Seizure (peds)

Background

• Consider neuroimaging for new-onset focal seizure
• Todd paralysis
  • Temporary focal deficit up to 36 hr post-seizure
• Lateral tongue biting - 100% sp

Differential Diagnosis

Pediatric seizure

• Epileptic seizure
  • First-time seizure
  • Seizure with known seizure disorder
  • Status epilepticus
  • Temporal lobe epilepsy
  • Non-compliance with or "outgrowing" AEDs
• Non-epileptic seizure
  • Febrile seizure
  • Brain inflammation
    • Meningitis
    • Encephalitis
    • CNS abscess
    • Intracranial hemorrhage
    • Neurocysticercosis
  • Increased ICP
    • Seizure with VP shunt
    • Hydrocephalus
    • Intracranial mass
  • Toxicologic
    • Alcohol withdrawal
    • Benzodiazepine withdrawal
    • Toxic ingestion
  • Metabolic abnormalities: hyponatremia, hypernatremia, hypocalcemia, hypomagnesemia, hypoglycemia, hyperglycemia
  • Pyridoxine responsive seizure
  • Eclampsia
  • Posterior reversible encephalopathy syndrome
  • Impact seizure (head trauma)
• Other mimics
  • Psychogenic nonepileptic seizure (pseudoseizure)
  • Syncope (peds)
  • Breath-holding spell
  • Hyperventilation syndrome
  • Migraine headache
  • Movement disorders
  • Narcolepsy/cataplexy
  • Post-hypoxic myoclonus (Status myoclonicus)
  • Infantile Spasms/West Syndrome

Diagnosis

Seizure with a Fever

• See Febrile Seizure

First-Time Afebrile Seizure

• If pt returns to baseline no labs/imaging necessarily indicated
  • Consider glucose, chemistry, utox
• LP only necessary if concern for meningitis
• EEG should be performed within 24-48hr
• Neuroimaging
  • Preferred test is outpt MRI
  • Consider emergent imaging for focal deficit, no return to baseline
• 40% have 2nd sz

Neonatal Seizure

• Often subtle, focal, poor prognosis
  • Less often have generalized tonic-clonic seizures
    • Findings include lip smacking, eye deviation, staring, ALTE
• Work-up
  • CBC, chemistry, UA, CSF (including HSV), utox (withdrawal)
  • Consider neuroimaging if concern for abuse, ICH, mass
  • Consider lactate, ammonia if concern for errors of metabolism
• Treatment
  • Start IV abx (including acyclovir)

Epileptic Seizures

• Epilepsy = 2 or more sz w/o acute provocation (fever, trauma)
• Often due to pt "outgrowing" their dosage
• Check levels of:
  • Phenytoin, carbamazepine, valproic acid
    • If low consider non-compliance, "outgrowing," vomiting, med interaction
• Pts with epilepsy may have lower sz threshold with febrile illness
  • Usually can limit ED w/u to fever evaluation

Seizure with VP Shunt

• Consider underlying epilepsy, shunt malfunction, CNS infection
  • If pt has fever seizure more likely 2/2 infection than malfunction
    • Consult pediatric neurosurgeon to tap the shunt
• Imaging
  • Obtain shunt series and head CT or MRI to evaluate for incr ventricular size

Seizure with Trauma

• "Impact seizures" (sz that occurs w/in minutes of head trauma)
  • Not associated with severe head injuries
• Sz that occur after this time more likely to represent intracranial injury

Status Epilepticus

• Seizure or recurrent sz lasting >5min w/o regaining consciousness
  • If prolonged postictal state or longer than usual consider nonconvulsive status
    • Obtain emergency EEG; if not available trial of anticonvulsants appropriate
• Management
  • Glucose, chemistry, CBC, LFT, ?CSF, ?neuroimaging
  • Intubate if e/o apnea and persistent hypoxia
  • If use paralytic EEG monitoring should be arranged

Treatment

1st Line

Drug	Route	Dose*	Maximum	Onset of Action	Duration of Action
Lorazepam	IV, IO, IN	0.1 mg/kg	4 mg	1–5 min	12–24 h
	IM	0.1 mg/kg	4 mg	15–30 min	12–24 h
Diazepam	IV, IO	0.1–0.3 mg/kg	10 mg	1–5 min	15–60 min
	PR	0.5 mg/kg	20 mg	3–5 min	15–60 min
Midazolam	IV, IO	0.1–0.2 mg/kg	4 mg	1–5 min	1–6 h
	IM	0.2 mg/kg	10 mg	5–15 min	1–6 h
	IN	0.2 mg/kg	10 mg	1–5 min	1–6 h
	Buccal	0.5 mg/kg	10 mg	3–5 min	1–6 h

2nd Line

• If sz persists for another 5 min after 2 doses of benzos switch to fosphenytoin or phenobarbital
  • Fosphenytoin is usually preferred 2nd line agent 
  • Consider phenobarb over fosphenytoin if febrile illness, <2yr

Drug	Route	Loading Dose	Repeat Dose	Maximum	IV Infusion
Fosphenytoin	IV, IM	15–20 mg/kg PE	5–10 mg/kg PE	30 mg/kg PE	3 mg/kg/min PE
Phenobarbital	IV	15–20 mg/kg	5–10 mg/kg	40 mg/kg	1–30 mg/min
Valproic acid	IV	20 mg/kg	15–20 mg/kg	40 mg/kg	5 mg/kg/hr
Levetiracetam	IV	20–30 mg/kg	—	3 grams	—
Pentobarbital	IV	5–15 mg/kg	1–2 mg/kg	15 mg/kg	0.5–5.0 mg/kg/hr
Propofol	IV	0.5–2.0 mg/kg	0.5–1.0 mg/kg	5 mg/kg	1.5–4.0 mg/kg/hr
Midazolam	IV	0.1–0.2 mg/kg	0.1–0.2 mg/kg	10 mg	0.05–0.4 mg/kg/hr

3rd Line

• Consider Valproic acid 20mg/kg over 1-5min; then infusion of 5mg/kg/hr

Hypoglycemia

• Defined as <50 mg/dL
• All seizing pts with hypoglycemia should be treated with 2 mL/kg 25% dextrose

Hyponatremia

• Consider as cause of sz, esp if Na <120 mEq/L
• Goal of therapy is to correct quickly to >120, slowly thereafter
  • In actively seizing pt treatment of choice is 3% NaCl
    • 3% NaCl (513 mEq/1000 mL)
      • Na deficit in total mEq = [(wt in kg)x(130 – serum Na level)x0.6] over 20min OR
    • 3% NaCl: 4-6 mL/kg over 20min
  • If no sz activity but Na <120 start 4-6 mL/kg 3% NaCl or 20 mL/kg of NS over 1hr
    • Check Na level after bolus to see if second bolus is necessary
  • If 3% unavailable start NS 20mL/kg

Hypocalcemia

• Administer 10% calcium gluconate 0.3 mL/kg over 5-10min

Other

• Consider Pyridoxine (vitamin B6) 1g per g of INH ingested (in D5W IV over 30 min)
• Consider Pyridoxine Responsive Seizure Disorder - 100mg/pyridoxine is generally effective

See Also

• Seizure
• Febrile Seizure
• Seizure Levels and Reloading