CNS Malformations

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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

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Neural tube defects
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Anencephaly
Failure of closure of the anterior
neuropore Common malformation Frog-like
facies Area cerebrovasculosa Underdeveloped
hypothalamus Adrenal cortical hyperplasia Multifac
torial-Folic acid supplementation
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Anencephaly
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Anencephaly
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SPINA BIFIDA
occulta
meningocele

• myelomenigocele

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SPINA BIFIDA

• Sacral dimple dermal sinus track with spina
  bifida

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MYELOMENINGOCELE

• Herniation of malformed cord meninges through
  vertebral defect
• Usually associated with Arnold-Chiari and
  hydrocephalus
• Lumbosacral level most common

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Myelomeningocele
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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

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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

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

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Chiari I Malformation

• Chronic protrusion of the cerebellar tonsils less
  than 1.5 cm below the foramen magnum
• Most patients asymptomatic
• Some develop hydrocephalus

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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

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DANDY-WALKER SYNDROME
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DANDY-WALKER SYNDROME
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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

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Holoprosencephaly

• Common associations TORCH infections, fetal
  alcohol syndrome, trisomy 13
• Classification
• Alobar
• Semilobar
• Lobar
• Arrinencephaly

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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

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Holoprosencephaly

• Cyclopia and cebocephaly

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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

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Holoprosencephaly
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Holoprosencephaly
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Holoprosencephaly
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Encephalocele
-Herniation of brain through skull
defect -Usually occipital, occasionally anterior
(frontal) at bridge of nose (nasal
glioma). -Asymmetric with overlying ulceration
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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

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AGENESIS OF CORPUS CALLOSUM

• Abnormal cingulate gyrus with radiating gyral
  pattern

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AGENESIS OF CORPUS CALLOSUM

• Bat wing shaped lateral ventricles
• Bundle of Probst

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MICROENCEPHALY
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MICROENCEPHALY

• Small brain
• Primary
• with micro-cephaly (small head)
• Secondary
• may have normocephaly
• Neurodegenerative diseases
• Ceroid lipofuscinosis (Battens disease)

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MEGALENCEPHALY

• Brain weight gt 2.5 standard deviation than mean
• Classification
• Primary familial, achondroplasia, isolated
• Secondary leukodystrophies (Alexanders),
  neurocutaneous syndromes, errors of metabolism
• May be associated with olivary heterotopia in
  autistic patients
• 1/3 with macroscopic and 1/3 with microscopic
  abnormalities

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CORTICAL DYSPLASIAPolymicrogyria
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CORTICAL DYSPLASIA
POLYMICROGYRIA
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TUBEROUS SCLEROSIS
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TUBEROUS SCLEROSIS
Wide, flat, firm gyri
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TUBEROUS SCLEROSIS
Candle gutterings
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TUBEROUS SCLEROSIS
SEGA
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Sturge-Weber Disease

• Port-wine stain or nevus
• Flammeus tuypical of
• Sturge-Weber, occurring in
• V1 distribution.

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Sturge Weber Disease

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

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Sturge-Weber Disease