A report from Iceland, and the ISOT conference
What’s the latest on loss of smell? What did we learn from ISOT (International Symposium on Olfaction and Taste) June 2024
I am back from a wonderful visit to Iceland. The most stunning surroundings, and the capital, Rejkjavik, is a fascinating city. I attended three sessions at the ISOT conference that were relevant to the ckos Network. Let me describe them to you.
In the first, “Olfaction and other senses” we heard from a number of clinicians and researchers about combined disturbances of smell and the other senses, and how these should be taken into account.
Professor Hummel talked about smell and trigeminal function. This is the way our sense of smell interacts with the function of the trigeminal nerve. Chili, ginger, wasabi, and horseradish all engage our trigeminal nerve: hot, spicy, tingly. It seems that the sense of smell depends more on the trigeminal nerve than we thought, and whether or not we realise it, almost all smells provoke some trigeminal reaction. So while we think of chili first as an obvious example, even the most unexpected smells have a very slight effect on the trigeminal nerve. Loss of trigeminal nerve function is a recognised part of Covid and many post-infectious cases of smell loss. Damage to this nerves interferes with our brain’s interpretation of what we smell and taste.
Professor Carl Philpott spoke about gustation and the taste buds, and how this contributes to our perception of flavour.
Antje Welge Lüssen and Caroline Huart spoke about smell loss and frailty in the elderly. Loss of smell is being used now as an index of frailty towards the end of life. Smell training can improve the sense of smell in the elderly, and also improves certain kinds of cognitive function.
The second session was called Mechanisms driving long-Covid olfactory dysfunction and potential therapeutic strategies
The presentations in this session were highly technical and above my understanding of science. Regarding how Covid affected the sense of smell, however, progress is slow and there are still no “eureka” breakthroughs—that was clear from the summaries. There was a presentation on the function of immune cells, as well as a presentation about inflammatory cytokines. Everyone seems to agree that in some people, inflammation persists and recurs (fluctuations) but the mechanism is not understood. One speaker, Dr Andrew Lane of Johns Hopkins (USA) was questioned directly about fluctuations. He said that unfortunately, we still do not know why this persists.
The third presentation was called Smell and Taste Disorders: Taking research and care further with patient organisations
There were two groups representing patient groups: Anosmie.org (France) and the ckos Network. Anosmie.org made four presentations: Claire Franchini spoke movingly about her experience of TBI; Jean-Michel Maillard spoke about the development of this organisation; Chabha Djouder spoke about how they are working with pharmaceutical companies with respect to biologics for polyps; and Claire Martin spoke about how to build relationships between scientists and patients. There were short recorded videos from STANA’s Katie Boateng on their “promising practices” for advancing research, and Fifth Sense’s Duncan Boak on their work in the UK.
Finally, I laid out my vision for how to support people with smell loss. While we are waiting for more research, there are ways to help ourselves feel better, and I made a plea for a program that will scoop up patients after they have been discharged from their doctor’s care, and help them with the other kinds of support they need: peer support, practical advice, information they can trust, and help with making food manageable.
