Loss of Smell in PD: by Dr. De Leon

Smell is a potent wizard that transports you across thousands of miles and all the years you have lived.” -Helen Keller


Imagine not being able to smell your favorite food, perfume, or flower in my case the star-gazer lily. Smell is intricately connected to our memories. Have you ever walked into a place and immediately transported to a bye gone era simply by an aroma?

Smell is a huge component of  our everyday life, as I first discovered as an undergraduate when we did an experiment in which we were asked to drink of a substance while holding our nose tightly….after sipping the clear substance, we all unanimously hailed it as water. But after, the professor asked for us to drink the same liquid without holding our nose our astonishment was evident—-it was LEMONADE! A simple pinching of our nose had altered our perception of the world!

Loss of smell can be one of the earliest signs of Parkinson’s disease. It is believed that the olfactory bulb impairment is due to clumping of alpha synuclein…. (a normal protein found abundantly throughout the brain and in smaller amounts in heart, muscles and other tissues- believed to be an important player in maintaining synaptic vesicles in pre-synaptic terminals- these are the ones responsible for release of neurotransmitters like dopamine).

Recent data suggests that >95% of Parkinson’s patients present with significant loss of smell. This may be supportive of new theory that Parkinson’s disease starts in the olfactory bulb and not in basal ganglia as previously believed.

Besides helping us with survival by avoiding harmful substances like toxic gases or rotten foods the olfactory system help us to maintain personal hygiene, which allows us to interact with others socially.

Loss of smell has been linked to cognitive decline and loss because of that primitive connection to our memory banks; therefore it should come as no surprise that this is a harbinger of dementia –olfactory loss being one of the first symptoms and signs of Alzheimer’s and PD. Loss of smell has also been linked to psychiatric problems such as depression another common symptom of PD.

However, most people don’t really notice a loss of smell per say but rather a loss or change in taste because as I mentioned earlier taste is directly linked to our ability to smell. So food begins tasting bland and sometimes even foul. But when formerly tested using a Snell smell test, PD patients show deficits in discrimination, detection, and identification of odors.

At this time there is no known cure for hyposmia (decrease ability to smell) or anosmia (complete loss of smell or inability to smell). Smell problems are often overlooked in the medical community since they are not deemed critical to living yet they have a great impact upon our lives as I stated before. Much research is needed in this field particularly if it has potential to alter our moods and cognition.

However, the best we can do is try to augment gustatory strategies and be cognizant of potential hazards and install protective measures such as fire alarms- since smoke may not be detected. Make sure inspect expiration dates of food carefully. Simulated odors are available to use while cooking for those of us who cannot smell to increase sensation of flavor. However, these odors are quiet pungent to normal smelling people so would not advice using if there are people who have normal smell in family.

Other ways to circumvent this is by enhancing gustatory senses via creative cooking such as preparing and eating foods which are spicy, crunchy, and full of aromatic herbs, as well as adding color and textures to your foods in order to engage your other senses like sight and make your whole mouth titillate and vibrate with joy….. Bon Appetite!th3UYAHPMC





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