Abstract
Objectives: Treatment for olfactory dysfunction is challenging
due to limited therapeutic options. Olfactory training has shown
improvement in smell identification, discrimination, and threshold for
odor detection. The primary objective is to assess the effect of
olfactory training in patients with olfactory dysfunction after
pituitary surgery, using functional Magnetic Resonance Imaging (fMRI).
Design: This study was designed as a two-arm pilot clinical
trial.
Setting: Chilean tertiary hospital providing endoscopic
pituitary surgery and olfactory evaluation and treatment.
Participants: We included two cohorts of subjects: healthy
subjects, and patients with post-surgical olfactory dysfunction. Healthy
patients were recruited voluntarily at the ENT clinic to assess fMRI
testing paradigms and as a control group for the olfactory dysfunction
group.
Main outcome measures: The main outcome measures were
functional activation analysis obtained by fMRI. Olfactory test
assessment scores were also obtained during each testing session.
Results: 119 patients that underwent an endoscopic
transsphenoidal approach were contacted and surveyed for olfactory
dysfunction. Twelve patients met inclusion criteria, but six of them
declined to participate. Six patients were randomized using
computer-generated random numbers. The patients in the trained group
showed a significant improvement in the olfactory test results after
olfactory training compared to the no-training group (P <
0.05). The group that underwent olfactory training showed more areas of
activation after training than in baseline analysis (P <
0.05).
Conclusion: Patients that underwent olfactory training showed
significant improvement in olfactory testing. fMRI results showed more
activated areas in the olfactory training group, which could be
compatible with neuroplasticity.
Key words : Olfaction disorders, Nasal surgical procedures,
Olfactory mucosa, Nasal cavity, Olfactory dysfunction.