Investigators at the National Institute of Neurological Disorders and Stroke (NINDS) are seeking children with stroke, cerebral palsy, and porencephaly for a study of abnormal acquired and genetic coagulation factors. In the study, researchers will measure a series of potential risk factors for stroke that include autoimmune, inflammatory, and genetic clotting factor abnormalities. By identifying the factors that contribute to childhood stroke, cerebral palsy, and porencephaly, researchers hope this study will lay the groundwork for future research projects that will explore potential treatments. Eligible patients must have a history of porencephaly, cerebral infarction (stroke), and/or cerebral palsy and have a diagnosis of porencephaly or stroke confirmed by computed tomography (CT), magnetic resonance imaging (MRI), and/or Doppler ultrasonography. The study consists of a 30-minute telephone interview/questionnaire, blood sample, and buccal smear. All study-related expenses will be paid by the NIH. The study will be carried out under testing and safety standards of the U.S. Department of Health and Human Services. For more information, physicians should send a referral letter and a copy of the patient's recent medical records to Dr. Karin Nelson or Dr. John Lynch, NINDS, NIH, 10 Center Drive, Building 10, Room 5S220, Bethesda, MD 20892-1447; telephone: (301) 496-1714; fax: (301) 496-2358; email: firstname.lastname@example.org.