CNS MalformationsCNS Malformations

SCOTT KULICH, M.D., Ph.D.RAFAEL MEDINA-FLORES, M.D.

RONALD L. HAMILTON, M.D.Division of Neuropathology

Neural tube defectsNeural tube defects

AnencephalyAnencephaly

Failure of closure of the anterior neuroporeCommon malformationFrog-like faciesArea cerebrovasculosaUnderdeveloped hypothalamusAdrenal cortical hyperplasiaMultifactorial-Folic acid supplementation

AnencephalyAnencephaly

AnencephalyAnencephaly

SPINA BIFIDASPINA BIFIDA

myelomenigocele

occulta meningocele

SPINA BIFIDA SPINA BIFIDA

Sacral dimple: dermal sinus track with spina bifida

MYELOMENINGOCELEMYELOMENINGOCELE Herniation of

malformed cord + meninges through vertebral defect

Usually associated with Arnold-Chiari and hydrocephalus

Lumbosacral level most common

MyelomeningoceleMyelomeningocele

Chiari II (Arnold Chiari)Chiari II (Arnold Chiari) Cerebellar tonsillar

herniation Small posterior fossa Extension of medulla

below foramen magnum Kinking of medulla (Z-

formation) Beaking of the

quadrigeminal plate Hydrocephalus Myelomeningocele

Chiari II (Arnold-Chiari)Chiari II (Arnold-Chiari) Cerebellar tonsillar

herniation Small posterior fossa Extension of medulla

below foramen magnum Kinking of medulla (Z-

formation) Beaking of the

quadrigeminal plate Hydrocephalus Myelomeningocele

Arnold-Chiari (Chiari II)Arnold-Chiari (Chiari II)

Arnold-Chiari (Chiari II)Arnold-Chiari (Chiari II)

Arnold-Chiari (Chiari II)Arnold-Chiari (Chiari II)

Chiari I MalformationChiari I Malformation

Sagittal MRI (T1) shows cerebellar tonsils 2-3 cm below foramen magnum, where the CSF space is narrow. There is no syrinx in the cervical cord & the 4th ventricle is normal size & configuration.

Chiari I MalformationChiari I Malformation Chronic protrusion of

the cerebellar tonsils less than 1.5 cm below the foramen magnum

Most patients asymptomatic

Some develop hydrocephalus

Dandy-Walker MalformationDandy-Walker Malformation

Dandy-Walker syndrome– Agenesis of cerebellar vermis– cystic dilatation of 4th venticle– enlargement of posterior fossa– Variable clinical manifestations– Hypothesized to result from arrest of

cerebellar development prior to the 3rd month

DANDY-WALKER DANDY-WALKER SYNDROMESYNDROME

DANDY-WALKER DANDY-WALKER SYNDROMESYNDROME

CEREBELLAR MALFORMATIONS: CEREBELLAR MALFORMATIONS: VERMIAN (PALEOCEREBELLUM)VERMIAN (PALEOCEREBELLUM)

Joubert syndrome– Clinical manifestations include episodic

hyperpnea, ataxia, eye movement abnormalities, and MR

– Familial – Agenesis of vermis, cystic dilatation of 4th

venticle (but less than DWS)– Microscopically normal cerebellar cortex

with numerous subcortical heterotopias

HoloprosencephalyHoloprosencephaly Common

associations: TORCH infections, fetal alcohol syndrome, trisomy 13

Classification:– Alobar– Semilobar– Lobar– Arrinencephaly

HoloprosencephalyHoloprosencephaly Failure of the cerebral

hemispheres to separate “face predicts brain”: cyclopia, proboscis, agnathia, cleft lip/ palate, etc.

Most cases sporadic Common associations:

maternal diabetes

HoloprosencephalyHoloprosencephaly

Cyclopia and cebocephaly

HoloprosencephalyHoloprosencephaly Failure of the cerebral

hemispheres to separate “face predicts brain”: cyclopia, proboscis, agnathia, cleft lip/ palate, etc.

Most cases sporadic Common associations:

maternal diabetes

HoloprosencephalyHoloprosencephaly

HoloprosencephalyHoloprosencephaly

HoloprosencephalyHoloprosencephaly

EncephaloceleEncephalocele

-Herniation of brain through skull defect

-Usually occipital, occasionally anterior (frontal) at bridge of nose (“nasal glioma”).

-Asymmetric with overlying ulceration

AGENESIS OF CORPUS AGENESIS OF CORPUS CALLOSUMCALLOSUM May be total or partial – Partial usually affects posterior

(splenium) May be sporadic or syndromic

– Acardi (infantile spasms, MR, polymicrogyria)

– Andermann (sensorimotor neuropathy, dysmorphic features)

– Meckel-Gruber (occipital encephalocele, liver/kidney abnl)

May be clinically silent

AGENESIS OF CORPUS AGENESIS OF CORPUS CALLOSUMCALLOSUM

Abnormal cingulate gyrus with radiating gyral pattern

AGENESIS OF CORPUS AGENESIS OF CORPUS CALLOSUMCALLOSUM

Bat wing shaped lateral ventricles

Bundle of Probst

MICROENCEPHALMICROENCEPHALYY

MICROENCEPHALMICROENCEPHALYY

“Small brain” Primary

– with micro-cephaly (small head) Secondary

– may have normocephaly– Neurodegenerative diseases

» Ceroid lipofuscinosis (Batten’s disease)

MEGALENCEPHALYMEGALENCEPHALY Brain weight > 2.5 standard deviation

than mean Classification

– Primary: familial, achondroplasia, isolated– Secondary: leukodystrophies (Alexander’s),

neurocutaneous syndromes, errors of metabolism

May be associated with olivary heterotopia in autistic patients

1/3 with macroscopic and 1/3 with microscopic abnormalities

CORTICAL DYSPLASIACORTICAL DYSPLASIAPolymicrogyriaPolymicrogyria

CORTICAL CORTICAL DYSPLASIADYSPLASIA

POLYMICROGYRIA

TUBEROUS TUBEROUS SCLEROSISSCLEROSIS

TUBEROUS TUBEROUS SCLEROSISSCLEROSIS

Wide, flat, firm gyri

TUBEROUS TUBEROUS SCLEROSISSCLEROSIS

Candle gutterings

TUBEROUS TUBEROUS SCLEROSISSCLEROSIS

SEGA

Sturge-Weber DiseaseSturge-Weber Disease

Port-wine stain or nevusFlammeus tuypical of Sturge-Weber, occurring inV1 distribution.

Sturge Weber DiseaseSturge Weber Disease

CT: Calcification of gyrus in the parietooccipital region with focal cortical atrophy & ipsilateral enlargement of the choroid plexus.

Sturge-Weber DiseaseSturge-Weber Disease