Time-frequency mapping of the rhythmic limb movements distinguishes convulsive epileptic from psychogenic nonepileptic seizures

Autor: Jade Bayly, Anita Vinton, Bernard Yan, Jayavardhana Gubbi, Dilini A. Fernando, Terence J. O'Brien, Michelle Smit, Marimuthu Palaniswami, Slavé Petrovski, John Carino
Rok vydání: 2013
Předmět:
Zdroj: Epilepsia. 54(8)
ISSN: 1528-1167
Popis: Purpose: A definite diagnosis of psychogenic nonepilepticseizures(PNES)usuallyrequiresin-patientvideo–electro-encephalography (EEG) monitoring. Previous researchhas shown that convulsive psychogenic nonepileptic sei-zures (PNES) demonstrate a characteristic pattern ofrhythmic movement artifact on the EEG. Herein wesought to examine the potential for time-frequency map-ping of data from a movement-recording device (acceler-ometer) worn on the wrist as a diagnostic tool todifferentiate between convulsive epileptic seizures andPNES.Methods: Time-frequency mapping was performed onaccelerometer traces obtained during 56 convulsiveseizure-like events from 35 patients recorded duringin-patient video-EEG monitoring. Twenty-six patientshad PNES, eight had epileptic seizures, and one had bothseizure types. The time-frequency maps were derivedfromfastFouriertransformationstodeterminethedomi-nant frequency for sequential 2.56-s blocks for the courseofeachevent.Key Findings: The coefficient of variation (CoV) of limbmovement frequency for the PNES events was less thanfor the epileptic seizure events (median, 17.18% vs.52.23%; p < 0.001). A blinded review of the time-fre-quencymapsbyanepileptologistwasaccurateindifferen-tiating between the event types, that is, 38 (92.7%) of 41and 6 (75%) of 8 nonepileptic and epileptic seizures,respectively, were diagnosed correctly, with seven eventsclassified as “nondiagnostic.” Using a CoV cutoff score of32% resulted in similar classification accuracy, with 42(93%) of 45 PNES and 10 (91%) of 11 epileptic seizureeventscorrectlydiagnosed.Significance: Time-frequency analysis of data from awristband movement monitor could be utilized as a diag-nostic tool to differentiate between epileptic and nonepi-lepticconvulsiveseizure-likeevents.KEY WORDS: Psychogenic nonepileptic seizures, Epilep-ticseizures,Time-frequencymapping,Limbmovements.
Databáze: OpenAIRE