Conference Coverage

Patients with PNES have increased mortality



Among patients with psychogenic nonepileptic seizures, the risk of death is more than twice as great as among the general population, according to data presented at the annual meeting of the American Epilepsy Society. Patients with PNES have a mortality rate comparable to that of patients with drug-resistant epilepsy.

“This [finding] emphasizes the importance of correct diagnosis and identification of relevant pathologies in order to avoid preventable deaths in an important group of patients, where medical attention is often inappropriately directed to a dramatic but ultimately irrelevant clinical feature of the condition,” said Russell Nightscales, a first-year medical student at the University of Melbourne.*

Although PNES sometimes is mistaken for epilepsy and treated accordingly, it is a form of conversion disorder. The elevated risk of death among patients with epilepsy is understood, but few researchers have studied mortality in patients with PNES.

Mr. Nightscales and his colleagues conducted a retrospective cohort study of patients who had been admitted for a comprehensive epilepsy evaluation to one of two tertiary hospital video EEG monitoring (VEM) units in Melbourne between Jan. 1, 1995, and Dec. 31, 2015. The investigators ascertained mortality and cause of death by linking patient data to the Australian National Death Index (NDI). When a coroner’s report was available, they refined the cause of death using information from the National Coronial Information System. Each patient’s diagnosis was based on the consensus opinion of experienced epileptologists at the Comprehensive Epilepsy Meeting following a review of the clinical history, VEM data, and investigations. The researchers compared mortality in patients with PNES, epilepsy, or both conditions. They extracted clinical data through medical record review. Finally, they determined lifetime history of psychiatric disorders through review of neuropsychiatric reports.

Of 3,152 patients who underwent VEM, the investigators included 2,076 patients in their analyses. Of this population, 631 patients had PNES, 1,339 had epilepsy, and 106 had both. The standardized mortality ratio (SMR) among patients with PNES was 2.6 times greater than among the general population. Patients with PNES between ages 30 and 39 had a ninefold higher risk of death, compared with the general population. The SMR of patients with epilepsy was 3.2. The investigators found no significant difference in the rate of mortality between any of the patient groups after excluding 17 patients with epilepsy and a known brain tumor at the time of VEM, who had a malignant neoplasm of the brain listed as their primary cause of death.

Death resulted from external causes in 20% of all deaths among patients with PNES and in 53% of deaths with a known cause among patients who died below the age of 50. Suicide accounted for 24% of deaths among patients with PNES in this age group. Neoplasia and cardiorespiratory causes were responsible for 51% of deaths with a known cause across all ages and 67% of those between ages 50 and 69. Among people with epilepsy, external causes accounted for 7% of all deaths. Neoplasia and cardiorespiratory causes were observed in 42% of people with epilepsy. Epilepsy was responsible for 28% of deaths with a known cause among patients with epilepsy

The research was funded by Australia’s National Health and Medical Research Council and the RMH Neuroscience Foundation.

SOURCE: O’Brien TJ et al. AES 2018, Abstract 1.139.

*Correction 12/4/18: An earlier version of this article misstated the name of the presenter. Russell Nightscales presented this study.

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