Differential Diagnosis of Paroxysmal Events

Non-epileptic paroxysmal events may mimic epilepsy. The duration, place, timing of the attacks, and state of consciousness may confuse pediatricians about the diagnosis of epilepsy and non epileptic paroxysmal events. Differential diagnoses of paroxysmal event may include:
  • Syncope
  • Cardiogenic
  • Cough
  • Migraine (confusional)
    • Time of course is usually longer than most complex partial seizures; EEG is normal during event.
  • Metabolic disorders
    • Hypoglycemia, hypocalcemia, and rapid sodium shifts can all cause non-epileptic seizures.
  • Paroxysmal vertigo
  • GER in infancy/childhood
    • Some patients may have actual seizures due to anoxia when the child aspirates. More commonly, they have chewing, mouthing movements when refluxing that look like complex partial seizures. This is easily distinguished using EEG and pH probe monitoring and resolves with anti-reflux medications. May patients also have arching with torticollis and dystonic posturing due to reflux, particularly observed in neurologically abnormal children (Sandifer's syndrome).
  • Breath-holding spells
    • Pallid and cyanotic types are both precipitated by a noxious event. Note that seizures may rarely occur from lack of oxygen during the spell, but these are reflex seizures, not seizures representative of epilepsy; they will not respond to antiepileptic drugs.
  • Rage attacks and temper tantrums
    • Tantrums are provoked by an adverse experience, and the patient has volitional motor activity and vocalizations.
  • Paroxysmal kinesiogenic or dystonic choreoathetosis
    • These are rare disorders characterized by episodic involuntary movements and preserved awareness.
  • Benign infantile myoclonus
    • This looks like infantile spasms, but with normal EEG and development.
  • Shuddering attacks
  • Daydreaming/inattention
    • Nonepileptic staring spells are most easily identified by preserved responsiveness to touch, body rocking, and initial identification by a teacher or health care professional. Epileptic events are more common when limb twitching, upward eye movement, interruption of play, or urinary incontinence is present. Nonepileptic staring spells are not provoked by hyperventilation.
  • Night terrors
    • The patient appears confused and frightened during stage 4 sleep. A sleep study is sometimes required to distinguish from complex partial seizures.
  • Tics/habit spasms
    • Tics can be consciously suppressed when pointed out, and the patient "feels better" when they're allowed to indulge the tic.
  • Narcolepsy/cataplexy/sleep apnea
    • There is a sudden loss of all muscle tone and patient falls to ground. Patient is fully aware but cannot move; occurs in response to strong emotion such as laughter.
  • Non-epileptogenic seizure
    • These often occur in the setting of epilepsy, so the patient has both real and facetious seizures. Telemetry will allow them to be distinguished from one another.
  • Munchausen syndrome by proxy
    • Consider when patient's seizures, EEG, and response to medications don't make sense. It is difficult to determine without EEG/video telemetry.


Helpful Articles

Stroink H, van Donselaar CA, Geerts AT, Peters AC, Brouwer OF, Arts WF.
The accuracy of the diagnosis of paroxysmal events in children.
Neurology. 2003;60(6):979-82. PubMed abstract

Uldall P, Alving J, Hansen LK, Kibaek M, Buchholt J.
The misdiagnosis of epilepsy in children admitted to a tertiary epilepsy centre with paroxysmal events.
Arch Dis Child. 2006;91(3):219-21. PubMed abstract / Full Text

Beach R, Reading R.
The importance of acknowledging clinical uncertainty in the diagnosis of epilepsy and non-epileptic events.
Arch Dis Child. 2005;90(12):1219-22. PubMed abstract / Full Text

Authors & Reviewers

Initial publication: February 2009; last update/revision: January 2019
Current Authors and Reviewers:
Author: Lynne M. Kerr, MD, PhD
Authoring history
2011: update: Lynne M. Kerr, MD, PhDA
2009: first version: Colin B. Van Orman, MDA
AAuthor; CAContributing Author; SASenior Author; RReviewer