Pediatric emergency medicine trisk 1423 1423
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CHAPTER 72 ■ SEIZURES
AMIR A. KIMIA, VINCENT W. CHIANG
Seizures are the clinical expression of abnormal, excessive, synchronous
discharges of neurons residing primarily in the cerebral cortex. This paroxysmal
activity is intermittent and its duration may last from a few seconds to many
hours. Seizures represent a neurologic emergency either due to the underlying
cause (e.g., bleed, infection) or the potential for neuronal death as a result of a
prolonged seizure. Approximately 5% of children will have at least one seizure in
the first 16 years of life. The immature brain, particularly in the neonate and
young infant, differs from the adult brain in the basic mechanisms of
epileptogenesis and propagation of seizures. It is more prone to seizures, but
seizures are also more apt to disappear as the child grows. Physicians must have a
fundamental knowledge of seizure classification (semiology), all aspects of
seizure management (including initial stabilization), determination of cause
(differential diagnosis), appropriate definitive treatment, and patient disposition.
BACKGROUND
A seizure is defined as a transient, involuntary alteration of consciousness,
behavior, motor activity, sensation, and/or autonomic function caused by an
excessive rate and hypersynchrony of discharges from a group of cerebral
neurons. A convulsion is a seizure with prominent alterations of motor activity.
Epilepsy, or seizure disorder, is a condition of susceptibility to recurrent seizures.
Seizures may be generalized or partial. Generalized seizures reflect
involvement of both cerebral hemispheres. These may be convulsive or
nonconvulsive. Consciousness may be impaired and this impairment may be the
initial manifestation. Motor involvement is bilateral. Types of generalized
seizures include absence (petit mal), myoclonic, tonic, clonic, atonic, and tonicclonic (grand mal) seizures.
Partial (focal, local) seizures reflect initial involvement limited to one cerebral
hemisphere. Partial seizures are further classified on the basis of whether
consciousness is impaired. When consciousness is not impaired, the seizure is
classified as a simple partial seizure. Simple partial seizures may have motor,
somatosensory/sensory, autonomic, or psychic symptoms. When consciousness is
impaired, the seizure is classified as a complex partial seizure. Both simple and
complex partial seizures may evolve into generalized seizures (Jacksonian
spread). The spread to deep subcortical regions and evolution to a bilateral tonic-
