Imaging of congenital central nervous system infections.

Congenital central nervous system (CNS) infections are a cause of significant morbidity and mortality. The recent Zika virus outbreak raised awareness of congenital CNS infections. Imaging can be effective in diagnosing the presence and severity of infection. In this paper we review the clinical presentations and imaging characteristics of several common and less common congenital CNS infections.

Infectious causes of microcephaly: epidemiology, pathogenesis, diagnosis, and management.

Microcephaly is an important sign of neurological malformation and a predictor of future disability. The 2015-16 outbreak of Zika virus and congenital Zika infection brought the world's attention to links between Zika infection and microcephaly. However, Zika virus is only one of the infectious causes of microcephaly and, although the contexts in which they occur vary greatly, all are of concern. In this Review, we summarise important aspects of major congenital infections that can cause microcephaly, and describe the epidemiology, transmission, clinical features, pathogenesis, management, and long-term consequences of these infections. We include infections that cause substantial impairment: cytomegalovirus, herpes simplex virus, rubella virus, Toxoplasma gondii, and Zika virus. We highlight potential issues with classification of microcephaly and show how some infants affected by congenital infection might be missed or incorrectly diagnosed. Although Zika virus has brought the attention of the world to the problem of microcephaly, prevention of all infectious causes of microcephaly and appropriately managing its consequences remain important global public health priorities.

Congenital brain infections.

Pediatric congenital intracranial infections are a group of different and important entities that constitute a small percentage of all pediatric infections. The causal factors and clinical presentations are different in children compared with adults. They require early recognition because delay diagnosis and initiation of treatment may have catastrophic consequences. Despite improvements in prenatal screening, vaccine safety, and antibiotics, infections of the central nervous system remain an important cause of neurological disabilities worldwide. This article reviews the most common congenital infections and their imaging findings.

Pediatric intracranial infections.

Infection of the central nervous system (CNS) in children is an important entity and early recognition is paramount to avoid long-term brain injury, especially in very young patients. The causal factors are different in children compared with adults and so are the clinical presentations. However, imaging features of CNS infection show similar features to those of adults. This article reviews some of the common types of pediatric infections, starting with the congenital (or in utero) infections followed by bacterial infections of the meninges and brain parenchyma.

Central nervous system disorders in infants with congenital cytomegalovirus infection.

BACKGROUND: Congenital cytomegalovirus is the most common cause of congenital infection in developed countries and a major etiology for neurological disability in children. In many countries, there is low awareness of the importance of this virus as a cause of neurological disorders. METHODS: We reviewed current knowledge regarding neurological disorders associated to congenital cytomegalovirus infection and analysed the epidemiology of this infection in Latin American countries. RESULTS: The incidence of congenital cytomegalovirus infection reported from Latin American countries ranges from 0 to 6.8% in different settings. Congenital cytomegalovirus infection is a common cause of hearing deficits and mental impairment in children. However, the impact of this infection as a cause of neurological disorders in Latin American countries remains poorly documented. DISCUSSION: Actions are needed to increase knowledge regarding the frequency and impact of congenital cytomegalovirus infection on Latin American children, as well as to increase awareness of the general population and the medical community regarding the need to identify infants infected in utero by this virus and to carefully evaluate their neurological development throughout childhood.

Neonatal MR imaging.

Recently, MR imaging has become the technique of choice in evaluating neonatal central nervous system diseases. It is the only imaging technique that can discriminate myelinated from neonatal unmyelinated white matter; it offers the highest sensitivity in detecting acute anoxic injury of the neonatal brain; and with proper coils and sequences, it can exquisitely depict neonatal brain anatomy and locate pathology, offering a robust and reliable tool in the prognostic assessment of neonatal central nervous system disease.

Central nervous system infections in the pediatric population.

Central nervous system infections and sequelae in the pediatric population may present differently depending on the patient's stage of development. Infections contracted from conception through the neonatal period may affect central nervous system formation, whereas infections acquired later tend to cause parenchymal destruction. This article discusses congenital, focal parenchymal, extra-axial, and diffuse parenchymal infections and their effect on the developing brain.

Incidence and clinical significance of echogenic vasculature in the basal ganglia of newborns.

Cranial sonography has become the main modality of the investigation and diagnosis of a wide variety of neonatal intracranial abnormalities. Occasionally, cranial sonograms reveal basal ganglia and thalami bright echoes. It is believed that these lesions are indicative of vasculitis due to intrauterine infections, in particular with cytomegalovirus (CMV). We hypothesized that the incidence of proven neonatal intrauterine TORCH infection is low and that screening of all asymptomatic infants with bright lenticulostriate echodensities would not be cost-effective. We reviewed brain sonograms of 3700 infants, performed over a period of 3 1/2 years. Echogenic basal ganglia vasculature were observed in 75 patients (2%). Chart review performed for clinical presentation and TORCH studies showed that only one infant had confirmed intrauterine congenital infection, which was by CMV. This infant had no signs or symptoms of CMV. In addition, there were 4 patients with chromosomal anomalies among the 75 patients (5%), of these one had trisomy 13 and another-trisomy 21. Our results indicate that echogenic basal ganglia blood vessels are not an exceptional finding on cranial sonograms, and are seldom associated with intrauterine infection. We conclude that it is not cost-effective to screen infants with echogenic basal ganglia blood vessels for intrauterine infection, unless clinical suspicion exists.

[Central nervous system lesions in fetuses and newborns in intrauterine infection caused by respiratory viruses]. / Porazheniia tsentral'noi nervnoi sistemy plodov i novorozhdennykh pri vnutriutrobnoi infektsii, vyzvannoi respiratornymi virusami.

Congenital respiratory viral infection is followed in the CNS of fetuses and newborns by grave dyscirculatory disturbances with glia proliferation and nervous tissue edema. The process is mainly localized in the periventricular regions of the brain ventricles. Neurologic and morphologic consequences of these damages in the CNS of fetuses and newborns need further studies.

Selected pediatric viral infections.

Viral infections of the central nervous system in infants and children are uncommon but potentially serious illnesses. Common causes have included the enteroviruses (particularly polioviruses and coxsackieviruses), herpes viruses (type 1 and type 2 herpes simplex, varicella, and cytomegalovirus), arboviruses, rubella, mumps, measles (including subacute sclerosing panencephalitis), and human immunodeficiency virus. Several of these viruses, such as cytomegalovirus, herpes simplex, and vertically transmitted human immunodeficiency virus, may cause congenital infections. Others are acquired later in childhood. In recent years, immunization programs have significantly reduced the occurrence of some of these diseases. A brief survey of the clinical and pathological manifestations of these illnesses will be discussed along with current incidence data.

Neurological manifestations of perinatally acquired HIV-1 infection.

Infection with the human immunodeficiency virus type 1 (HIV-1) remains a major potential cause of neurological disorders in children and adults throughout the world. This article provides an overview regarding the epidemiology, clinical manifestations, and neuropathogenesis of perinatally acquired HIV-1 infection. Insights regarding the mechanisms of neuroinvasion and neuropathogenesis may allow novel strategies for treating or preventing the devastating consequences of HIV-1 infection of the central nervous system (CNS).

The longitudinal assessment of congenitally infected infants.

Infants with congenital infections are at high risk for developmental disabilities. Because of this increased-risk status, they require comprehensive, longitudinal follow-up that should begin in the neonatal period with sensory, developmental, and neuromotor assessments as well as neuroradiological imaging. Reassessments of general development, sensory function, neuromotor abilities, and emerging language should be done during the early years, with cognitive, preacademic, and phonologic-awareness skills assessed during the preschool years. Serial evaluations of cognitive, academic, language, attention, neuromotor and sensory functions are needed through adolescence. Such surveillance of children with congenital infections is required to identify specific disabilities, to determine educational/intervention needs, and to investigate the total effects of congenital infection.

Conditions mimicking congenital infections.

Several disorders caused by factors other than infectious pathogenes produce clinical features that mimic the congenital infections summarized in this issue. This article describes selected disorders that should be considered in the differential diagnosis in infants and young children who appear to have congenital infections but lack microbiological confirmation.