The document discusses fetal cortical development disorders, with an emphasis on microcephaly. It describes how the cerebral cortex develops in an orderly process involving neuronal and glial proliferation, migration from the periventricular zone, and organization. Injuries during this process can result in a wide range of cortical malformations that may cause neurological deficits or seizures. Specific disorders discussed include microcephaly from abnormal proliferation, macrocephaly, hemimegalencephalia from overgrowth of one hemisphere, lissencephaly from abnormal migration, and heterotopias from abnormal organization. The signatures of these disorders are described along with their typical clinical presentations and prognosis.

1. MASTERCLASS: NEUROLOGÍA FETAL
TRANSTORNOS DE DESARROLLO CORTICAL
*ENFASIS EN MICROCEFALIA
ADELITA HÍJAR SIFUENTES
GINECÓLOGA – OBSTETRA
FELLOW MEDICINA MATERNO FETAL
ULTRASONIDO EN GINECO OBSTETRICIA Y DIAGNÓSTICO PRENATAL DE III NIVEL
(Clínica Universitaria Colombia – Fundación Universitaria Dexeus)
NEUROSONOGRAFÍA FETAL – NEUROLOGÍA FETAL
(Maternal Fetal Medicine Group)
ECOCARDIOGRAFÍA FETAL
(Clínica Universitaria Colombia – Fundación Clinic de Barcelona)
SERVICIO DE MEDICINA FETAL HONADOMANI SAN BARTOLOMÉ
CLÍNICA SAN FELIPE
OCTUBRE 2016

2. TRANSTORNOS DEL DESARROLLO CORTICAL
• El desarrollo de la corteza cerebral fetal y la formación de giros y
sulcos es un proceso ordenado que se superpone con hitos bien
definidos.
• Este proceso incluye:
• Proliferación de neuronas y células gliales
• Migración desde la zona periventricular
• Organización de neuronas

3. TRANSTORNOS DEL DESARROLLO CORTICAL
• Injurias durante este proceso produce un amplio rango de
malformaciones corticales que podrían devenir en déficit neurológico
y/o convulsiones.
• Las malformaciones del desarrollo cortical podrían ser debido a:
• Factores genéticos
• Lesiones prenatales
• Trauma
• Infecciones
• Teratógenos

5. • The cerebral cortex is a modular structure: modules of neurons are
induced in a neuroepithelial sheet and subsequently differentiate,
migrate and organize into a functioning cerebral cortex.
• Neuronal induction is regulated by interplay between intrinsic genetic
mechanisms and extrinsic information relayed to cortex by
thalamocortical input and other, largely unknown, factors.
• Although details of the neural cell proliferation differ among
mammalian species.

6. HISTOLOGÍA: CORTEZA CEREBRAL FETAL

9. Group I: malformations secondary to abnormal neuronal and glial proliferation or
apoptosis
• Groups I.A and III.D: microcephaly
• Group I.B: megalencephalies
• Group I.C: cortical dysgeneses with abnormal cell proliferation
Group II: malformations due to abnormal neuronal migration
A. Lissencephaly/subcortical band heterotopia.
B. Cobblestone complex/ congenital muscular dystrophy syndromes.
C. Heterotopia: subependymal, subcortical, marginal.
Group III: malformations secondary to abnormal postmigrational development
A. Polymicrogyria and schizencephaly.
B. Cortical dysplasia without balloon cells.
C. Microdysgenesis.

10. SIGNOS ECOGRÁFICOS DE MDC

11. TRANSTORNOS DE PROLIFERACIÓN: MICROCEFALIA
• Antenatally is even more difficult, because affected fetuses have usually
normal cranial measurements in early gestation, that only decline in late
gestation or after birth.
• The incidence is estimated to be 1.6 per 1000 singlebirth deliveries. Only
14 % of all microcephalic infants diagnosed by the first year of age had
been detected at birth.
• The available literature suggests that the risk of mental retardation with an
head circumference between – 2 and – 3 SDs is in the range of 10-30%,
rising to 50-60% for measurements below – 3 SDs.

12. abnormal
neurologic
development
small head
MICROCEPHALY

14. G.MALINGER G.MALINGER

15. G.PILU

16. Daniel-Spiegel et al—Establishment of Fetal Biometric
Charts Using Quantile Regression Analysis. J Ultrasound
Med 2013; 32:23–33 | 0278-4297

18. 24ss

19. TRANSTORNOS DE PROLIFERACIÓN: MACROCEFALIA
• Head circumference above the 98th percentile or more than 2
standard deviations above the mean.
• Macrocephaly is relatively frequent in children and adults and is a
common cause for genetic consultation.
• The diagnosis assumes that other obvious causes of head
enlargement, such as hydrocephalus and cerebral tumors, have been
excluded. Usually, macrocephaly is familial and benign and frequently
it manifests only late in pregnancy or after delivery.

20. TRANSTORNOS DE PROLIFERACIÓN: MACROCEFALIA

21. 28ss

23. TRANSTORNOS DE PROLIFERACIÓN:
HEMIMEGALENCEFALIA
• Sobrecrecimiento de un hemisferio cerebral
Aislado (50%) o asociado a síndromes neurocutáneos.
• Clínica:
Convulsiones
Hemiparesia
Retraso mental
Hemihipertrofia en resto del cuerpo

24. Unilateral hypertrophy of the affected hemisphere, often associated with ipsilateral
ventricular dilatation and midline shift.
May be hemihypertrophy of the cerebellum, brainstem and body.
Thought to occur as a result of an insult to the germinal matrix between 8 and 16
post menstrual weeks of gestation.
May find focal increased echogenicity of the affected hemisphere.
No abnormal karyotypic abnormality has been described.

26. TRANSTORNOS DE MIGRACIÓN

27. TRASNTORNOS DE
MIGRACIÓN:
LISENCEFALIA
Lissencephaly, type I is characterized by agyria with or without pachygyria, a
wide cortical mantle and minimal or no hydrocephalus. Four layer cortex.
· Miller-Dieker syndrome (17p13 deletion) has lissencephaly combined
with dysmorphic facial features and other possible associated anomalies.
· Norman-Roberts syndrome
· Isolated type I lissencephaly
Lissencephaly, type II. Vascular bundles and fibroglial tissue are present in
the cortex and subarachnoid space. Lissencephaly, type II typically has
hydrocephalus and additional serious central nervous system defects. It is
usually part of a syndrome.
· HARD+/-E syndrome, an acronym for Hydrocephalus, Agyri, Retinal
dysplasia, Encephalocele (Walker-Warburg syndrome)
· COMS (Cerebro-oculomuscular syndrome)
· Other subtypes of type II lissencephaly are possible
Lissencephaly is found in Neu-Laxova syndrome, lethal autosomal
recessively inherited disorder consisting of growth retardation,
microcephaly, lissencephaly, corpus callosum agenesis, intracranial
calcifications, cerebellar hypoplasia, facial dysmorphism, microophthalmia,
exophthalmus, cataracts, absent eyelids, hydrops, ichthyosis, contractures of
extremities and syndactyly.

28. 27
ss
• Malformación severa de corteza cerebral,
que resulta de falla en migración neuronal
durante el 3° y 4° mes de gestación.
• Clínica:
Retraso psicomotor severo
Retraso del desarrollo
Convulsiones
Retraso en crecimiento
• Este defecto acarrea un mal pronóstico del
RN, con RM y alta tasa de recurrencia, si está
ligado a defectos genéticos.

30. TRANSTORNOS DE MIGRACIÓN: HETEROTOPIA
(CORTICAL – PERIVENTRICULAR)

31. TRANSTORNOS DE ORGANIZACIÓN

33. 27ss

34. 26ss

35. adelita.h.s@gmail.com
987700681