Table 2.

summary of studies reviewed for treatment

Author	Population	Findings
Poletti et al.	Post-viral or post-traumatic olfactory loss	Olfactory training was associated with olfactory improvement, with a three-time improvement in post-viral olfactory loss patients compared to the post-traumatic group. A greater stimulus (high molecular weight) was associated with more improvement.
Patel et al.	Patients with subjective loss of smell and olfactory loss were randomized to olfactory training or control for 6 months.	6/19 patients in the OT group showed significant improvement, while only 2/16 (13%) in the control group improved. Increasing age and duration of loss were significantly correlated to lack of improvement.
Damm et al.	A randomized controlled trial with university centers	Olfactory function improved greatly in the high-training group in 18 of 70 participants (26%), compared to the low-training group (15%). In subjects with a duration of olfactory dysfunction of <12 months, olfactory function improved in 15/24 participants (63%) of the high-training group and in 6/31 participants (19%) of the low-training group (P = .03).