A mega cisterna magna is thought to occur in ~1% of all brains imaged postnatally. It constitutes 54% of all cystic posterior fossa malformations 4. Associations Especially if noted antenatally, a mega cisterna magna has been associated with: infarction inflammation/infection: particularly cytomegalovirus Mega cisterna magna refers to a cystic posterior fossa malformation that is characterized by an enlarged cisterna magna, absence of hydrocephalus, and an intact cerebellar vermis. It must be differentiated from persistent Blake's pouch cyst, posterior fossa cysts, Dandy-Walker variant, and posterior fossa neoplasia.
18 Mega Cisterna Magna Radiology Key
The cisterna magna is a cerebrospinal fluid (CSF) filled space located in the posterior fossa dorsal to the medulla and caudal to the cerebellum. Mega cisterna magna refers to a cystic posterior fossa malformation characterized by an enlarged cisterna magna, absence of hydrocephalus, and an intact cerebellar vermis. [1] [2] Prevalence: 1 in 5,000 births. Ultrasound diagnosis: The cisterna magna is >10 mm in the transverse cerebellar view. Vermis: normal. Differential diagnosis: Blake's pouch cyst (expansion of the 4 th ventricle into the cisterna magna resulting in a unilocular, avascular cyst in the posterior fossa; vermis normal in size with upward rotation), arachnoid cyst (cyst in the cisterna magna with. What are mega cisterna magna (MCM) and arachnoid cysts (AC)? MCM involves the enlargement of normal fluid-filled space in the brain with no other structural differences anomaly in other cerebral structures. ACs are usually benign, cerebro-spinal fluid-like collections that develop within the layers of the membranes that wrap the brain. A mega cisterna magna is a controversial subject. In general, however, the term refers to non-pathological enlargement of the retrocerebellar CSF space, not associated with cerebellar abnormalities (normal cerebellar vermis and hemispheres).
Mega cisterna magna Radiology Case
Mega Cisterna Magna (MCM) MCM refers to a retro- and infracerebellar CSF space greater than 10 mm on mid-sagittal images. It is thought to arise during embryogenesis from a defect of the posterior membranous area of the roof of the fourth ventricle, with mildly deficient fenestration of Blake's pouch ( Robinson and Ederies, 2016 ). Mega Cisterna Magna The cisterna magna is a cerebrospinal fluid (CSF) filled space located in the posterior fossa dorsal to the medulla and caudal to the cerebellum. Mega cisterna magna refers to a cystic posterior fossa malformation characterized by an enlarged cisterna magna, absence of hydrocephalus, and an intact c. The cisterna magna is located between the cerebellum and the dorsal surface of the medulla oblongata at and above the level of the foramen magnum. CSF produced in the ventricular system drains into the cisterna magna from the fourth ventricle via the median aperture (of Magendie) and the lateral apertures (of Luschka) 1,2. Cisterna Magna. A mega cisterna magna (also called a retrocerebellar arachnoid pouch, communicating arachnoid cyst, and Blake pouch) is a developmental variation of the posterior fossa characterized by an enlarged bony/dural posterior fossa, expansion of the cisterna magna (which freely communicates with the perimedullary subarachnoid spaces), and an intact vermis with a normal fourth.
Mega cisterna magna Radiology Case
Dandy-Walker malformation ( DWM ), also known as Dandy-Walker syndrome ( DWS ), is a rare congenital brain malformation in which the part joining the two hemispheres of the cerebellum (the cerebellar vermis) does not fully form, and the fourth ventricle and space behind the cerebellum (the posterior fossa) are enlarged with cerebrospinal fluid. Introduction Fetal central nervous system (CNS) abnormalities are fairly common, with an incidence of about 0.1%-0.2% in live births and an even higher occurrence of about 3%-6% in stillbirths. They are second only to cardiac malformations in terms of frequency of occurrence ( 1 ).
The cisterna magna ( posterior cerebellomedullary cistern, [1] or cerebellomedullary cistern [2] [3]) is the largest of the subarachnoid cisterns. The authors present two cases of mega cisterna magna associated with mania and catatonic schizophrenia. Dandy-Walker malformation is a rare congenital abnormality characterized by large posterior fossa cyst with open communication between the fourth ventricle,.
Mega cisterna magna Radiology Case
Results: Subjects with isolated mega cisterna magna had a lower performance on memory tasks [RAVLT saving score (0.8 +/- 0.2 vs. 1.02 +/- 0.2, P = 0.003)] and verbal fluency [phonemic fluency (9.4 +/- 4.5 vs. 13.6 +/- 5.3, P = 0.02), semantic fluency (19.8 +/- 5.8 vs. 24.4 +/- 7.5, P = 0.05)]. Cisterna magna is a normal CSF (cerebrospinal fluid) filled space on the backside of the brain. However, in many individuals, it can be more extensive, called mega cisterna magna, and that usually does not cause any symptom to the patient. It needs to be differentiated from an arachnoid cyst or cerebellar atrophy, or dandy walker syndrome.
