Children aged 1 to 18 years with acute ischemic stroke, seen at Indiana University, and young adults aged >18 to 45 years, identified from the Indiana University and Northwestern University Young Adults Stroke Registries, were classified in subtypes as atherothrombotic (AT), cardioembolic (CE), small-vessel (SV), or other determined or unknown causes. The percentages of these stroke subtypes in children cf young adults were as follows: AT 0/16, CE 15/14, SV 0/3, other 49/44, and unknown 36/23. Prothrombotic causes (sickle cell disease) were more common in children (25/14%), and dissections more common in young adults (3/15%). Causes of stroke in the 15 to 18 year group of children were more similar to the young adults. 
COMMENT. Children with cardioembolic stroke have cyanotic heart disease, and sickle cell disease and moyamoya are the most common causes of the “other determined” subtype in this age group. Young adults with CE stroke have right-toleft atrial shunts due to patent foramen ovale, and arterial dissection and antiphospholipid antibodies are the most common “other determined” causes. Age 15 years is the most appropriate dividing line for subtyping ischemic stroke in children and young adults.
Protein C and S deficiency are risk factors for stroke, according to a study at the Childrens Hospital, Los Angeles, CA . Among 37 children with ischemic stroke, protein C and S deficiencies were the only identified risk factors in 2 (5.4%) and 5 (14%) patients, respectively.
Transcranial doppler screening for long-term stroke risk in chidren with sickle cell disease was studied at the Medical College of Georgia, Augusta, GA. Elevated TCD velocities, 200 cm/sec or greater, predict increased stroke risk. 
Language delay in children with sickle cell disease and stroke is reported in 10 children studied at the University of Arkansas, Little Rock.