Peripheral Changes in the Trigeminal Sensory System of Migraine Patients

Objectives: We have recently defined interictal changes in the trigeminal sensory system (TSS) of migraineurs with aura (MWA) and without aura (MWoA) when compared to age and gender-matched healthy controls (HC). Both migraine groups presented similarities from thickening of the somatosensory cortex to microscopic diffusional changes (fractional anisotropy-FA) along the thalamocortical tract. However, MWA and MWoA had also diffusional changes in the trigeminothalamic tract and PAG, respectively. To extend our investigation from central to peripheral TSS we evaluated diffusional changes in the trigeminal ganglion in both migraine groups.

Methods: Groups of MWA, MWoA, and HC were scanned at the Martinos Center for Biomedical Imaging, MA. Each group was composed of twelve gender- and age-matched subjects. Two MPRAGE sequences (1.0 x 1.0 x 1.3mm, 128 slices, 256x256, echo time (TE)=3.25 ms; repetition time (TR)=2530 ms; flip=7°) were acquired, motion-corrected and averaged to create a single image volume. The imaging parameters for DTI were TR/TE: 8300/89ms - 9200/91ms, b=700s/mm2, 60 directions of encoding, 2mm isotropic resolution, 64 slices. Individual FA maps were registered and normalized to a Talairach/MNI T2 atlas. Voxel-wise ttests were performed on the FA maps, comparing each migraine group to HC.

Results: We found decreased FA in the trigeminal ganglion only in the MWA group, and those changes were contralateral to the central areas most affected in the trigeminal system of those particular patients. These findings suggest that migraine attacks have consequences in the peripheral TSS at the level of the trigeminal ganglion. This may be due to repetitive meningeal sensory fibers activation following aura attacks, as also demonstrated in animal models of cortical spreading depression. To our knowledge this is the first report on peripheral changes in migraine in-vivo.

Conclusion: Our findings indicate that migraine is correlated with neuroplastic changes in all levels of the TSS. (NIH-5P01NS35611-09;K12–DE014528)