Congenital malformations of brain

Congenital Malformations Of the brain

By Dr Abinash SamalMIMS

Prosencephalon (Forebrain) ----------> Diencephalon + Telencephalono (1) Telencephalon ------> Cerebral Hemisphereso (2) Diencephalon Mesencephalon (Midbrain) ---------> (3) Midbrain Rhombencephalon (Hindbrain)o Metencephalon ----------------------> (4) Pons, Cerebellumo Myelencephalon --------------------> (5) Medulla Oblongata

Classification of congenital malformation of brain

• I.Disorders of organogenesis:• Neural tube closure• Divericulation and cleavage• Sulcation / cellular migration • Cerebellar hypoplasia / dysplasia• II.Disorders of Histogenesis:• Neurocutaneous syndromes( phakomatoses)• III.Disorders of cytogenesis:• Congenital vascular malformations• Congenital neoplasms of brain• IV.Disorders of myelination • Leukodystrophies

disorder of organogenesis: neural tube closure defects: chiari malformations cephalocoeleCorpus callosum anomalies

• I.Disorders of organogenesis :

Chiari malformations

• Chiari I malformation:• Tonsillar decent 5mm below BOL• The tonsil appear compressed and pointed(peg like)

instead of gently rounded. Tonsilar folia are angled odliquely instead of transversly Retrocerebellar csf spaces at fm/c1 level are effaced.

•

• Associated anomalies• Brain : normal• Ventricles : • mild– moderate hydrocephalus• Spinal cord : • Syringohydromyelia (30-60%)• Skeletal anomalies :• basilar invagination • klippel feil• atlanto occipital assimilation

Chiari II malformation • Brain involvement :• Cascading protrusion of vermian nodules ,fourth

ventricle, choroid plexus and the medulla into the spinal canal with formation of cervicomedullary spur and kink

• Upward herniation of cerebellar hemispheres and vermis through gaping incisura (towering cerebellum) producing tectal deformity ( beaked tectum )

• Cerebellar hemispheres creep around to engulf the brainstem

• Large massa intermedia• Hydrocephalus (90%) with serrated appearance of

lateral ventricles

mIage above shows a T1 weighted MRI of patient with Type 1 Chiari malformation: Cerebellar tonsils are displacedthrough the foramen magnum (white bar) to the lower aspect of C2. A syrinx (asterisk) is visible extending from C3 to T2.

• Spine and cord involvement:• Myelomeningocele ( nearly 100% )• Syringohydromyelia (70-90%)• Diastematomyelia• Associated anomalies:• Corpus callosal dysgenesis,heteropias, polynucrogyria

A thoracic-level myelomeningocele (short arrow) is seen in a patient with a Chiari II malformation (long arrow).

Sagittal T2-weighted magnetic resonance image in a patient with a Chiari II malformation. This image shows a thoracic-level myelomeningocele (arrows). The spinal cord, in addition to the thoracic placode, also extends distally and is further tethered at the sacral level.

(1) colpocephaly; (2) beaked tectum; (3) cascade of an inferiorly displaced vermis behind the medulla; (4) elongated, tubelike fourth ventriclei; (6) cerebellar hemispheres wrapping around the brainstem anteriorly; (7) concave clivus; (8) medullary spur; and (9) medullary kink.

Axial computed tomography scan in a patient with a Chiari II malformation. This image shows a gaping, somewhat heart-shaped tentorial incisura (large arrowheads) that appears to be completely plugged with the upwardly herniating cerebellum. The cerebellar hemispheres extend anteromedially (small arrowheads) and almost completely engulf the brainstem. The petrous ridges are concave (arrows).

Sagittal midline T1-weighted magnetic resonance image in a patient with a Chiari II malformation. This image shows a large massa intermedia (long arrow) and a beaked tectum (short arrow). Other posterior fossa abnormalities are also seen in this patient.

Coronal T1-weighted magnetic resonance image in a patient with a Chiari II malformation. This image shows low-lying transverse sinuses (arrows), hydrocephalus, and a small posterior fossa. A hypoplastic tentorium cerebelli with gaping incisura (arrowhead) is present with a towering cerebellum (small arrows).

Axial T2-weighted magnetic resonance image in a patient with a Chiari II malformation. This image shows a hypoplastic fenestrated falx cerebri with striking interdigitation of the gyri (arrows).

Deep scalloping between the bony septations that characterize the lacunar skull (luckenschadel) (arrows) are best appreciated on an axial computed tomography section, as in this patient with a Chiari II malformation.

Chiari III malformation• Features of Chiari II malformation with a low occipital or high

cervical encephalocele • The encephalocele may contain meninges , cerebellum ,

occipital lobe or brainstem.cisterns and dural sinuses may also present.

Neonate with Chiari malformation type III. 3D reformatted CT scan shows lacunar skull and a large defect in the occipital regional striae

Neonate with Chiari malformation type III. T2-weighted mid-sagittal MRI scan of the patient shows a small posterior fossa,an deep parieooccipitalis fissure (open arrow), ad a partial callosal agenesis (curved arrow), and a caudal herniation of part of the brain stem through the foramen magnum, with inferior tip appearing between C5 and C6 (closed arrow).

Image above shows an axial brain CT image showing herniation of cerebellum through in a midline occipital bone defect in a type 3 Chiari malformation patient.

Image above shows sagittal T2-weighted MR image showing encephalocele in the occipital region and fusion of C4-5 and C5-6 vertebrae. Note the syringomyelia in craniocervical junction

Chiari IV malformation• Severe cerebellar hypoplasia or dysplasia, small brainstem and

large posterior fossa CSF space• No hydrocephalus and other CNS anomalies•

Cephalocele

• Characterised by protrusion of intracranial contents through a

congenital defect in the dura and skull• Usually located at or near the midline• Pathological classification of cephaloceles (based on the

contents of the herniated sac )• Meningoceles (leptomeninges and CSF)• Meningoencephalocele (leptomeninges, CSF and brain)• Meningoencephalocystocele (leptomeninges,CSF,brain and

ventricles)• Atretic cephalocele (small nodule of fibrous fatty tissue)• Gliocele (CSF lined by glial tissue )

Anatomic classification of cephalocele (based on location)

• Occipital –most common• Parietal • Temporal • Frontl or Frontoethemoidal (sincipital)- most common in Asia• Transsphenoidal –uncommon • Nasal • The herniated brain dysgenetic and non-functional• Absence or erosion of the crista galli with enlargement of

foramen cecum is a constant feature of a nasal cephalocele

The radiograph shows a well-defined thinning of the parietal bone (arrow).

Encephalocele and cervical meningocele.

• Differential diagnosis of a nasal cephalocele includes congenital masses (dermoid)-crista galli is present but split

• Antenatal ultrasound and MRI are useful in evaluation of content of the sac.

• CT is useful in demonstrating bony defect• Associated anomalies :• Chiari II & III malformation (seen with occipital cephalocele)• Corpus callosum agenesis , Dandy-walker malformation (seen

with parietal cephalocele)

Fronto-ethmoidal-sphenoidal encephaloceleFronto-ethmoidal-sphenoidal encephalocele -MRI (sagittal)

Corpus Callosum Agenesis • Corpus callosum a midline commissure connects 2 cerebral

hemispheres• Develops in cephalocaudal direction , beginning with genu

then followed by the body and splenium,the rostrum is last to develop

• 2 types :complete or partial

Complete callosal agenesis• Absence of entire corpus callosum, cingulate gyrus and sulcus• High riding 3rd ventricle with spoke like orientation of gyri

around it• Widely separated paralell and non converging lateral ventricles • Probst bundles (longitudinal white matter tracts ) indent

superomedial lateral ventricles• Colpocephaly (dilated occipital horns )-common,frontal horns-

small and pointed• High incidence of dorsal interhemispheric cyst

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows complete absence of the corpus callosum. The cingulate sulcus is absent, and the medial hemispheric sulci reach the third ventricle in a radial fashion.

Corpus callosum, agenesis. Axial nonenhanced CT of the brain shows colpocephaly, caused by dilation of the atria, and occipital horns of the lateral ventricle. Note the parallel configuration of the lateral ventricles. Interdigitation of gyri from fenestration of the falx may be noted incidentally.

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain. Parasagittal section through the lateral ventricle shows dilatation of the atrium and occipital horn (colpocephaly).

Partial callosal agenesis• Splenium and rostrum absent or hypoplastic• Genu and body present to various degrees• Associated anomalies :• Migration disorders

(Heterotopias,lissencephaly,schizencephaly )• Chiari II malformation • Dandy-Walker malformation• Holoprosencephaly• Corpus callosal lipoma

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows partial agenesis of the corpus callosum. The genu and anterior body of the corpus callosum are visualized, whereas the posterior body, splenium, and rostrum are absent.

Corpus callosum, agenesis. Sagittal T1-weighted MRI of the brain shows apparent atypical callosal dysgenesis in lobar holoprosencephaly. The body and splenium of the corpus callosum are well formed, whereas the genu and rostrum are hypoplastic.

• Diverticulation and cleavage failure: Holoprosencephalies Alobar Semilobar Lobar

Holoprosencephaly

Characterised by complete or partial failure of cleavage and differentiation of developing cerebrum (prosencephalon ) into hemispheres and lobes

• Cerebellum and brainstem relatively normal• Classified into 3 types• Alobar (most severe )• Semilobar (moderately severe )• Lobar (mildest form )

Alobar prosencephaly• Near complete lack of hemispheric cleavage• Cresent shaped monoventricle• Absence of septum pellucidum , corpus callosum , falx cerebri

and interhemispheric fissure• Fused thalami and basal ganglia• Associated anomalies :Dorsal interhemispheric cyst , severe craniofacial anomaly.

Fetal magnetic resonance image shows alobar holoprosencephaly

Holoprosencephaly in a child with abnormal growth and development. CT coronal images of brain show (a) alobar holoprosencephaly with a large central monoventricle (asterisk) and thin cortical mantle (arrow); (b) semilobar holoprosencephaly with H-shaped monoventricle (asterisk). Basal ganglia and thalami are partially fused (arrow). Pituitary gland (not shown) appeared normal

Semilobar holoprosencephaly• Partial brain diverticulation • H shaped holoventricle with rudimentary occipital and

temporal horns.Rudimentary third ventricle may be present.• Septum pellucidum absent ,callosal splenium may be formed,

falx cerebri and interhemispheric fissure partially developed posteriorly

• Thalami and basal ganglia partially separated• Associated anomalies:Dorsal interhemispheric cyst , variable

craniofacial anomalies

Lobar Holoprosencephaly• Nearly complete brain cleavage • Squared off or box like configuration of frontal horns due to

absence of septum pellucidum . • variable degree of anterior extention of corpus callosum , well formed falx cerebri and interhemispheric fissure with

some anteroinferior fusion of hemispheres • Thalami and basal ganglia well separated• Associated anomalies : schizencephaly (most common )

Axial T1-weighted magnetic resonance image shows septo-optic dysplasia, representing a variant of lobar holoprosencephaly.

Disorders of sulcation and cellular migration

LissencephalyNon-lissencephalic cortcal dysplasiaHterotopiaSchinzencephaly

lissencephaly• Lissencephaly (Agyria-Pachygyria)• Smooth brain with absent or poor sulcation• Complete (agyria ) or incomplete (pachygyria )• Intermediate • Three types : I,II,III• Type I (classical ) lissencephaly :• Typical figure 8 configuration of brain with oblique and

shallow sylvian fissures.• Thickened cortex with flat broad gyri and smooth grey-

white matter interface • Colpocephaly • Associated with Miller-Dieker syndrome

• Type II (cobblestone ) lissencephaly :• Thickened cortex with polymicrogyric appearance .• Concurrent hypomyelination of underlying white matter

present.• Associated with fukuyama congenital muscular

dystrophy ,walker-warburg syndrome and muscle – eye-brain syndrome.

• Type III (Cerebrocerebellar) lissencephaly • microcephaly with moderately thickened cortex and

hypoplastic cerebellum and brainstem

Nonlissencephalic cortical dysplasia

• Two types : polymicrogyria and pachygyria• Polymicrogyria :• Characterised by diffusely thickened cortex with irregular

bumpy gyral pattern• MRI :Thick cortex with flat surface , irregular grey white

matter junction.

Postnatal axial T2-weighted image demonstrates volume loss and polymicrogyria involving the left frontal and parietal lobes (arrow).

• Pachygyria :• focal areas of thickened and flattened cortex with blurred

grey-white matter junction • Both types of cortical dysplasia show relative paucity and

marked T2 prolongation of underlying white matter.

Heterotopias

• Presence of normal neurons at abnormal sites • 2 types : Nodular type (common ),• Band(laminar ) type(uncommon )• Nodular type : • Multiple masses of grey matter – variable sizes• Common location : subependymal • subcortical • Focal or diffuse • Subependymal focal nodules – indent ventricular wall• Diffuse heterotopias border the walls of lateral ventricle

• Differential diagnosis : subependymal nodules tuberous sclerosis

• Subcortical heterotopias are less frequent

• Band or laminar type :• A layer of neurons interposed b/w ventricle and cortex ,

seen as alternating layer of grey and white matter band

• The cortex overlying the heterotypia is nearly always abnormal with pachygyria or polymicrogyria

multiple nodular heterotopia (arrows) lining the frontal horn of the right lateral ventricle and extending into the center of the frontal white matter. The right hemisphere is reduced in size. The overlying cortex is thin and has a reduced number of sulci. The sulci present are abnormally shallow. The corpus callosum is agenetic.

Axial T2-weighted MR image shows thick band heterotopia, the so-called double cortex

Schizencephaly (Split Brain )• Presence of herotopic grey matter lined cleft that extends from

the ventricular ( ependyma) to periphery ( pial surface ) of brain , traversing through the white matter

• Unilateral / bilateral• 2 types : closed lip ( type I ), open lip ( type II )• Closed lip type :• Walls of the cleft oppose each other & no intervening CSF • Imaging : outpouching or nipping at the ependymal

surface of the cleft

Axial T2-weighted MRI in unilateral closed-lip (type I) schizencephaly. The cleft is lined by gray matter and extends from the pial surface to the lateral ventricle.

• Open lip type : • walls of the cleft is widely separated and cleft is occupied by

CSF• Severe form of open lip schizencephaly – “basket brain “• closest differential is porencephalic cyst – CSF space is lined by

gliotic white matter

. Axial T2-weighted MRI demonstrates a small open-lip schizencephaly. The septum pellucidum is absent.

Hemimegalencepaly

• Hamartomatous overgrowth of a part or all of one cerebral hemisphere

• MR shows enlargement of a part or whole of one cerebralhemisphere , ipsilateral ventricle is frequently dilated and the frontal horn is stretched

• Cortex – diffuse migration anomaly (polymicrogyria or pachygyria )

• White matter is gliotic and dysmyelinated • Total hemimegalencephaly• Heterotopias may present• Associated anomalies : Epidermal nevus syndrome , Klippel-

trenauny-weber syndrome, Neurofibromatosis type I

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Disorders of cerebellar hypoplasia / dysplasia• Dandy-walker complex :• Dandy walker malformation and Dandy walker varient• Dandy walker malformation : • Large posterior fossa with cystic dilatation of the fourth

ventricle , that elevates the tentorium , torcular herophili and the transverse sinuses above the lambdoid suture (lambdoid torcula inversion )

• Partial or complete vermian agenesis associated with hypoplastic cerebellar hemispheres

• The hypoplastic superior vermis is everted above the cyst and the hemispheres- are displaced anterolaterally against the petrous ridge – ‘’winged outward ‘’

• Brainstem compressed against the clivus• Hydrocephalus present in 80% of untreated cases• Associated anomalies : corpus callosum agenesis,

heterotopias, schizencephaly, cephaloceles• Closest differentials : mega cisterna magna , posterior fossa

arachnoid cyst

shows a large posterior fossa cyst elevating the torcular herophili and sinus rectus (short arrow). The hypoplastic vermis is everted over the posterior fossa cyst (long arrow). The cerebellar hemispheres and brainstem (b) are hypoplastic. Thinned occipital squama is seen (arrowheads).

An axial T2-weighted MRI scan that shows hydrocephalus, a large cerebrospinal fluid cyst in the posterior fossa, thinned occipital bone (arrows), and hypoplastic cerebellar hemispheres with a winged appearance (c).

• Dandy walker variant : • Inferior vermian hypoplasia with communication of fourth

ventricle and cistern magna through an enlarged vallecula – Key hole deformity

• Tentorial position and posterior fossa size are normal• Brainstem –N & hydrocephalus –uncommon

This sagittal T1-weighted MRI shows agenesis of the corpus callosum and a hypoplastic inferior vermis in a 13-year-old girl with thoracal scoliosis and Dandy-Walker variant. The fourth ventricle is slightly enlarged, but the posterior fossa typically is normal in size.

Mega cistern magna• Variable size dilatation of cistern magna – communicates with

both the fourth ventricle and adjacent subarachnoid spaces ( straight sinus superiorly & C1-C2 inferiorly)

• severe cases – enlargement of posterior fossa and scalloping of occipital sqamae +nt

• Fourth ventricle , vermis , cerebellar hemispheres are normal . No hydrocephalus

• Vermian hypoplasia may mimic maga cistern magna – look for size of vermis

Posterior fossa arachnoid cyst• A collection within the layers of arachnoid membrane – not

communicates fully with fourth ventricle or adjacent subarachnoid spaces

• 4th ventricle , vermis , cerebellar hemispheres are normal – displaced by the cyst

• Imaging – non enhancing round to oval lesion attenuation and signal intensity – closely parallels CSF

• DDs : Dandy walker malformation , mega cistern magna

T2-weighted sagittal MRI image of the brain in a 28-year-old woman with an incidental finding of a superior cerebellar cistern arachnoid cyst (arrow).

Joubert’s syndrome ( congenital vermian hypoplasia )

• Inherited vermian dysgenesis , enlarged superior cerebellar peduncles and high riding fourth ventricle

• MR imaging : vermis is completely or partially absent.• Superior 4th ventricle is bat-wing or umbrella shaped (on axial

) has convex roof (on Sagittal) • The superior cerebellar peduncles are elongated, thin ,running

parallel to each other• Isthmus is narrow • Midbrain – molar tooth appearance• Hydrocephalus is absent• All pts should screened for occipital encephalocele, callosal

dysgenesis , cortical dysplasia , hypothalamic hamartomas and occular, hepatic & renal diseases

Rhombencephalosynapsis• Vermian agenesis / hypogenesis combined with midline fusion

of cerebellar hemispheres , peduncles and dentate nuclei• MR imaging : folia and sulci are continuous throughout the

midline ( on axial ) monolobated cerebellum lies in mid sagittal plane ( on sagittal ) posterior fossa is small.

• Associated anomalies : ventriculomegaly (common ), callosal dysgenesis , absent septum pellucidum , cephalocele and schizencephaly.

The cerebellar hemispheres are fused, without a normal vermis identified.

Tectocerebellar dysraphism• Vermian hypoplasia , occipital cephalocele , marked

deformation of quadrigeminal plate and the brainstem• Fusion of colliculi forms a tectal beak – points towards the site

of the cephalocele• Cerebellar hemispheres – engulf the brainstem• Associated anomalies : hydrocephalus , supratentorial

abnormalities

Lhermitte-Duclos disease• Known as dysplastic gangliocytoma of cerebellum• Gross thickening of cerebellar folia with or without mass effect • MR imaging : pseudomas having laminated or folia pattern of

incrased signal on T2W.• May/may not enhance on contrast • Mass effect & displacement of fourth ventricle • Calcification / hydrocephalus +nt • Associated anomalies : cowden syndrome (common ) ,

megalencephaly , heterotopias, cortical dysplasia, multiple visceral hamartomas and neoplasms

T2WI showed a mixed intensity lesion in the inferior right cerebellar hemisphere which contained some “dark stripes”.

Disorders of histogenesis• Neurocutaneous syndromes or phakomatoses• Cutaneous lesions + CNS anomalies • Neurofibromatosis : 2 types • Neurofibromatosis type I ( NF I ) • known as Von Recklinghausen disease or peripheral

neurofibromatosis• >90% of all NF cases • Incidence : 1:2000 to 3000 live births

Diagnostic criteria ( 2 or more +nt) • 6 or more café –au-lait spots ( >5mm in pre pubertal children ,

>15mm in post pubertal )• One plexiform neurofibroma or 2 or more neurofibromas of

any type• 2 or more pigmented iris hamartomas ( Lisch nodule )• Optic nerve glioma• Osseous lesions – dysplasia of greater wing of sphenoid ,

pseudoarthrosis • First degree relative with NF I

CNS lesions ( 15-20 % )• Optic nerve glioma ( most common ) – optic chiasma , optic

tract, optic radiation and lateral geniculate bodies• Non optic gliomas – brainstem , tectum , periaquiductal region • Plexiform neurofibroma – hallmark of NF I • Unencapsulated neurofibroma along the path of major

cutaneous nerve of the scalp and neck –first division of trigeminal nerve. associated with dysplasia of sphenoid bone & bony orbit.

• Non neoplastic hamartomatous lesions (80%)• Astrocytic proliferation of retina , intracranial aneurysms ,

vascular ectasia • Spinal lesions : cord astrocytoma / hamartoma , dural ectasia

& lateral / anterior intrathoracic meningoceles• Skeletal dysplasias : hypoplasia of sphenoid bone , bony orbit ,

kyphoscoliosis,scalloping of posterior aspect of vertebral bodies

Frontal skull radiograph in a patient with NF1 shows asymmetry of the orbits but a normal sphenoid ridge.

Sagittal T1-weighted unenhanced MRI scan in a 28-year-old woman shows dural ectasia and a large lobulated anterior sacral meningocele (M).

CT scan through the orbits in a patient with NF1 shows a right optic glioma.

2-weighted transaxial MRI shows bilateral optic nerve gliomas (arrows), as well as a right temporal lobe and left brainstem lesions, which may represent additional gliomas or spongiform white matter changes of NF1.

Neurofibromatosis type 2• Known as central neurofibromatosis • Incidence : 1:50,000 live births• Cutaneous manifestations rare• CNS manifestations ( 100% cases )• Bilateral acoustic schwannomas , hallmark of NF 2 • Schwannomas of other cranial nerves – trigeminal • Meningiomas – multiple• Choroid plexus calcification • Spinal lesions- cord ependymomas , meningiomas , multilevel

bulky schwannomas of exiting roots

Axial T1-weighted postcontrast image demonstrates bilateral internal auditory canal-enhancing masses that are diagnostic for neurofibromatosis type 2 (NF2). No biopsy is necessary for the diagnosis. Notice the en plaque meningioma anterior to the brainstem.

Sagittal T1-weighted postcontrast image of the thoracic spine demonstrates an enhancing extra-axial meningioma (arrow) anterior to the cord with a complex enhancing mass (arrowheads) that represents a conus ependymoma filling the spinal canal in the lower thoracic spine.

Tuberous sclerosis • Known as Bourneville disease or multiple hamartomatous

syndrome• Incidence : 1:10,000 to 50,000 live births• Classical triad of popular facial lesions (adenoma sebaceum) ,

seizure disorder and mental retardation • CNS lesions :• Cortical tubers or hamartomas (95% cases)• MR imaging : lesions can expand and distort the affected gyri

and show age-related signal changes• Enhancement on contrast (<5%cases )• Calcifications

• Subependymal nodules or hamartomas –(95% cases ) located on ventricular surface of caudate nucleus , just behind the foramen of Manro followed by atria, temporal horn of lateral ventricles , 3rd & 4th ventricle

• MR imaging : hypointense to white matter on T2W show minimal contrast enhancement

• Closest differential : nodular heterotopias

• Subependymal gaint cell astrocytoma – (15% cases )• located at or near foramen Manro • MR imaging : intense uniform contrast enhancement .• Frequently calcified• Obstructive hydrocephalus – common

• Dysplastic / disorganised benign white matter lesions • MR imaging :• straight curvilinear bands extends from the ventricle

through the white matter to the cortex• wedge shaped lesions• tumefactive / conglomerate foci• cerebellar radial bands • Other CNS lesions : retinal hamartomas , intracranial

aneurysms , vascular ectasia • Non CNS lesions : hamartomatous growths in multiple organ

system

a patient with tuberous sclerosis reveals subependymal calcifications. A hypointense right frontal lesion represents a white matter lesion or tuber; it extends from the lateral ventricle through the cerebral cortex.

Contrast-enhanced head CT scan reveals a low-attenuating cortical tuber (arrow) in a 10-year-old patient with tuberous sclerosis

Sturge- weber syndrome• Encephalotrigeminal angiomatosis • Facial port wine vascular nevus flammeus in the trigeminal

nerve distribution (1st division), leptomeningeal venous angiomatosis of ipsilateral brain , hemiparesis , homonymous hemianopia and seizure

• Pathology : leptomeningeal venous angiomatosis with congenital absence of cortical veins blood is shunted towards hypertrophied deep medullary veins & to choroid plexus venous stasis and vascular congestion with hypoxia of affected cortex

• Occipital and posterior parietal lobe on the side of facial angioma –most commonly involved

• Tram-track or gyriform pattern of cortical calcification -diagnostic

• Severe cortical atrophy – marked dilatation of ipsilateral ventricle , thickening of calvarium , prominence of ipsilateral sinuses

• The pial angiomas , cortical infarcts and enlarged ipsilateral choroid plexus show intense post contrast enhancement

• Ocular lesions : sclera and choroid angiomas • Associated anomalies : Klippel –Trenaunyay syndrome

Axial contrast-enhanced CT scan through the occipital horns of the lateral ventricles shows right cerebral atrophy and an enlarged right choroid plexus in a patient with Sturge-Weber syndrome.

Plain radiographs of the skull in a 16-year-old male adolescent shows asymmetry of the skull with a smaller hemicranium on the affected side. Note the underlying tramline gyriform intracranial calcification in the subcortical occipital region.

Von Hippel – Lindau syndrome • Multisystem disease – cysts , angiomas , neoplasms of the CNS

and abdominal viscera• CNS lesions :• Cerebellar (75%), retinal (50%), spinal cord (25%)

hemangiblastomas• MR imaging :• majority have cystic appearance with intensely enhancing

mural nodule.• angiographic appearance of the hemangioblastoma –tangles

of tightly packed vessels that become opacified in early arterial phase

Scans show a midline cerebellar cystic lesion with an enhancing nodule (arrow) due to cerebellar hemangioblastoma.

von Hippel-Lindau syndrome. T1-weighted transaxial gadolinium-enhanced MRIs of the same patient as in the previous image show a well-defined hypervascular enhancing mass.

von Hippel-Lindau syndrome. Coronal T1-weighted contrast enhanced MRI shows an intensely enhancing cerebellar lesion (red arrow) with a large cystic tumor component (white arrow)

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