Olfactory neuroepithelium in the superior and middle turbinates: which is the optimal biopsy site?

Medial flap middle turbinoplasty for solid middle turbinate hypertrophy: improving airway, speeding healing and preserving olfaction

PURPOSE

The techniques to be performed for bullous middle turbinates are well-defined and widely accepted in the literature. However, in the case of solid middle turbinate hypertrophy, information on surgical techniques that take into account function and sense of smell is very limited in the literature. The aim of this study was to compare the airway patency and olfaction results of patients diagnosed with solid middle turbinate hypertrophy, who underwent subtotal (transverse) resection or medial flap turbinoplasty of the middle turbinates.

METHODS

Thirty-five adult patients who were diagnosed with solid middle turbinate hypertrophy were divided into two groups, namely medial flap middle turbinoplasty (study group = 17) and transverse resection to the middle turbinate (control group = 18). Acoustic rhinometry, anterior rhinomanometry, peak nasal inspiratory flowmeter test, odor identification test, and n-butanol threshold measurements were performed before and 3 months after the surgery. In addition, preoperative and postoperative nasal obstruction and olfactory senses of the patients were evaluated with visual analog scale and nasal obstruction symptom evaluation scale.

RESULTS

Visual analog scores for olfaction were significantly higher in the study group compared to the control group. In odor identification test, a significant improvement was observed in the study group, while a decrease was observed in the control group. While there was a decrease in the n-butanol thresholds values in the study group, there was an increase in the control group.

CONCLUSIONS

Medial mucosal flap technique is an effective and functional turbinoplasty technique that can be used in solid hypertrophy of the middle turbinate, which offers advantages in terms of enhanced airway healing and olfactory results.

Combining skin and olfactory α-synuclein seed amplification assays (SAA)-towards biomarker-driven phenotyping in synucleinopathies

Seed amplification assays (SAA) are becoming commonly used in synucleinopathies to detect α-synuclein aggregates. Studies in Parkinson's disease (PD) and isolated REM-sleep behavior disorder (iRBD) have shown a considerably lower sensitivity in the olfactory epithelium than in CSF or skin. To get an insight into α-synuclein (α-syn) distribution within the nervous system and reasons for low sensitivity, we compared SAA assessment of nasal brushings and skin biopsies in PD (n = 27) and iRBD patients (n = 18) and unaffected controls (n = 30). α-syn misfolding was overall found less commonly in the olfactory epithelium than in the skin, which could be partially explained by the nasal brushing matrix exerting an inhibitory effect on aggregation. Importantly, the α-syn distribution was not uniform: there was a higher deposition of misfolded α-syn across all sampled tissues in the iRBD cohort compared to PD (supporting the notion of RBD as a marker of a more malignant subtype of synucleinopathy) and in a subgroup of PD patients, misfolded α-syn was detectable only in the olfactory epithelium, suggestive of the recently proposed brain-first PD subtype. Assaying α-syn of diverse origins, such as olfactory (part of the central nervous system) and skin (peripheral nervous system), could increase diagnostic accuracy and allow better stratification of patients.

Olfactory Neuroblastoma: Surgical Treatment Experience of 42 Cases

Objective

Our purpose was to estimate the safety and effectiveness of the endoscopic endonasal approach (EEA) in olfactory neuroblastoma (ONB) and determine whether preservation of the dura and olfactory bulb could be considered in selected patients.

Methods

We retrospectively reviewed patients diagnosed with ONBs between July 2010 and June 2021 at our institution, and collected data on demographic, disease stage, surgical approach, overall survival (OS), disease-free survival (DFS), and postoperative complications.

Results

The study sample included 42 patients (8 treated for recurrence and 34 initial cases), 28 of which were men and 14 were women with a median age of 47.19 years. The mean duration from the beginning of treatment and follow-up time was 8.91 and 51 months, respectively. Among the 42 patients, 32 had unilateral lesions, and the rest had bilateral lesions. Patient symptoms were predominantly nasal, and four patients presented without any symptoms. The modified Kadish staging was A in three patients, B in 14 patients, C in 17 patients, and D in 8 patients. According to the preoperative examinations, five patients had cervical lymph node metastasis, and no patients had distant metastases. EEA was used in 38 patients, cranioendoscopic approach in 3, and open craniofacial approach in 1. The 5-year OS and DFS rates were 89.1 and 79.2%, respectively. The 2-year OS and DFS rates were both 89.1%. The overall surgical complication incidence was 9.52% (one cerebrospinal fluid rhinorrhea, one cervical hematoma, and two epileptic seizures).

Conclusion

The present results support the importance of earlier treatment for advanced ONB and the fact that it is safe and efficacious to treat ONBs via EEA. The preservation of the dura can be considered for select patients—specifically those without skull base involvement and who underwent postoperative comprehensive therapy.

Visualizing in deceased COVID-19 patients how SARS-CoV-2 attacks the respiratory and olfactory mucosae but spares the olfactory bulb

Anosmia, the loss of smell, is a common and often the sole symptom of COVID-19. The onset of the sequence of pathobiological events leading to olfactory dysfunction remains obscure. Here, we have developed a postmortem bedside surgical procedure to harvest endoscopically samples of respiratory and olfactory mucosae and whole olfactory bulbs. Our cohort of 85 cases included COVID-19 patients who died a few days after infection with SARS-CoV-2, enabling us to catch the virus while it was still replicating. We found that sustentacular cells are the major target cell type in the olfactory mucosa. We failed to find evidence for infection of olfactory sensory neurons, and the parenchyma of the olfactory bulb is spared as well. Thus, SARS-CoV-2 does not appear to be a neurotropic virus. We postulate that transient insufficient support from sustentacular cells triggers transient olfactory dysfunction in COVID-19. Olfactory sensory neurons would become affected without getting infected.

Anterior part middle turbinoplasty in endoscopic sinus surgery: a randomized controlled study

OBJECTIVE

Resection of middle turbinate in the setting of endoscopic sinus surgery is a controversial procedure. Our aim is to assess the impact of the anterior part middle turbinoplasty on the outcome of endoscopic sinus surgery, incidence of synechia between the middle turbinate and the lateral nasal wall, intra- and post-operative accessibility to the paranasal sinuses.

METHODS

Single blinded randomized controlled study of 120 patients with chronic rhinosinusitis without polyps, they were allocated into two groups, we performed anterior part middle turbinoplasty in the group one "60 patients", and we preserved the middle turbinate in the group two "60 patients". We assessed the patients pre-operatively by Sino-nasal outcome Test (SNOT-22), intra-operatively by Likert scale score for the sinuses accessibility. At least 6 months post-operatively, we assessed the patients by SNOT-22, and Likert scale score for sinus accessibility.

RESULTS

During and after surgery, the Likert scale score in the group one showed statistically significant better sinuses accessibility than in the group two. We noticed synechia between the MT and the lateral nasal wall in 9.2% and 18.2% of the operated sides in group one and group two, respectively. SNOT-22 and its smell item improved significantly in both groups with no statistically significant differences between them. No major complications were reported.

CONCLUSION

Anterior part middle turbinoplasty is a safe and effective technique during endoscopic sinus surgery to improve the intra- and post-operative sinus accessibility, and decrease the incidence of post-operative synechia, with no adverse effect on olfaction or bleeding.

Lipidomic profile of human nasal mucosa and associations with circulating fatty acids and olfactory deficiency

The nasal mucosa (NM) contains olfactory mucosa which contributes to the detection of odorant molecules and the transmission of olfactory information to the brain. To date, the lipid composition of the human NM has not been adequately characterized. Using gas chromatography, liquid chromatography coupled to mass spectrometry and thin layer chromatography, we analyzed the fatty acids and the phospholipid and ceramide molecular species in adult human nasal and blood biopsies. Saturated and polyunsaturated fatty acids (PUFAs) accounted for 45% and 29% of the nasal total fatty acids, respectively. Fatty acids of the n-6 family were predominant in the PUFA subgroup. Linoleic acid and arachidonic acid (AA) were incorporated in the main nasal phospholipid classes. Correlation analysis revealed that the nasal AA level might be positively associated with olfactory deficiency. In addition, a strong positive association between the AA levels in the NM and in plasma cholesteryl esters suggested that this blood fraction might be used as an indicator of the nasal AA level. The most abundant species of ceramides and their glycosylated derivatives detected in NM contained palmitic acid and long-chain fatty acids. Overall, this study provides new insight into lipid species that potentially contribute to the maintenance of NM homeostasis and demonstrates that circulating biomarkers might be used to predict nasal fatty acid content.

Superior turbinate management and olfactory outcome after endoscopic endonasal transsphenoidal surgery for pituitary adenoma: a propensity score-matched cohort study

Background

Surgical management of the superior turbinate (ST) is required to access the sella in endoscopic endonasal transsphenoidal surgery (EETS) for pituitary adenoma. Two common ST management techniques include partial resection of the ST (PRST) and intentional lateralization of the ST (ILST). Given the concentrated distribution of the olfactory nerve fibers on the medial surface of the ST, in this study we aimed to ascertain whether PRST worsens the objective olfactory outcome when compared with ILST.

Methods

A retrospective, propensity score‒matched cohort study was performed at a tertiary referral center. A total of 232 adult patients undergoing EETS for pituitary adenoma were analyzed. The threshold test (STT) and the 12‐item identification test (SIT‐12) from “Sniffin’ Sticks” were administered for separate nostrils preoperatively and 6 months postoperatively.

Results

Of 232 patients, 109 had right‐sided PRST and 123 received right‐sided ILST. Propensity score matching—controlling for olfactory‐related confounding factors, including gender, age, medical comorbidities, surgical technique, and preoperative olfaction—resulted in 74 matched pairs. When comparing the 6‐month postoperative olfactory performance of the right nostril, the STT score was significantly lower in the PRST group than the ILST group (p = 0.036, η² for effect size estimate = 0.030), but the SIT‐12 scores were similar in the 2 groups (p = 0.325). Overall, the olfactory outcomes for the right nostril did not qualitatively differ between the PRST and ILST groups (p = 0.401).

Conclusion

Despite its association with threshold impairment, PRST in EETS does not seem to carry an additional risk of postoperative olfactory dysfunction.

[Isolation of neurospheres and neural progenitor cells from the olfactory epithelium]

The olfactory epithelium (OE) is an accessible source of neural stem cells and progenitor cells. The objective of the study was to compare the effectiveness of various biopsy sites to isolate and propagate neural progenitor cells from the olfactory epithelium (OE). The authors assessed OE cell count in OE in different sites of the nasal cavity and showed the possibility of isolation neurospheres from nasal biopsies. In total, 45 inpatinets were included in the study. Biopsy specimens were obtained from 30 patients undergoing septoplasty and/or turbinate surgery. Three areas of OE were biopsied: lower third section of the nasal septum (A), anterior part of the middle turbinate (B), upper third of the nasal septum (C). Immunocytochemistry and fluorescence-activated cell sorting showed that OE cells were NCAM-positive. Mean percentage of NCAM+ cells was 7.8% for A, 42.7% for B and 18.2% for C. The difference was significant between A and B (p=0.0001) and B and C (p=0.01). Therefore, the anterior part of the middle turbinate was an easily accessible and safe site to obtain neural cells. To confirm this, neurospheres were obtained in 15 patients with schizophrenia who underwent in-office endoscopy.

[Olfactory neuroepithelium as a model for the studies of molecular mechanisms of schizophrenia]

Olfactory neuroepithelium (OE) is shown to be a suitable experimental model to study neuronal biomarkers of psychiatric diseases including schizophrenia. Olfactory neuronal precursors can be useful for studying neurodevelopmental stages, neuronal markers, pharmacological screening. However, a limited number of research groups have used this cell model in a small number of patients and healthy people that can be explained by several factors. Based on literature reports and own research, the authors analyze the advantages and limitations of OE-derived cell/tissue models. The main limitations of these models are decreased rate of harvesting and culturing OE-derived cell and low percentage of patients who agreed to participate in the study. Our results showed that only 10% of patients with schizophrenia signed informed consent for nasal biopsy, 80% of them underwent biopsy.

The Middle Turbinate Resection and Its Repercussion in Olfaction with the University of Pennsylvania Smell Identification Test (UPSIT)

Introduction  Nasal obstruction is a common complaint, and, for some, the middle turbinate resection is still a controversial issue among the surgical options due to the possibility of deleterious effects on olfaction. The University of Pennsylvania smell identification test (UPSIT) is considered the gold standard of smell identification tests, but data about it is still incipient in Brazil.

Objective  To evaluate if the middle turbinectomy has any repercussion on the sense of olfaction by using the UPSIT as an assessment tool.

Methods  A prospective study performed between 2013 and 2015 with 27 patients who were treated with middle turbinectomy by the same surgeon and tested with the UPSIT pre- and post-surgery, with a minimum interval of 3 months.

Results  Twenty-five patients completed the study. The mean age was 27.9 years. There was no statistical correlation between middle turbinectomy and the UPSIT score, or between gender and the UPSIT score.

Conclusion  There was no clinical repercussion on olfaction from partial middle turbinectomy.