Post-COVID-19 Hyposmia Does Not Exhibit Main Neurodegeneration Markers in the Olfactory Pathway.

The biological substrate of persistent post-COVID-19 hyposmia is still unclear. However, as many neurodegenerative diseases present with smell impairment at onset, it may theoretically reflect degeneration within the central olfactory circuits. However, no data still exist regarding the post-COVID-19 patients. As the olfactory neurons (ONs) mirror pathological changes in the brain, allowing for tracking the underlying molecular events, here, we performed a broad analysis of ONs from patients with persistent post-COVID-19 OD to identify traces of potential neurodegeneration. ONs were collected through the non-invasive brushing of the olfactory mucosa from ten patients with persistent post-COVID-19 hyposmia (lasting > 6 months after infection) and ten age/sex-matched controls. Immunofluorescence staining for protein quantification and RT-PCR for gene expression levels were combined to measure ONs markers of α-synuclein, amyloid-ß, and tau pathology, axonal injury, and mitochondrial network. Patients and controls had similar ONs levels of oligomeric α-synuclein, amyloid-ß peptide, tau protein, neurofilament light chain (NfL), cytochrome C oxidase subunit 3 (COX3), and the heat shock protein 60 (HSP60). Our findings thus did not provide evidence for synucleinopathy and amyloid-ß mismetabolism or gross traces of neuronal injury and mitochondrial dysfunction within the olfactory system in the early phase of persistent post-COVID-19 hyposmia.

Assessing Cognitive Effort in Ménière's Disease: Pupillometry as a Novel Tool for Postural Control.

BACKGROUND: This study aimed to investigate the utility of pupillometry as a measure of cognitive effort in individuals with Ménière's disease experiencing chronic postural destabilization. By integrating pupillometry with static posturography, we sought to gain deeper insights into the cognitive demands and arousal levels associated with postural control in this specific patient population. METHODS: The study included 36 patients who met the diagnostic criteria for Ménière's disease and a control group comprising 36 healthy volunteers. We performed static posturography using a computerized static posturography platform to objectively assess postural imbalance. Additionally, pupillometry was recorded using infrared video-oculoscopy. Pupil dilation was measured before and after participants walked for 7 steps on-site with their vision obscured. RESULTS: Baseline tonic pupil size showed no significant difference between healthy controls and Ménière's patients. However, after walking stimulation, Ménière's patients exhibited highly significant abnormal walking-induced pupil dilation. This suggests increased arousal in response to the challenging task of walking with closed eyes, linked to static upright stance imbalance as correlated with posturography parameters. CONCLUSION: Pupillometry holds promise as an objective tool to assess cognitive effort and arousal during postural control in Ménière's disease. Implementing pupillometry in clinical practice could enhance the management of postural instability in these patients. Our findings contribute to the understanding of cognitive aspects in balance control and open new avenues for further investigations in vestibular dysfunction.

Autoantibody profiles assessment in individuals with persistent olfactory impairment following SARS-CoV-2 infection.

BACKGROUND: Olfactory impairment, particularly hyposmia and anosmia, has emerged as a distinctive early symptom of SARS-CoV-2. Drawing on the historical association of autoimmune diseases with olfactory function, this study delves into the connections between COVID-19, autoimmunity, and persistent olfactory dysfunctions, focusing on individuals experiencing long-lasting smell disorders (3-18 months post-SARS-CoV-2 infection). METHODS: The study comprised 36 Long Covid patients with persistent olfactory dysfunctions, alongside two control groups. Olfactory functionality was assessed using the Sniffin' Sticks extended test. Non-invasive olfactory mucosa brushing and nasal secretions were processed for nasal samples, while serum samples were obtained through peripheral venous sampling. A panel of autoantibodies, including Immunocirculating Complexes, ANA, ENA, and AECA, was investigated in serum and brush supernatant samples. RESULTS: Contrary to expectations, the absence of traditional autoantibodies challenges the proposed autoimmune etiology of Long Covid-associated olfactory dysfunction. However, the presence and potential pathogenic role of AECA suggest viral cytopathic and inflammatory involvement in specific anatomical districts. One hypothesis explores the impact of inflammation and cytokine release induced by the viral infection, altering neuronal signaling and contributing to persistent hyposmia. CONCLUSION: This research contributes to our understanding of the complex relationships between autoimmunity, olfactory impairment, and COVID-19. The absence of classical autoantibodies challenges prevailing theories, while the prominence of AECA hints at unique viral-induced pathogenic mechanisms. By unraveling these complexities, this study enhances our comprehension of post-acute sequelae, offering valuable perspectives on immune-mediated responses in the aftermath of the pandemic.

Transnasal Endoscopic Treatment of Tension Pneumocephalus Caused by Posttraumatic or Iatrogenic Ethmoidal Damage.

Background: Tension pneumocephalus is a neurosurgical emergency caused by progressive accumulation of air in the intracranial spaces mediated by a valve mechanism. Tension pneumocephalus usually presents with headaches, reduced consciousness, and even death. One of the most common causes is an ethmoidal defect resulted by nasal surgery or facial traumas. Methods: A literature review about tension pneumocephalus resulting from ethmoidal damages was performed. Surgery strategies included decompression by frontal burr holes and multilayer repair of the ethmoidal defect. In this paper, an endoscopic technique that exploits the ethmoidal defect to decompress the intracranial spaces and to resolve tension pneumocephalus with fewer complications and shorter hospitalization in comparison to frontal craniotomy is proposed. Conclusion: The proposed endonasal endoscopic technique could be effectively used as a first-line treatment for symptomatic tension pneumocephalus caused by posttraumatic or iatrogenic ethmoidal defect.

Correction: Guerrieri et al. Nasal and Salivary Mucosal Humoral Immune Response Elicited by mRNA BNT162b2 COVID-19 Vaccine Compared to SARS-CoV-2 Natural Infection. Vaccines 2021, 9, 1499.

The authors wish to make the following corrections to this paper [...].

Evaluation of the accuracy in the mucosal detection of anti-SARS-CoV-2 antibodies in nasal secretions and saliva.

COVID-19 vaccination with mRNA vaccines induces immune responses capable of neutralizing SARS-CoV-2. Commercially available serological anti-SARS-CoV-2 quantitative and neutralizing assays are essential for the determination of immune responses to vaccines. Nevertheless, at present there is a lack of validated tests to assess the mucosal response to COVID-19 vaccination and standardized analytic and pre-analytic methods have not yet been defined. The aim of our study was to evaluate the accuracy of two diagnostic immunoassays for COVID-19 (ELISA for IgA-S1 and chemiluminescent assay for IgG-RBD) on serum, saliva, and nasal secretions, by the enrollment of three study populations (healthy controls, vaccinated subjects, and subjects recovered from COVID-19 infection). In order to obtain an appropriate cut-off value for the biological matrices studied, ROC curve analyses were performed. Data demonstrate that the analytical and pre-analytical method we have developed can provide accurate and reliable results for the detection of anti-SARS-CoV-2 mucosal specific antibodies (IgA-S1 and IgG-RBD) on saliva and, as a novelty, on nasal secretions, either after COVID-19 infection or in vaccinated subjects.

Adult onset Xanthogranuloma presenting as a solitary laryngeal localization: case report and review of literature.

Juvenile Xanthogranuloma (XG) is a rare disorder that belongs to the heterogeneous group of histiocytic neoplasms, characterized by a clonal expansion of non-Langerhans cell histiocytes that share a dermal macrophage phenotype. Although the head and neck region is the most common reported site of involvement by the Juvenile Xanthogranuloma family, laryngeal localization is extremely rare. We report a unique case of Adult Onset Xanthogranuloma with subglottic localization, presenting as a solitary laryngeal mass without other systemic or cutaneous lesions. A review of the previously described cases of laryngeal Xanthogranuloma has been performed, highlighting 7 cases of Juvenile Xanthogranuloma and only 3 cases of Adult Onset Xanthogranuloma. Despite the extreme rarity of laryngeal localization of XG, this histiocytic neoplasm should be considered as a differential diagnosis for laryngeal masses causing airway obstruction, even in the absence of other concomitant manifestations.

Nasal and Salivary Mucosal Humoral Immune Response Elicited by mRNA BNT162b2 COVID-19 Vaccine Compared to SARS-CoV-2 Natural Infection.

SARS-CoV-2 antibody assays are crucial in managing the COVID-19 pandemic. Approved mRNA COVID-19 vaccines are well known to induce a serum antibody responses against the spike protein and its RBD. Mucosal immunity plays a major role in the fight against COVID-19 directly at the site of virus entry; however, vaccine abilities to elicit mucosal immune responses have not been reported. We detected anti-SARS-CoV-2 IgA-S1 and IgG-RBD in three study populations (healthy controls, vaccinated subjects, and subjects recovered from COVID-19 infection) on serum, saliva, and nasal secretions using two commercial immunoassays (ELISA for IgA-S1 and chemiluminescent assay for IgG-RBD). Our results show that the mRNA BNT162b2 vaccine Comirnaty (Pfizer/BioNTech, New York, NY, USA) determines the production of nasal and salivary IgA-S1 and IgG-RBD against SARS-CoV-2. This mucosal humoral immune response is stronger after the injection of the second vaccine dose compared to subjects recovered from COVID-19. Since there is a lack of validated assays on saliva and nasal secretions, this study shows that our pre-analytical and analytical procedures are consistent with the data. Our findings indicate that the mRNA COVID-19 vaccine elicits antigen-specific nasal and salivary immune responses, and that mucosal antibody assays could be used as candidates for non-invasive monitoring of vaccine-induced protection against viral infection.