Researchers investigate whether SSRI therapy may help prevent sudden unexplained death in patients with medically refractory partial epilepsy.
TORONTO—Selective serotonin reuptake inhibitors (SSRIs) reduce the likelihood of severe ictal oxygen desaturations in patients with intractable partial epilepsy without secondarily generalized convulsions, investigators reported at the 62nd Annual Meeting of the American Academy of Neurology.
“Ictal respiratory dysfunction occurs very commonly in patients with partial epilepsy and may also contribute to sudden unexplained death in epilepsy (SUDEP),” said Lisa M. Bateman, MD, of the University of California–Davis (UCD), noting that animal models have pointed to respiratory dysfunction as a potential underlying mechanism of SUDEP and demonstrated the reversal of ictal respiratory arrest with fluoxetine. “This, therefore, led us to question whether SSRIs could have an effect on ictal respiratory dysfunction in our patients with localization-related epilepsy.”
Dr. Bateman and colleagues retrospectively reviewed 73 consecutive patients with a total of 496 seizures, including 16 patients taking SSRIs (eight males) with a total of 87 seizures, from UCD’s epilepsy monitoring unit.
In a patient analysis, a statistically significant difference was found regarding severe oxygen desaturation—less than 85% saturation—with 25% of SSRI subjects and 52.8% of subjects in the non-SSRI group having severe oxygen desaturation. However, the difference was no longer evident when the researchers looked at generalized convulsions.
“There is no statistically significant difference in the ictal associated desaturation once the seizures progressed to a convulsion,” Dr. Bateman reported. “If we look at the seizures themselves, we see a similar finding.”
However, in an analysis of seizures, the researchers noted a significant difference in mean ictal desaturation nadir in subjects taking SSRIs (mean, 94.1%), compared with those not taking SSRIs (mean, 89.7%). There was also a trend toward an increased proportion of generalized convulsions and increased seizure duration in patients taking SSRIs, but this was not statistically significant.
“Use of SSRIs in our patients was associated with reduced severity of ictal oxygen desaturation, but not with the duration of the desaturation, and this was only seen in seizures that did not generalize,” Dr. Bateman said. “This suggests that SSRIs have some type of protective effect, but once a generalized convulsion occurs, there may be other types of pulmonary dysfunction, such as transient neurogenic pulmonary edema or pulmonary arteriovenous shunting, which is not reversed by or protected against by the SSRI.”