Introduction
Seizures are episodic, involuntary, and recurring alterations of brain function
that affect motor activity, behavior, sensation, or autonomic function. Studies show that
approximately 1-2 percent of the general pediatric population is affected by recurring
non-febrile convulsions. Nearly, 2-5 percent of patients between the ages of 6 months and
6 years have febrile seizures. A febrile seizure is defined as convulsions associated with
elevated temperatures in patients without evidence of intracranial infection or other
defined causes. The International Classification of Seizures divides seizures into two
types, based on electrical activity in the brain: partial (seizure beginning locally); and
generalized (seizures without local onset and involving all parts of the cortex
simultaneously).
History
Given a child who has just experienced an initial or recurrent seizure,
the following important historical information should be obtained:
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How the event began.
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Whether there were any precipitating events (including trauma).
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What actually happened during the event?
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What was the duration of the event?
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Has the child been ill (meningitis)?
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Prenatal, perinatal, and developmental history.
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Personal history of seizures.
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Family history of seizures.
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Medications the patient had been taking for his or her seizure disorder.
Physical exam
The patient who presents with a history of new or recurring seizures needs a
complete general and neurodevelopmental physical examination. Measure and plot the head
circumference (there are standard charts for head growth to 18 years of age). Always
examine fundi (hemorrhage). On neurological examination, evaluate for any focal deficit.
Observe for asymmetry of gait, arm swing, or imbalance. Ask the patient about any changes
in mental abilities or personality. Examine the skin closely for evidence of hypopigmented
patches or other signs of a neurocutaneous syndrome. The hypopigmented macules of tuberous
sclerosis can sometimes only be seen with a Wood's lamp.
Laboratory and other studies
Laboratory studies include a complete blood
count, urinalysis, and serum
electrolytes, calcium, magnesium, phosphorus, protein, and blood sugar. If the patient is
a small infant (< 3 months), is febrile, or shows other signs of a central nervous
system (CNS) infection, do a lumbar puncture (LP), including a cell count, glucose,
protein, a gram stain, and culture of the
CSF. If there is clinical evidence of increased
intracranial pressure, obtain a CT scan before the LP. An imaging procedure (CT scan or
MRI study of the brain) is a necessary part of the evaluation for seizures. An EEG is
essential. Also consider a toxicological
screen.
Differential diagnosis
There is a large spectrum of disorders that present in a fashion similar to
seizures. The differential diagnoses include breath-holding spells, syncope, sleep
disorders (such as night terrors), benign paroxysmal vertigo, and pseudoseizures. A large
part of ruling out these nonepileptiform disorders will depend on the history obtained.
Management
Consider admitting patients with first seizures of unknown etiology for evaluation
and sometimes for treatment, as well as in response to parental anxiety. If the seizure
was a classic episode for a patient with a chronic seizure history that is on a
subtherapeutic drug regimen, he or she can probably be discharged after the seizure
medications are adjusted and follow-up is arranged. Patients with febrile seizures can
probably be discharged if no underlying life-threatening infection (e.g., meningitis,
shigella) is detected, although many are admitted overnight for parental support. All
patients with complex recurrent seizures should be referred to a neurologist.
Treatment Options
Treatment varies with clinical presentation. New or recurrent generalized or
partial seizures should be treated only after the clinician is confident that the patient
has a disorder that requires treatment. Most neurologists will not prescribe
anticonvulsant medication to a patient after a first or even a second idiopathic (and
afebrile) seizure. Even now we don't have the perfect anticonvulsant, which would
absolutely prevent seizures and have absolutely no adverse effects. Treatment with these
medications is often worse than the underlying condition. Also, the decision to treat
implies a commitment to at least 2 full years of medication as well as the potential
limitation of personal activities, employment, and driving privileges (teenagers).
Commonly Used Anticonvulsants
These are included for information purposes only.
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Carbamazipine (Tegretol): up to 25 mg/kg/day divided TID or QID with therapeutic blood
levels of 4-12 ug/ml; side effects include nausea, anorexia, drowsiness, visual
disturbances, ataxia, leukopenia, aplastic anemia, agranulocytosis.
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Valproic acid (Depakene): 15-60 mg/kg/day divided TID with therapeutic blood levels of
40-100 ug/ml (occasionally up to a trough level of 120); side effects include behavioral
changes, interference with cognition, rash.
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Phenytoin (Dilantin): 4-8 mg/kg/day divided BID-TID with therapeutic blood levels of
10-20 ug/ml; side effects include gingival hyperplasia, dermatitis, hirsutism,
lymphadenopathy, megaloblastic anemia, leukopenia, pulmonary fibrosis, hepatitis.
Summary
In general you should always obtain a consultation on patients presenting with
new-onset seizure disorder. The urgency of the consultation depends on the severity of the
seizure event and the complexity of the historical and laboratory evaluation.
Reviewed by CDR Wendy Bailey, MC, USN, Pediatric Specialty Leader, Naval Medical
Center San Diego, San Diego, CA (1999).