Generalized Periodic Discharges: Nonconvulsive Status Epilepticus or Diffuse Encephalopathy—A Case Comparison

SUMMARY: Nonconvulsive status epilepticus (NCSE) refers to persistent epileptiform discharges on EEG meeting the Salzburg criteria. Nonconvulsive status epilepticus with coma mostly occurs in critically ill patients without preceding convulsions and without a history of chronic epilepsy, where the EEG typically shows generalized periodic discharges (GPDs). Nonconvulsive status epilepticus without coma is typically described in patients with chronic epilepsy and is associated with a different alteration of consciousness where patients are awake with eyes open, retained posture, however unresponsive with amnesia (known as dialepsis). The GPDs in NCSE with coma could represent an epiphenomenon and the coma might not be a direct result of the GPDs. In contrast, the dialeptic state in NCSE without coma is a true manifestation of the epileptiform discharges, hence warranting treatment with antiseizure medications. In this report, a case of NCSE with coma is described caused by ceftriaxone-induced neurotoxicity and its electroclinical characteristics are compared with a case of NCSE without coma in a patient with chronic focal epilepsy.