Neuroimaging Findings in the Evaluation of Dementia: A Review (original) (raw)
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Neuroimaging in dementia: an update for the general clinician
Progress in Neurology and Psychiatry, 2016
Structural neuroimaging is a fundamental part of a routine dementia assessment to rule out treatable causes of cognitive impairment, and to support early, accurate dementia subtype diagnosis. Dr Rayment and colleagues discuss the different types of imaging and when they should be used, as well as analysing some typical imaging findings from common dementia subtypes. Axial MRI (T2): Grossly enlarged ventricles in normal pressure hydrocephalus. Case courtesy of Dr G Balachandran, Radiopaedia.org, rID: 15942 Axial CT: Chronic left subdural haemorrhage. Case courtesy of Dr Jeremy Jones, Radiopaedia.org, rID: 6136 Axial MRI (FLAIR): Large left frontotemporal meningioma. Case courtesy of Dr Frank Gaillard, Radiopaedia.org, rID: 30745 Box 1. Imaging can be used to rule out treatable causes of progressive cognitive impairment
Neuroimaging in Dementia: A Comprehensive Evaluation Across Various Types(Atena Editora)
Neuroimaging in Dementia: A Comprehensive Evaluation Across Various Types(Atena Editora), 2024
INTRODUCTION Dementia, marked by a progressive decline in cognitive functions, poses a growing public health challenge. The introduction provides an overview of dementia, highlighting the importance of early diagnosis and the pivotal role of neuroimaging in identifying structural and functional brain changes. It traces the historical development of neuroimaging techniques and discusses various modalities, including MRI, CT, PET, and SPECT, and their contributions to understanding different dementia types. OBJETIVE To evaluate the role of neuroimaging in diagnosing and differentiating various types of dementia, including Alzheimer's disease, vascular dementia, Lewy body dementia, and frontotemporal dementia, and to assess the structural and functional changes associated with each type. METHODS This is a narrative review which included studies in the MEDLINE – PubMed (National Library of Medicine, National Institutes of Health), COCHRANE, EMBASE and Google Scholar databases, using as descriptors: “Neuroimaging” AND “Dementia Diagnosis” AND “Alzheimer's Disease” OR “Brain Atrophy” OR “Functional MRI” in the last years. RESULTS AND DISCUSSION The results and discussion sections delve into the specific findings from neuroimaging studies across different dementia types. MRI reveals significant hippocampal atrophy in Alzheimer's disease, white matter lesions in vascular dementia, and distinct patterns in Lewy body and frontotemporal dementias. PET imaging shows amyloid plaques and tau tangles in Alzheimer's disease, while fMRI studies reveal disruptions in brain connectivity. The use of advanced techniques like DTI provides insights into white matter integrity. Comparative analyses, longitudinal studies, and the impact of genetic factors are also discussed, highlighting the diagnostic and prognostic value of CONCLUSION Neuroimaging has significantly advanced the diagnosis and management of dementia, providing detailed assessments of brain structure and function. Despite challenges such as high costs and variability in protocols, ongoing advancements promise improved sensitivity and specificity of imaging biomarkers. Neuroimaging-based models for early detection and disease progression monitoring are crucial for timely interventions and better patient outcomes. The integration of neuroimaging in clinical practice continues to enhance our understanding and treatment of dementia, underscoring its indispensable role in modern medicine.
Ontario health technology assessment series, 2014
Diagnosis of dementia is challenging and requires both ruling out potentially treatable underlying causes and ruling in a diagnosis of dementia subtype to manage patients and suitably plan for the future. This analysis sought to determine the appropriate use of neuroimaging during the diagnostic work-up of dementia, including indications for neuroimaging and comparative accuracy of alternative technologies. A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2000 and 2013. Data on diagnostic accuracy and impact on clinical decision making were abstracted from included studies. Quality of evidence was assessed using GRADE. The search yielded 5,374 citations and 15 studies were included. Approximately 10% of dementia cases are potentially treatable, though less than 1% reverse partially or fully. Neithe...
Evaluation of dementia: the case for neuroimaging all mild to moderate cases
Annals of the Academy of Medicine, Singapore, 2006
The aim of this study was to assess the usefulness of 4 clinical prediction rules, the neuroimaging guidelines from the Canadian Consensus Conference on Dementia (CCCAD) and the modified Hachinski's Ischaemic Score (HIS) in identifying patients with suspected dementia who will benefit from neuroimaging. Two hundred and ten consecutive patients were referred to the memory clinic in a geriatric unit for the evaluation of possible dementia. Sensitivity, specificity and likelihood ratios (LR) were calculated for each of the prediction rules and the CCCAD guidelines, in terms of their ability to identify patients with significant lesions [defined firstly as space-occupying lesions (SOL) alone and secondly as SOL or strokes] on neuroimaging. Similar analyses were applied for the HIS in the detection of strokes. When considering SOL alone, sensitivities ranged from 28.6% to 100% and specificities ranged from 21.7% to 88.4%. However, when strokes were included in the definition of signi...
Journal of the American Geriatrics Society, 2010
OBJECTIVES-To determine how often neuroimaging confirms, clarifies, or contradicts initial diagnoses of late life cognitive disorders. DESIGN-Retrospective case review. SETTING-An outpatient clinic specializing in memory disorders. PARTICIPANTS-193 consecutively referred, cognitively impaired patients. MEASUREMENTS-Diagnoses using research criteria were developed for each patient at the first visit, and ranged from cognitive impairment without dementia to dementias of single, complex, or indeterminate etiology. Structural (non-contrast MRI) and perfusion (Tc-99m ECD SPECT) images were categorized together as normal, suggestive of specific diseases, or abnormal/ not diagnostic. RESULTS-When a single neurodegenerative disease was suspected clinically (n=94) imaging confirmed the diagnosis in 50, contradicted the diagnosis in 32, and was abnormal/not diagnostic in 12. When more than one neurodegenerative etiology was clinically suspected (n=21) imaging assigned a single diagnosis in 13 and only cerebrovascular disease in 1, and was abnormal/not diagnostic in 7. In dementia NOS (n=33), imaging suggested a specific etiology in 23 and was abnormal/not diagnostic in 10. Abnormal/not diagnostic images were more common in cognitive disorder NOS (n=25) than in other clinical groups (68% vs. 22%, χ 2 = 22.8 p < 0.001).
Neuroimaging in dementia: a practical guide
Practical neurology, 2013
Over 800 000 people in the UK are demented. Alzheimer's disease, dementia with Lewy bodies, vascular dementia and frontotemporal lobar degeneration account for the majority. Although detailed clinical assessment forms the basis of evaluating a patient with cognitive impairment, structural and functional imaging techniques are increasingly being used. Neuroimaging can identify changes to supplement the clinical diagnosis and help to distinguish dementia subtypes. This may be important for treatment, prognosis and care planning. Furthermore, early changes on structural and functional imaging may have a role in preclinical detection, perhaps allowing people to start any treatments early. In this review, we explain the tools available to the neuroradiologist and examine the implications of imaging findings in assessing patients with cognitive impairment or dementia.
Neuroimaging of dementia in 2013: What radiologists need to know
2013
The structural and functional neuroimaging of dementia have substantially evolved over the last few years. The most common forms of dementia, Alzheimer disease (AD), Lewy body dementia (LBD) and fronto-temporal lobar degeneration (FTLD), have distinct patterns of cortical atrophy and hypometabolism that evolve over time, as reviewed in the first part of this article. The second part discusses unspecific white matter alterations on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images as well as cerebral microbleeds, which often occur during normal aging and may affect cognition. The third part summarises molecular neuroimaging biomarkers recently developed to visualise amyloid deposits, tau protein deposits and neurotransmitter systems. The fourth section reviews the utility of advanced image analysis techniques as predictive biomarkers of cognitive decline in individuals with early symptoms compatible with mild cognitive impairment (MCI). As only about half of MCI cases will progress to clinically overt dementia, whereas the other half remain stable or might even improve, the discrimination of stable versus progressive MCI is of paramount importance for both individual patient treatment and patient selection for clinical trials. The fifth and final part discusses the interindividual variation in the neurocognitive reserve, which is a potential constraint for all proposed methods. Key Points • Many forms of dementia have spatial atrophy patterns detectable on neuroimaging.