OVERVIEW

What are neonatal subependymal cysts?

Neonatal subependymal cysts are a relatively common type of neonatal brain injury caused by various factors, closely related to congenital development, premature birth, intrauterine distress, and intraventricular hemorrhage. Simple neonatal subependymal cysts generally do not lead to severe neurodevelopmental complications and often resolve on their own without requiring intervention or treatment.

In rare cases, they may have some impact on the growth and intellectual development of newborns and infants. Within the first year of life, temporary delays in physical and cognitive development may occur, with the latter potentially persisting until preschool age.

Therefore, neonatal subependymal cysts are of concern to obstetricians and pediatricians, necessitating follow-up and cranial ultrasound examinations.

Are neonatal subependymal cysts the same as adult subependymal cysts?

Adult subependymal cysts are rare and originate from ectopic ependymal tissue during embryonic development. Although both are cysts, their prognoses differ.

Some neurological conditions such as epilepsy, mild hemiplegia, and increased intracranial pressure may be associated with adult subependymal cysts. In such cases, diagnosis requires imaging via CT or MRI, and treatment may involve surgical cyst removal, cyst-ventricle fenestration, or cyst-peritoneal shunt procedures.

SYMPTOMS

What are the symptoms of subependymal cysts in newborns?

The vast majority of infants with subependymal cysts show no symptoms, and the cysts are usually solitary. These cysts typically resolve on their own within 3 to 6 months after birth.

Some infants may exhibit slightly delayed intellectual and physical development compared to normal children within the first 6 months of life, but they generally catch up by around 1 year of age. Very few continue to lag behind beyond school age.

A small number of newborns with varying degrees of congenital anomalies may experience delayed cyst absorption until 6 to 9 months after birth, accompanied by significantly slower intellectual and physical development.

Where are subependymal cysts located in newborns?

The ventricles of the brain are lined with a membrane called the ependyma. Cysts that form beneath this membrane are referred to as subependymal cysts.

Are subependymal cysts common in newborns?

Their occurrence is not rare among newborns. Depending on ethnicity, approximately 0.5% to 5% of full-term and late preterm infants are affected. In low-birth-weight preterm infants, particularly those with very low birth weight, the incidence can be as high as 43% to 55%, likely due to subependymal hemorrhage leading to cyst formation.

Subependymal cysts are common in newborns, but since most cases have no adverse effects, they are rarely discussed in medical literature.

CAUSES

What causes subependymal cysts in newborns?

The etiology of subependymal cysts varies among different sources. Currently, it is recognized that there are two types of subependymal cysts: one is acquired hemorrhagic cysts, and the other is congenital, related to disturbances during embryonic development. However, distinguishing between them through imaging is challenging.

• Congenital cysts may result from placental defects, vascular abnormalities, hypoxic-ischemic injury, hemorrhage, or viral infections during fetal development. Common viruses include cytomegalovirus and rubella virus, with a few cases caused by toxoplasmosis. Other factors such as metabolic disorders, chromosomal abnormalities, and maternal drug use may also contribute.

• Acquired hemorrhagic cysts are primarily located in the caudothalamic groove and are more common in preterm infants.

Is it necessary to actively investigate the cause of subependymal cysts in newborns?

Clinically, subependymal cysts caused by central nervous system lesions are relatively common. However, isolated subependymal cysts—those without other abnormalities—are also frequently observed in healthy newborns. These cysts typically resolve on their own over time, making active investigation of the cause unnecessary.

DIAGNOSIS

How to Diagnose Subependymal Cysts in Newborns?

Clinical diagnosis of subependymal cysts in newborns must rely on imaging methods. Among various imaging techniques, ultrasound is the preferred choice due to its non-invasive nature, low cost, and high resolution, and it facilitates dynamic monitoring and observation.

Meanwhile, ultrasound examination of fetal subependymal cysts has been recognized by the medical community, providing important evidence for the diagnosis and differential diagnosis of fetal subependymal cysts.

What Should Subependymal Cysts in Newborns Be Distinguished From?

After clinical confirmation, no differential diagnosis is required.

On ultrasound imaging, subependymal cysts mainly need to be distinguished from choroid plexus cysts and arachnoid cysts.

TREATMENT

Which department should be visited for neonatal subependymal cysts?

Most neonatal subependymal cysts are diagnosed during the fetal period or discovered through cranial ultrasound after birth. Follow-up visits can be conducted in the pediatrics, pediatric neurosurgery, or pediatric cranial surgery departments.

How are neonatal subependymal cysts treated?

Asymptomatic neonatal subependymal cysts primarily require follow-up and observation, as most can resolve on their own within 3 to 6 months after birth.

If there are abnormalities in growth and development, or if the cysts persist for 6 to 9 months or longer without regression, the progression of the cysts can be assessed by comparing previous examinations. A neurosurgeon will then evaluate whether further intervention is necessary.

DIET & LIFESTYLE

Does subependymal cyst in newborns affect life and diet?

Subependymal cysts in newborns have no impact on the infant's daily diet or lifestyle. Routine infant care, breastfeeding or formula feeding, complementary food introduction, and guidance for neuropsychological development can proceed normally.

PREVENTION

Can subependymal cysts in newborns be prevented?

There are no specific measures to prevent the occurrence of subependymal cysts in newborns.

However, standardized pregnancy management, regular prenatal check-ups, and reducing abnormal pregnancy conditions such as premature birth and hypoxic-ischemic events, as well as avoiding infections (e.g., cytomegalovirus, rubella virus, toxoplasmosis, etc.) during the preconception and pregnancy periods, can help reduce the occurrence of subependymal cysts.