The causes and manifestations of seizure activity are numerous, ranging from benign to life threatening. Precipitants of seizures can include head injury, structural brain abnormalities, fever, CNS infection, hypoglycemia, electrolyte abnormalities, hypoxemia, toxin exposure, dysrhythmias, metabolic disorders, congenital infections, or neurocutaneous syndromes.
The clinical features of seizure activity depend on the area of the brain affected and can range from classic tonic-clonic movements to very subtle behavioral changes; they may be generalized (with loss of consciousness) or partial (with focal motor or behavioral features). Rhythmic repetitive movement, incontinence of bowel or bladder, postictal state after a seizure, and tongue biting are strong clues to a seizure.
Motor changes (tonic or clonic) may be focal or generalized, and seizures may present with atony (sudden loss of tone or “drop attack”) in some age groups. More subtle symptoms include staring spells (“absence”) or changes in mental status or behavior, which can be complex, such as automatisms (blinking, bicycling, or lip smacking in infants), vocalizations, or hallucinations.
Signs may include alteration in autonomic dysfunction, such as mydriasis; diaphoresis; tachypnea or apnea; tachycardia; hypertension and salivation; and postictal somnolence. Transient focal deficits may represent Todd's paralysis following a seizure.
The diagnosis of seizure disorder is based primarily on history and physical examination. Bedside glucose testing should be performed on all children who are seizing or postictal, but the clinical scenario should direct additional laboratory and imaging tests. Screening tests for electrolytes are not indicated in most cases of childhood seizures including simple febrile seizures or first time afebrile seizures, unless otherwise indicated by the specific history. The suggested ED evaluation of differing clinical scenarios presenting with seizure is listed in Table 76-1.
Table 76-1 Suggested ED Evaluation of Pediatric Seizures ||Download (.pdf)
Table 76-1 Suggested ED Evaluation of Pediatric Seizures
|Clinical Scenario||Suggested ED Evaluation||Comments|
|Simple febrile seizure||Routine testing and imaging not indicated||Consider testing for source of fever (eg, urinalysis)|
|First afebrile seizure without focal deficits in ED||Routine testing not indicated. Routine LP not recommended||Consider outpatient MRI, EEG|
|Seizure in known epileptic||Serum drug levels for anti-epileptic medications||Some medication levels not immediately available. Low or high levels may cause seizures|
|Seizure in setting of ventriculo-peritoneal shunt||Plain radiographs of shunt and neuroimaging. Consider CSF evaluation from shunt-tap if febrile||Quick brain MRI preferred to CT if available. Neurosurgery consult required for shunt tap|
|Posttraumatic seizure||Consider head CT||Imaging not required for brief impact seizures|
|Febrile status epilepticus||Head CT and lumbar puncture||Additional evaluation for fever as indicated|
|Nonfebrile status epilepticus or new-onset focal seizure or focal neurologic deficit in ED|
Complete metabolic panel
Consider toxicology screens
ECG for possible arrhythmia
|Consider nonaccidental trauma and toxic ingestions|
|Seizure in infants||Bedside glucose, complete metabolic panel, ionized calcium and serum magnesium, ammonia, lactate, urinalysis (look for ketones suggestive of metabolic disease). ...|