In patients with headaches, imaging may show widespread higher white matter (WM) diffusion compared with headache-free individuals in the general population, according to study results published in The Journal of Headache and Pain.
The researchers note that while the association between headache and WM microstructure has been investigated with diffusion tensor imaging (DTI), this was limited to a small clinic-based sample and the results were inconclusive. The goal of this study was to assess WM microstructure in patients with headache in a large sample from the general population.
Data from the Nord-Trøndelag Health Study (Norwegian acronym HUNT), an ongoing large population based study were used in the current study. In a neuroimaging substudy of HUNT3 (HUNT-MRI), 1006 participants (aged 50-66 years, 530 women) underwent brain imaging with standardized magnetic resonance imaging protocol. Of these, 640 patients had successful DTI scan and complete data.
Of those studied, 277 individuals (mean age 58.7, 39% women) were free from headaches and 246 reported having headaches (mean age 58, 62% women), most commonly tension-type headache (n=76) or migraine headache (n=69), in the year prior to the scanning.
Several measures were obtained from DTI and provide information on the WM microstructure, including fractional anisotropy, mean diffusivity, axonal diffusivity, radial diffusivity, and tract volume.
Data showed that those with headache had widespread higher WM mean diffusivity, axonal, and radial diffusivity compared with headache-free individuals. The largest effects were seen in those with new-onset headache and in those with headache that began in middle age, who also had a decrease in WM fractional anisotropy, compared with those without headache.
Overall, the effects were small and there was no dose-response relationship between headache frequency and WM microstructure.
The researchers acknowledged several study limitations, including relatively long interval between completing the headache questionnaire and imaging, limitations regarding the diagnosis of the type of headache, missing information about the use of prophylactic medication, and possible over-adjustments in some of the statistical models.
“Middle-age onset headache may be related to a widespread process in the white matter leading to altered microstructure,” concluded the researchers. They indicate the need for additional studies to investigate WM morphology related to age of those with headache and the age of onset of the headaches.
Reference
Kattem Husøy A, Eikenes L, Håberg AK, Hagen K, Stovner LJ. Diffusion tensor imaging in middle-aged headache sufferers in the general population: a cross-sectional population-based imaging study in the Nord-Trøndelag health study (HUNT-MRI). J Headache Pain. 2019;20:78.