Hyperventilation and photic stimulation are useful additions to a placebo-based suggestive seizure induction protocol in patients with psychogenic nonepileptic seizures.
The early and definitive diagnosis of psychogenic nonepileptic seizures is a common challenge in epileptology practice. Suggestive seizure induction is a valuable tool to aid the differentiation between epileptic and psychogenic nonepileptic seizures, especially when long-term video-EEG monitoring is inconclusive or unavailable. In this retrospective analysis, we compared the diagnostic yield of a classical, placebo-based induction protocol with that of an extended protocol that includes hyperventilation and photic stimulation as means of suggestion while also implementing more open, standardized patient information. We investigated whether the diversification of suggestive seizure induction has an effect on diagnostic yield and whether it preempts the administration of placebo. Data from 52 patients with confirmed psychogenic nonepileptic seizures were analyzed. While suggestive seizure induction using only placebo-based suggestion provoked a typical event in 13 of 20 patients (65%), the extended protocol was positive in 27 of 34 cases (84%); this improvement was not significant (p=0.11). Noninvasive suggestion techniques accounted for 78% of inductions, avoiding placebo administration in a majority of patients. Still, placebo remains an important part of suggestive seizure induction, responsible for 22% (6 out of 27) of successful inductions using our extended protocol. Our study demonstrates that the diversification of suggestive seizure induction is feasible and beneficial for both patients and diagnosticians.
Ruhr-Epileptology, Department of Neurology, Knappschaftskrankenhaus, Ruhr-University of Bochum, Bochum, Germany. Electronic address: popkirov@gmail.com.
Stoyan
S
Popkirov
Ruhr-Epileptology, Department of Neurology, Knappschaftskrankenhaus, Ruhr-University of Bochum, Bochum, Germany.
Wenke
W
Grönheit
Ruhr-Epileptology, Department of Neurology, Knappschaftskrankenhaus, Ruhr-University of Bochum, Bochum, Germany.
Jörg
J
Wellmer
D000328:Adult; D002985:Clinical Protocols / Q000592:standards*; D005260:Female; D006801:Humans; D006985:Hyperventilation; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D012640:Seizures / Q000175:diagnosis* / Q000209:etiology; D013001:Somatoform Disorders / Q000175:diagnosis*; D013404:Suggestion
Hyperventilation; PNES; Photic stimulation; Provocative techniques; Psychogenic nonepileptic seizures; Seizure induction