence given VTA overlap with specific structures; (3) normative functional connectomics to define flashback-associated brain-wide networks. RESULTS: A distinct diencephalic region was associated with greater flashback likelihood. Fornix, bed nucleus of stria terminalis, and anterior commissure involvement predicted memory events with 72% accuracy. Flashback-inducing stimulation exhibited greater functional connectivity to a network of memory-evoking and autobiographical memory-related sites. DISCUSSION: These results clarify the neuroanatomical substrates of stimulation-evoked flashbacks.


Asunto(s)
Enfermedad de Alzheimer/terapia , Estimulación Encefálica Profunda , Fórnix , Memoria/fisiología , Anciano , Encéfalo , Femenino , Humanos , Aprendizaje Automático , Imagen por Resonancia Magnética , Masculino
16.
Mov Disord ; 35(5): 845-850, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32034933

RESUMEN

OBJECTIVE: There are few neuropathological studies on Parkinson's disease with mild cognitive impairment (PD-MCI). Those published reveal coexisting Lewy body and Alzheimer's disease pathology. Our objective is to determine the pathology that underlies PD-MCI. METHODS: We used data from the Arizona Study of Aging and Neurodegenerative Disorders, a longitudinal clinicopathological study. Of 736 autopsied subjects with standardized movement and cognitive assessments, 25 had PD-MCI. Neuropathological findings, including Lewy body and Alzheimer's disease pathology, were compared in PD subjects with amnestic MCI (A-MCI) and nonamnestic MCI (NA-MCI). RESULTS: Significant pathological heterogeneity within PD-MCI was found. This included varying Lewy body stages, Alzheimer's disease pathology, and cerebral amyloid angiopathy. There was a significant increase in the severity of Lewy body pathology (meeting The Unified Staging System for Lewy Body disorders neocortical stage) in nonamnestic MCI (7/1, 63%) when compared with amnestic MCI (3/14, 21%, P = 0.032). CONCLUSION: Although a small study, distinct pathological changes may contribute to PD-MCI phenotype. © 2020 International Parkinson and Movement Disorder Society.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad por Cuerpos de Lewy , Enfermedad de Parkinson , Disfunción Cognitiva/etiología , Humanos , Cuerpos de Lewy , Enfermedad por Cuerpos de Lewy/complicaciones , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/epidemiología
17.
J Magn Reson Imaging ; 52(6): 1811-1826, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32621405

RESUMEN

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease that affects aging populations. Current MRI techniques are often limited in their sensitivity to underlying neuropathological changes. PURPOSE: To characterize differences in voxel-based morphometry (VBM), apparent diffusion coefficient (ADC), and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) metrics in aging populations. Additionally, to investigate the connection between cognitive assessments and neuroimaging metrics. STUDY TYPE: Prospective/cross-sectional. POPULATION: In all, 49 subjects, including 13 with AD dementia, 12 with mild cognitive impairment (MCI), and 24 healthy controls (HC). FIELD STRENGTH/SEQUENCE: 3T/magnetization-prepared rapid acquisition gradient echo (MP-RAGE) and IVIM-DWI ASSESSMENT: All participants completed a cognitive screening battery prior to MRI. IVIM-DWI maps (pure diffusion coefficient [D], pseudodiffusion coefficient [D*], and perfusion fraction [f]) were generated from a biexponential fit of diffusion MRI data. VBM was performed on the standard T1 -weighted MP-RAGE structural images. Group-wise templates were used to compare across groups. STATISTICAL TESTS: Analysis of covariance (ANCOVA) with gender and age as covariates (familywise error [FWE] corrected, post-hoc comparisons using Bonferroni correction) for group comparisons. Partial-η2 and Hedges' g were used for effect-size analysis. Spearman's correlations (false discovery rate [FDR]-corrected) for the relationship between cognitive scores and imaging. RESULTS: Clusters of significant group-wise differences were found mainly in the temporal lobe, hippocampus, and amygdala using all VBM and IVIM methods (P < 0.05 FWE). While VBM showed significant changes between MCI and AD groups and between HC and AD groups, no significant clusters were observed between HC and MCI using VBM. ADC and IVIM-D demonstrated significant changes, at P < 0.05 FWE, between HC and MCI, notably in the amygdala and hippocampus. Several voxel-based correlations were observed between neuroimaging metrics and cognitive tests within the cognitively impaired groups (P < 0.05 FDR). DATA CONCLUSION: These findings suggest that IVIM-DWI metrics may be earlier biomarkers for AD-related changes than VBM. The use of these techniques may provide novel insight into subvoxel neurodegenerative processes. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2 J. MAGN. RESON. IMAGING 2020;52:1811-1826.


Asunto(s)
Enfermedad de Alzheimer , Enfermedades Neurodegenerativas , Enfermedad de Alzheimer/diagnóstico por imagen , Benchmarking , Estudios Transversales , Imagen de Difusión por Resonancia Magnética , Humanos , Movimiento (Física) , Estudios Prospectivos
18.
Alzheimers Dement ; 16(11): 1553-1560, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-31706733

RESUMEN

Development of disease-modifying treatments for Alzheimer's disease (AD) has been challenging, with no drugs approved to date. The failures of several amyloid-targeted programs have led many to dismiss the amyloid beta (Aß) hypothesis of AD. An antiamyloid antibody aducanumab recently showed modest but significant efficacy in a phase 3 trial, providing important validation of amyloid as a therapeutic target. However, the inconsistent results observed with aducanumab may be explained by the limited brain penetration and lack of selectivity for the soluble Aß oligomers, which are implicated as upstream drivers of neurodegeneration by multiple studies. Development of agents that can effectively inhibit Aß oligomer formation or block their toxicity is therefore warranted. An ideal drug would cross the blood-brain barrier efficiently and achieve sustained brain levels that can continuously prevent oligomer formation or inhibit their toxicity. A late-stage candidate with these attributes is ALZ-801, an oral drug with a favorable safety profile and high brain penetration that can robustly inhibit Aß oligomer formation. An upcoming phase 3 trial with ALZ-801 in APOE4/4 homozygous patients with early AD will effectively test this amyloid oligomer hypothesis.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/antagonistas & inhibidores , Anticuerpos Monoclonales Humanizados/farmacología , Descubrimiento de Drogas , Humanos , Taurina/análogos & derivados , Taurina/farmacología , Valina/análogos & derivados , Valina/farmacología
19.
Alzheimers Dement ; 16(4): 641-650, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31879235

RESUMEN

INTRODUCTION: This clinical trial evaluates the efficacy and safety of a 6-week course of daily neuroAD™ therapy. METHODS: 131 subjects between 60 and 90 years old, unmedicated for Alzheimer's disease (AD), or on stable doses of an acetylcholinesterase inhibitor and/or memantine, with Mini-Mental State Examination scores between 18 and 26, clinical dementia rating scale scores of 1 or 2, enrolled for a prospective, randomized, double-blind, sham-controlled, multicenter clinical trial. Structural brain MRIs were obtained for transcranial magnetic stimulation targeting. Baseline Alzheimer's disease assessment scale-cognitive (ADAS-Cog) and Clinical Global Impression of Change were assessed. 129 participants were randomized to active treatment plus standard of care (SOC) or sham treatments plus SOC. RESULTS: Subjects with baseline ADAS-Cog ≤ 30 (~85% of study population) showed a statistically significant benefit favoring active over sham. Responder analysis showed 31.7% participants in the active group with ≤ -4 point improvement on ADAS-Cog versus 15.4% in the sham group. DISCUSSION: neuroAD™ Therapy System provides a low-risk therapeutic benefit for patients with milder AD (baseline ADAS-Cog ≤30) beyond pharmacologic SOC.


Asunto(s)
Enfermedad de Alzheimer/terapia , Estimulación Magnética Transcraneal/instrumentación , Anciano , Anciano de 80 o más Años , Inhibidores de la Colinesterasa/uso terapéutico , Método Doble Ciego , Femenino , Humanos , Masculino , Memantina/uso terapéutico , Escala del Estado Mental , Persona de Mediana Edad , Estudios Prospectivos
20.
J Int Neuropsychol Soc ; 25(6): 569-582, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31030698

RESUMEN

OBJECTIVES: Despite changes to brain integrity with aging, some functions like basic language processes remain remarkably preserved. One theory for the maintenance of function in light of age-related brain atrophy is the engagement of compensatory brain networks. This study examined age-related changes in the neural networks recruited for simple language comprehension. METHODS: Sixty-five adults (native English-speaking, right-handed, and cognitively normal) aged 17-85 years underwent a functional magnetic resonance imaging (fMRI) reading paradigm and structural scanning. The fMRI data were analyzed using independent component analysis to derive brain networks associated with reading comprehension. RESULTS: Two typical frontotemporal language networks were identified, and these networks remained relatively stable across the wide age range. In contrast, three attention-related networks showed increased activation with increasing age. Furthermore, the increased recruitment of a dorsal attention network was negatively correlated to gray matter thickness in temporal regions, whereas an anterior frontoparietal network was positively correlated to gray matter thickness in insular regions. CONCLUSIONS: We found evidence that older adults can exert increased effort and recruit additional attentional resources to maintain their reading abilities in light of increased cortical atrophy.


Asunto(s)
Envejecimiento , Atención/fisiología , Corteza Cerebral , Comprensión/fisiología , Lenguaje , Red Nerviosa , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/patología , Envejecimiento/fisiología , Atrofia/patología , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/patología , Corteza Cerebral/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Red Nerviosa/patología , Red Nerviosa/fisiología , Lectura , Adulto Joven
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