Several other infections of late fetal life or the neonatal period are only mentioned here, for to describe them all would be excessive and would elucidate no new neurologic principles. Meningitis as a result of the small gram-positive rod L. monocytogenes may be acquired in the usual way, at the time of passage through an infected birth canal or in utero, as a complication of maternal and fetal septicemia because of this organism. In the latter case, it causes abortion or premature delivery. Neonatal bacterial meningitis with this organism is a particularly devastating and often fatal type of bacterial infection, not easily diagnosed unless the pediatrician is alert to the possibility of a silent meningitis in every case of neonatal infection. Coxsackievirus B, polioviruses, other enteroviruses, and arboviruses (western equine) seem to be able to cross the placental barrier late in pregnancy and cause encephalitis or encephalomyelitis in the near-term fetus, which is indistinguishable from the disease in the very young infant. Herpes zoster may occur in utero, leaving cutaneous scars and retarding development. Or zoster may appear soon after birth, the infection having been contracted from the mother. Only later in childhood can varicella induce an autoimmune perivenous demyelination and possibly a direct infection, affecting predominantly the cerebellum (see Chap. 32), or it may precede the now rare Reye syndrome.
Epstein-Barr virus is another frequent cause of meningoencephalitis. In some instances, it may present as aseptic meningitis or a Guillain-Barré type of acute polyneuritis. This infection tends to affect the nervous system of children rather than that of adults, but there are exceptions to this comment. It is estimated that approximately 2 percent of children and adolescents with this infection have some type of neurologic dysfunction; rarely will this be the only manifestation of the disease. Stupor, chorea, and aseptic meningitis were the main neurologic findings in the case reported by Friedland and Yahr, and acute cerebellar ataxia and deafness were observed in the case of Erzurum and associates (see also Chaps. 31 and 32).
The major types of seizure disorder have already been discussed in some detail in Chap. 15. In bringing them up here, attention is drawn to the fact that epilepsy is mainly a disease of infancy and childhood. Approximately 75 percent of epileptics fall into these age periods, and some of the most interesting and unique types of seizures are peculiar to these epochs of life. Epilepsies that are observed exclusively in infants and children are benign neonatal convulsions; benign myoclonic epilepsy of infancy; febrile seizures (both genetic and acquired); infantile spasms of West; absence seizures; the Lennox-Gastaut syndrome; rolandic and occipital paroxysms and other benign focal epilepsies; and the juvenile myoclonic epilepsies.