Modifications of gray matter volume in migraine patients over four years: a tensor-based morphometry study
Elisabetta Pagani1, Maria Assunta Rocca1,2, Roberta Messina1, Bruno Colombo2, Giancarlo Comi2, Andrea Falini3, and Massimo Filippi1,2

1Neuroimaging Research Unit, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 2Department of Neurology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy, 3Department of Neuroradiology, San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy

Synopsis

Aim of the study was to explore longitudinal gray matter (GM) changes over a four-year follow up in migraine patients and their association with patients’ clinical characteristics and disease activity. Brain dual-echo and 3D T1-weighted scans were acquired from 25 patients with migraine and 25 healthy controls at baseline and after 4 years. At follow up, compared to controls, migraine patients had an increased volume of fronto-parietal regions, whereas they developed atrophy of the right thalamus and occipital areas. The migraine brain changes dynamically over time. Various pathophysiological mechanism might affect different brain regions in migraineurs after 4 years.

Background

Previous studies have shown diffuse gray matter (GM) abnormalities in regions involved in pain and visual processing in migraine patients. A longitudinal study found GM atrophy of sensory-discriminative brain regions in these patients after one year.

Purpose

To explore longitudinal GM changes over a four-year follow up in migraine patients and their association with patients’ clinical characteristics and disease activity.

Methods

Using a 3.0 Tesla scanner, brain dual-echo and 3D T1-weighted scans were acquired from 25 patients with migraine and 25 healthy controls at baseline and after 4 years (range of follow-up years: controls 1.7-6.6, patients: 2.9-5.6 years). Tensor-based morphometry (1) and SPM12 were used to assess longitudinal changes of GM volumes in migraine patients after 4 years and according to the disease duration and attack frequency and their changes. Pairwise longitudinal registration (2) was used to align the first and second scan of each subject: the method is based on pairwise inverse-consistent registration and incorporates a bias field correction. The rate of volume change was quantified by saving the map of divergence of the velocity field, where positive values indicate expansion and negative values contraction. The mid-point average template image was also saved and used for groupwise alignment (3) to the final customized template and then to the standard space (MNI atlas).

Results

Eight patients (32%) reported an increased number of migraine attacks at follow up. At baseline, compared to controls, migraine patients showed cerebellar GM atrophy and higher volume of regions of the right fronto-temporo-parietal lobes. At follow up, compared to controls, migraine patients had an increased volume of fronto-parietal regions (Figure 1), which was related to a higher number of migraine attacks at baseline (r=0.58, p<0.001) and was more prominent in those patients with increasing number of attacks during the study. At follow up, compared to controls, migraine patients developed GM atrophy of the right thalamus and occipital areas (Figure 2). Thalamic atrophy was more pronounced in patients with a longer disease duration.

Conclusions

The migraine brain changes dynamically over time. Various pathophysiological mechanisms might affect different brain regions in migraineurs after 4 years. GM volume increase of fronto-parietal areas involved in nociception might represent a compensatory response to high migraine attack frequency. GM atrophy of the thalamus, which plays a fundamental role in migraine pathophysiology, might be influenced by disease progression.

Acknowledgements

No acknowledgement found.

References

1) Ashburner J. Computational anatomy with the SPM software. Magn Reson Imaging. 2009;27(8):1163-74.

2) Ashburner J, Ridgway GR. Symmetric diffeomorphic modeling of longitudinal structural MRI. Front Neurosci 2012; 6:197.

3) Ashburner J. A fast diffeomorphic image registration algorithm.Neuroimage. 2007;38(1):95-113.

Figures

Figure 1. Longitudinal GM volume increase in migraine patients compared to controls. Clusters of significant longitudinal increase, yellow-coded according to their t values, are shown over the customized template (p<0.001 uncorrected).

Figure 2. Longitudinal GM volume decrease in migraine patients compared to controls. Clusters of significant longitudinal decrease, yellow-coded according to their t values, are shown over the customized template (p<0.001 uncorrected).



Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)
1254