N EUROLOGICAL disease in childhood has been a long-neglected field in pediatrics. The neurologists have not understood children with such disease and the pediatrician’s knowledge of neurology has been scanty. The result has been a long list of descriptions of hereditary degenerative diseases, named usually by the first describer, but still too little knowledge of how brain injury occurs in the fetus and newborn and of how growth and maturation affect the development of a damaged nervous system. The interest in this field, however, is increasing rapidly and intensive research is under way. Researchers are trying to find not only those metabolic disorders which cause mental deficiency, but also the effect of anoxia on the fetus and neonate. Most of the children who have neurological disorders are among the cerebral palsied, the mentally retarded, and the epileptics. These three conditions vastly outnumber the hereditary degenerative diseases, and at piesent there is no indication that these conditions are on the decrease. On the contrary, it is more probable that the number will increase in the near future; many more prematures are saved now than even a decade ago, and antibiotics keep defective children alive much longer. The newer hazards of living include such things as head injuries from car accidents, and suffocation from skin diving and plastic bags. There are severe gaps in our knowledge about what causes brain injury in fetuses and the newborn and of the seemingly random mechanisms by which anoxia damages the brain. Clinically, it is still impossible to predict at birth whether a child who has had a certain degree of anoxia will develop a particular kind of brain damage or indeed whether any brain damage will result. Some children develop spasticity, athetosis, or some other type of cerebral palsy, epilepsy with or without other neurological defects, or become mentally defective without motor involvement, while others are classified in a group now known to have organic brain damage without cerebral palsy or epilepsy.