Lactate as a diagnostic marker in transient loss of consciousness.

Purpose: The diagnostic classification of disorders of consciousness is often challenging, particularly the distinction between epileptic and non-epileptic seizures. The aim of the study was to examine serum lactate as a diagnostic marker of transient loss of consciousness.

Method: Serum lactate levels in blood samples drawn within 2h of the event were compared retrospectively between patients with generalized tonic-clonic seizures (n=195) and patients with other seizures (syncopes [n=52], psychogenic non-epileptic seizures [n=17], and complex focal seizures [n=37]), respectively.