PracticeUpdate Neurology February 2019

EXPERT OPINION 20

Provocative Induction of Psychogenic Nonepileptic Seizures By Barbara Ann Dworetzky MD Dr. Dworetzky is Associate Professor of Neurology at Harvard Medical School and Chief of the Epilepsy Division at Brigham and Women’s Hospital in Boston, Massachusetts. This commentary is based upon the article Provocative induction of psychogenic nonepileptic seizures: Noninferiority of an induction technique without versus with placebo by Chen et al.

Psychogenic nonepileptic seizures (PNES), the most common form of functional neurologic disorder (FND), have a relatively poor prognosis, especially if they are not diagnosed early. 1 Delay in diagnosis is common, leading to a large burden on the healthcare system, including costs for repeated testing, urgent and emergent visits/hospitalizations, loss of employment, disability, and lower quality of life for those suffering and those caring for them. 2 N eurologists with specialized training in epi- lepsy utilize video EEG monitoring for definitive diagnosis of uncontrolled seizures, a key step leading to treatment, as many patients have difficulty accepting the emotional underpin- nings of the disorder. Unfortunately, the events may not be captured despite monitoring off-seizure med- ication, leaving the patient with an “indeterminate” diagnosis. Improving the success rate of confirmed diagnosis by utilizing activation procedures with suggestion or placebo has been debated in the literature for many years, with recent recommenda- tions to abandon the use of IV saline injections as deceptive and unethical. 3,4 However, not having a definitive diagnosis keeps patients and physicians in limbo, further delaying treatment, impacting loved ones, employment, and overall quality of life. Fur- thermore, achieving the highest level of confidence in the diagnosis can minimize the role of physicians

in reinforcing incorrect diagnoses and perpetuat- ing unnecessary treatments. Therefore, there is still a role for provocative procedures in the diagnosis of PNES. 5 Chen et al provide retrospective data (collected 2009–2013 and 2013–2018) for two cohorts of 170 patients admitted to the epilepsy monitoring unit (EMU) at a veteran’s hospital. 6 The EMU changed their method of induction from IV saline injection with suggestion to hyperventilation and photic stim- ulation with suggestion, known techniques that can promote seizures in some individuals. Only those suspected of having PNES were provoked. When the two cohorts were compared, Chen and colleagues found that hyperventilation and photic stimulation with suggestion were noninferior to provocation with IV saline in successfully eliciting a typical episode. They concluded that placebo injection for the diag- nosis of PNES should be abandoned. There are important limitations to their study. It was not randomized or prospective, and there was a bias in their selecting which patients should undergo a provocative procedure rather than every EMU

" …before widely recommending the proper provocation techniques, there is necessary work to improve clinician attitudes and understanding of PNES and other FND so that lack of transparency or deception of any sort is abandoned in favor of the goal of helping improve patient–clinician communication and patient health and quality of life. " PRACTICEUPDATE NEUROLOGY