Literature Review

MRI Reveals Less Cortical Thickness Among Patients With Persistent Posttraumatic Headache

More frequent headaches are associated with less cortical thickness in the left and right superior frontal regions.


 

Patients with persistent posttraumatic headache have less cortical thickness in bilateral frontal regions and right hemisphere parietal regions of the brain, compared with healthy controls, according to research published in the January issue of Headache. Among patients with persistent posttraumatic headache, more frequent headaches are associated with less cortical thickness in the left and right superior frontal regions, the researchers said.

Catherine D. Chong, PhD

“These results indicate that, although general linear model vertex-by-vertex comparisons indicate that large areas over the frontal cortex are overall thinner in patients with persistent posttraumatic headache, it is specifically the frequency of headaches that associates with cortical thinning in the superior frontal regions,” said Catherine D. Chong, PhD, a researcher at the Mayo Clinic in Phoenix.

Patients With Persistent Posttraumatic Headache vs Healthy Controls

Posttraumatic headaches are common after concussion. When these headaches persist for longer than three months, they are classified as persistent posttraumatic headaches. Studies have shown functional changes and anatomical changes such as volume loss and cortical thinning following concussion, but there are insufficient data about the association between brain morphologic changes and headache symptoms in patients with persistent posttraumatic headache, the researchers said.

To investigate differences in cortical thickness between patients with persistent posttraumatic headaches and healthy controls and to assess whether cortical morphology relates to headache burden, Dr. Chong and colleagues studied 33 patients with persistent posttraumatic headache and 33 healthy controls. Healthy controls had never had headaches or had infrequent tension-type headache. Exclusion criteria for all subjects included pregnancy, contraindications to MRI, moderate or severe head trauma, and previous history of migraine. Patients with persistent posttraumatic headache who were taking abortive or preventive headache medications were not excluded.

Patients with persistent posttraumatic headache were diagnosed according to ICHD-3 beta criteria. Participants underwent brain MRI on a 3-T scanner. Researchers calculated vertex-by-vertex whole brain estimates of cortical thickness. They used a general linear model design to determine differences in cortical thickness between patients with persistent posttraumatic headache and healthy controls.

Anxiety and Depression Scores Differed Between Groups

Researchers enrolled 68 patients into the study. They excluded data for two because of abnormal findings. The median age of participants with persistent posttraumatic headache was 36, and the median age of healthy controls was 33. About 39% of subjects with persistent posttraumatic headaches were female, and about 58% of healthy controls were female. Six participants reported one traumatic brain injury (TBI) in their lifetime, 15 reported two TBIs, three reported five TBIs, and six participants reported six or more TBIs. Concussions that led to persistent posttraumatic headache were due to explosion or blast injuries, sports-related accidents, falls, and motor vehicle accidents. In addition, there were significant between-group differences in levels of anxiety and depression.

“Patients with persistent posttraumatic headache had comorbid symptoms of mild depression and anxiety. Although there was not an association between mood alteration and headache frequency in patients with persistent posttraumatic headache, it is impossible to completely disentangle the effect that mood dysfunctions may have had on altering cortical thickness patterns in patients with persistent posttraumatic headache,” said the researchers.

Thinner Cortex in Patients With Persistent Posttraumatic Headache

Overall, patients with persistent posttraumatic headache had less cortical thickness in the left and right frontal (superior frontal, caudal middle frontal, and precentral) regions and right parietal (precuneus supramarginal, inferior, and superior parietal) regions. In addition, there were no regions in which patients with persistent posttraumatic headache had more cortical thickness, relative to healthy controls.

A correlation analysis of regions with less cortical thickness in patients with persistent posttraumatic headache found a negative correlation between left and right superior frontal thickness and headache frequency. No association was observed between regional cortical thickness and years lived with persistent posttraumatic headache.

“Further investigation is required to determine if the findings of our study are specific for persistent posttraumatic headache or if they are generalizable to other chronic pain conditions and other symptoms that occur following concussion,” said Dr. Chong and colleagues.

“Future studies using larger patient cohorts will be needed to better detect how repetitive concussions, concussion mechanism (sports-related vs motor vehicle accident vs blast injuries vs falls), and medical history alter brain pathophysiological processes, as well as affect headache patterns in patients with persistent posttraumatic headache.”

—Erica Tricarico

Suggested Reading

Chong CD, Berisha V, Chiang CC, et al. Less cortical thickness in patients with persistent posttraumatic headache compared with healthy controls: an MRI study. Headache. 2018;58(1):53-61.

Next Article:

Migraine and Elevated Vascular Biomarkers Linked

Related Articles