Seizure Mimics

Seizure Mimics

Few things will frighten parents more than seeing their child appear to shake all over.  Fortunately, many times seizure activity is due to benign causes like simple febrile seizures.  Unfortunately, our job is quite difficult and we need to deal with other more troublesome entities like complex febrile seizures or neonatal seizures.  Of course we also need to consider entities that may provoke seizures, like hypoglycemia, AVMs, or pyridoxine deficiency.  While juggling all of the potential causes of seizures, we also need to pause and ask ourselves a simple question: was this even a seizure?  Perhaps we are dealing with a Seizure Mimic!


Seizure Numbers

  • Seizures are the most common pediatric neurologic emergency.
  • Seizures affect 4-10% of children during their lifetime.  (Hauser, 1994)
  • ~10% of new onset seizures present to the ED in status epileptics. (Singh, 2010)


Some Seizure Mimics

Since seizures are the most common neurologic emergency encountered in pediatric patients, it is reasonable to have it on the Ddx list of any child presenting with odd movements and/or behavior; however, there are also other significant conditions that should be considered in that situation! Here are some that could alter your initial management!

  • Arrhythmias
    • Long QT and torsades
    • VTach
    • Anytime there is poor cardiac output impairing cerebral perfusion, you can see motor activity / hypoxic convulsions.
  • Breath-Holding Spells
    • Actually not associated with inspiratory hold. The child typically screams/cries and exhales fully.
    • They can loose postural tone and have motor activity.
    • Up to 15% will have generalize hypoxic convulsions. (DiMario, 2001)
  • Syncope
    • Commonly encountered in teenagers
    • May have eye-rolling, incontinence, and motor twitching.
    • There are many causes of syncope (don’t forget the pregnancy test!) to consider… like Hair Grooming Syncope.
  • Sandifer Syndrome
    • Gastroesophageal reflux may cause generalized stiffness or posturing.
    • Can have apnea also.
    • Often occurs 20-30 min after a meal.
  • Dystonic Reactions
    • Always look at the medication list!!
  • Migraine Syndromes
    • Basilar Migraine
    • Familial Hemiplegic Migraine
  • Sleep-Related Phenomena
    • Benign sleep myoclonus
    • Periodic sleep jerks
    • Narcolepsy


Moral of the Morsel:




Luat AF, Kamat D, Sivaswamy L. Paroxysmal nonepileptic events in infancy, childhood, and adolescence. Pediatr Ann. 2015 Feb 1;44(2):e18-23. PMID: 25658214. [PubMed] [Read by QxMD]

Agarwal M1, Fox SM. Pediatric seizures. Emerg Med Clin North Am. 2013 Aug;31(3):733-54. PMID: 23915601. [PubMed] [Read by QxMD]

Singh RK1, Stephens S, Berl MM, Chang T, Brown K, Vezina LG, Gaillard WD. Prospective study of new-onset seizures presenting as status epilepticus in childhood. Neurology. 2010 Feb 23;74(8):636-42. PMID: 20089940. [PubMed] [Read by QxMD]

Obeid M1, Mikati MA. Expanding spectrum of paroxysmal events in children: potential mimickers of epilepsy. Pediatr Neurol. 2007 Nov;37(5):309-16. PMID: 17950415. [PubMed] [Read by QxMD]

DiMario FJ Jr1. Paroxysmal nonepileptic events of childhood. Semin Pediatr Neurol. 2006 Dec;13(4):208-21. PMID: 17178351. [PubMed] [Read by QxMD]

DiMario FJ Jr1. Prospective study of children with cyanotic and pallid breath-holding spells. Pediatrics. 2001 Feb;107(2):265-9. PMID: 11158456. [PubMed] [Read by QxMD]

Hauser WA1. The prevalence and incidence of convulsive disorders in children. Epilepsia. 1994;35 Suppl 2:S1-6. PMID: 8275976. [PubMed] [Read by QxMD]


Sean M. Fox
Sean M. Fox
Articles: 583


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