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A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
Olfactory hypersensitivity in migraineurs: a H(2)(15)O-PET study
G Demarquay1, J P Royet, G Mick
1Service de Neurologie, Hôpital de la Croix-Rousse; INSERM, U821, Université Claude-Bernard, Institut Fédératif des Neurosciences de Lyon, Lyon, France. genevieve.demarquay@chu-lyon.fr
Cephalalgia : an International Journal of Headache
|August 30, 2008
Summary
Olfactory hypersensitivity in migraine patients shows altered brain activity, particularly in olfactory processing regions. This suggests a unique neurobiological basis for smell sensitivity in migraineurs, potentially linked to odour-triggered attacks.
Area of Science:
- Neuroscience
- Neurology
- Medical Imaging
Background:
- Olfactory hypersensitivity (OHS) is a common symptom during migraine attacks and in migraine-free periods.
- OHS is associated with odour-triggered migraine attacks, but its underlying pathophysiology is not understood.
Purpose of the Study:
- To investigate olfactory processing in migraineurs with OHS.
- To compare regional cerebral blood flow (rCBF) during olfactory stimulation between migraineurs with OHS and controls.
Main Methods:
- A H(2)(15)O-positron emission tomography (PET) study was conducted on 11 migraineurs with OHS and 12 controls.
- Participants underwent PET scans with olfactory stimulation (odour) and a non-olfactory baseline (odourless air).
- Voxel-based and region-of-interest analyses compared rCBF between groups.
Main Results:
- Migraineurs with OHS exhibited higher baseline rCBF in the left piriform cortex and antero-superior temporal gyrus compared to controls.
- During odour stimulation, migraineurs showed increased activation in the left temporal pole but decreased activation in frontal and temporo-parietal regions, posterior cingulate, and right locus coeruleus.
Conclusions:
- Altered rCBF patterns during olfactory stimulation in migraineurs with OHS may indicate a specific role for the piriform cortex and antero-superior temporal gyrus.
- These findings suggest potential cerebrovascular or top-down regulatory abnormalities contributing to OHS and odour-triggered migraines.
- Further research comparing migraineurs with and without OHS is needed to clarify the causal relationship.
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