Alzheimer Disease

Abstract

Purpose of review: This article discusses the recent advances in the diagnosis and treatment of Alzheimer disease (AD).

Recent findings: In recent years, significant advances have been made in the fields of genetics, neuroimaging, clinical diagnosis, and staging of AD. One of the most important recent advances in AD is our ability to visualize amyloid pathology in the living human brain. The newly revised criteria for diagnosis of AD dementia embrace the use for biomarkers as supportive evidence for the underlying pathology. Guidelines for the responsible use of amyloid positron emission tomography (PET) have been developed, and the clinical and economic implications of amyloid PET imaging are actively being explored.

Summary: Our improved understanding of the clinical onset, progression, neuroimaging, pathologic features, genetics, and other risk factors for AD impacts the approaches to clinical diagnosis and future therapeutic interventions.

Figure 3-1

Coronal T1-weighted MRI slices with findings suggestive of Alzheimer disease (AD) pathology show mesial temporal atrophy (A, B, arrows) and, in the more advanced stages, global brain atrophy with pronounced ventricular enlargement.

Figure 3-3

Cortico-subcortical microhemorrhages are often found on gradient echo MRI sequences and are suggestive of the presence of vascular amyloidosis.

Figure 3-2

Temporal (thick arrows) and parietal (thin arrows) hypometabolism on fluorodeoxyglucose positron emission tomography (FDG-PET) is often seen in patients with Alzheimer disease dementia.

Figure 3-4

Amyloid positron emission tomography (PET) imaging allows the detection of amyloid pathology of the brain. A negative scan (A) shows only nonspecific white matter binding and indicates no to sparse amyloid plaque deposition, while a positive amyloid PET scan (B) shows significant uptake in multiple cortical areas and indicates the presence of moderate to severe amyloid pathology.