Relationship Between Parkinson’s Disease and Loss of Smell

Parkinson's disease and loss of sense of smell are strongly connected. The majority of people with Parkinson’s will experience the loss of sense of smell at some stage of their condition. It is one of the first signs of early Parkinson's disease and is easily overlooked by doctors. Many patients find they lose their sense of smell years before they get a Parkinson's diagnosis, while others don't even notice the changes. So why does this happen, and is there any way to get your sense of smell back? Let's look at the relationship between Parkinson's disease and loss of sense of smell, as well as possible treatments and outlook.

Parkinson’s Disease and Loss of Sense of Smell: Why It Happens

Parkinson's disease and loss of sense of smell is also known as hyposmia. Not everyone with hyposmia goes on to develop Parkinson's disease, but most people with the condition report change or loss of smell as one of their early symptoms.

No one quite knows what causes loss of sense of smell in Parkinson’s disease. One theory – based on the research of Heiko Braak, MD – suggests that Parkinson’s disease may not start in the substantia nigra (the region of the brain that controls dopamine cells), but, controversially, in the gastrointestinal system and the olfactory bulb – the part of the brain responsible for your sense of smell. Braak hypothesizes that Parkinson’s disease forms in these parts of the body first before migrating to other parts of the brain, including the substantia nigra, but this theory has not been proven.

Parkinson’s Disease and Loss of Smell: Is There a Cure?

Sadly, there is currently no cure for Parkinson's disease, nor is there a way to prevent the progression of  Parkinson's symptoms. Various treatment options exist to control motor, non-motor and emotional effects of Parkinson's disease, including medication, occupational therapy and surgical intervention. However, there is currently no treatment for loss of sense of smell.

If you experience Parkinson's disease and loss of sense of smell, you may find that this change affects your appetite, as smell and taste are strongly connected. If this happens, it's crucial to seek nutritional advice to help you manage your weight and stay healthy. As your condition progresses, you may need help cooking and feeding yourself, but it can take years or even decades for patients to get to this stage.

I've Lost My Sense of Smell: What Should I Do?

Loss or change of sense of smell doesn't necessarily mean you have Parkinson's disease. Many people lose their sense of smell as they get older. For this reason, loss of sense of smell alone is not always indicative of a neurological condition; there are plenty of other possible causes, such as sinus infection, allergies or growths in your nose (nasal polyps). You could try cleaning your nose with a saltwater solution, which you can pick up from your nearest pharmacy.

One way to test your sense of smell is to sniff strong-smelling foods like licorice and dill pickles. If you notice changes to your sense of smell, it's important to see your doctor – especially if you're over 60 when Parkinson's disease is more common. Early detection is key to treating Parkinson's disease, and loss of sense of smell can be one of the earliest signs before there are noticeable motor symptoms attributed to Parkinson's disease.

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