Stress and Seizures: What Drives the Relationship?

Pauline Anderson

December 06, 2012

San Diego, California — Emerging research is illuminating the contribution of stress, which many patients with epilepsy describe as a trigger, to the occurrence of seizures.

Results of new studies examining how stressful situations might affect seizure frequency, and increase brain activation, were presented here at the American Epilepsy Society (AES) 66th Annual Meeting.

Neurologists should determine whether there is an underlying depression or anxiety disorder in patients convinced that stress is driving their epilepsy because this could very well be the case, according to results of a study carried out by Michael Privitera, MD, professor, and director, Cincinnati Epilepsy Center, University of Cincinnati, and his colleagues.

Stress Positive

The study included 203 outpatients at the epilepsy center who believe that stress plays a role in triggering their seizures. Researchers asked these "stress-positive" patients to identify times when stress lasting days to months made their seizures more likely and also instances where an acute stress lasting minutes to hours triggered a seizure.

Patients were asked whether they had tried stress reduction techniques and whether they thought these efforts reduced their seizures. They were also queried about their ability to predict seizures.

The investigators also gathered relevant information on seizure type and history of and treatment for depression and anxiety.

Midway through the study, researchers gathered data on a control population of 28 patients who thought stress played no role in their seizures, or "stress-negative" patients. Dr. Privitera commented that finding such patients was somewhat difficult.

The study showed that 85% of stress-positive patients believed that chronic stress was a seizure trigger, and 68% endorsed acute stress as a trigger. In these patients, 57% used some type of relaxation or stress reduction treatment, and of those, 88% thought it improved seizures.

"What was really interesting was that these people have tried all kinds of stress reduction methods, and yoga was number one, which is surprising since this is Cincinnati," and not California, where such approaches might be more popular, he said. Patients also tried relaxation and other stress reduction techniques.

Interestingly, 25% of stress-negative patients tried relaxation or stress reduction and 71% of them thought their seizures subsequently improved.

A history of depression, higher anxiety scores (Generalized Anxiety Disorder 7-item [GAD-7]) and depression scores (Neurological Disorders Depression Inventory for Epilepsy) are factors associated with being stress positive (odds ratio [OR] > 1), according to the study. In a multivariable logistic regression analysis, only GAD-7 score and seizure prediction were associated with being stress positive.

Stress-positive patients were more likely to believe they could at least occasionally predict seizures (51.8% vs 14.3% for stress-negative patients; OR, 8.6; P = .0005), the study found.

The researchers are now carrying out a randomized clinical trial of a stress reduction intervention (behavioral focused attention consisting of twice-daily practices of breathing exercises and other techniques) in drug-resistant patients with epilepsy who believe their seizures are triggered by stress.

Asked to comment, Jane Allendorfer, PhD, instructor, University of Alabama at Birmingham, who has done research on the role of stress in seizures, said the results of the study are consistent with previous findings of patients with epilepsy who reported stress as a seizure trigger, some of whom believe they can predict seizures. Other research shows that up to 50% of people with epilepsy believe stress is a trigger for seizures.

"It's interesting, but not surprising, that patients who tried stress reduction techniques believed it reduced seizures," she said. "Given the authors' indication of a controlled trial of stress reduction methods in patients with medication resistant epilepsy, I would like to see their data broken up into patients who have their seizures controlled versus other patients."

Significant Brain Response

A study Dr. Allendorfer carried out while she was at the University of Cincinnati and that she presented at the AES meeting here suggests that people who believe stress plays a role in their seizures actually do have significant differences in brain response to stress.

In a series of experiments, patients who perceived stress as an important contributing factor to their seizures had more brain activation when under stress. The stress was created by having to complete a mathematical problem in a finite time with an overhead voice providing negative feedback and telling them that they had to finish soon or they couldn't contribute to the study.

The increases in brain activation were seen bilaterally in the superior temporal gyrus, posterior cingulate, and parietal areas, and unilaterally in the left insula.

Conversely, brain activation did not increase in a control group of patients who didn't think stress was a major factor in seizures. This lack of brain activation in controls was surprising, said Dr. Allendorfer.

The increased brain activation in patients who believe seizures are triggered by stress may be part of a compensatory mechanism — trying to perform as well as other participants, said Dr. Allendorfer.

American Epilepsy Society (AES) 66th Annual Meeting. Abstracts 1.184, 1.243. Presented December 1, 2012.