Jason Karlawish

Frontotemporal dementia: clinicopathological correlations.

Frontotemporal lobar degeneration (FTLD) is characterized by impairments in social, behavioral, and/or language function, but postmortem studies indicate that multiple neuropathological entities lead to FTLD. This study assessed whether specific clinical features predict the underlying pathology.

The A4 Study: Stopping AD Before Symptoms Begin?

A new secondary prevention trial in older people with amyloid accumulation at high risk for Alzheimer’s disease dementia should provide insights into whether anti-amyloid therapy can delay cognitive decline. A new secondary prevention trial in older people with amyloid accumulation at high risk for Alzheimer’s disease dementia should provide insights into whether anti-amyloid therapy can delay cognitive decline.

Appropriate use criteria for amyloid PET: A report of the Amyloid Imaging Task Force, the Society of Nuclear Medicine and Molecular Imaging, and the Alzheimer's Association

Positron emission tomography (PET) of brain amyloid β is a technology that is becoming more available, but its clinical utility in medical practice requires careful definition. To provide guidance to dementia care practitioners, patients, and caregivers, the Alzheimers Association and the Society of Nuclear Medicine and Molecular Imaging convened the Amyloid Imaging Taskforce (AIT). The AIT considered a broad range of specific clinical scenarios in which amyloid PET could potentially be used appropriately. Peer‐reviewed, published literature was searched to ascertain available evidence relevant to these scenarios, and the AIT developed a consensus of expert opinion. Although empirical evidence of impact on clinical outcomes is not yet available, a set of specific appropriate use criteria (AUC) were agreed on that define the types of patients and clinical circumstances in which amyloid PET could be used. Both appropriate and inappropriate uses were considered and formulated, and are reported and discussed here. Because both dementia care and amyloid PET technology are in active development, these AUC will require periodic reassessment. Future research directions are also outlined, including diagnostic utility and patient‐centered outcomes.

Current State of Research on Decision-Making Competence of Cognitively Impaired Elderly Persons

As the number of cognitively impaired elderly persons increases, the need for evidence-based assessments of their capacity to consent to medical treatment and research participation will grow. The authors conducted an electronic and manual literature search for all English-language articles examining the decision-making capacity of elderly persons with dementia or cognitive impairment, reviewing articles in relation to key areas of methodological, clinical, and policy importance. The 32 relevant studies identified were highly heterogeneous, even in their definitions and measurements of decisional capacity. Although incapacity is common, many persons with dementia are capable of making their own medical and research decisions. In Alzheimer disease, memory and executive-function deficits predict decisional impairment. Still, at least in early stages of dementia, interventions may improve decisional abilities. Short and simple cognitive screening may be useful by identifying persons in need of more intensive evaluations. The use of expert judgment-based methods may mitigate the problem of a lack of a criterion standard for competence. Research into the decision-making competence of cognitively impaired elderly persons is a growing field. It is beginning to yield findings with practical implications for preserving the autonomy and welfare of this group of vulnerable elderly patients.

Trends in the prevalence and mortality of cognitive impairment in the United States: Is there evidence of a compression of cognitive morbidity?

Recent medical, demographic, and social trends might have had an important impact on the cognitive health of older adults. To assess the impact of these multiple trends, we compared the prevalence and 2‐year mortality of cognitive impairment (CI) consistent with dementia in the United States in 1993 to 1995 and 2002 to 2004.

Novel ubiquitin neuropathology in frontotemporal dementia with valosin-containing protein gene mutations

Frontotemporal dementia (FTD) with inclusion body myopathy and Paget disease of bone (IBMPFD) is a rare, autosomal-dominant disorder caused by mutations in the valosin-containing protein (VCP) gene, a member of the AAA-ATPase gene superfamily. The neuropathology associated with sporadic FTD is heterogeneous and includes tauopathies and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U). However, there is limited information on the neuropathology in IBMPFD. We performed a detailed, systematic analysis of the neuropathologic changes in 8 patients with VCP mutations. A novel pattern of ubiquitin pathology was identified in IBMPFD that was distinct from sporadic and familial FTLD-U without VCP gene mutations. This was characterized by ubiquitin-positive neuronal intranuclear inclusions and dystrophic neurites. In contrast to FTLD-U, only rare intracytoplasmic inclusions were identified. The ubiquitin pathology was abundant in the neocortex, less robust in limbic and subcortical nuclei, and absent in the dentate gyrus. Only rare inclusions were detected with antibodies to VCP and there was no biochemical alteration in the VCP protein. VCP is associated with a variety of cellular activities, including regulation of the ubiquitin-proteasome system. Our findings are consistent with the hypothesis that the pathology associated with VCP gene mutations is the result of impairment of ubiquitin-based degradation pathways.

Plasma multianalyte profiling in mild cognitive impairment and Alzheimer disease

Objectives: While plasma biomarkers have been proposed to aid in the clinical diagnosis of Alzheimer disease (AD), few biomarkers have been validated in independent patient cohorts. Here we aim to determine plasma biomarkers associated with AD in 2 independent cohorts and validate the findings in the multicenter Alzheimers Disease Neuroimaging Initiative (ADNI). Methods: Using a targeted proteomic approach, we measured levels of 190 plasma proteins and peptides in 600 participants from 2 independent centers (University of Pennsylvania, Philadelphia; Washington University, St. Louis, MO), and identified 17 analytes associated with the diagnosis of very mild dementia/mild cognitive impairment (MCI) or AD. Four analytes (apoE, B-type natriuretic peptide, C-reactive protein, pancreatic polypeptide) were also found to be altered in clinical MCI/AD in the ADNI cohort (n = 566). Regression analysis showed CSF Aβ42 levels and t-tau/Aβ42 ratios to correlate with the number of APOE4 alleles and plasma levels of B-type natriuretic peptide and pancreatic polypeptide. Conclusion: Four plasma analytes were consistently associated with the diagnosis of very mild dementia/MCI/AD in 3 independent clinical cohorts. These plasma biomarkers may predict underlying AD through their association with CSF AD biomarkers, and the association between plasma and CSF amyloid biomarkers needs to be confirmed in a prospective study.

The ability of persons with Alzheimer disease (AD) to make a decision about taking an AD treatment.

Objective: To examine the severity of impairments in the decision-making abilities (understanding, appreciation, reasoning, and choice) and competency to make a decision to use an Alzheimer disease (AD)-slowing medication in patients with AD and the relationships between these impairments, insight, and overall cognition. Methods: Semistructured in-home interviews were conducted with 48 patients with very mild to moderate AD and 102 family caregivers of patients with mild to severe AD recruited from the Memory Disorders Clinic of an AD center. The interview measured performance on the decision-making abilities and three expert psychiatrists’ judgment of competency based on their independent review of the patient interviews. Results: There was considerable variation in patients’ performance on the measures of decision-making abilities. Three expert raters found 19 of 48 (40%) of the subjects competent. Competent patients were more likely to show awareness of their symptoms, prognosis, and diagnosis. A sensitivity analysis suggests that a MMSE score is helpful in discriminating capacity from incapacity only when below 19 or above 23. Conclusions: Persons with mild to moderate Alzheimer disease (AD) have notable impairments in their ability to make an AD treatment decision, especially persons with moderate AD and persons who lack awareness of symptoms, prognosis, or diagnosis.

Appropriate use criteria for amyloid PET: A report of the Amyloid Imaging Task Force, the Society of Nuclear Medicine and Molecular Imaging, and the Alzheimer’s Association

Positron emission tomography (PET) of brain amyloid β is a technology that is becoming more available, but its clinical utility in medical practice requires careful definition. To provide guidance to dementia care practitioners, patients, and caregivers, the Alzheimer’s Association and the Society of Nuclear Medicine and Molecular Imaging convened the Amyloid Imaging Taskforce (AIT). The AIT considered a broad range of specific clinical scenarios in which amyloid PET could potentially be used appropriately. Peer-reviewed, published literature was searched to ascertain available evidence relevant to these scenarios, and the AIT developed a consensus of expert opinion. Although empirical evidence of impact on clinical outcomes is not yet available, a set of specific appropriate use criteria (AUC) were agreed on that define the types of patients and clinical circumstances in which amyloid PET could be used. Both appropriate and inappropriate uses were considered and formulated, and are reported and discussed here. Because both dementia care and amyloid PET technology are in active development, these AUC will require periodic reassessment. Future research directions are also outlined, including diagnostic utility and patient-centered outcomes.

Novel CSF biomarkers for Alzheimer’s disease and mild cognitive impairment

Altered levels of cerebrospinal fluid (CSF) peptides related to Alzheimer’s disease (AD) are associated with pathologic AD diagnosis, although cognitively normal subjects can also have abnormal levels of these AD biomarkers. To identify novel CSF biomarkers that distinguish pathologically confirmed AD from cognitively normal subjects and patients with other neurodegenerative disorders, we collected antemortem CSF samples from 66 AD patients and 25 patients with other neurodegenerative dementias followed longitudinally to neuropathologic confirmation, plus CSF from 33 cognitively normal subjects. We measured levels of 151 novel analytes via a targeted multiplex panel enriched in cytokines, chemokines and growth factors, as well as established AD CSF biomarkers (levels of Aβ42, tau and p-tau181). Two categories of biomarkers were identified: (1) analytes that specifically distinguished AD (especially CSF Aβ42 levels) from cognitively normal subjects and other disorders; and (2) analytes altered in multiple diseases (NrCAM, PDGF, C3, IL-1α), but not in cognitively normal subjects. A multi-prong analytical approach showed AD patients were best distinguished from non-AD cases (including cognitively normal subjects and patients with other neurodegenerative disorders) by a combination of traditional AD biomarkers and novel multiplex biomarkers. Six novel biomarkers (C3, CgA, IL-1α, I-309, NrCAM and VEGF) were correlated with the severity of cognitive impairment at CSF collection, and altered levels of IL-1α and TECK associated with subsequent cognitive decline in 38 longitudinally followed subjects with mild cognitive impairment. In summary, our targeted proteomic screen revealed novel CSF biomarkers that can improve the distinction between AD and non-AD cases by established biomarkers alone.