Amygdala size in amyotrophic lateral sclerosis without dementia: an in vivo study using MRI volumetry

Abstract

Background: Evidence for extra-motor involvement in non-demented patients with amyotrophic lateral sclerosis (ALS) has been provided by multiple studies, in particular neuropathological studies have demonstrated neuronal loss in the amygdala. The aim of this study was to investigate possible alterations of amygdala volumes in vivo.

Methods: Twenty-two moderately disabled patients with definite ALS without cognitive or behavioural deficits and 22 age-matched healthy controls were included. Amygdala and total brain volumes were measured by region-of-interest-based volumetry in 3-D MRI.

Results: A trend was observed with reduced amygdala size in the ALS group, since mean absolute and brain size-corrected amygdala volumes were 6.9% and 7.6% lower in the patient group compared to those in normal controls (P = 0.086 and P = 0.110), respectively.

Conclusion: Volumetrically identifiable alterations of the amygdala can be mapped in vivo and may be associated with psychopathological findings in later stages of ALS.

Figure 1

Examples of single 3-D MRI slices, showing delineation of in-slice volumes of total brain (left) and amygdala (right) [green] and the defined superior limit according to Watson et al. [14] [white] within MRreg.

Figure 2

Relative amygdala volumes plotted against total brain volumes in ALS patients and controls.