The human anatomy is extremely complex, the olfactory system in particular is much so. The olfactory system is nothing but the part of the sensory system that is used for smelling; it comprises over 400 different types of receptor cells consisting six to ten millions of cells. These cells are in turn linked to multiple neural pathways and brain structures which are involved in memory, emotion and movement functions.
A defect in this system or simply loss of the ability to smell has been associated with a number of disorders and ailments in the past years, such as common cold, a history of smoking, viral infections, head injuries and getting older. But this function of the body is often ignored as to being insignificant when compared to the loss of senses of hearing and sight.
In a new study, scientists are trying to test the concept of whether this very sense when lost could be an indicator of serious disorders like the Alzheimer’s disease and Parkinson’s disease. They believe this could improve diagnosis of these incurable conditions as impaired smell is the earliest and one of the most common signs of these neurodegenerative disorders, owing to the fact that these
“It’s important, not just because it’s novel and interesting and simple but because the evidence is strong,” says a professor of psychiatry and neurology at Columbia University, Davangere Devanand, who has just published a review on this subject.
Past researches have shown that an impaired smell is more apt as a predictor of cognitive decline in currently healthy adults, than memory problems. It is especially found to be able to accurately forecasting the progression from mild cognitive impairment (MCI) to a full-blown Alzheimer’s disease. According to the Alzheimer’s Association, a US NGO, about 15 to 20 percent of people over the age of 65 have MCI and about half this number go on to develop Alzheimer’s. The sooner this 50% of the patients who are likely to develop the disorder are identified, the earlier can doctors begin treatment according Devanand.
Further, Parkinson’s patients experience loss of smell more often than the tremors which are common, specific to this disorder. The problem in olfactory system is found t0 precede even the classic motor signs of this disease by a number of years.
Therefore, scientists now believe that it is time we consider the outcomes of these smell tests to consider far more serious and rare possibilities.
“If a person scores very well on a smell identification test, then you can be pretty sure they’re not going to have Parkinson’s, at least within the next four years,” says researcher G. Webster Ross, Veterans Affairs Pacific Islands Health Care System.
Despite no solid evidence as to this link, continuing to sniff (pun intended) around might help something materialize.
