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 Underdeveloped hypothalamus Adrenal cortical hyperplasia Multifactorial-Folic acid supplementation
Anencephaly
Anencephaly
SPINA BIFIDA
occulta meningocele
myelomenigocele
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
Myelomeningocele
Chiari II (Arnold Chiari)
Cerebellar tonsillar herniation Small posterior fossa Extension of medulla below foramen magnum Kinking of medulla (Zformation) 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 (Zformation) Beaking of the quadrigeminal plate Hydrocephalus Myelomeningocele
Arnold-Chiari (Chiari II)
Arnold-Chiari (Chiari II)
Arnold-Chiari (Chiari II)
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 4 th 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
DANDY-WALKER SYNDROME
DANDY-WALKER SYNDROME
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
Holoprosencephaly
Holoprosencephaly
Holoprosencephaly
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) abnl)
– Meckel-Gruber (occipital encephalocele, liver/kidney
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
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
CORTICAL DYSPLASIA
POLYMICROGYRIA
TUBEROUS SCLEROSIS
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.
Sturge-Weber Disease