Moretti DV, Paternico D, Binetti G, Zanetti O and Frisoni GB
Background: The nucleus accumbens (NAc) has been associated with impulsive behavior in subjects with
early cognitive impairment; grey matter (GM) changes of basal ganglia have been demonstrated to be involved
in Alzheimer’s disease (AD). Moreover, the increase of EEG alpha3/alpha2 ratio has been associated with ADconverters
subjects with mild cognitive impairment (MCI).
Objective: To study the association of EEG marker with specific GM changes of NAc in subjects with MCI
Methods: 74 adult subjects with mild cognitive impairment underwent EEG recording and high resolution 3D
magnetic resonance imaging (MRI). The alpha3/alpha2 ratio was computed for each subject. Three groups were
obtained according to increasing tertiles values of alpha3/alpha2. Grey matter density differences between groups
were investigated using a Voxel Based Morphometry technique.
Results: Subjects with lower a3/a2 and middle a3/a2 ratio ratio showed greater gray matter reduction in the NAc
bilaterally when compared to subjects with higher a3/a2 ratio.
Conclusion: The a3/a2 ratio was associated with increase of grey matter density inside the NAc in MCI subjects
at major risk to develop AD.