Management and rehabilitation of patients with persistent olfactory disorders (hypo- and anosmia) (literature review)

We present a review of the literature and our own data on the management and rehabilitation of impairment or persis‑tent loss of the olfactory function – hypo‑ and anosmia. Approaches for restoring impaired olfactory function can be divided into olfactory training, pharmacological and physiotherapy. Smell training is carried out according to a number of protocols that differ mainly in the used arsenal of smells, as well as in the frequency of their presentation. Pharma‑cologically, it is proposed to use steroids used both topically (intranasally) and systemically; there is no common view on the effectiveness of this approach. Physiotherapy involve electrical stimulation of the olfactory filaments in the area of their exit into the nasal cavity (lateral masses of the ethmoid bone). In our opinion the most rational approach is the use of training methods using different smells.

About cystic stretching of the Highmor's cavity

The existence of cystic stretching of the frontal and sphenoid sinuses, as well as the labyrinth of the ethmoid bone, is beyond any doubt - a similar kind of disease has been described at different times by many authors.

Septal chondrocyte hypertrophy contributes to midface deformity in a mouse model of Apert syndrome

Midface hypoplasia is a major manifestation of Apert syndrome. However, the tissue component responsible for midface hypoplasia has not been elucidated. We studied mice with a chondrocyte-specific Fgfr2S252W mutation (Col2a1-cre; Fgfr2S252W/+) to investigate the effect of cartilaginous components in midface hypoplasia of Apert syndrome. In Col2a1-cre; Fgfr2S252W/+ mice, skull shape was normal at birth, but hypoplastic phenotypes became evident with age. General dimensional changes of mutant mice were comparable with those of mice with mutations in EIIa-cre; Fgfr2S252W/+, a classic model of Apert syndrome in mice. Col2a1-cre; Fgfr2S252W/+ mice showed some unique facial phenotypes, such as elevated nasion, abnormal fusion of the suture between the premaxilla and the vomer, and decreased perpendicular plate of the ethmoid bone volume, which are related to the development of the nasal septal cartilage. Morphological and histological examination revealed that the presence of increased septal chondrocyte hypertrophy and abnormal thickening of nasal septum is causally related to midface deformities in nasal septum-associated structures. Our results suggest that careful examination and surgical correction of the nasal septal cartilage may improve the prognosis in the surgical treatment of midface hypoplasia and respiratory problems in patients with Apert syndrome.

Computed tomography at preoperative preparation of patients for endoscopic endonasal interventions

Introduction. Computed tomography is a non-invasive technique for examining patients and is helps to study the structures of the paranasal sinuses before endonasal interventions. The purpose of the study: to develop the criteria for assessing the architectonics of the ethmoid bone using computed tomography to determine the anatomical and topographic features of its structure, for endonasal surgical treatment planning. Tasks: to study variants of the anatomical structure of the nasal cavity, ethmoid bone, using the method of x-ray computed tomography and determine their role in planning tactics of endonasal surgical interventions. Materials and methods: 130 patients were examined, two groups of patients were formed — the first 65 people with cerebrospinal fluid lick, and the other 65 people with inflammatory diseases of the paranasal sinuses. All the patients underwent computed tomography, after which we studied the anatomical structure of the ethmoid plate of the ethmoid bone and cells of the ethmoid labyrinth and the contents of the paranasal sinuses were evaluated. Research results. The study revealed 6 basic anatomical and topographic types of the structure of the ethmoid bone. We evaluating the position of the plane of the ethmoid plate, a conclusion was made about the location of the roof of the nasal cavity: high, medium or low. The deeper the olfactory fossa is, the lower the general nasal passage is. Conclusions. The revealed low location of the roof of the nasal cavity was regarded as a predisposing factor to the development of iatrogenic cerebrospinal fluid lick with endoscopic endonasal intervention.

Anatomycal features of the ethmoidal labyrinth and nasal cavity structures in childhood

The morphotopometric variability of the ethmoidal labyrinth and the parameters of the nasal cavity for 87 childrens cranium (121 years) has been determined. The growth of the ethmoidal labyrinth and the nasal cavity occurs undulating and unevenly. The increase of the height of the ethmoidal labyrinth begins earlier than its width and length from 23 years to 1316 years old. Growth periods the height of ethmoidal labyrinth occur for 23 years, 812 and 1316 years; widths 47, 812 and 1721 years; length 47, 812 and 1316 years. At the ethmoidotomy in the infant and early childhood, the smallest size of the ethmoidal labyrinth should be taken into account: width 78 mm, height 1416 mm, length 2729 mm, so in these age periods there is a high risk of damage of the cribriform and orbital plates ethmoid bone with the development of iatrogenic complications. The nasal cavity штchildren expands posteriorly as well as in adults. In the infancy, the width of the nasal cavity at the back corresponds to the width in the front section, from 2 years prevails than in front and by adolescence becomes larger for 33,5 mm. Knowing these agerelated features of the structure of the childrens nasal cavity, during surgery the rhinosurgeon when shifting the middle nasal shells medially or laterally should ensure to maintain the physiological model of the nasal cavity. In infancy, the width of the ethmoidal labyrinth is larger than the width of the nasal cavity by 38,5%, and by adolescence this ratio increases to 76,8%. The length of the nasal cavity increases from 47 years to adolescence, the length of the ethmoidal labyrinth grows parallel to the maximum length of the nasal cavity and it is less for more than a half in all childrens age groups: in the infancy by 74%, in adolescence by 85.1%. The height of the nasal cavity is twice the height of the labyrinth in any childhood age, the distance from the bottom of the nasal cavity to the lower edge of the middle nasal shell must be correlated with the distance above the level of the average nasal shell during intranasal surgeries and do not exceed it for the introduction of tools.

Age-related features of the ethmoid bone in children and their clinical value

Objective. To determine the variability of morphometric parameters of ethmoid bone structures in childhood and to identify the most significant of them to optimize surgical interventions. Materials and methods. Craniometry of 87 native samples of children's skulls aged 1-21 years without gender identity, and 85 computer tomograms (CT) scans of children of the same age were carried out. Measurements on skulls were made with caliper gage, metal ruler. The CT scan was performed on «Toshiba» 4-slice computer scanner «Asteion-S4» with a 0.5-1.0 mm increment. To assess the validity of the differences between the rows, the t-criterion was used for independent samples. Results. The ethmoidal labyrinth at the age of 1-1.5 and 2-3 years has the smallest size: length - 26.9-28.7 mm, width - 7.1-7.7 mm, height - 14.1-15.9 mm. However, the cribriform plate reaches in infancy almost the same size as an adult (length 21.7 mm, width 10.4 mm at the front and 11.2 mm at the back) and is rectangular or oval in shape. By adolescence, its shape changes to trapezoidal or triangular. Frequency of pneumatization of crista galli (8.3-82.4%) increases in children's age groups similar to that of sinuses. Trans-ethmoid access to the base of the skull during endonasal operations is significantly difficult in children under 4 years old. Transcribriform access to the anterior cranial fossa and crista galli can be used from infancy. Conclusion. The ethmoid bone is mostly formed by the time of birth. The increase is observed by the age of 2 years, and then in 13-16 years, in 17-21 years the growth of the ethmoid bone stabilizes.

Orbital Anatomy: Anatomical Relationships of Surrounding Structures

Advances in skull base and orbital surgery have led to an increased need to understand the anatomy of the orbit and surrounding structures to safely perform surgeries in this area. The purpose of this article is to review the surrounding anatomy of the orbit from a practical and operative point of view. We describe the orbit from an inferomedial endoscopic endonasal perspective (focusing on its inferior relationship with the maxillary sinus and related structures and its medial relationship with the ethmoid bone), from a posterior and superolateral intracranial perspective (describing the anatomy of the superior orbital fissure, optic canal, inferior orbital fissure, cavernous sinus, orbitofrontal cortex, and surrounding dura) and from an anterior perspective (focusing on the muscles, connective tissue, lateral and medial canthus, and relevant neurovascular anatomy). A deep knowledge of the critical neurovascular and osseous structures surrounding the orbit is necessary for adequately choosing and performing the most favorable orbital approach in every case.

18F-FDG brain PET metabolism in post-SARS-CoV-2 infection: substrate for persistent/delayed disorders?

Purpose: Several brain complications of SARS-CoV-2 infection have been reported. It has been moreover speculated that this neurotropism could potentially cause a delayed outbreak of neuropsychiatric and neurodegenerative diseases of neuroinflammatory origin. A propagation mechanism has been proposed across the cribriform plate of the ethmoid bone, from the nose to the olfactory epithelium, and possibly afterwards to other limbic structures, and deeper parts of the brain including the brainstem. Methods: Review of clinical examination, and whole-brain voxel-based analysis of 18F-FDG PET metabolism in comparison to healthy subjects (p-voxel<0.001, p-cluster<0.05), of two patients with confirmed diagnosis of SARS-CoV-2 pneumonia explored at the post-viral stage of the disease.Results: Hypometabolism of the olfactory/rectus gyrus was found on the two patients, especially one with 4 weeks prolonged anosmia. Additional hypometabolisms were found within bilateral amygdala, hippocampus, cingulate cortex, thalamus, pons and medulla brainstem in the other patient who complained of delayed onset of an atypical painful syndrome.Conclusion: These preliminary findings reinforce the hypotheses of SARS-CoV-2 neurotropism through the olfactory bulb, and the possible extension of this impairment to other limbic structures and to the brainstem. 18F-FDG PET hypometabolism could constitute a cerebral quantitative biomarker of this involvement. Post-viral cohort studies are required to specify the exact relationship between limbic/brainstem hypometabolisms and the possible persistent disorders, especially involving cognitive or emotion disturbances, residual respiratory symptoms or painful complaints.