ScienceDaily (Mar. 9, 2007) — Alzheimer´s disease (AD) is the most common form of dementia. An important goal for current AD research is to find preclinical markers of impending disease. Apolipoprotein E sigma4 (APOE epsilon4) is the chief known genetic risk factor for AD.

A number of neuroimaging studies have reported structural and functional brain alterations in non-demented APOE epsilon4-carriers. Such results have tentatively been interpreted as early signs of impending dementia, but the findings have been inconsistent across studies. To further address this issue, the overall aim of this thesis was to examine asymptomatic cognitively well-functioning APOE epsilon4-carriers with magnetic resonance imaging (MRI) techniques, together with longitudinal neuropsychological testing.

Study I revealed that carriers of APOE epsilon4 expressed reduced functional brain activity during incidental episodic encoding. In the parietal cortex, a genetic dose-effect was seen such that the activity reduction was more pronounced for homozygous than heterozygous APOE epsilon4-carriers. In addition, it was found that APOE epsilon4-carriers had structural changes in white-matter tracts in the hippocampus and the posterior corpus callosum (Study II), and grey matter reductions in the hippocampus (Study III). Study IV demonstrated that the degree of functional activity in the parietal cortex predicted subsequent episodic memory decline within the group of APOE epsilon4-carriers.

Collectively, the results suggest that a combination of genetic, neuropsychological, and neuroimaging strategies is beneficial in predicting AD development.

Related Stories

Blood Clots May Hold Key To Treating Dementia (Apr. 28, 2006) — Spontaneous blood clots or debris from arterial disease in the brain (known as cerebral emboli) may hold the key to preventing or treating dementia, say researchers from the University of Manchester ...  > read more

Mayo Clinic Study Finds Weight Loss Precedes Dementia Diagnosis In Women (July 16, 2006) — Mayo Clinic researchers have found that women who develop dementia experience a decline in weight as many as 10 years prior to the onset of memory loss, compared to peers who do not develop ...  > read more

Getting Diabetes Before 65 More Than Doubles Risk For Alzheimer's Disease (Jan. 28, 2009) — Diabetics have a significantly greater risk of dementia, reveals important new data from an ongoing study of twins. The risk of dementia is especially strong if the onset of diabetes occurs in middle ...  > read more

Omega-3 Supplements Can Help With Alzheimer's Symptoms, Study Suggests (June 22, 2007) — Omega-3 supplements can, in certain cases, help combat the depression and agitation symptoms associated with Alzheimer's disease, according to a new clinical ...  > read more

Search ScienceDaily

Predicting Alzheimer's