title: Serum creatine phosphokinase is helpful in distinguishing generalized tonic-clonic seizures from psychogenic nonepileptic seizures and vasovagal syncope.
abstract: OBJECTIVE
  Distinguishing epileptic generalized tonic-clonic seizures (GTCS) from either psychogenic nonepileptic seizures (PNES) or vasovagal syncope (VVS) is important. In this study, we investigated the use of postictal serum creatine phosphokinase (CPK) concentrations in distinguishing between these events.
  
  
  METHODS
  Patients admitted to the Neurology Ward at Namazi Hospital in Shiraz, Iran, with an attack of transient loss of consciousness and abnormal movements witnessed by a neurologist were studied. We categorized the patients into three groups: 20 patients with GTCS, 22 with VVS, and 20 with PNES. A group of 20 normal healthy individuals were included in the study as the control group. Serum CPK concentration was measured 12-15 h after the attack in all patients and at one time in the control group. A P value less than 5% was considered significant.
  
  
  RESULTS
  There were no significant differences between the four groups with respect to age and sex. Mean CPK concentrations statistically significantly differed between the four groups, with higher levels in patients with GTCS (P=0.0001). Serum CPK concentration had a sensitivity of 75% and specificity of 86% for the diagnosis of GTCS. CPK concentration was above 160 mg/dl in 75% of patients with GTCS, 15% of patients with PNES, 13.6% of patients with VVS, and 15% of the control group (P=0.0001). The PNES, VVS, and control groups did not statistically significantly differ with respect to CPK concentrations.
  
  
  CONCLUSIONS
  In patients with a recent loss of consciousness and abnormal movements, serum CPK concentration is a useful, practical, and relatively accurate parameter to assist in the differentiation of epileptic seizures from either VVS or PNES.
authors.affiliation: Department of Neurology, Shiraz University of Medical Sciences, Shiraz, Iran. petramfar@yahoo.com
authors.forename: Peyman
authors.initials: P
authors.lastname: Petramfar
authors.forename: Ehsan
authors.initials: E
authors.lastname: Yaghoobi
authors.forename: Reza
authors.initials: R
authors.lastname: Nemati
authors.forename: Ali A
authors.initials: AA
authors.lastname: Asadi-Pooya
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D003402:Creatine Kinase / Q000097:blood*; D004827:Epilepsy / Q000097:blood* / Q000175:diagnosis*; D004830:Epilepsy, Tonic-Clonic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011602:Psychophysiologic Disorders / Q000097:blood*; D019462:Syncope, Vasovagal / Q000097:blood*; D055815:Young Adult
chemical_list: D003402:Creatine Kinase