central nervous system malformations · karim d. kalache department of obstetrics & gynecology...
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Karim D. Kalache Department of Obstetrics & Gynecology Sidra Medical and Research Center – Doha, Qatar
Central Nervous System Malformations
• Head shape• Cerebellum• Cisterna magna
• Lateral ventricles• Thalami• Cavum septi pellucidi
Ultrasound Obstet Gynecol 2010
© 2003 by the American Institute of Ultrasound in Medicine
Head•Cerebellum •Cisterna magna •Lateral cerebral ventricles•Choroid plexus •Midline falx •Cavum septi pellucidi
5
a
b
c
VentricleThalami
Cerebellum
Basic US Examination of the Fetal Brain at 19-22 Weeks
Diagnostic Imaging in Obstetrics. Woodward (2006)
Lateral Ventricle
Cerebellum
8
+
+Yes
+
+no
+
+
no
Ultrasound Obstet Gynecol 2007; 29: 109–116
Lateral Ventricle Measurement
90°
Definition LVW (mm)Borderline 10-12Ventriculomegaly ≥12, ≤15Hydrocephaly > 15
• Targeted Ultrasound • TORCH • Amniocentesis • MRI?
"isolated"
Corpus callosumFetal Neurosonographie Vermis cerebelli
Site of the soul (18th century)
Prevents the cerebral hemispheres from collapsing onto each other (20th century)
Transfer of information between the two hemispheres (1950‘s)
Corpus callosum
Agenesis of the Corpus Callosum
Diagnostic Imaging in Obstetrics. Woodward (2006)
Lateral Displacement
Formation achieved by 17 weeks
genu
splenium
rostrum
Lateral Displacement
Absent CSP
Colpocephaly
Dilated 3rd V
Dysgenesis
Spectrum of Abnormalities
Complete agenesis
Partial agenesis
Atypical (HPZ)
Autosomal recessive
• Corpus callosum agenesis
• Cranial abnormalities
• Post-axial polydactyly, syndactyly
• Mental retardation
Acrocallosal Syndrom
Fernandez et al. Acta Neuropathol (2008) 115:151–156
Bromley et al. Prenat Diagn 2000
X-linked dominant (Only affects female)
• Corpus callosum agenesis, microcephaly, Polymicrogyria; Intracranial calcifications
• Vertebral anomalies
• Infantile spasm
Sanchis et al. The Journal of Pediatrics 2005
Aicardi Syndrom
Agenesis of the Corpus Callosum
• To define in which percentage ACC indirect signs are already present < 24 weeks.
• N= 44 cases: 31 cases of cACC and 23 cases of pACC
• Atrial width (>9.9 mm) / Colpocephaly / Absent CSP
• pACC may not show any abnormality of the transventricular screening view < 24 gestational weeks in 43.5% of cases
Blake’s pouch within the developing cisterna magna
Mega cisterna magna Persistent Blake’s Pouch
Spinal Dysraphism
- Myelomeningocele - Myelocele
- Subcutaneous mass?
Closed
Yes No
- Meningocele - Lipomyelomeningocele - Lipomyelocele - Myelocystocele
Simple - Lipoma - Tethered cord
Complexe - Spilt cord - Caudal regression - Neurenteric cyst
Open
No
Rufener S L et al. AJR 2010;194:S26-S37
Myelomeningocele Myelocele
Rufener et al. 2010
Bulas 2010
Dandy Walker Malformation
Diagnostic Imaging in Obstetrics. Woodward (2006)
(1) Abnormally high tentorium
(3) Vermian agenesis(complete or partial)
(2) Cystic dilatation of the posterior fossa communicating with the 4th ventricle
Cerebellar Vermian Craniocaudal Diameter
Robinson et al. Ultrasound Quarterly 2007;23:211-223
< 40°
Tegmentum-Vermis-Angle
Robinson et al. Ultrasound Quarterly 2007;23:211-223
Pons
Medulla oblongata
4th ventricle
Quadrigeminal plate
MesencephalonVermis
Tentorium
Vermis/Pons ratio
Prenat Diagn 2010; 30: 739–745.
30°
Pontocerebellar Hypoplasia
• Autosomal recessive• Abnormal growth and function of the brainstem and cerebellum
• PCH2 –Respiratory and feeding difficulties–Severe developmental impairment–Progressive microcephaly–Frequent death in childhood
Gupta et al. 2002
Cortical Brain Layer Formation
Proliferation • Too high (Hemimegalencephaly) • Too low (Microcephaly)
Neuronal migration • Reduced (Classical lissencephaly (Type I) • Accentuated (Cobble stone lissencephaly
(Type II)
• Ectopic (Subependymal heterotopia)
Organization • Polymicrogyria / Schizencephaly
Barkovich et al. 2005
Subependymal Heterotopia
