title: Panic symptoms in transient loss of consciousness: Frequency and diagnostic value in psychogenic nonepileptic seizures, epilepsy and syncope.
abstract: OBJECTIVE
  Previous studies suggest that ictal panic symptoms are common in patients with psychogenic nonepileptic seizures (PNES). This study investigates the frequency of panic symptoms in PNES and if panic symptoms, just before or during episodes, can help distinguish PNES from the other common causes of transient loss of consciousness (TLOC), syncope and epilepsy.
  
  
  METHODS
  Patients with secure diagnoses of PNES (n=98), epilepsy (n=95) and syncope (n=100) were identified using clinical databases from three United Kingdom hospitals. Patients self-reported the frequency with which they experienced seven symptoms of panic disorder in association with their episodes. A composite panic symptom score was calculated on the basis of the frequency of symptoms.
  
  
  RESULTS
  8.2% of patients with PNES reported "never" experiencing any of the seven panic symptoms in their episodes of TLOC. Patients with PNES reported more frequent panic symptoms in their attacks than those with epilepsy (p<0.001) or syncope (p<0.001), however, patients with PNES were more likely "rarely" or "never" to report five of the seven-ictal panic symptoms than "frequently" or "always" (45-69% versus 13-29%). A receiver operating characteristic analysis demonstrated that the composite panic symptom score distinguished patients with PNES from the other groups (sensitivity 71.1%, specificity 71.2%), but not epilepsy from syncope.
  
  
  CONCLUSIONS
  Patients with PNES report TLOC associated panic symptoms more commonly than those with epilepsy or syncope. Although panic symptoms are reported infrequently by most patients with PNES, a composite symptom score may contribute to the differentiation between PNES and the other two common causes of TLOC.
authors.affiliation: Academic Neurology Unit, University of Sheffield, Royal Hallamshire Hospital, Sheffield, S10 2JF, United Kingdom.
authors.forename: G H
authors.initials: GH
authors.lastname: Rawlings
authors.affiliation: Academic Neurology Unit, University of Sheffield, Royal Hallamshire Hospital, Sheffield, S10 2JF, United Kingdom. Electronic address: jen.khoda@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Jamnadas-Khoda
authors.affiliation: Mental Health Liaison Team, Derbyshire Healthcare NHS Foundation Trust Hartington Unit, Chesterfield, S44 5BL, United Kingdom. Electronic address: maczb@btinternet.com.
authors.forename: M
authors.initials: M
authors.lastname: Broadhurst
authors.affiliation: Department of Neurology Sheffield Teaching Hospitals NHS Foundation Trust, Glossop Road, Sheffield, S10 2JF, United Kingdom. Electronic address: richard.grunewald@sth.nhs.uk.
authors.forename: R A
authors.initials: RA
authors.lastname: Grünewald
authors.affiliation: Department of Neurology Sheffield Teaching Hospitals NHS Foundation Trust, Glossop Road, Sheffield, S10 2JF, United Kingdom. Electronic address: Stephen.Howell@sth.nhs.uk.
authors.forename: S J
authors.initials: SJ
authors.lastname: Howell
authors.affiliation: Department of Clinical and Experimental Epilepsy, University College London, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom. Electronic address: m.koepp@ucl.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Koepp
authors.affiliation: Institute of Cellular Medicine, Newcastle University, Newcastle, NE2 4HH, United Kingdom. Electronic address: steve.parry@nuth.nhs.uk.
authors.forename: S W
authors.initials: SW
authors.lastname: Parry
authors.affiliation: Department of Clinical and Experimental Epilepsy, University College London, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom. Electronic address: s.sisodiya@ucl.ac.uk.
authors.forename: S M
authors.initials: SM
authors.lastname: Sisodiya
authors.affiliation: Department of Clinical and Experimental Epilepsy, University College London, Institute of Neurology, Queen Square, London, WC1N 3BG, United Kingdom. Electronic address: m.walker@ucl.ac.uk.
authors.forename: M C
authors.initials: MC
authors.lastname: Walker
authors.affiliation: Academic Neurology Unit, University of Sheffield, Royal Hallamshire Hospital, Sheffield, S10 2JF, United Kingdom. Electronic address: ghrawlings1@sheffield.ac.uk.
authors.forename: M
authors.initials: M
authors.lastname: Reuber
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004827:Epilepsy / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010200:Panic; D016584:Panic Disorder / Q000209:etiology*; D012640:Seizures / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D057566:Self Report; D011795:Surveys and Questionnaires; D013575:Syncope / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D014474:Unconsciousness / Q000150:complications / Q000175:diagnosis* / Q000523:psychology
keywords: Anxiety; Epilepsy; Panic; Psychogenic nonepileptic seizures; Syncope