Very Early Changes in Olfactory Functioning Due to Alzheimer's Disease and the Role of Apolipoprotein E in Olfaction a

  title={Very Early Changes in Olfactory Functioning Due to Alzheimer's Disease and the Role of Apolipoprotein E in Olfaction a},
  author={Anna W. Bacon and Mark W. Bondi and David P. Salmon and Claire Murphy},
  journal={Annals of the New York Academy of Sciences},
ABSTRACT: Alzheimer's disease (AD) is a progressive neurodegenerative illness marked by memory loss and at least one other cognitive disturbance. Early diagnosis of the disease has proved difficult and has therefore been the focus of much research. Apolipoprotein E (ApoE), a protein manufactured and distributed throughout the body, has shown specificity of binding to the βA4 peptide, the primary component in the senile plaques of AD. Furthermore, the ApoE, epsilon 4 (ɛ4) allele, is… 

Olfactory Dysfunction in ApoE ɛ4/4 Homozygotes with Alzheimer's Disease.

Investigation of olfactory functioning in homozygous ɛ4/4 older adults diagnosed with probable AD shows deficits in odor identification and remote odor memory as measured by odor familiarity ratings, which give insight into how the presence of two ɚ4 alleles may differentially affect the progression of AD and suggest the usefulness of odor tasks in detecting those at risk for AD.

Apo E4 Alleles and Impaired Olfaction as Predictors of Alzheimer’s Disease

Present research on the significance of Apolipoprotein E and olfaction to AD is reviewed, current studies on the associations and mechanisms of ApoE and Olfactory dysfunction are summarized, and important gaps are highlighted to further advance the translational application of the olfactory paradigm to early, preclinical diagnosis and treatment of AD.

Loss of Olfactory Function in Patients With Alzheimer’s Disease

Characteristic neuropathological changes in AD include cell loss, granulovacuolar degeneration, and an increased number of neuritic plaques and neurofibrillary tangles.

Effects of the ApoE ε4 allele on olfactory function in Down Syndrome

The hypothesis that individuals with DS who have an additional genetic risk factor for AD, the ApoE epsilon4 allele, exhibit greater deficits in odor identification is supported.

Olfactory Dysfunctions in Alzheimer’s Disease

Stage 1-2, considered “clinically silent”, includes a series of non-cognitive clinical changes that are essential for the timely diagnosis of the disease, including olfactory changes.

Loss of Olfactory Function in Dementing Disease

  • C. Murphy
  • Psychology, Biology
    Physiology & Behavior
  • 1999

Olfactory and other sensory impairments in Alzheimer disease

  • C. Murphy
  • Biology, Psychology
    Nature Reviews Neurology
  • 2018
The potential for olfactory and other sensory impairments as very early indicators of AD is examined and the important questions that remain to be answered are considered.

Olfaction in Aging and Alzheimer's Disease

Olfactory and cognitive processing deficits in ApoE ɛ4+ individuals are investigated using a cross‐modal recognition memory task and an objective electrophysiological measure, the event‐related potential (ERP), which is consistent with a compensatory hypothesis that nondemented individuals will expend greater effort in cognitive processing or engage in alternative strategies and therefore require greater activation of neural tissue or recruitment of different neural populations.



Olfaction and Alzheimer's disease

  • M. Serby
  • Psychology, Biology
    Progress in Neuro-Psychopharmacology and Biological Psychiatry
  • 1986

Apolipoprotein E status as a predictor of the development of Alzheimer's disease in memory-impaired individuals.

Patients with mild cognitive impairment can be clinically defined, many members of this group progress to Alzheimer's disease, and APOE epsilon 4 allele status appears to be a strong predictor of clinical progression.

Apolipoprotein E: high-avidity binding to beta-amyloid and increased frequency of type 4 allele in late-onset familial Alzheimer disease.

It is demonstrated that there was a highly significant association of apolipoprotein E type 4 allele (APOE-epsilon 4) and late-onset familial Alzheimer disease.

Differences in olfactory test performance between normal aged, Alzheimer and vascular type dementia individuals

Differences in age and severity of dementia did not fully account for the findings, suggesting that differential diagnosis of Alzheimer ‐ type dementia could be facilitated and improved by the use of olfactory tasks.

Episodic memory changes are associated with the APOE- epsilon 4 allele in nondemented older adults

Results suggest that episodic memory changes in older adults are associated with APOE- epsilon 4 allele; sensitive cognitive markers such as those of the CVLT may precede the subsequent development of DAT.

Olfactory dysfunction in alzheimer's disease

Positron emission tomographic studies with (F‐18)2‐fluoro‐2‐deoxy‐D‐glucose performed on 15 probable AD subjects showed no relation between olfactory performance and cerebral metabolic asymmetries, but relations to visual discrimination were found.

The nature and course of olfactory deficits in Alzheimer's disease.

Olfactory identification is impaired early in Alzheimer's disease and may be more influenced by cognitive status than is acuity of odor detection, which is not altered until later in the disorder.