The project documented the frequency of primary intracranial neoplasms in the pediatric populations of Rochester, MN, and the state of Connecticut. In addition, using the records-linkage system available for residents of Rochester, MN, we investigated the magnitude and risk factors for cerebrovascular disease in infants and children. The same Rochester, MN, records-linkage system was used to determine temporal trends in the incidence rates of cerebral palsy as well as the distribution of clinical subtypes and survival by clinical subtype, for the years 1950-1976. For the state of Minnesota, sex-specific neonatal mortality rates (NMR) in gestational age/birthweight risk subgroups were delineated for the years 1970-1976, and sex- and birthweight-specific NMR trends were determined for the years 1967-1976. The same record linkage system has been used to identify all possible cases of complex partial seizures occurring in the years 1935-1979. A case-control study is being conducted to identify risk factors associated with the occurrence of such seizures. Similiar studies will be conducted for tonic-clonic seizures, absence seizures and myoclonic seizures.