Seizures are a common yet frightening problem in pediatric populations. The majority of children with epilepsy have normal neurologic examinations and imaging studies. Therefore a careful and detailed history is paramount for an accurate diagnosis.
Seizure: a single convulsive episode or multiple such episodes within 24 hrs with return to consciousness between the episodes.
Seizure types included
- Partial (simple, complex, or partial with secondary generalization)
- Generalized tonic-clonic
Seizure types excluded
- Seizure due to obvious causes, such as fever, CNS trauma, infection, tumor, metabolic imbalances
- Absence, myoclonic, and atonic seizures (often difficult to recognize unless they become repetitive)
- Neonatal seizures (≤28 days of life)
- Is this a true seizure?
- Is there a stimulus for the seizure?
- What is the likelihood of seizure recurrence or development into chronic epilepsy?
- What are the risks/benefits of antiepileptic drug (AED) therapy
Differential Diagnosis of a Seizure-like Episode
- Infants (<2 years old): breath-holding spells, GERD, dystonia, paroxysmal torticollis, cyclic vomiting, infantile spasms
- Childhood (>2 years old): migraine, syncope (cough syncope, long QT), narcolepsy-cataplexy, paroxysmal dyskinesia/benign paroxysmal vertigo, hyperventilation, pseudoseizure/psychogenic seizure, startle disease, night terrors
- Relevant HPI: description of event (setting/environment-are events specific to a certain time of day or location), focal/generalized (specific description of limb movements, opening/closing of eyes and mouth), duration, aura/pre-ictal events, postictal state, autonomic instability, incontinence, automatisms, activity/behavior immediately before, during and after the seizure
- Medical history: seizure-like events, psychiatric disorders
- Family history
- Recent illnesses/exposures at seizure onset
- State screening results
- Physical examination
- Neurologic: focal deficits, mental status
- Ophthalmic: congenital defects, retinal changes associated with neurocutaneous/neurodegenerative disorders, signs of infection
- Abdominal: HSM may indicate a storage disorder
- Cardiac: decreased cardiac output may mimic complex partial seizure presentation
- Skin: as above, some neurocutaneous disorders may be associated with epilepsy (TS, Sturge-Weber, NF, linear nevus syndrome, Ito; Wood lamp examination may be useful
- Blood chemistries (especially glucose): useful only if history or clinical findings are suggestive (vomiting, diarrhea, dehydration, continued altered mental status)
- Toxicology screen: useful if have any suspicion of drug exposure/abuse
- Lumbar puncture: NOT useful routinely, useful only in very young children (<6 mo) with persistent altered mental status of unknown cause
- EEG: very useful in characterizing seizure type, location, and predicting risk of recurrence; highest yield of abnormalities within 24-48 hrs but also may show post-ictal slowing which complicates interpretation; outpatient EEG may be arranged; sleep versus awake EEG is often useful since seizures may only occur in one state
- Neuroimaging (CT or MRI): first seizure should NOT be a sole indication for neuroimaging; if imaging is needed, MRI is preferred because of increased sensitivity, especially for progressive lesions (tumors, vascular malformations, cortical dysplasia); emergent imaging is recommended at any age if a child has prolonged post-ictal focal deficit (Todd’s paresis), or fails to return to baseline after several hours post-seizure; non-urgent imaging is recommended if child has cognitive/motor deficits w/o known cause, abnormal neurologic exam, focal seizure, abnormal EEG that does not represent a benign seizure of childhood, children < 1 year old
- EKG: long QT syndrome can often mimic seizure-like presentation, including an aura
- Vining E.P. Freeman J.M. Management of nonfebrile seizures. Pediatrics in Rev. 1986
- Haslam R.H. Nonfebrile seizures. Pediatrics in Rev. 1997
- Hirtz D. et al. Practice Parameter: Evaluation a first nonfebrile seizure in children. Neurology September 2000
- Riviello J.J. et al. Practice parameter: diagnostic assessment of the child with status epilepticus (an evidence-based review): Report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society. Neurology 2006
- Tekgul H. The Current Etiologic Profile and Neurodevelopmental Outcome of Seizures in Term Newborn Infants. Pediatrics April 2006
- American Academy of Neurology Diagnostic Assessment of the Child with Status Epilepsy Neurology 2006