Seizure (Case 17)

Chapter 47 Seizure (Case 17)



Cynthia Gibson, MD, FAAP




Case


A 6-month-old presents with extremity shaking for 10 minutes and is now sleepy.




Differential Diagnosis













Infection Epilepsy Metabolic and electrolyte disturbances
Trauma Toxic ingestion Tumor


Speaking Intelligently


Acute management of seizures includes assessment and stabilization of airway, breathing, and circulation (ABCs) before administration of antiseizure medication, typically a benzodiazepine. Persistent seizures and those in neonates are often treated with phenobarbital, which requires monitoring for respiratory depression and hypotension. Therapy should be implemented while simultaneously investigating etiology. Febrile seizures are the most common type of childhood seizure and typically carry an excellent prognosis (see Chapter 87, Status Epilepticus).



Patient Care



Clinical Thinking



• Support the ABCs.

• Is the patient stable, or is intensive care required?

• Seizures have many possible causes, which will dictate treatment. A detailed history and examination may suggest infection, toxic ingestion, or trauma. If the seizure recurs or does not respond to antiepileptics, other correctable causes must be considered.

• Review treatable causes such as hypoglycemia or hyponatremia.

• Are there preexisting neurologic abnormalities?

• Diagnoses that mimic seizures include benign paroxysmal vertigo, breath holding, syncope, shuddering attacks, narcolepsy, night terrors, pseudoseizures, benign myoclonus of infancy, and tics.

• Proceed in a stepwise fashion to avoid unnecessary testing.


History



• Obtain a detailed description, including circumstances, prodrome, focality, duration, frequency, and postictal state.

• Fever in an otherwise healthy child may suggest febrile seizure or central nervous system (CNS) infection.

• Recent trauma and rapid symptom progression suggest intracranial hemorrhage.

• Obtain detailed history of possible ingestion, including all household medications.

• Localizing neurologic signs point to an intracranial mass.

• Dehydration or metabolic disorder may suggest an electrolyte abnormality.


Physical Examination



• Assess and stabilize the ABCs.

Vital signs:


• Realize that heart rates, blood pressure, and respiratory rates vary with age.

• Hypertension, tachycardia, and arrhythmias may manifest during a seizure.

• Assess hydration status.

• Thorough neurologic examination includes: mental status, cranial nerves, reflexes, muscle strength and tone. Focal findings such as weakness or paralysis may localize a lesion.

• Fontanelle size and character in infants can be helpful but are inconsistent.

• Funduscopic examination may reveal retinal hemorrhages or papilledema.

• Assess for dysmorphology and neurocutaneous lesions.


Tests for Consideration



• Complete blood count (CBC): Leukocytosis with infection $116

• Electrolytes: Sodium, calcium, magnesium, phosphorous, and blood glucose levels are correctable abnormalities that may provoke seizure $392

• Blood culture: If concern for infection $152

• Lumbar puncture: If concern for meningitis/encephalitis; includes Gram stain, cell count, protein level, glucose level, culture, enterovirus polymerase chain reaction (PCR), herpes PCR $1028

• Electroencephalogram (EEG): To evaluate seizure character or abnormal brain activity $727

• If suspected undiagnosed metabolic disorder:
• Serum amino acids $322

• Urine organic acids $609

• Serum lactate $211


Imaging Considerations


→ Head computed tomography (CT) noncontrast: To assess for intracranial hemorrhage or mass $1827


→ Magnetic resonance imaging (MRI) (when clinically stable): More definitive for brain structure $2331




Clinical Entities: Medical Knowledge



















Infection
Pϕ CNS infections are commonly caused by bacteria or viruses and may result in meningitis, encephalitis, and occasionally intracranial abscesses. These infections typically occur via direct injury or inflammation of neurons or their supportive structures. Seizures may develop from infection-related inflammation and/or cell death.
TP CNS infections may present with symptoms of fever, altered consciousness (lethargy or irritability), headaches, vomiting, bulging fontanelle, widened sutures, and papilledema. Signs of systemic illness, such as petechiae in Neisseria meningitis, may occur over hours to days. About 20% of patients with meningitis will have seizures; 80% of those will be complex seizures.
Dx In meningitis, lumbar puncture is usually diagnostic; in encephalitis it may be unrevealing. Special cerebrospinal fluid polymerase chain reaction (CSF PCR) studies may be required to confirm etiologies such as herpes simplex virus (HSV) and enterovirus. In some cases EEG or imaging findings—such as paroxysmal lateralizing electrical discharges (PLEDs) on EEG associated with herpes infections—will suggest the diagnosis.
Tx Treatment includes antimicrobial and supportive therapy. Initially, broad-spectrum antibiotics are appropriate pending culture results. Causative microorganisms differ according to age. In neonates, the most common organisms are Escherichia coli, other gram-negative organisms, and group B streptococcus. After 4 to 6 weeks of age, Streptococcus pneumoniae and Neisseria meningitidis occur more commonly (see Chapter 46, Neonatal Fever, and Chapter 49, Meningitis). See Nelson Essentials 100 and 101.











Toxic Ingestion
Pϕ Many drugs of abuse, household substances, or medications taken inappropriately or accidentally cause seizures via direct excitatory or sedative-hypnotic effects on the brain. Seizures may also result from medication side effects such as hypoglycemia.
TP There may not be a history of ingestion. Knowing which medications are present in the household may provide a clue. Intentional ingestions are more common in adolescents; accidental ingestions typically occur in toddlers. Many drugs have characteristic symptoms called toxidromes. Poison control centers are useful in these cases. Common causes of toxin-induced seizures can be remembered using the mnemonic OTIS CAMPBELL:

• Organophosphates
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  4. Intraventricular Hemorrhage (Case 37)

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Jul 18, 2016 | Posted by in PEDIATRICS | Comments Off on Seizure (Case 17)

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