Differential diagnosis of paroxysmal events

  • Syncope
  • Cardiogenic
  • Cough
  • Migraine (confusional) - time 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 but more commonly have chewing, mouthing movements when refluxing that look like complex partial seizures. Easily distinguished using EEG and pH probe monitoring, resolves with anti-reflux medications. May 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, and they will not respond to antiepileptic drugs.
  • Rage attacks and temper tantrums - provoked by an adverse experience, volitional motor activity and vocalizations
  • Paroxysmal kinesiogenic or dystonic choreoathetosis - rare disorders characterized by episodic involuntary movements and preserved awareness
  • Benign infantile myoclonus - 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 twitches, upward eye movement, interruption of play, or urinary incontinence are present. Additionally, nonepileptic staring spells are not provoked by hyperventilation.
  • Night terrors - Patient appears confused and frightened during stage four sleep. Sleep study is sometimes required to distinguish from complex partial seizures
  • Tics/habit spasms - can be consciously suppressed when pointed out, and patient "feels better" when they're allowed to indulge the tic
  • Narcolepsy/cataplexy/sleep apnea - 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 - 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 - when patient's seizures, EEG, and response to medications don't make sense. 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


Author: Colin Van Orman, MD - 2/2009