Neurological and electroencephalographic abnormalities after febrile seizures. Possible association with cytomegalovirus

Congenital human cytomegalovirus infection and neurologic diseases in newborns

Objective:

This review aimed to summarize research progress regarding congenital cytomegalovirus (cCMV) infection-related nervous system diseases and their mechanisms.

Data sources:

All literature quoted in this review was retrieved from PubMed and Web of Science using the keywords “Cytomegalovirus” and “Neurologic disease” in English. To identify more important information, we did not set time limits.

Study selection:

Relevant articles were selected by carefully reading the titles and abstracts. Then, different diagnosis and clinical treatment methods for human CMV infection-related neurologic diseases were compared, and the main mechanism and pathogenesis of neurologic damage caused by CMV were summarized from the selected published articles.

Results:

cCMV infection is a major cause of neonatal malformation. cCMV can infect the fetal encephalon during early gestation and compromise neurodevelopment, resulting in varying degrees of neurologic damage, mainly including hearing impairment, central nervous system (CNS) infection, neurodevelopmental disorders, ophthalmic complications, cerebral neoplasms, infantile autism, epilepsy, and other neurologic abnormalities.

Conclusions:

cCMV infection-induced neurodevelopmental abnormalities, which were directly caused by fetal encephalon infection, thus inducing neuroimmune responses to damage nerve cells. Such abnormalities were also caused by suppression of the proliferation and differentiation of neural progenitor cells by CMV's gene products. cCMV infection in the fetal encephalon can also inhibit neuronal migration and synapse formation and indirectly trigger placental inflammation and thus disrupt the oxygen supply to the fetus.

Nonfebrile seizures after febrile convulsions: possible role of chronic cytomegalovirus infection

Twelve hundred children with convulsions when feverish were studied during a period of five years. Among them 52 subjects (4.33%) developed nonfebrile seizures after a period of eight months to five years from the first febrile convulsion (group A). Twenty-three children had neither afebrile seizures nor EEG abnormalities during the period of observation (group B). The two groups were comparable for age of the first febrile convulsion onset, sex, and socioeconomic status. None had risk factors for subsequent epilepsy or clinical signs of congenital cytomegalovirus infection. The isolation rate of CMV from urine was 53.84% in patients of group A, 26.09% in children of group B, and 26.83% in healthy control children. Twelve CMV-positive children from group A were followed for one to more than three years. In five of seven children with persisting EEG abnormalities, cytomegaloviruria was still present 13 to 41 months after the first isolation, whereas none of five patients with normal electroencephalograms had viruria after a comparable period. We found that CMV-positive children generally lacked cell-mediated immunity to the virus, whereas CMV-negative patients had positive reactions. Our data suggest a correlation between persistence of neurologic abnormalities and CMV excretion in children with nonfebrile seizures and CMV infection.