ABSTRACT
Introduction: Olfactory dysfunction (OD) affects more than 3 million US adults. The number of patients with post viral olfactory dysfunction (PVOD) is expected to increase secondary to the worldwide COVID-19 pandemic. Preliminary studies have demonstrated the efficacy of platelet-rich plasma (PRP) in restoration of smell in both animals and humans. To date, human studies have utilized injectable PRP only. We describe our pilot study investigating the use of topical PRP as a novel delivery method for smell restoration and contribute to existing literature demonstrating the promise of PRP as a therapeutic. Method(s): Pilot study from September 2020 to January 2022. Patients >18 years with hyposmia diagnosed via Brief Smell Identification Test (B-SIT) score <8 were included. PRPimpregnated Surgifoam was placed into bilateral olfactory clefts monthly for at least 3 months. Patients completed the B-SIT at baseline and 1 month after each treatment. Result(s): Eight patients underwent at least 3 treatments and completed the B-SIT at month 4. Average age was 56.3 years;mean smell loss duration was 19.3 months. Etiologies included PVOD, post-COVID (5), and idiopathic. Mean change in B-SIT after 3 treatments was +1.06. Of patients, 62.5% had achieved the minimal clinically significant difference of >1 on B-SIT after treatments 2 and 3. Patients with smell loss <12 months demonstrated greater B-SIT scores at 4 months (+1.6 vs +0.2). Two patients achieved B-SIT >8 after 3 treatments. Of patients who have returned thus far for a fourth treatment, 1 additional patient scored >8. Conclusion(s): We present the largest pilot study to date for the use of PRP in treatment of OD and the first study to develop methods for topical delivery in human subjects. Topical PRP may serve as a less invasive, efficacious therapy for patients. Further, randomized control trials are warranted to investigate the required number of topical PRP treatments for smell restoration.
ABSTRACT
Introduction: Almost 30% of olfactory dysfunction (OD) arises after a viral infection with increased incidence due to COVID-19. Hypothesized SARS-CoV-2 viral attachment to the olfactory epithelium differs from the traditional postviral OD (PVOD) mechanism. Hence, manifestations of OD may differ between the two etiologies. This study evaluates the difference in smell perception between post-COVID-19 OD and postviral or idiopathic etiologies. Method(s): This observational study, approved by the institutional review board, was conducted between September 2020 and January 2022 in adult patients with more than 6 months nontraumatic OD with no perceived improvement in smell even after 3 months of conservative treatment. OD in these patients was categorized as COVID-19 or non-COVID-19 related. Demographics, duration of OD, and Brief Smell Identification Test (B-SIT) scores were analyzed. Continuous variables were compared by t test, while categorical variables were compared by chi2 test using SPSS 27 (IBM Corp). Result(s): Of the 26 patients included in the study, 42.3% reported persistent OD following COVID-19 infection, while 57.7% had non-COVID-19-related OD. The mean B-SIT score in post-COVID-19 OD was 6.81+/-2.15 compared with 3.87+/-2.2 in the non-COVID-19 OD group, with the difference being statistically significant at 3.40 (P=.001). While race and gender ratios were similar between the groups, age (42 vs 54, P=.048) and duration of loss of smell (10 months vs 49 months, P<.001) had significant differences. Conclusion(s): This study shows that patients suffering from COVID-19-related OD may have normal scores on scratch and sniff smell tests, possibly because of the difference in the affected site of the olfactory pathway. Current hypotheses focus on olfactory epithelial damage in COVID-19 vs neuronal in PVOD. Differences seen in age and duration of smell loss between groups may be secondary to newfound worldwide attention to OD, while patients with OD etiologies predating COVID-19 may have newly sought treatment at this time. Olfactory threshold testing may be required for accurate assessment of post- COVID-19 OD. Larger studies are required to help delineate differences between these olfactory disturbance etiologies.
ABSTRACT
Introduction: We assess the role of topical platelet-rich plasma (PRP) in the management of anosmic patients;aim to understand the mechanism of action of topical PRP in the olfactory groove;and differentiate and analyze objective vs subjective improvement in patients receiving topical PRP for anosmia. Anosmia affects up to 20% of the general population, has significant negative impact on quality of life, and has been associated with increased mortality. Further, an estimated 30% to 75% of patients who contract COVID-19 develop anosmia or hyposmia. Despite the commonality and adverse impact of this disorder, there are very few effective treatment options. This abstract/ manuscript presents encouraging, late-breaking data showing that topical PRP placed in the olfactory groove may show some efficacy in managing persistent, long-standing anosmia. Methods: Ten patients with persistent anosmia for at least 6 months were included in this pilot study. All 10 patients had failed previous medical management and olfactory training. An absorbable sponge was soaked in PRP and placed in the patient's olfactory groove on one side in a single-blinded and randomized fashion. The other side received an absorbable sponge soaked in saline. The patient was subsequently seen at 4-week intervals for an additional 2 months, with this procedure repeated at each interval. The same side of the nose was treated with PRP at each encounter and was randomized only at the beginning of the trial. At each interval, a Brief Smell Identification Test (B-SIT) was performed on each nostril independently. Results: Nine patients completed 3 treatment sessions, and 1 patient was lost to follow-up after two treatments. The average overall presenting B-SIT score was 3.5 ± 1.76 (scores <4 are considered anosmic);3.9 ± 2.02 in the treatment nostril and 3.1 ± 1.37 in the control nostril. B-SIT scores improved after each subsequent visit, regardless of the nostril side treated. After completion of the 3 treatments, or at the time of exiting the study, the average overall B-SIT score improved to 4.5 ± 1.92;4.6 ± 1.81 in the treatment nostril and 4.4 ± 2.12 in the control nostril. All patients reported subjective improvement in their sense of smell. Conclusion: Topical PRP placed in the olfactory groove appears to show some efficacy in managing persistent, longstanding anosmia.