Longitudinal Testing of Olfactory and Gustatory Function in Patients with Multiple Sclerosis

Area of Science:

• Neurology
• Neuroscience
• Sensory Science

Background:

• Multiple sclerosis (MS) is a chronic neurological disease affecting the central nervous system.
• Olfactory and gustatory (smell and taste) functions are often impacted in neurological disorders.
• Understanding sensory changes in MS is crucial for patient care and disease monitoring.

Purpose of the Study:

• To investigate longitudinal changes in olfactory and gustatory capacity in patients with multiple sclerosis.
• To explore the relationship between sensory deficits and disease activity in MS patients.

Main Methods:

• Longitudinal study of 20 MS patients over 3 years.
• Subjective olfaction assessed using the Threshold Discrimination Identification (TDI) test.
• Objective olfaction evaluated via olfactory evoked potentials (OEP) using EEG.
• Gustatory function tested using the Taste Strip Test (TST).

Main Results:

• Significant olfactory dysfunction detected in 45% of patients via TDI and 50% showed delayed OEPs.
• 20% of patients exhibited gustatory dysfunction.
• Despite mild disease activity (0.3 ± 0.5 relapses), no significant overall change in sensory capacity was observed.
• A significant inverse correlation was found between odor discrimination ability and the number of relapses (r = -0.5, p ≤ 0.05).
• Patients were generally aware of their olfactory deficits.

Conclusions:

• Olfactory and gustatory dysfunction are prevalent symptoms in MS patients.
• Sensory deficits may serve as potential biomarkers for estimating MS disease progression.
• The observed olfactory dysfunction suggests potential damage in higher central nervous system regions.