Stroke in the pediatric population is being identified more frequently, and its effects, once thought to be limited, are now being recognized as more serious. Estimates of incidence range between 2 and 8 per 100,000, with neonates being disproportionately affected. A recent population-based study found that perinatal arterial ischemic stroke (PAS) was recognized in 1 in 2300 term infants.1 The rise in diagnosis of stroke is in part attributable to improved diagnostic techniques and to greater survival of susceptible children.2,3 Definitions and epidemiology of specific types of stroke in children are detailed below in the discussion of differential diagnosis.
In the past, it was felt that children generally recover from stroke with minimal long-term deficit (due to plasticity of the young brain). Recent studies reveal, however, that only 31% of children with ischemic stroke recovered to a normal neurological examination. Approximately 17% had persistent cognitive deficits. Disability can include physical, cognitive, behavioral, and psychiatric sequelae. Despite significant advances in management, stroke continues to be one of the leading causes of death among children.
The relative lack of controlled clinical trials significantly limits the current treatment guidelines, and the evidence-based interventions established for adults cannot be directly extrapolated to pediatric patients. Differences in the hemodynamic and coagulation pathways as well as in the significant risk factors that contribute to cerebrovascular events distinguish the two. For instance, atherosclerosis is one of the most common sources of adult stroke but rarely contributes to stroke risk in the pediatric population.3
Ischemic strokes occur secondary to insufficient cerebral oxygen delivery. This may occur because of occlusion of a vessel secondary to plaque formation (more common in adults), fibromyscular dysplasia, or vascular dissection. Cardioembolic sources of stroke are more common in children. Hematologic sources of stroke include hyperviscosity syndromes, sickle cell disease, and leukemia. Each of these disorders is discussed in much greater detail in the following sections.
Intracranial hemorrhage also occurs in several distinct subtypes. Subarachnoid hemorrhage may arise secondary to aneurysm rupture or trauma. Subdural and epidural hematomas often occur secondary to traumatic injury. Parenchymal hemorrhages may be related to a number of etiologies including trauma, abuse, collagen vascular diseases, and ischemic stroke.
In order to know appropriately manage stroke patients (see "Management" later in the chapter), the acutely presenting pediatric stroke patient must be recognized in a timely fashion. Unfortunately, the average delay between symptom onset and first diagnostic study is 28.5 hours, largely prohibiting the institution of hyperacute interventions.4 This delay stems from the often nonspecific symptoms with which pediatric stroke patients present. Neonates with underlying stroke frequently present with seizures as well as lethargy and apnea, whereas older children may present with more focal neurological deficits such as speech abnormalities, visual or sensory changes, or hemiparesis.5
The differential diagnosis can be vast, including infections and metabolic imbalances. A few key stroke masqueraders should ...