番茄社区

NEW ORLEANS -- Patients taking a selective serotonin reuptake inhibitor (SSRI), tricyclic antidepressant, or antipsychotic drug were less likely to have seizures in the epilepsy monitoring unit (EMU), researchers reported here.

Conversely, patients on serotonin norepinephrine reuptake inhibitor (SNRI) medication were more likely to have seizures in the EMU, according to Brittany Chapman, MD, of the University of Louisville, and co-authors, in a poster presentation at the annual meeting.

"In the EMU, we want to make the most of the time patients are there, and we do things to increase the chance they will have a seizure -- photo-stimulation with strobe lights, hyperventilation, and sleep deprivation, for example," Chapman told 番茄社区.

Anti-seizure medications are often tapered or discontinued before a patient is admitted to the EMU, but psychotropic medications are not, she said: "Antidepressants, anti-anxiety medications, and anti-psychotics are typically continued because we usually feel those don't contribute to seizures too much." But psychiatric comorbidities are high among people with epilepsy and there's little data about how psychotropic drugs may affect seizure frequency in the EMU, she noted.

In this analysis, Chapman and her team studied 682 patients admitted to the University of Louisville EMU for more than one day to have seizures evaluated from 2014 to 2016. Patients were an average age of 42, and 62% were women. The average length of stay in the EMU was 3.45 days, and patients with psychogenic non-epileptic seizures were excluded from the study.

Comparing seizure frequency in the EMU, the researchers found:

• Patients not using SSRI drugs (n=504) were 1.6 times more likely to have seizures than patients on SSRI drugs (n=178), with an incidence risk ratio (IRR) of 1.64, 95% CI 1.21-2.24; P=0.002
• Patients not using antipsychotic drugs (n=637) were 2.4 times more likely to have seizures than patients on antipsychotic drugs (n=45): IRR 2.41, 95% CI 1.23-4.73, P=0.011
• No patients using tricyclic antidepressant drugs (n=35) had seizures
• Patients on SNRI drugs (n=43) were 1.9 times more likely to have seizures than patients not on SNRI drugs (n=639): IRR 1.85, 95% CI 1.19-2.86; P=0.006

"Most patients on these drugs were less likely to have seizures, so the question is why," Chapman said. "We know that these medications affect certain stages of sleep and sleep has an intricate interaction with seizures; maybe that indirectly affects seizures."

It's also possible other variables are at work. "There are many factors influencing seizure frequency in the EMU that could be playing a part," observed Michael Privitera, MD, of the University of Cincinnati, who was not involved with the study.

"In this EMU study, it is possible that the people taking psychotropic drugs had lower stress, but this is speculation and would need to be validated with specific measures," Privitera told 番茄社区. Other research has shown that higher baseline rates of anxiety were associated with stress as a seizure trigger, but that research looked only at long-term outpatient seizure frequency, not seizure occurrence in the EMU, he noted.

"There may well have been differences in the epilepsy syndrome," added Shlomo Shinnar, MD, PhD, of the Albert Einstein College of Medicine in the Bronx, New York, who was not involved with the study. "We know, for example, that those with frontal lobe epilepsy have seizures more quickly in the EMU than those with temporal lobe epilepsy," he told 番茄社区.

In certain sleep studies, patients have to come off psychotropic medications for 2 weeks before a test, Chapman observed. "Some patients are not comfortable doing that because their mood disorder is quite bad; you have to be careful when you start and stop these drugs abruptly," she said. While this preliminary analysis does not mean that EMU patients should stop using psychotropic medications, it does point to new areas to investigate, she noted: "The evidence right now does not support that we should do this, but it may be worth studying."

This analysis has several other limitations, Chapman said: patients stayed in the EMU for varying lengths of time, and some people may have had more seizures if they had stayed longer. There also was not a fixed protocol for seizure medication withdrawal in the EMU; some patients stopped abruptly and others tapered.