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Updated: Jun 11, 2026
A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
Olfactory Evoked Potentials and Brain MRI Outcomes in Multiple Sclerosis Patients: A Cross-Sectional Study
Rosella Ciurleo1, Simona De Salvo1, Fabrizia Caminiti1
1IRCCS Centro Neurolesi Bonino Pulejo, 98124 Messina, Italy.
Abstract:
Background: Olfactory dysfunction (OD) is an underestimated symptom in multiple sclerosis (MS). Multiple factors may play a role in the OD reported by MS patients, such as ongoing inflammation in the central nervous system (CNS), damage to the olfactory bulbs due to demyelination, and the presence of plaques in brain areas associated with the olfactory system. Indeed, neuroimaging studies in MS have shown a clear association of the OD with the number and activity of MS-related plaques in frontal and temporal brain regions. However, these studies have used only psychophysical tests to evaluate the OD in MS patients. Olfactory Event-Related Potentials (OERPs) are a method to assess olfaction with the clear advantage of its objectivity in comparison with psychophysical tests. The aim of this study was to investigate the association between the parameters of OERP components (latency and amplitude) and the lesion load of the brain regions which are involved in olfaction in a cohort of relapsing-remitting (RR) MS patients. Methods: In this cross-sectional study, we enrolled 30 RRMS patients and 30 healthy controls. The parameters of OERP components and magnetic resonance imaging data (lesions in the CNS) were analyzed in RRMS patients. Results: The association found between the RRMS patient groups with and without OERPs and the number of lesions in the frontal area as well as the correlation between the lesion load in the temporal area and OERP parameters suggest how brain alterations may impact on olfactory performance in MS. In addition, the predictive value of the number of lesions in the frontal and parietal areas for P2 amplitude also highlights the potential for OERP measures to serve as markers for disease progression in MS. Conclusions: This approach to assess the olfaction in MS could improve our understanding of the disease's neurological impact and contribute to the development of new targeted interventions to mitigate olfactory sensory deficits.
Insights
Olfactory dysfunction in multiple sclerosis (MS) is linked to brain lesions. Objective Olfactory Event-Related Potentials (OERPs) correlate with lesion load, suggesting potential as MS progression markers.
Area of Science:
- Neuroscience
- Neurology
- Olfactory research
Background:
- Olfactory dysfunction (OD) is an underrecognized symptom in multiple sclerosis (MS).
- Central nervous system (CNS) inflammation, demyelination, and lesions in olfactory-related brain regions contribute to OD in MS.
- Previous studies linked OD in MS to lesion load using subjective psychophysical tests.
Purpose of the Study:
- To investigate the association between Olfactory Event-Related Potential (OERP) parameters and brain lesion load in relapsing-remitting MS (RRMS) patients.
- To explore the potential of OERPs as objective biomarkers for olfactory deficits in MS.
Main Methods:
- Cross-sectional study involving 30 RRMS patients and 30 healthy controls.
- Assessment of OERP components (latency, amplitude).
- Analysis of magnetic resonance imaging (MRI) data for CNS lesion load.
Main Results:
- Associations observed between RRMS patient groups (with/without OERPs) and frontal lesion count.
- Correlation found between temporal lesion load and OERP parameters.
- Frontal and parietal lesion load predicted P2 amplitude, indicating OERPs' potential as MS progression markers.
Conclusions:
- Objective OERP measures correlate with brain lesion load in RRMS patients.
- OERP parameters may serve as valuable biomarkers for olfactory deficits and disease progression in MS.
- This approach enhances understanding of MS's neurological impact on olfaction and aids in developing targeted interventions.
