Magnetic resonance analysis of amygdalar volume in Alzheimer's disease

Abstract

Purpose of review: With the rising prevalence of Alzheimer's disease, there is an increasing need for better comprehension of its pathophysiology. The purpose of this article is to review recent studies investigating the association between amygdalar volume and clinical symptoms in Alzheimer's disease. The first part describes the technique of MRI segmentation of amygdala. The advantages and risks of various segmentation techniques are noted. In the second part, the role of amygdalar volume in the assessment of clinical diagnosis is discussed. The third part encounters the relationship between the amygdalar atrophy and its neuropsychological correlates.

Recent findings: Numerous MRI studies showed the same degree of hippocampal and amygdalar volume loss. MRI volumetry of the amygdala may be relevant as a marker of dementia severity in Alzheimer's disease. Asymmetry in amygdalar atrophy is useful in separating Alzheimer's disease and frontotemporal lobar degeneration. There has been a lack of direct relationship between the atrophy of amygdala and neuropsychiatric symptoms in Alzheimer's disease.

Summary: Although time-consuming, the manual tracing represents the golden standard in MRI volumetry of amygdala. The pathogenesis of neuropsychiatric symptoms in Alzheimer's disease is complex and their manifestation is therefore not attributable to the amygdalar atrophy only.