RNA therapies for CNS diseases.

Neurological disorders are a diverse group of conditions that pose an increasing health burden worldwide. There is a general lack of effective therapies due to multiple reasons, of which a key obstacle is the presence of the blood-brain barrier, which limits drug delivery to the central nervous system, and generally restricts the pool of candidate drugs to small, lipophilic molecules. However, in many cases, these are unable to target key pathways in the pathogenesis of neurological disorders. As a group, RNA therapies have shown tremendous promise in treating various conditions because they offer unique opportunities for specific targeting by leveraging Watson-Crick base pairing systems, opening up possibilities to modulate pathological mechanisms that previously could not be addressed by small molecules or antibody-protein interactions. This potential paradigm shift in disease management has been enabled by recent advances in synthesizing, purifying, and delivering RNA. This review explores the use of RNA-based therapies specifically for central nervous system disorders, where we highlight the inherent limitations of RNA therapy and present strategies to augment the effectiveness of RNA therapeutics, including physical, chemical, and biological methods. We then describe translational challenges to the widespread use of RNA therapies and close with a consideration of future prospects in this field.

Invasive Cytomegalovirus (CMV) Sinusitis in an Acquired Immunodeficiency Syndrome (AIDS) Patient.

A patient with acquired immunodeficiency syndrome presented with findings concerning for acute invasive fungal sinusitis, which is typically associated with Mucorales. However, debridement and pathological analysis revealed Cytomegalovirus, a pathology rarely encountered. Laryngoscope, 134:92-96, 2024.

Nanotechnology-enabled topical delivery of therapeutics in chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease of the paranasal sinuses which represents a significant health burden due to its widespread prevalence and impact on patients' quality of life. As the molecular pathways driving and sustaining inflammation in CRS become better elucidated, the diversity of treatment options is likely to widen significantly. Nanotechnology offers several tools to enhance the effectiveness of topical therapies, which has been limited by factors such as poor drug retention, mucosal permeation and adhesion, removal by epithelial efflux pumps and the inability to effectively penetrate biofilms. In this review, we highlight the successful application of nanomedicine in the field of CRS therapeutics, discuss current limitations and propose opportunities for future work.

Chronic sinusitis is a common inflammatory condition of the sinuses, which affects patients' quality of life and consumes significant healthcare resources. It is primarily treated with corticosteroids, a type of medication that reduces inflammation, as a nasal spray or taken orally. Nasal sprays are preferred, to minimize side effects elsewhere in the body. Recently, another class of drugs ­ 'biologic agents' ­ has been approved for a subtype of chronic sinusitis that causes polyps (grape-like swellings of the sinus lining). However, a lasting cure is elusive, because inflammation frequently returns once these medications are stopped. As our understanding of what causes chronic sinusitis improves, researchers are seeking therapies that more accurately target the cause of inflammation, rather than broadly suppressing all types of inflammation using corticosteroids. The use of nanotechnology allows the design of drugs to overcome various challenges in treating chronic sinusitis, potentially enabling more accurate delivery of drugs into the sinuses, improving drugs' ability to remain on the sinus lining and penetrate it, reducing the amount of drug lost due to the action of outflow pumps and overcoming additional defenses built up by bacteria when they form thick films. Here, we describe how nanomedicine has been used to develop drugs for chronic sinusitis, discuss current limitations and propose opportunities for future work.

Update on allergic fungal rhinosinusitis.

Allergic fungal rhinosinusitis (AFRS) is a unique clinical entity that falls under the broader umbrella of chronic rhinosinusitis with nasal polyps with type 2 inflammation. It is characterized by nasal polyposis, production of characteristic thick eosinophilic mucin, and expansile change of involved sinus cavities. The diagnosis is classically made using the Bent and Kuhn criteria. However, recent studies have indicated the lack of specificity of some major criteria. The need to fulfill all 5 criteria before diagnosing AFRS partially mitigates this but renders the criteria cumbersome to use, and highlights the need to develop more specific criteria. Our understanding of AFRS pathophysiology has advanced significantly and has helped elucidate the lack of histatins contributing to the inability to clear fungal spores, consequently leading to fungi-induced disruption of the epithelial barrier and stimulation of sinonasal epithelial cells. These trigger a cascade of type 2 inflammatory cytokines driven by both the adaptive and innate immune system. Although more research is needed, these findings could hypothetically point to a limited type 3 immune response at the sinus mucosa, resulting in a compensatory overstimulation of type 2 inflammatory processes. Treatment for AFRS remains centered on surgery and topical corticosteroids. Short courses of systemic corticosteroids may be used with caution, and fungal-specific immunotherapy and systemic antifungals are options in recalcitrant disease. Biologics show early promise, as we await data from randomized controlled trials under way. Finally, new insights into AFRS pathology provide opportunities for novel therapeutic strategies.

Osteoradionecrosis of the lamina papyracea leading to recurrent orbital infections-A case study.

Osteoradionecrosis (ORN) is a well-known complication of radiotherapy (RT) to the sino-nasal cavity and nasopharynx. Here, we report a case of recurrent orbital infections secondary to ORN of the lamina papyracea (LP). A 66-year-old female presented to our unit with right periorbital swelling and pain after having undergone chemotherapy and proton beam irradiation to her ethmoid sinuses for sino-nasal undifferentiated carcinoma (SNUC) 5 years prior. She had also undergone endoscopic sinus surgery for chronic rhinosinusitis about a year prior to the current presentation. Her post-operative course was notable for recurrent episodes of pre-septal cellulitis occurring about 3 months apart that were increasingly severe. Examination revealed right proptosis, and endoscopy showed an exposed and denuded LP with scant crusting of the ethmoid sinuses. Microbial studies did not yield any significant growth, and imaging showed enhancement of the right orbit. The working diagnosis was acute right orbital cellulitis secondary to ORN of the right LP. She was treated with broad spectrum intravenous antibiotics and systemic steroids, but experienced minimal symptomatic improvement. She then underwent endoscopic resection of the right LP, and histopathological examination showed osteonecrosis on an inflammatory background. Post-operatively, all orbital symptoms resolved and she was well at 6 months' follow up. In the discussion, we highlight additional factors in our patient that may have contributed to this clinical presentation, and hope that this report raises awareness of a rare complication of RT to the sino-nasal cavity.

Allergic Fungal Rhinosinusitis: The Role and Expectations of Biologics.

Allergic fungal rhinosinusitis (AFRS) is a noninvasive subtype of chronic rhinosinusitis with nasal polyps (CRSwNP) that usually develops in immunocompetent atopic individuals and is more common in geographic regions characterized by warm temperatures and high humidity, conducive to higher environmental fungal presence. Allergic fungal rhinosinusitis usually presents with unique computed tomography findings and significant polyp burden, yet patients often report minimal sinus symptoms. Patients with AFRS often have extremely elevated serum total and fungal-specific IgE levels. Treatment almost always requires surgery, in which adjuvant medical therapy is critical to success. However, until recently the choice of adjuvant therapy has consisted primarily of either oral and/or topical steroids. Although oral corticosteroids decrease recurrence after surgery, data for the effectiveness of other adjunctive pharmacologic agents, including topical and oral antifungal agents and immunotherapy, have remained unclear and hence are not recommended in recent guidelines including the International Consensus of Allergy and Rhinology. Three biologics, omalizumab, dupilumab, and mepolizumab, have recently been approved for treating CRSwNP in general, but clinical trials to date with these biologics did not involve AFRS patients. Recently published case reports and smaller prospective studies have shown good efficacy of these biologics on the AFRS subgroup of patients. This article provides an overview of the understanding of the pathophysiology of AFRS, implications of this understanding on the possible role of biologics, and clinical reports on the use of biologics in treating AFRS. Because biologics are indicated for treating CRSwNP, follow up real-world evidence studies are needed for AFRS.

Grisel's Syndrome in an Adult After Endoscopic Nasopharyngectomy.

BACKGROUND: Grisel's syndrome is rare in adults, and is characterized by nontraumatic atlanto-axial subluxation secondary to infection. Here, we report a case of Grisel's syndrome occurring after endoscopic nasopharyngectomy. METHODS: A 67-year-old man complained of fever and neck pain with reduced lateral rotation after an endoscopic nasopharyngectomy for recurrent nasopharyngeal carcinoma. Flexion and extension X-rays of the cervical spine demonstrated atlanto-axial subluxation, and magnetic resonance imaging showed infective changes with cervical osteomyelitis. A diagnosis of Grisel's syndrome with cervical spine osteomyelitis was made. A later computed tomography (CT) scan demonstrated subluxation of C1 on C2, as well as the occipital-C1 joint. RESULTS: The patient was treated with intravenous antibiotics and offered surgery for spinal stabilization, but declined. He remained well 15 months post-op on a cervical collar with minimal pain and no neurologic deficits. CONCLUSION: A high index of suspicion for Grisel's syndrome is suggested in patients who have neck pain with reduced range of motion postnasopharyngectomy, and imaging is useful in clinching the diagnosis. LEVEL OF EVIDENCE: 4.