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\begin{document}

\title{Olfactory training assists in olfactory recovery after sinonasal surgery}



\author[1]{ Joon Yong Park}%
\author[2]{Jiyeon Lee}%
\author[1]{Hansol Kim}%
\author[1]{Taesik Jung}%
\author[1]{Jin Kook Kim}%
\affil[1]{Konkuk University School of Medicine}%
\affil[2]{Konkuk University Chungju Hospital}%


\vspace{-1em}



  
  \date{May 25, 2024}


\begingroup
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\selectlanguage{english}
\begin{abstract}
Abstract Objectives: In patients with chronic rhinosinusitis (CRS),
olfactory dysfunction (OD) is a common complaint. The focus of this
research was to evaluate the effectiveness of olfactory training (OT) in
patients with CRS after sinonasal surgery. Design : Prospective
controlled trial. Participants: We enrolled 111 Korean CRS patients who
underwent sinonasal surgery. Main Outcome Measures: At baseline and
three months after starting OT, both participants were assessed by an
olfactory function test and endoscopy. The Korean version of the
Sniffin' stick II (KVSS-II) was used to perform the olfactory function
test. A visual analog scale and the Mini-Mental State Examination were
used to assess nasal and psychological functions. Over the course of
three months, five odorants were used in OT (rose, lemon, cinnamon,
orange, and peach). Results: Over a 12-week duration, OT increased
olfactory activity in nearly 62 percent of subjects than in non-OT
subjects. The OT group had significantly higher olfactory outcomes for
the total KVSS-II and identification scores than the non-OT group
between the initial and follow-up assessments. The initial score
influenced the degree of olfactory improvement after OT. Conclusions: OT
patients exhibited significantly higher total KVSS-II scores compared
with non-OT patients after sinonasal surgery; in particular, the odor
identification score was different between the two groups. The results
of this study show that a 12-week period of repeated short-term exposure
to various odors could be useful in enhancing olfactory activity in
patients who underwent sinonasal surgery for the improvement of
sensory-neural olfactory impairment.%
\end{abstract}%



\sloppy


\textbf{Abstract}

\textbf{Objectives:} In patients with chronic rhinosinusitis (CRS),
olfactory dysfunction (OD) is a common complaint. The focus of this
research was to evaluate the effectiveness of olfactory training (OT) in
patients with CRS after sinonasal surgery.

\textbf{Design :} Prospective controlled trial.

\textbf{Participants:} We enrolled 111 Korean CRS patients who underwent
sinonasal surgery.

\textbf{Main Outcome Measures:} At baseline and three months after
starting OT, both participants were assessed by an olfactory function
test and endoscopy. The Korean version of the Sniffin' stick II
(KVSS-II) was used to perform the olfactory function test. A visual
analog scale and the Mini-Mental State Examination were used to assess
nasal and psychological functions. Over the course of three months, five
odorants were used in OT (rose, lemon, cinnamon, orange, and peach).

\textbf{Results:} Over a 12-week duration, OT increased olfactory
activity in nearly 62 percent of subjects than in non-OT subjects. The
OT group had significantly higher olfactory outcomes for the total
KVSS-II and identification scores than the non-OT group between the
initial and follow-up assessments. The initial score influenced the
degree of olfactory improvement after OT.

\textbf{Conclusions:} OT patients exhibited significantly higher total
KVSS-II scores compared with non-OT patients after sinonasal surgery; in
particular, the odor identification score was different between the two
groups. The results of this study show that a 12-week period of repeated
short-term exposure to various odors could be useful in enhancing
olfactory activity in patients who underwent sinonasal surgery for the
improvement of sensory-neural olfactory impairment.

\textbf{Key points}

1. The aim of this study was to evaluate the effectiveness of olfactory
training (OT) in patients with CRS after sinonasal surgery. 2. Patients
were divided into an OT group that received frequent short-term exposure
to various odors over a 12-week period, and their olfactory function was
compared to that of a control group that did not receive post-operative
OT. 3. OT patients exhibited significantly higher total TDI scores
compared to non-OT patients at the end of 3 months. In the subset
analysis, the odor identification scores differed between the two groups
after 3 months. 4. Age, sex, median duration, and LM score at baseline
assessment were not correlated with recovery of olfactory function. 5.
The group with anosmia at baseline assessment showed a significantly
higher increase in KVSS-II test results compared with the other patients

\textbf{Keywords:} Sinonasal surgery; Olfactory recovery; Olfactory
training

\textbf{Introduction}

Olfactory dysfunction (OD) can be classified into conductive and
sensorineural types, although these are not mutually exclusive. In
conductive losses, such as nasal polyps and chronic rhinosinusitis
(CRS), inspired odorants are unable to enter the olfactory cleft in the
nasal cavity. In sensorineural loss, the damage of olfactory receptor
neurons or their central projection contribute to
OD.\textsuperscript{1}Attempted treatments have included medical
(topical and systemic steroids, zinc, etc.) and surgical treatment.
Hummel et al.\textsuperscript{2} studied the effectiveness of olfactory
training(OT) in a group of patients with olfactory loss due to
post-infectious, post-traumatic, or idiopathic etiologies. OT has shown
promise as an alternative treatment modality for several causes of OD,
with the exception of sinonasal disease.

Previous research found that exposing various odors in patients with
post-infectious and post-traumatic OD for 16 weeks increased their
olfactory function.\textsuperscript{3} According to a recent
meta-analysis, OT is a promising clinical therapy for patients with OD,
and many other trials have shown that OT has good olfactory outcomes
with no serious side effects. \textsuperscript{4} Recently, we reported
that OT resulted in olfactory improvement reflected in the total
threshold, discrimination and identification (TDI) score, threshold
score, and identification score in patients with post-infectious
olfactory dysfunction (PIOD) as compared to a control group using five
odorants familiar to Koreans.\textsuperscript{5} Moreover, OT can be
considered for patients with persistent COVID-19-related OD because this
therapy is inexpensive and has negligible adverse
effects.\textsuperscript{6}

In patients with chronic rhinosinusitis (CRS), OD is a common
complaint.\textsuperscript{7-9} Although the main mechanism of
CRS-induced OD is unclear, it is thought to be a combination of
mechanical obstruction from edematous mucosa or polyposis, as well as
sensorineural damage from chronic inflammatory injury to the olfactory
neuroepithelium.\textsuperscript{10} Endoscopic sinonasal surgery (ESS)
is used to improve sinus function and access to topical medical
treatment in patients with medically refractory CRS. However, olfactory
function after ESS can be unpredictable.\textsuperscript{11-12} An early
study endorsed the effect of ESS in reducing CRS-related OD. However,
several recent studies on the outcomes of OD after ESS have reported
conflicting results.\textsuperscript{13} A study found that OT improved
the olfactory activity of sinonasal patients, but did not evaluate the
effects of OT on post-sinonasal-operative patients. A separate study
reported that no significant changes in individual component values of
TDI scores were observed in sinonasal patients. However, that research
did not include a control group.\textsuperscript{14} Therefore, the
effectiveness of OT in CRS patients who experienced mixed (conductive
and sensorineural) olfactory dysfunction after resolving the conductive
cause by sinonasal surgery has not been investigated.

\emph{Objectives}

The aim of this study was to evaluate the effectiveness of olfactory
training (OT) in patients with CRS after sinonasal surgery compared to
non-OT patients.

\textbf{Methods}

\emph{Ethical considerations}

This study was performed in accordance with the principles of the
Declaration of Helsinki. The study was reviewed by the Institutional
Review Board of {[}removed for blind peer review{]}, and written
informed consent was obtained from all patients. The study design was
approved by the ethics committee of the medical faculty at the
{[}removed for blind peer review{]}.

\emph{Participants}

Adult CRS patients with or without nasal polyps who required sinonasal
surgery and were unresponsive to medication treatment were recruited
from a sub-specialized rhinology clinic. To be included, the patients
had to be [?] 18years of age with bilateral chronic or recurrent
rhinosinusitis, and have a Lund-MacKay (LM) CT scan score difference [?] 3
between the right and left sides of the nasal cavity. Patients were
excluded if they were unable or unwilling to comply with the required
postoperative visits for data collection, or if they were ineligible for
informed consent, displayed unilateral disease, had an olfactory cleft
obstruction on preoperative CT scan or pre/perioperative endoscopic
finding, had an underlying bleeding disorder, or a CT scan revealed a
significant difference in disease status between the nasal cavities (LM
score difference \textgreater{} 3).

\emph{Design}

Sinonasal surgery was performed to improve the conductive cause of OD.
Surgery was performed by one surgeon under general anesthesia.
Penicillin-based antibiotics were intravenously administrated for two
days. Patients were treated endoscopically with debridement once a week
as outpatients for the first month after discharge from the hospital.
Oral antibiotics and intranasal corticosteroids were administrated for
two weeks. Saline nasal irrigation was administrated once a day during
postoperative care. Patients were treated once a month till the third
month after the second month. Patients were assessed by an olfactory
function test until the third month. The perioperative sinus endoscopy
(POSE) scoring system was performed on all patients by a single
experienced otorhinolaryngologist.

Following bilateral sinonasal surgery, patients started OT over a period
of 12 weeks after their nasal packing was removed. The details of the OT
procedure was explained to all patients who underwent bilateral ESS and
they were offered the choice of continuing with the training program or
waiting for a spontaneous recovery. The OT protocol and counselling on
behavior and lifestyle modification was performed in accordance with our
previously published method.\textsuperscript{5} Briefly, The patients
were exposed to five different odorants twice a day: rose, lemon,
cinnamon, orange, and peach. These odorants were chosen to represent
odors that Koreans are familiar with. They were instructed to sniff the
odorants for 10 seconds each morning and evening, with a 10-second break
between each odorant. With the exception of OT, postoperative medical
treatment did not differ between groups. Both groups were evaluated at
4, 8 and 12 weeks after the operation.

\emph{Main outcome measures}

The Korean version of the Sniffin' stick II (KVSS-II) was used to
perform the olfactory function test. A visual analog scale and the
Korean version of the Mini-Mental State Examination (K-MMSE) were used
to assess nasal and psychological functions. Three months after the
baseline examination, all subjects were reviewed using endoscopy and the
KVSS-II..

The baseline LM score, POSE score, visual analogue scale (VAS) for
olfactory ability, and KVSS II score (threshold, discrimination,
identification) were collected. The LM scoring system was used to
compare preoperative status. Likewise, the POSE scoring system was used
for the comparison of postoperative status. Olfactory function was
evaluated using KVSS-II. The LM score was used to describe the CT
findings. This score ranges from 0 (complete lucency of all sinuses) to
24 (complete opacity of all sinuses).\textsuperscript{15}

\emph{Statistical analyses}

SPSS version.21.0 (SPSS Inc., Chicago, IL, USA) was used for statistical
analysis. The mean \selectlanguage{ngerman}± standard deviation or percentage (\%) was used to
present the demographic and clinical data. The t-test for independent
samples was used to make comparisons between the training patients and
controls. For categorical data, Pearson's chi-square test was applied.
Paired t-test was used to compare olfactory function in each group at
baseline and 12 weeks afterwards. Univariable linear regression analysis
was performed to investigate the relationship between changes in TDI
scores and age, sex, duration of disease, the severity of OD, LM score,
and OT. Factors with a p-value of \textless{}0.1 were subjected to
multivariable linear regression analysis. Multivariable linear
regression analysis was performed to investigate the relationship
between changes in TDI scores and sex, the severity of OD, and OT.

\textbf{Results}

\emph{Participant demographics}

We enrolled 111 Korean participants (mean age: 45 ± 15.4 years; range:
18-74 years). There were 68 patients in the OT group (mean age: 45.6
years; 41 males and 27 females) and 43 patients in the non-OT group
(mean age: 44 years; 23 men and 20 women). Bilateral ESS was performed
on all patients, and septoplasty was performed in some patients (total
26 patients: 17 patients in the OT group and 9 patients in the non-OT
group) who had nasal septal deviation. After sinonasal surgery, there
were no issues other than some minor postoperative bleeding in the
hospital. There were no differences between the study groups at the
baseline assessment in terms of the LM score, initial TDI scores,
initial VAS score, or POSE score. Table 1 shows the descriptive
statistics of the findings.

\emph{The effects of OT after sinonasal surgery.}

There were no significant differences in TDI scores between the two
groups at baseline, and there were no significant differences in odor
threshold, discrimination, or identification subset tests.

Following sinonasal surgery, patients who underwent OT showed a
significant increase in TDI scores after 3 months. The subset analysis
of the TDI scores showed that the odor threshold, discrimination, and
identification scores increased significantly in the OT group. The
non-training group also showed improvement in the threshold score
compared with the other scores, but the difference was not statistically
significant. In either group, there were no significant variations in
VAS scores between the test times. Table 2 shows the descriptive
statistics for the outcomes.

OT patients exhibited significantly higher total TDI scores compared to
non-OT patients at the end of 3 months. In the subset analysis, the odor
identification scores differed between the two groups after 3 months.
Table 1 and Figure 1 show the descriptive statistics of the findings.

\emph{Comparison of olfactory recovery by sex, age, severity, and
duration of olfactory dysfunction}

When the KVSS-II scores were adjusted for sex and degree of dysfunction,
OT showed a significant effect on the difference in the KVSSII score (p
\textless{} 0.05). Age, median duration, and LM score at baseline
assessment were not correlated with recovery of olfactory function in
univariable linear regression analysis. Following adjustment for the
degree of dysfunction and olfactory training factors, sex had no
correlation with the difference in KVSS-II score. The group with anosmia
at baseline assessment showed a significantly higher increase in KVSS-II
test results compared with the other patients. Table 3 shows descriptive
data for the outcomes.

\textbf{Discussion}

The following are the significant findings among CRS patients from this
study: 1) When compared to non-OT patients, those who received OT showed
statistically significant improvements in both total TDI score and
identification score. 2) Differences in KVSS-II scores were independent
of age, sex, LM score, and duration of disease and 3) Patients with
anosmia at baseline assessment showed a significantly higher increase in
the KVSS-II score compared with the other patients.

In this study, the patients who underwent sinonasal surgery with OT
showed a significant improvement in TDI scores after 3 months. The
subset analysis of the TDI scores showed that the odor threshold,
discrimination, and identification scores increased significantly in the
OT group. The non-training group also showed improvement in the
threshold score compared with the other scores, but the difference was
not statistically significant. According to a study of 20 trials
published since 1991, olfaction generally improved following functional
ESS. However, there has been limited research on the impact of OT on
individuals with sinonasal disorders.\textsuperscript{16} There are also
controversies about whether olfactory function improves with ESS in CRS
patients. According to one prospective study, the University of
Pennsylvania Smell Identification Test (UPSIT) score in the Chronic
rhinosinusitis with nasal poloyp (CRSwNP) subgroup improved considerably
following endoscopic sinus surgery. The evaluated UPSIT olfactory
function improved after surgery in 46.0\% of patients, did not change
after surgery in 12.7\% of patients, and worsened in 41.3\% of
patients.\textsuperscript{17} A 5-year prospective research with 75\% of
the participants having CRSwNP found a considerable improvement in
measured olfaction at 2 years after surgery, however this became
non-significant at 5 years.\textsuperscript{18} There were also studies
that reported negative olfactory outcomes after ESS. One study reported
that the mean postoperative T\&T recognition threshold test of the
eosinophilic CRS group declined after 12 months.\textsuperscript{19}From
another study, 34\% of patients had a decline in olfactory function
after sinonasal surgery\textsuperscript{20} According to a meta-analysis
of olfactory outcomes after ESS for CRS, ESS improved subjective and
objective olfactory parameters, with patients with nasal polyposis and
prior olfactory dysfunction showing the greatest
benefits.\textsuperscript{21}

We also observed significantly higher total TDI and identification
scores in the OT group compared to non-OT patients. In our analysis,
with the exception of the initial KVSS-II score, the difference in
KVSSII score was independent of age, sex, LM score, and duration of
disease. There were no significant differences between the OT and non-OT
groups in terms of age, sex distribution, or duration of the condition
in our prior study on PIOD patients. \textsuperscript{5} This is another
significant difference compared to previous studies.

In this study of sinonasal patients, only the total TDI and
identification score increased significantly. Our previous study on PIOD
patients showed a significantly increased total TDI score, threshold
score, and identification score after OT. The majority of prior research
found that OT improved composite TDI, discrimination and identification
scores in people with PIOD. The majority of prior research found that OT
improved composite TDI, identification, and discrimination scores in
people with PIOD.\textsuperscript{22}

The odor threshold appears to be relatively unimpaired in central
sources of olfactory dysfunction and is poorly connected with cognitive
tests, therefore the threshold score is more strongly tied to peripheral
abnormalities in the olfactory system.\textsuperscript{4} In this study,
sinonasal surgery was performed in both groups and the surgical
procedure improved the peripheral olfactory function and conduction of
olfactory molecules. This could lead to improved threshold scores.
Another KVSS-II score (total, identification) was significantly
increased in the OT group, similar to our previous study on patients
with PIOD.

The group with anosmia at baseline showed significantly higher
improvements in KVSS-II score compared to the other patients. Long-term
exposure to various odors enhances the survival of newly generated
interneurons\textsuperscript{2} and odor
memory,\textsuperscript{11}indicating that adult neurogenesis can play a
role in olfactory memory. OT based on repeated stimulation by odors
could promote the survival of immature new neurons and eliminate more
mature neurons.\textsuperscript{23} Based on this mechanism, patients
with lower olfactory function could improve significantly after OT.

There were some limitations to this study. First of all, only a small
number of patients is involved. To better understand the effects of OT,
larger studies are needed. Second, those who had less severe OD in the
preoperative state could have been included in the non-OT group. This
can be considered a selection bias. Third, OT was applied for only 12
weeks. Therefore, it is unclear if long-term OT exposure is helpful to
olfactory function.

In conclusion, OT patients exhibit significantly higher total TDI scores
than non-OT patients after sinonasal surgery. In particular, odor
identification scores were different between the two groups. According
to the findings, a 12-week course of repeated short-term exposure to
various odors could be useful in enhancing olfactory function in
patients who had sinonasal surgery for sensory-neural OD.

\textbf{Reference}

{[}1{]} Goncalves S, Goldstein BJ. Pathophysiology of olfactory
disorders and potential treatment strategies. Curr Otorhinolaryngol Rep
2016;4:115--121.

{[}2{]} Hummel T, Rissom K, Redden J, Hahner A, Weidenbecher M,
Huttenbrink K-B. Effects of olfactory training in patients with
olfactory loss. Laryngoscope 2009;119:496-499.

{[}3{]} Konstantinidis I, Tsakiropoulou E, Bekiaridou P, Kazantzidou C,
Constantinidis J. Use of olfactory training in post-traumatic and
postinfectious olfactory dysfunction. Laryngoscope 2013;123:E85-E90.

{[}4{]} Pekala K, Chandra RK, Turner JH. Efficacy of olfactory training
in patients with olfactory loss: a systematic review and meta-analysis.
Int Forum Allergy Rhinol 2016;6:299--307.

{[}5{]} Choi BY, Jeong H, Noh H, Park JY, Cho JH, Kim JK. Effects of
olfactory training in patients with postinfectious olfactory
dysfunction. Clin Exp Otorhinolaryngol 2021;14: 88--92.

{[}6{]} Whitcroft KL, Hummel T. Olfactory dysfunction in COVID-19:
Diagnosis and management. JAMA 2020;323:2512-2514.

{[}7{]} Litvack JR, Mace JC, Smith TL. Olfactory function and disease
severity in chronic rhinosinusitis. Am J Rhinol Allergy 2009;23:139--44.

{[}8{]} Soler ZM, Mace J, Smith TL. Symptom-based presentation of
chronic rhinosinusitis and symptomspecific outcomes after endoscopic
sinus surgery. Am J Rhinol 2008;22:297--301.

{[}9{]} Jiang RS, Lu FJ, Liang KL, Shiao JY, Su M-C, Hsin C-H. Olfactory
function in patients with chronic rhinosinusitis before and after
functional endoscopic sinus surgery. Am J Rhinol 2008;22:445--8.

{[}10{]} Raviv JR, Kern RC. Chronic sinusitis and olfactory dysfunction.
Otolaryngologic Clin North Am 2004;37:1143-57.

{[}11{]} Yamagishi M, Hasegawa S, Suzuki S, Nakamura H, Nakano Y. Effect
of surgical treatment of olfactory disturbance caused by localized
ethmoiditis. Clin Otolaryngol Allied Sci 1989;14:405--409.

{[}12{]} Klimek L, Moll B, Amedee RG, Mann WJ. Olfactory function after
microscopic endonasal surgery in patients with nasal polyps. Am J Rhinol
1997;11:251--255.

{[}13{]} Pade J, Hummel T. Olfactory function following nasal surgery.
Larygoscope 2008;118:1260-1264.

{[}14{]} Fleiner F, Lau I, Göktas Ö. Active olfactory training for the
treatment of smelling disorders. Ear, Nose Throat J 2012;91:198-215.

{[}15{]} Oluwole M, Russell N, Tan L, Gardiner Q, White P. A comparison
of CT staging systems in chronic sinusitis. Clin Otolaryngol Allied Sci
1996;21:91--5.

{[}16{]} Hummel T, Whitcroft KL, Altundag A, Cinghi C, Costanzo RM, Damm
M, et al. Position paper on olfactory dysfunction. Rhinol Suppl
2017;54:1-30.

{[}17{]} Andrews PJ, Poirrier A-L, Lund VJ, Choi D. Outcomes in
endoscopic sinus surgery: olfaction, nose scale and quality of life in a
prospective cohort study. Clin. Otolaryngol. 2016;41:798-803.

{[}18{]} Rowe-Jones JM, Medcalf M, Durham SR, Richards DH, Mackay IS.
Functional endoscopic sinus surgery: 5 year follow up and results of a
prospective, randomised, stratified, double-blind, placebo controlled
study of postoperative fluticasone propionate aqueous nasal spray.
Rhinology 2005;43:2--10.

{[}19{]} Oka H, Tsuzuki K, Takebayashi H, Kojima Y, Daimon T, Sakagami
M. Olfactory changes after endoscopic sinus surgery in patients with
chronic rhinosinusitis. Auris Nasus Larynx 2013;40:452-457.

{[}20{]} Kimmelman CP. The risk to olfaction from nasal surgery.
Laryngoscope 1994;104:981--988.

{[}21{]} Kohli P, Naik AN, Farhood Z, Ong AA, Nguyen SA, Soler ZM, et
al. Olfactory outcomes after endoscopic sinus surgery for chronic
rhinosinusitis: A meta-analysis. Otolaryngol Head Neck Surg
2016;155:936-948.

{[}22{]} Sorokowska A, Drechsler E, Karwowski M, Hummel T. Effects of
olfactory training: a meta-analysis. Rhinology.2017;55:17-26.

{[}23{]} Mouret A, Gheusi G, Gabellec M-M, de Chaumont F, Olivo-Marin
J-C, Lledo P-M. Learning and Survival of Newly Generated Neurons: When
time matters. J Neurosci;2008;28:11511--11516.

\textbf{Figure legends}

\textbf{Figure 1.} In the olfactory training (OT) and non-OT groups, the
total threshold, discrimination, and identification (TDI) score (A),
threshold score (B), discrimination score (C), identification score (D),
and difference between the initial and final evaluations are compared.
KVSS-II, Korean version of Sniffin' stick. *P\textless{}0.05

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