This chapter deals with causes of sudden natural death in the young involving the nervous system, a large number of which are due to vascular or infective disorders. It should be stressed, however, that trauma should always be suspected if intracranial hemorrhage is unexpectedly found at autopsy. Detailed review of the presenting history should then be undertaken with a complete radiologic survey of the body in infants and young children. If a traumatic etiology can be excluded, then other conditions such as cerebrovascular disease may be considered.
Stroke is defined as “rapidly developing clinical signs of focal (or global) disturbance of cerebral function, with symptoms lasting 24 hours or longer or leading to death, with no apparent cause other than of vascular origin”. Although not common in the pediatric age group, it is possible that any of the causes of occlusive vascular disease or hemorrhage that result in childhood stroke can also result in sudden and/or unexpected death. The incidence of stroke in children varies among different populations from 2.1 to 13 cases per 100,000 children per year. More than 33% of arterial ischemic strokes are found in neonates, with almost 50% occuring by 1 year of age. There is a male-to-female ratio of 1.5 : 1.
Abnormalities of the vasculature such as stenoses, dissections, Moyamoya disease, and vasculitis can be demonstrated in 80% of children with ischemic stroke.