Prevalence of Atherosclerotic Risk Factors Among Children and Young Adults With Arterial Ischemic Stroke | Adolescent Medicine | JAMA Neurology | JAMA Network [Skip to Navigation] Figure 1. Identification of Cases and Controls in Children and Young Adults ICD-9 indicates International Classification of Diseases, Ninth Revision; KPNC, Kaiser Permanente Northern California. Table 1. Demographic Characteristics of Arterial Ischemic Stroke Cases and Stroke-Free Controls Table 2.