Serum creatine phosphokinase is helpful in distinguishing generalized tonic-clonic seizures from psychogenic nonepileptic seizures and vasovagal syncope.
Petramfar P, Yaghoobi E, Nemati R, Asadi-Pooya AA. Serum creatine phosphokinase is helpful in distinguishing generalized tonic-clonic seizures from psychogenic nonepileptic seizures and vasovagal syncope. Epilepsy Behav. 2009 Jul; 15(3):330-2.