title: Diagnostic delay in psychogenic seizures and the association with anti-seizure medication trials.
abstract: OBJECTIVE
  The average delay from first seizure to diagnosis of psychogenic non-epileptic seizures (PNES) is over 7 years. The reason for this delay is not well understood. We hypothesized that a perceived decrease in seizure frequency after starting an anti-seizure medication (ASM) may contribute to longer delays, but the frequency of such a response has not been well established.
  
  
  METHODS
  Time from onset to diagnosis, medication history and associated seizure frequency was acquired from the medical records of 297 consecutive patients with PNES diagnosed using video-electroencephalographic monitoring. Exponential regression was used to model the effect of medication trials and response on diagnostic delay.
  
  
  RESULTS
  Mean diagnostic delay was 8.4 years (min 1 day, max 52 years). The robust average diagnostic delay was 2.8 years (95% CI: 2.2-3.5 years) based on an exponential model as 10 to the mean of log10 delay. Each ASM trial increased the robust average delay exponentially by at least one third of a year (Wald t=3.6, p=0.004). Response to ASM trials did not significantly change diagnostic delay (Wald t=-0.9, p=0.38).
  
  
  CONCLUSIONS
  Although a response to ASMs was observed commonly in these patients with PNES, the presence of a response was not associated with longer time until definitive diagnosis. Instead, the number of ASMs tried was associated with a longer delay until diagnosis, suggesting that ASM trials were continued despite lack of response. These data support the guideline that patients with seizures should be referred to epilepsy care centers after failure of two medication trials.
authors.affiliation: Department of Biomathematics, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States. Electronic address: WesleyTK@UCLA.edu.
authors.forename: Wesley T
authors.initials: WT
authors.lastname: Kerr
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Janio
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Justine M
authors.initials: JM
authors.lastname: Le
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Hori
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Akash B
authors.initials: AB
authors.lastname: Patel
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Norma L
authors.initials: NL
authors.lastname: Gallardo
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Janar
authors.initials: J
authors.lastname: Bauirjan
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Chau
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Shannon R
authors.initials: SR
authors.lastname: D'Ambrosio
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Cho
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States; Departments of Neurology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Jerome
authors.initials: J
authors.lastname: Engel
authors.affiliation: Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA, United States; Departments of Neurology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States; Departments of Radiology, Psychology, Biomedical Physics, and Bioengineering, University of California Los Angeles, Los Angeles, CA, United States; California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, United States.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Cohen
authors.affiliation: Departments of Neurology and Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States.
authors.forename: John M
authors.initials: JM
authors.lastname: Stern
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000494:pharmacology; D002648:Child; D057210:Delayed Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011602:Psychophysiologic Disorders / Q000175:diagnosis* / Q000188:drug therapy; D012640:Seizures / Q000175:diagnosis* / Q000188:drug therapy; D013997:Time Factors; D017211:Treatment Failure; D055815:Young Adult
chemical_list: D000927:Anticonvulsants
keywords: Antiepileptic drugs; Diagnostic delay; Evidence based medicine; Non-epileptic seizures