What are symptoms of prominent cisterna magna?
The majority of patients are asymptomatic; however, variable neurodevelopmental outcomes, including delayed speech and language development, motor development delay, visiospatial perception difficulties, and attention problems, has been observed in some patients.
What is a normal cisterna magna measurement?
The cisterna magna is the space between the inferior margin of the vermis and the posterior rim of the foramen magnum. The normal cisterna magna measures between 3 mm and 8 mm, and mega cisterna magna (MCM) is diagnosed when it reaches 10 mm or more.
Which condition is associated with the presence of blood in the cisterna magna?
Sometimes the septa are bowed laterally by the presence of intraventricular hemorrhage extending posterior to the vallecula (Figure 9). Blood in the cisterna magna has previously been shown to have a high positive predictive value for development of posthemorrhagic hydrocephalus.
What is the function of cisterna magna?
The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata. Cerebrospinal fluid produced in the fourth ventricle drains into the cisterna magna via the lateral apertures and median aperture.
What is normal size of cisterna magna?
The normal cisterna magna measures between 3 mm and 8 mm, and mega cisterna magna (MCM) is diagnosed when it reaches 10 mm or more. MCM is separable from DWM because cystic dilation of the fourth ventricle does not exist, the cerebellar vermis is present and normal in size, and the posterior fossa is not enlarged.
What causes cisterna magna?
Causes of an enlarged cisterna magna include cerebellar hypoplasia, communicating hydrocephalus, and normal variation. Cerebellar hypoplasia is a frequent finding in the trisomies and therefore a careful search should be made for associated cardiac anomalies, growth retardation, and polyhydramnios.
What is a small cisterna magna?
A small cisterna magna might signal that a neural tube defect (i.e., spina bifida) is present. Hydrocephalus (“water in the brain”) is easily visible by ultrasound since the lateral ventricles will be markedly dilated.
What does mega cisterna magna mean in ultrasound?
On antenatal ultrasound, mega cisterna magna refers to an enlarged retrocerebellar CSF space: Typically seen as prominent retrocerebellar cerebrospinal fluid (CSF) appearing space with a normal vermis, normal 4 th ventricle, and normal cerebellar hemispheres.
Is it normal to have a 10 mm cisterna magna?
Longer follow-up was available in eight cases (range, 2 to 69 months), and all eight of these infants were normal. Our results suggest that isolated enlargement of the cisterna magna to more than 10 mm is associated with normal pregnancy and neonatal outcome.
What kind of fluid is in the cisterna magna?
Typically seen as prominent retrocerebellar cerebrospinal fluid (CSF) appearing space with a normal vermis, normal 4th ventricle, and normal cerebellar hemispheres. An enlarged cisterna magna usually measures >10 mm on midsagittal images. An enlarged posterior fossa can sometimes be present 6.
What kind of cyst is enlarged cisterna magna?
The main differential diagnosis of an enlarged cisterna magna is a posterior fossa arachnoid cyst. Arachnoid cysts are benign collections of cerebrospinal fluid that collect within the arachnoid space.