Correlation of olfactory function with changes in the volume of the human olfactory bulb.

Objective: To investigate changes of olfactory bulb (OB) volume over time in relation to olfactory function.

Design: Prospective, before-after trial.

Setting: Outpatient clinic of a university clinic for otorhinolaryngology.

Reduced olfactory bulb volume in post-traumatic and post-infectious olfactory dysfunction.

The olfactory bulb is a highly plastic structure the volume of which partly reflects the degree of afferent neural activity. In this study, 22 patients with post-infectious olfactory deficit, nine participants with post-traumatic olfactory deficit, and 17 healthy controls underwent magnetic resonance volumetry of the olfactory bulb. Patients presented with significantly smaller olfactory bulb volumes than controls; significant correlations between olfactory function and bulb volume were observed.