Underlying anxiety was the only difference between patients who thought that their seizures were triggered by stress and those who did not. Patients who did not think that stress triggered their seizures had significantly lower scores on the Generalized Anxiety Disorders–7.
Subsequently, Dr. Haut, Dr. Privitera, and colleagues conducted the Stress Management Intervention for Living with Epilepsy (SMILE) study, a prospective, controlled trial assessing the efficacy of a stress reduction intervention for reducing seizures, as well as measuring seizure self-prediction (Neurology. 2018 Mar 13;90[11]:e963-70). The researchers randomized patients to a progressive muscle relaxation intervention or to a control group; patients in the control group wrote down their activities for the day.
Patients posted diary entries twice daily into a smartphone, reporting stress levels and mood-related variables. As in Dr. Haut’s earlier study, patients predicted whether having a seizure was extremely unlikely, unlikely, neutral, likely, or extremely likely. Mood and stress variables (such as feeling unpleasant or pleasant, relaxed or stressed, and not worried or extremely worried) were ranked on a visual analog scale from 0 to 100.
The trial included participants who had at least two seizures per month and any seizure trigger. Medications were kept stable throughout the study. During a 2-month baseline, patients tracked their seizures and stress levels. During the 3-month treatment period, patients received the active or control intervention.
In all, 64 subjects completed the study, completing all diary entries on 94% of the days. In the active-treatment group, median seizure frequency decreased by 29%, compared with a 25% decrease in the control group. However, the difference between the groups was not statistically significant. Although the 25% reduction in the control group probably is partly attributable to the placebo effect, part of the decrease may be related to a mindfulness effect from completing the diary, Dr. Privitera said.
The active-treatment group had a statistically significant reduction in self-reported stress, compared with the control group, but this decrease did not correlate with seizure reduction. Changes in anxiety levels also did not correlate with seizures.
“It does not disprove the [stress] hypothesis, but it does tell us that there is more going on with stress and seizure triggers than just patients’ self-reported stress,” Dr. Privitera said.
Patients’ predictions
The seizure prediction findings in SMILE were similar to those of Dr. Haut’s earlier study. Among the 10 highest predictors out of the 64 participants, “when they said that a seizure was extremely likely, they were 8.36 times more likely to have a seizure than when they said a seizure was extremely unlikely,” Dr. Privitera said.
Many patients seemed to increase their predicted seizure probabilities in the days after having a seizure. In addition, feeling sad, nervous, worried, tense, or stressed significantly increased the likelihood that a patient would predict that a seizure was coming. However, these feelings were “not very accurate [for predicting] actual seizures,” he said. “Some people are better predictors, but really the basis of that prediction remains to be seen. One of my hypotheses is that some of these people may actually be responding to subclinical EEG changes.”
Together, these self-prediction studies include data from 4,500 seizures and 26,000 diary entries and show that “there is some information in patient self-report that can help us in understanding how to predict and when to predict seizures,” Dr. Privitera said.
