Headache, Depression, and Mild TBI: A Complex Relationship

Pauline Anderson

July 03, 2014

LOS ANGELES — Headache and depression have a complicated relationship, especially after mild traumatic brain injury (mTBI).

Just how intertwined these conditions are was highlighted in a new study presented here at the American Headache Society (AHS) 56th Annual Scientific Meeting.

A year after suffering an mTBI, patients with headache were about 5 times more likely to be depressed than patients with mTBI without headache, and those who were depressed were more likely to suffer headaches, the study showed.

"Early identification and treatment of both these conditions may reduce their impact over time," said lead researcher Sylvia Lucas MD, PhD, clinical professor of neurology and neurological surgery, University of Washington Medical Center, Seattle.

"Hopefully, more research will be directed at this to see if we can change the trajectories over time as well."

Although there has been a lot of research on headache occurring with depression in primary headache, there is little in the literature directed at this comorbidity after mTBI, said Dr. Lucas.

About 75% of TBIs are mild.

For the study, researchers examined headache over the course of 1 year in 212 patients with mTBI at a single center, the University of Washington, which has a level 1 trauma center.

Participants had a mean age of 44 years and were mostly male (76%), white (75%), and had at least a high school education (83%). Their injuries primarily involved vehicle accidents (58%), followed by falls (24%), assaults (5%), and sports mishaps (3%).

Researchers carried out baseline assessments during face-to-face interviews within 7 days of the injury. Follow-up interviews using a structured questionnaire were completed over the telephone at 3, 6, and 12 months postinjury.

Headache Evaluation

The headache evaluation included information about incidence and prevalence of headache and headache characteristics at baseline and at 3 subsequent points. Dr. Lucas noted that the study deviated from the International Headache Classification, 2nd Edition (ICHD-2), requirement for posttraumatic headache that the headache be reported within 1 week of an injury.

"We asked people if they had a headache at any time point over 1 year, and we asked them to describe it," she said.

Most of the headaches were reported within 3 months of the injury; however, a significant number of participants reported new or worsened headache after that, said Dr. Lucas.

The incidence and cumulative incidence of new or worsened headache over the course of 1 year was 91%. This, said Dr. Lucas, is higher than for moderate to severe TBI, which is on the order of 71%.

Using ICHD-2 criteria, researchers categorized the headaches. Migraine and probable migraine (59% at baseline and 53% at 1 year) was the most common phenotype, followed by tension-type headache (37% at baseline and 32% at 1 year) and cervicogenic headache (4% at baseline and 4% at 1 year).

Looking at headache and depression together, the researchers found that 52% of patients had headache alone at baseline, and 43% had headache alone at 1 year. Depression without headache was rather rare: About 4% of the mTBI patients had depression without headache at baseline, and 2% had it at 1 year.

However, depression occurring along with headache was not rare: This comorbidity increased from 11% at baseline to 25% at 1 year.

Although early after the injury headache and depression were unrelated, after 1 year, participants who had headache were much more likely to be depressed than those without headache (relative risk [RR], 5.43; P ˂ .001).

Likewise, depressed patients were significantly more likely to have headache than their nondepressed counterparts at 1 year (RR, 1.56; P ˂ .001).

"The majority of subjects who had headache and depression at baseline continued to have both at 1 year," commented Dr. Lucas.

Ongoing Monitoring

She stressed the importance of ongoing monitoring of mTBI patients. "Even if we see these people early on in our clinic or in the emergency room and they have no symptoms, it's certainly worth seeing them in follow-up."

Some 2.3 million traumatic brain injuries occur every year in the United States. This figure does not capture military-related injuries or those for which patients do not seek care. "So this figure is very much an underestimate," said Dr. Lucas.

Asked whether the researchers had investigated posttraumatic stress disorder in this group of mTBI patients, Dr. Lucas said they had not but that they had looked at cognitive outcomes and are "slowly getting to that data."

Another audience member wondered whether Dr. Lucas had a sense of the pathophysiology of posttraumatic headache, given that headache seems to persist long after fatigue, dizziness, and visual problems subside after an mTBI.

Dr. Lucas said she could only speculate about the physical correlates, but that it could have something to do with a persistent microvascular disease or with calcium channels. "It's an interesting observation that these symptoms do not go together. They may have individual etiologies."

Dr. Lucas reports receiving research funding from the National Institute on Disability and Rehabilitation Research, the Department of Defense, Allergan, Amgen, and the Wadsworth Foundation; being on advisory boards of Kineta, Allozyne, and MAP/Allergan; and receiving honoraria from BiogenIdec, Genzyme, and Zogenix.

American Headache Society (AHS) 56th Annual Scientific Meeting. Scientific Paper Presentation OR15. Presented June 28, 2014.


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