Objectives To determine the incidence of neonatal stroke by gender, race and geographic region, to describe medical disorders commonly associated with neonatal stroke, and to characterize the burden of disease due to neonatal stroke.
Methods National Hospital Discharge Survey data from 1979-2002 was analyzed for children 0 to 28 days of age with any-listed discharge diagnosis of stroke according to the International Classification of Disease-9th Revision-Clinical Modification (ICD-9-CM) codes 430-431 (hemorrhagic) and 433-437 (ischemic). Incidence rates were calculated as the estimated number of strokes divided by the total number of births for each study period. Rates were compared between stroke subtypes (ischemic and hemorrhagic), gender, race, and geographic region. Medical disorders associated with stroke were ascertained by ICD-9-CM codes in order to identify potential risk factors. The annual burden of disease was estimated as years of life lost and disability-adjusted life-years. Chi-square was used to test for significance.
Results From 1979-2002, there were an estimated 20,800 neonatal strokes in the United States, for an annual rate of 22.5 per 100,000 live births. Rates of stroke (per 100,000 live births) were higher for ischemic compared to hemorrhagic stroke (16.9 vs. 5.6, p≤0.05), females to males (25.2 vs. 19.8, p≤0.05), blacks to whites (21.7 vs. 21.0, p≤0.05) and in the Northeast as compared to other regions of the United States (31.0 vs. 20.5, p≤0.05). The most common medical disorders reported among newborns hospitalized with stroke included seizures (50% of ischemic strokes and 44% of hemorrhagic strokes), cardiac disorders (28% and 12%), infections (26% and 34%), respiratory conditions (21% and 11%), low birth weight (14% and 16%), and birth trauma (13% and 1%). The overall in-hospital mortality rate was 10%, which resulted in over 156,000 years of life lost due to neonatal stroke over the study period. Long-term disability due to stroke in neonates has been estimated at 57%, resulting in over 800,000 disability-adjusted life-years lost due to neonatal stroke during the study period.
Conclusions Stroke is an important cause of morbidity and mortality in neonates. We estimate that stroke is diagnosed in 1/4400 live births; however, many neonatal strokes are not detected in the first month of life, so this figure is presumably an underestimation. Stroke is diagnosed more frequently among females and individuals in the Northeast United States. Cardiac disorders and infection are important risk factors for stroke in neonates.