What is the recommended standard emergency department workup for a 2-year-old child experiencing a non-febrile seizure for the first time?

Emergency Department Workup for First-Time Non-Febrile Seizure in a 2-Year-Old

For a 2-year-old with a first non-febrile seizure, laboratory studies should be ordered only when the history or physical examination suggests specific abnormalities (such as vomiting, diarrhea, dehydration, or failure to return to baseline), not routinely. 1

Immediate Assessment

Critical first steps:

• Check temperature immediately to confirm the seizure is truly non-febrile, as this fundamentally changes the diagnostic approach 2
• Assess return to baseline mental status within 5-10 minutes after seizure cessation 2
• Evaluate for postictal focal deficits that do not quickly resolve 1, 2
• Perform thorough neurologic examination to identify any abnormalities 1

Laboratory Testing

Laboratory studies are NOT routinely indicated for first-time non-febrile seizures in children 1. The American Academy of Neurology specifically states that labs should be ordered based on individual clinical circumstances 1.

Order laboratory tests only when:

• History suggests vomiting, diarrhea, or dehydration 1
• Child has not returned to baseline alertness 1
• Physical examination suggests metabolic abnormality 1
• Consider toxicologic screening if any question of drug exposure exists 1

Important caveat: Routine electrolytes, calcium, magnesium, and glucose rarely cause seizures in children and do not contribute to seizure therapy when ordered routinely 3. In one study, abnormal serum chemistries were never found to have caused seizure and none required treatment 3. Another study found only 7% of laboratory tests yielded clinically significant results, and these were predicted by history 4.

Neuroimaging

Emergent neuroimaging is indicated when: 1, 2

• Child exhibits postictal focal deficit that does not quickly resolve
• Child has not returned to baseline within several hours after the seizure
• Abnormal neurologic examination is present

Non-urgent MRI (preferred modality) should be considered for: 1

• Children aged <1 year 1
• Significant cognitive or motor impairment of unknown etiology 1
• Seizure of partial (focal) onset 1
• Unexplained abnormalities on neurologic examination 1

CT head has limited utility in this scenario. Only 2% of low-risk patients (no predisposing condition, no focal seizure) had abnormal imaging findings 1. CT may be appropriate only if the child is clinically unstable and requires rapid assessment 1.

EEG

An EEG is recommended as part of the neurodiagnostic evaluation of a child with an apparent first unprovoked seizure 1. This is a standard recommendation, not an option 1. The EEG should be performed during wakefulness and sleep 5.

Lumbar Puncture

LP is of limited value for first non-febrile seizure and should be used primarily when there is concern about possible meningitis or encephalitis 1. The threshold should be based on clinical suspicion of CNS infection, not performed routinely 6.

Age-Specific Considerations

For children <2 years old (which includes your 2-year-old patient):

• There is a trend toward increased yield of laboratory testing in this age group (7% difference in clinically significant abnormalities) 4
• Non-urgent MRI should be seriously considered, as age <1 year is specifically mentioned as warranting imaging 1
• At age 2, clinical judgment based on history and examination should guide the decision

Common Pitfalls to Avoid

• Do not order routine laboratory panels without clinical indication—this is costly and does not contribute to management 3
• Do not obtain emergent CT if the child has returned to baseline with normal neurologic examination 1
• Do not skip the EEG—this is a standard recommendation for first unprovoked seizure 1
• Do not assume metabolic causes are common—severe electrolyte imbalance or hypoglycemia causing seizures occurred in only 3 of 319 patients in one study 7

Disposition

Activate EMS or admit if: 1

• Seizure lasted >5 minutes
• Multiple seizures without return to baseline between episodes
• Difficulty breathing or traumatic injuries
• Child does not return to baseline within 5-10 minutes after seizure stops

Outpatient management is appropriate if the child has returned to baseline, has a normal neurologic examination, and no concerning features on history 2. Arrange outpatient EEG and consider non-urgent MRI based on clinical findings 2.