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CNS Malformations. SCOTT KULICH, M.D., Ph.D. RAFAEL MEDINA-FLORES, M.D. RONALD L. HAMILTON, M.D. Division of Neuropathology. Neural tube defects. Anencephaly. Failure of closure of the anterior neuropore Common malformation Frog-like facies Area cerebrovasculosa
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CNS Malformations SCOTT KULICH, M.D., Ph.D. RAFAEL MEDINA-FLORES, M.D. RONALD L. HAMILTON, M.D. Division of Neuropathology
Anencephaly Failure of closure of the anterior neuropore Common malformation Frog-like facies Area cerebrovasculosa Underdeveloped hypothalamus Adrenal cortical hyperplasia Multifactorial-Folic acid supplementation
SPINA BIFIDA • myelomenigocele occulta meningocele
SPINA BIFIDA • Sacral dimple: dermal sinus track with spina bifida
MYELOMENINGOCELE • Herniation of malformed cord + meninges through vertebral defect • Usually associated with Arnold-Chiari and hydrocephalus • Lumbosacral level most common
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) • 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 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 Malformation • Chronic protrusion of the cerebellar tonsils less than 1.5 cm below the foramen magnum • Most patients asymptomatic • Some develop hydrocephalus
Dandy-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
CEREBELLAR MALFORMATIONS: 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
Holoprosencephaly • Common associations: TORCH infections, fetal alcohol syndrome, trisomy 13 • Classification: • Alobar • Semilobar • Lobar • Arrinencephaly
Holoprosencephaly • Failure of the cerebral hemispheres to separate “face predicts brain”: cyclopia, proboscis, agnathia, cleft lip/ palate, etc. • Most cases sporadic • Common associations: maternal diabetes
Holoprosencephaly • Cyclopia and cebocephaly
Holoprosencephaly • Failure of the cerebral hemispheres to separate “face predicts brain”: cyclopia, proboscis, agnathia, cleft lip/ palate, etc. • Most cases sporadic • Common associations: maternal diabetes
Encephalocele -Herniation of brain through skull defect -Usually occipital, occasionally anterior (frontal) at bridge of nose (“nasal glioma”). -Asymmetric with overlying ulceration
AGENESIS OF CORPUS CALLOSUM • 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 CALLOSUM • Abnormal cingulate gyrus with radiating gyral pattern
AGENESIS OF CORPUS CALLOSUM • Bat wing shaped lateral ventricles • Bundle of Probst
MICROENCEPHALY • “Small brain” • Primary • with micro-cephaly (small head) • Secondary • may have normocephaly • Neurodegenerative diseases • Ceroid lipofuscinosis (Batten’s disease)
MEGALENCEPHALY • 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 DYSPLASIA POLYMICROGYRIA
TUBEROUS SCLEROSIS Wide, flat, firm gyri
TUBEROUS SCLEROSIS Candle gutterings
TUBEROUS SCLEROSIS SEGA
Sturge-Weber Disease Port-wine stain or nevus Flammeus tuypical of Sturge-Weber, occurring in V1 distribution.
Sturge Weber Disease CT: Calcification of gyrus in the parietooccipital region with focal cortical atrophy & ipsilateral enlargement of the choroid plexus.