Changes in Peripheral Olfactory Pathways in Rheumatoid Arthritis

We investigated olfactory bulb (OB) volumes and olfactory sulcus (OS) depths in patients with rheumatoid arthritis (RA).

In this retrospective study, cranial magnetic resonance images of 68 adult patients were included. Group 1 consisted of 34 adult patients with RA. The control group (group 2) consisted of 34 adult patients without RA. In both groups, peripheral odor pathways (OB volumes and OS depths) were measured by magnetic resonance imaging.

Our results showed that the OB volumes of the RA group were significantly lower than those in the control group bilaterally (P < 0.05). In each of the RA and control groups, the OS depth of the right side was found to be significantly higher than those on the left side (P < 0.05). On the left side, OS depth values of RA patients who used biological agents were significantly higher than those RA patients who did not use biological agents (P < 0.05). Correlation tests showed that there were positive correlations between OB volumes and OS depths bilaterally. In older patients with RA, bilateral OS depth values were decreased (P < 0.05).

Our study has shown that the peripheral olfactory pathways in patients with RA can be affected to a degree that is reflected in anatomical measurements. The use of biological agents contributes to the protection of odor functions to a certain extent. The importance of evaluating the sense of smell in patients with RA clinically and radiologically should be emphasized.