Seizure (peds)

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Background

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

Seizure Types

Classification is based on the international classification from 1981[1]; More recent terms suggested by the ILAE (International League Against Epilepsy) task Force.[2]

Focal seizures

(Older term: partial seizures)

  • Without impairment in consciousness– (AKA Simple partial seizures)
    • With motor signs (ex. facial twiching or rhythmic ipsilateral extremity movements)
    • With sensory symptoms (ex. tingling or pereiving a certain smell)
    • With autonomic symptoms or signs (ex. tachycardia or diaphoresis)
    • With psychic symptoms (including aura, ex. sense of déjà-vu)
  • With impairment in consciousness - (AKA Complex Partial Seizures--Older terms: temporal lobe or psychomotor seizures)
    • Simple partial onset, followed by impairment of consciousness
    • With impairment of consciousness at onset
  • Focal seizures evolving to secondarily generalized seizures
    • Simple partial seizures evolving to generalized seizures
    • Complex partial seizures evolving to generalized seizures
    • Simple partial seizures evolving to complex partial seizures evolving to generalized seizures

Generalized seizures

  • Absence seizures (Older term: petit mal; brief dissociative states without postural changes)
    • Typical absence seizures
    • Atypical absence seizures
  • Myoclonic seizure (violent muscle contractions)
  • Clonic seizures (rhythmic jerking)
  • Tonic seizures (stiffening)
  • Tonic–clonic seizures (Older term: grand mal)
  • Atonic seizures (loss of muscle tone)

SUDEP[3]

  • Sudden Unexpected Death in Epilepsy
  • Generalized tonic-clonic seizure is the major risk factor for SUDEP, and seizure freedom is strongly associated with decreased risk
    • Annual incidence of SUDEP in children is 1 in 4500
    • Incidence in adults is 1 in 1000

Clinical Features

  • Abrupt onset, may be unprovoked
  • Brief duration (typically <2min)
  • AMS
  • Jerking of limbs
  • Postictal drowsiness/confusion
  • Todd paralysis
  • Lateral tongue biting - 100% specificity

Differential Diagnosis

Pediatric seizure

Diagnosis

Seizure with a Fever

First-Time Afebrile Seizure

  • If patient 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)
    • Consider B6 and folic acid responsive etiologies unresponsive to benzos[5]
      • x2 doses pyridoxal phosphate 10 mg/kg/dose 2 hrs apart
      • If persistent, x2 doses of folinic acid 5 mg 6 hrs apart
      • EEG monitoring during this period is helpful

Epileptic Seizures

  • Epilepsy = 2 or more sz w/o acute provocation (fever, trauma)
  • Often due to patient "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 patient has fever seizure more likely secondary to 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

Management

1st Line

Drug[6] 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 patients 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 patient 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) [7]
  • Consider Pyridoxine Responsive Seizure Disorder - 100mg/pyridoxine is generally effective [8]

Disposition

If negative workup

  • EEG and MRI outpt Rx
  • Diastat (diazepam) Rectal Kit
    • 2-5 yrs: 0.5 mg/kg
    • 6-11 yrs: 0.3 mg/kg
    • 12+ yrs: 0.2 mg/kg

See Also

External Links

References

  1. Proposal for revised clinical and electroencephalographic classification of epileptic seizures. From the Commission on Classification and Terminology of the International League Against Epilepsy. Epilepsia 1981; 22:489.
  2. Epilepsia 2015; 56:1515-1523.
  3. Harden C et al. American Academy of Neurology and the American Epilepsy Society. Practice guideline summary: Sudden unexpected death in epilepsy incidence rates and risk factors. Neurology April 25, 2017 vol. 88 no. 17 1674-1680.
  4. Baxter P. et al. Pyridoxine‐dependent and pyridoxine‐responsive seizures. Developmental Medicine & Child Neurology 2001, 43: 416–42
  5. Robert Surtees and Nicole Wolf. Treatable neonatal epilepsy. Arch Dis Child. 2007 Aug; 92(8): 659–661.
  6. LaRoche SM, Helmers SL. The New Antiepileptic Drugs: Scientific Review. JAMA. 2004;291:605-614.
  7. Minns AB, Ghafouri N, Clark RF. Isoniazid-induced status epilepticus in a pediatric patient after inadequate pyridoxine therapy. Pediatr Emerg Care. 2010; 26(5):380-1.
  8. Pyridoxine dependent seizures a wider clinical spectrum. Archives of Disease in Childhood.1983 (58) 415-418. http://adc.bmj.com/content/58/6/415.full.pdf