Hope for restoring lost sense of smell

For the first time in South Africa, patients who have lost their sense of smell through illness or an accident have a chance at restoring their lost sense with a new plasma-based therapy.

In January 2024, Cape Town otolaryngologists (ear, nose and throat specialists) Dr Nic Goncalves and Dr Darlene Lubbe began offering plasma therapy to patients at their ENT practice at Mediclinic Cape Town. While they have only completed the procedure on one patient so far, results can take up to three months to show.

Losing your sense of smell (anosmia), having a distorted sense of smell (parosmia) or a reduced sense of smell (hyposmia) can significantly affect your quality of life and have psychological implications, including causing depression and anxiety. “The loss of smell can be quite debilitating and severely impact your quality of life,” says Dr Goncalves. “It might mean you can’t taste, or struggle to differentiate tastes.”

Dr Goncalves adapted research done by ENTs at Stanford University to investigate a promising potential smell-restoration treatment developed in 2022. Looking for faster and more successful treatments than existing options, this US study on a small sample of patients focused on injecting into a patient’s nasal cavity a substance derived from the patient’s own blood: platelet-rich plasma.

“Up to now, there was very little you could do about nerve damage to restore a person’s sense of smell,” explains Dr Goncalves. “Various treatments have been tried, including smell therapy or olfaction training, to restore a sense of smell in patients who have had a brain injury or trauma to the nose, to retrain the brain through exposure to common smells.”

During COVID-19 these were the main treatment options, with varying degrees of success, along with steroid nose sprays or irrigation to reduce inflammation and salvage, or at least reduce, nerve loss.

Why do people lose their sense of smell?

Losing your sense of smell can be the result of a conduction problem or nerve damage, explains Dr Goncalves.

In the case of a conduction problem, there is usually an obstruction in the nasal cavity, such as a polyp or inflammation, that blocks the diffusion of smell to the nerves. When there has been nerve damage, the nerves can’t interpret smell.

“We have seen a huge increase in patients with loss of smell during COVID-19 as a result of nerve damage, because the coron virus damages the nerve endings in the nasal cavity and, in particular, those responsible for smell,” says Dr Goncalves.

A shot of platelet-rich plasma

The developed treatment uses platelet-rich plasma, which is full of growth factors, to restore a sense of smell in patients who had been unable to smell for at least six months and who had tried olfactory training and steroid sprays, to no effect.

Blood is taken from the patient and spun in a centrifuge to extract the platelet-rich plasma, which is rich in growth factors. This is then injected into the area of the nose where one smells in the hope that it will either restore or partly restore nerve generation to help with smell loss.

In the clinical trial, patients were divided into two groups: one group received the plasma injections, while the second received a placebo. “What was quite clear is that most of the plasma patients received significant clinical benefits either in partially improving or fully restoring their sense of smell,” says Dr Goncalves.

Side-effect-free procedure

One of the advantages of the treatment is that it uses the patient’s own plasma, meaning there is no risk of side-effects or allergic reactions. The growth factors in the plasma have been shown previously by orthopaedic surgeons to boost regeneration in other parts of the body, including cartilage in joints, such as knees.

“The biggest risk is that it may not work, but from the trial, it shows there might be a benefit to those who have lost their sense of smell. The treatment needs to be done after six months and within the first year of losing your sense of smell, as after 14 months there is usually permanent nerve damage and the longer you have a loss of smell, the less likely you will regain it,” says Dr Goncalves.

“Based on the Stanford studies, we wanted to offer the treatment in South Africa because it seems promising. Sometimes it takes a crisis to push the boundaries in science and, in this case, COVID-19 was that catalyst in pushing the science to try to help patients.”

This minor procedure is done in theatre, with patients receiving the platelet-rich plasma (PRP) injections, usually under a general anaesthetic, with the patient being able to go home the same day. If the treatment proves to have been effective after three months, this should be a lifelong benefit, says Dr Goncalves.

For more information, contact 021 180 3662 or email: admin@sinussurgeons.co.za