Abstract
Background: Olfactory dysfunction is present since the earliest stage of
Alzheimer’s disease (AD). In AD patients, the olfactory impairment has been correlated
with atrophy of some structures of the olfactory system, but the role of the olfactory
bulb remains unclear.
Objective: The aim of our work is to test if patients suffering from AD
exhibit a statistically significant reduction of the average volume of the olfactory bulb
(OBV) compared to healthy subjects.
Methods: 78 subjects were enrolled in the study and divided into three
groups: 28 healthy elderly (22 females, 6 males, mean age 69.4 ± 9.2), 25 patients with
mild cognitive impairment (MCI) amnestic type (14 females, 11 males, mean age 74.5 ± 7.5),
and 25 mild AD patients (14 females, 11 males, mean age 73.7 ± 6.8). Every subject
underwent an MRI study of the olfactory bulb and an olfactory assessment with the Sniffin’
Stick Extended Test.
Results: The statistical analysis showed no correlation between the OBV and
MCI or AD. Moreover, olfactory function and OBV were not correlated in any of the three
groups.
Conclusion: The reduction of OBV does not seem to represent an index of
neuronal damage in the earliest stages of AD.
