MS Patients’ Diminished Sense of Taste Linked in Study to Severity of Brain Lesions

Margarida Azevedo, MSc avatar

by Margarida Azevedo, MSc |

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MS and taste

Taste deficits are considerably more prevalent in multiple sclerosis (MS) patients than previously thought, and correlate directly with the severity of MS-related brain lesions, researchers report in an article titled ā€œTaste dysfunction in multiple sclerosis,ā€ published in the Journal of Neurology.

Sensory problemsĀ are common MS symptoms, with a large number of patients reporting some form of numbness and tingling, and vision problems. Symptoms related to the gustatory system, namely taste deficits, are less wellĀ understood or studied, and little is known regarding the correlation between taste dysfunction and myelin damage. Previous research intoĀ taste dysfunction put its prevalence between 5 percent and 20 percent of people, whichĀ mightĀ be attributed to patientsā€™ difficulty in self-analyzing less noticeable tastes, and the tendency to confuse this dysfunction with olfactory issues.

Researchers at theĀ University of Pennsylvania’s Smell and Taste CenterĀ sought to assess the prevalence of taste dysfunction in MS patients compared to healthy controls, and possibly correlate it withĀ the disease’s myelin-related brain lesions. The study enrolled 73 people with MS and 73 healthy controls, each undergoingĀ a standard, 96-trial test of four tastes ā€” sweet (sucrose), sour (citric acid), bitter (caffeine), and salty (sodium chloride) ā€” administeredĀ to different tongue regions. The number and size of lesions were assessed through magnetic resonance imaging (MRI) ofĀ 52 MS-affected brain regions.

According to the results, peopleĀ with MS wereĀ significantlyĀ affected in their ability to identify tastes, Ā more than previously reported. Their taste identification scores, in fact, were noticeablyĀ lower for all tested tastes, and especially with sweet and salty. Significant portionsĀ of MS patients hadĀ taste scores falling below the 5th percentile of controls ā€” with 15.07 percent below the 5th percentile for caffeine, 21.9 percent for citric acid, 24.66 percent for sucrose, and 31.50 percent forĀ sodium chloride. Importantly, researchers also found that taste scores were inversely proportional to the amount and volume of lesions detected by MRI in different brain regions.

“This study represents the most comprehensive study preformed to date on the influences of MS on the ability to taste. It appears that a sizable number of these patients exhibit taste deficits, more so than originally thought. This suggests that altered taste function, though less noticeable than changes in vision, is a relatively common feature in MS,ā€ Dr. Richard Doty, the study’s lead authorĀ andĀ director of theĀ Smell and Taste Center, said in a press release. “These findings give us a better insight about that relationship, as well as the areas of the brain that are more likely to impact the dysfunction when scarred from the disease.”