Sudden loss of smell is a common symptom associated with COVID-19 and SARS-CoV-2 infection of neurons in the olfactory system has been reported in both hamsters and humans. The vast majority of patients with COVID-19 recover olfactory function within a few weeks. However, a significant minority of infected individuals (1 in 5 cases), still suffer from olfactory disorders (anosmia, hyposmia and/or parosmia) several months after primary infection. These olfactory disorders are frequently associated with depressive behavior and cognitive complaints. In PET, it is even possible to correlate this cognitive dysfunction with hypometabolism of certain brain regions, including the olfactory gyrus.
This project proposes to evaluate and follow the evolution, during one year, of the olfactory capacities of patients with persistent smell disorder since one year (+/- 4 months) following COVID-19. We propose to study the link between viral persistence in the olfactory sensory organ, chronic inflammation, and central damage to the olfactory system. The follow-up of the evolution of olfactory and neurocognitive capacities, in an integrative way by means of molecular, physiological and behavioral approaches, will inform us on the specificities of the “COVID-long” and on the level of peripheral and/or central damage of the olfactory system.
Within this framework, thirty participants will be recruited and followed in the ENT department of the Lariboisière Hospital during two one-day visits spaced out over 12 months. During these two visits, the participants will perform
- complete evaluation of their olfactory abilities:
- A self-evaluation questionnaire
- A “Sniffing stick test” (Threshold, Discrimination and Olfactory Identification test)
- A recording of their brain activity in response to odors (PEO)
- A Brushing of their olfactory slits for analysis of their olfactory mucosa.
- A complete neurocognitive assessment :
- Evaluation questionnaires
- A blood sample for the search of plasma markers of neurological damage (12mL or 3 tubes)