In some cases of multiple sclerosis, patients report a decrease in their sense of smell. This by itself is not unusual given the nature of the disease. A small study from Turkey, however, suggests that problems relating to sense of smell begin early on in multiple sclerosis. Could this provide a new method of diagnostic, or a way to track progression? Keep reading to learn more, or find more information at the original source.
Previous research seems to suggest that multiple sclerosis patients do experience some degree of olfactory disability. The new research supports this claim, and adds that as multiple sclerosis worsens, so too does the olfactory difficulty. According to the researchers, this reflects
“more extensive involvement of the central nervous system and olfactory network in [multiple sclerosis].”
This notion, however, is somewhat disputed among scientists. Lesions on the olfactory nerve do not seem to be a common occurrence. Many studies show olfactory impairment to go hand-in-hand with multiple sclerosis, while many others report no connection at all.
To investigate this disagreement, researchers in Turkey carried out a validated test. They would target the link between olfactory impairment, and duration and progression of multiple sclerosis. They also examined the cognition of each patient. To this end, researchers employed both the Connecticut Chemosensory Clinical Research Center olfactory test, and the Montreal Cognitive Assessment.
Researchers studied 31 adult patients. A minimum follow up period of five years existed as a standard. 24 patients formed the control group. Anyone with another condition which may impact olfactory sensation was excluded.
After testing, researchers examined their results to find that multiple sclerosis patients performed worse on the olfactory tests than did the control group. This proved especially true for patients who had suffered with multiple sclerosis the longest, and those with higher numbers of relapses. Cognitive status, meanwhile, appears to be positively correlated to better olfactory scores.
The investigators said their results have “important clinical implications: olfactory testing could be a useful surrogate for cognitive dysfunction in [multiple sclerosis] patients, apart from their physical disability status.”
Also of important note, however, was the fact that the poorer sense of smell observed in multiple sclerosis patients compared to the control group appeared more pronounced in this study than in previous ones. Considering the patients tested were in the earlier stages of their disease, this seems unusual. Either way, more testing and further research will need to be conducted.
The study does support, as the researchers say, a possible relationship between the olfactory system and multiple sclerosis. Perhaps in time, sense of smell will become a valuable diagnostic tool for multiple sclerosis.
