الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 116 |  |  |
| | | from | 116 | | |
Abstract
Causes of olfactory dysfunction can be due to physical blockage of airflow to olfactory mucosa that is called the conductive type or due to disruption of the olfactory-neural signaling pathway which is the sensory-neural type. The Conductive types include diseases of the nasal and paranasal sinuses (including nasal stenosis, allergic rhinitis, chronic rhinosinusitis with polyposis, and tumors. The Sensory-neural types include post viral (upper respiratory tract infections), head injury, neurodegenerative disorders, congenital (Kallman’s syndrome), and toxins. It is the belief of the scientific community that olfactory dysfunction is potentially an early symptom of COVID-19 and a characteristic finding of COVID-19 patients, which can be the only symptom or with other symptoms. Several mechanisms for the anosmia in COVID-19 have been suggested such as Olfactory cleft obstruction, local inflammation in the nasal epithelium, atrophy of the olfactory bulbs, Olfactory cleft syndrome, early apoptosis of olfactory cells, changes in olfactory cilia and odor transmission, damage to microglial cells, epithelial olfactory injury, and damage to olfactory neurons and stem cells. The aim of our study is to investigate the olfactory bulb changes in COVID-19 patients with anosmia through MRI. We evaluated 110 patients with COVID-19 olfactory dysfunction. All patients were anosmic at the time of imaging based on smell test scores. And a control limb of 50 normal individuals. Our finding could be summarized as follows : -OB volumes were significantly higher in case group when compared to the control group indicating olfactory epithelial inflammation and subsequent olfactory bulb edema. -OC edema was seen in 57.3% indicating a conductive olfactory loss. Some cases reported OB atrophy (14.6%). The majority of our patients were mild cases as regard chest condition, there were no abnormalities (score 0 and 1) detected in the CT chest in most of the cases 91.82%.