okzipitale Enzephalozele

Imaging of
skull vault tumors in adults. Calvarial pseudolesions. NECT (a, c–f), T2WI (b), MR venography (g, h). Parasagittal occipital arachnoid granulation (a). Occipital encephalocele (b). Dilated vascular canals and lacunae (c). Hyperostosis frontalis interna (d). Bilateral thinning of the parietal bones (e). Enlarged parietal foramina (f). Congenital sinus pericranii (g). Iatrogenic acquired sinus pericranii from a prior ventricular drainage (h)
insightsimaging.springeropen.com • CC-by-4.0
Newborn with
a large posterior skull mass. Lateral radiograph of the skull shows a large round soft tissue mass arising from the base of the skull.The diagnosis was occipital encephalocele.
pediatricimaging.org • CC-by-nc-sa 4.0
Newborn with
an abnormal bump in the posterior midline at the skull base. Axial CT without contrast of the cervical spine shows a defect in the posterior skull at the craniocervical junction with cerebellar tissue herniating posteriorly through it.The diagnosis was Chiari III malformation with an occipital encephalocele.
pediatricimaging.org • CC-by-nc-sa 4.0
Giant
occipital encephalocele: a case report, surgical and anesthetic challenge and review of literature. A MRI T2 weighted image of Giant Occipital Meningoencephalocele. B MRI T2 weighted image showing a huge meningoencephalocele without hydrocephalus
EJNS.springeropen.com • CC-by-4.0
Rare case of
a large congenital parietal meningoencephalocele associated with open lip schizencephaly. Midline sagittal T1W post-contrast image of brain shows polymicrogyria complex adjacent to open lip schizencephaly. Dilated third ventricle and partial agenesis of the posterior body & splenium of corpus callosum is noted.
www.eurorad.org • CC by-nc-sa-4.0
Rare case of
a large congenital parietal meningoencephalocele associated with open lip schizencephaly. Sagittal T1W post-contrast image shows a parietal open lip schizencephaly with dysplastic thickened grey matter adjacent to it.
www.eurorad.org • CC by-nc-sa-4.0
Rare case of
a large congenital parietal meningoencephalocele associated with open lip schizencephaly. Coronal T2W FLAIR image shows large parietal meningoencephalocele as evidenced by herniation of CSF and dysmorphic brain parenchyma through midline skull vault defect.
www.eurorad.org • CC by-nc-sa-4.0
Rare case of
a large congenital parietal meningoencephalocele associated with open lip schizencephaly. Sagittal T1 Inversion Recovery Image shows partial agenesis of the posterior body & splenium of corpus callosum, meningoencephalocele and dilated third ventricle.
www.eurorad.org • CC by-nc-sa-4.0
Rare case of
a large congenital parietal meningoencephalocele associated with open lip schizencephaly. Coronal T1W post-contrast image shows involvement of superior sagittal sinus and meningoencephalocele.
www.eurorad.org • CC by-nc-sa-4.0
Occipital
Meningoencephalocele case report and review of current literature. Axial T1, T2 weight MRI on A&B showing no evidence of brain parenchymal injury with widening of the posterior fontanel measuring around 3 × 3 cm. Flair weighted MRI on C&D that shows a widening of the posterior fontanel with evidence of partial left parietal lobe herniation covered with CSF with no evidence of underlying brain parenchymal abnormal signal or mass with no intra or extra axial areas blood signal
cnjournal.biomedcentral.com • CC-by-4.0
Prenatal
diagnosis of occipital encephalocele. MRI T2W image shows a well defined hyperintense lesion (arrow) protruding through a bone defect in the occipital region with herniation of the brain parenchyma within the lesion (arrowhead).
www.eurorad.org • CC by-nc-sa-4.0
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okzipitale Enzephalozele

Enzephalozele Radiopaedia • CC-by-nc-sa 3.0 • de

Encephalocele, also known as meningoencephalocele, is a form of neural tube defect and a type of cephalocele where brain tissue and overlying meninges herniate out through a defect in the cranium.

Terminology

It should be distinguished from cranial meningocele in which the lesion contains only meninges, and from extracranial brain herniation in which brain herniates through a dural and skull defect (e.g. post-trauma or surgery).

Epidemiology

They are thought to occur in one of every 4,000 live births. Frontoethmoidal encephaloceles are more common in the south and south-east Asian populations. There is no recognized gender predilection.

Genetics

Most cases tend to be sporadic.

Associations

Occipital encephaloceles may be associated with a number of additional abnormalities:

Clinical presentation

Frontoethmoidal encephaloceles manifest as a clinically visible mass along with the nose. The intracranial root of most frontoethmoidal encephaloceles lies at the foramen cecum, a small ostium located at the bottom of a small depression anterior to the crista galli and formed by the closure of the frontal and ethmoid bones.

Basal encephaloceles are internal and are not generally externally visible, although they may manifest as a lump or bump in the oropharynx or nasopharynx.

Small temporal encephaloceles are increasingly recognized as causes of refractory epilepsy in some individuals and are also encountered as asymptomatic sequelae of idiopathic intracranial hypertension.

Pathology

Encephaloceles, when congenital (most common) are a form of neural tube defect and occur due to a failure of fusion during embryogenesis of the cartilaginous neurocranium, the membranous neurocranium or viscerocranium .

In adults, encephaloceles are mainly due to traumatic or iatrogenic causes but are also increasingly recognized in idiopathic intracranial hypertension.

Classification

Numerous classification systems exist for encephaloceles, many of which are only of subspecialty interest, and most use very similar terminology, sometimes with different meanings . As a result reading about this topic can be frustrating. The term nasal encephalocele is, for example, variably used, often to encompass both frontoethmoidal and basal encephaloceles .

A fairly common classification still widely used is that first described by Suwanwela and Suwanwela in 1972 which divides the encephaloceles according to location :

Radiographic features

Antenatal ultrasound

An encephalocele may be seen as a purely cystic mass or may contain echoes from herniated brain tissue. If the mass appears cystic, the meningocele component predominates, while a solid mass indicates predominantly an encephalocele. Larger encephaloceles may show accompanying microcephaly.

CT/MRI

MR imaging is the best imaging modality for defining the contents of an encephalocele prior to surgery. High-resolution CT may also be used to display the bone anatomy, but the intracranial connection is best defined with MR imaging. The extent of cerebral tissue in an encephalocele is also better defined with MR imaging, which aids in prognosis and surgical planning. In some instances, focal herniation of brain parenchyma occurs into an arachnoid granulation protruding into a dural venous sinus . The cause and effect, however, is unclear and controversial.

Treatment and prognosis

The prognosis is variable depending on the presence of associated anomalies and the presence of microcephaly (carries a much poorer prognosis). A Cesarian delivery may be considered to allow for less traumatic birth for the fetal head.

Siehe auch:
Assoziationen und Differentialdiagnosen zu okzipitale Enzephalozele:
Meningoenzephalozele
 
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