Postnatal Intracranial Findings Following Fetal Repair of Spinal Dysraphisms
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Published on: February 29, 2020
Susana Calle1, Eliana Bonfante1, Garrett Simmons1
1From the Division of Neuroradiology, Department of Diagnostic and Interventional Imaging.
Insights
Postnatal MRI after fetal repair for spinal dysraphisms shows common persistent Chiari II features. Many infants had resolution of tonsillar ectopia, but posterior fossa abnormalities remained frequent.
Area of Science:
- Neuroimaging
- Pediatric Neurosurgery
- Developmental Biology
Background:
- Spinal dysraphisms are congenital conditions affecting the spine and spinal cord.
- Fetal repair aims to mitigate neurological damage.
- Chiari II malformation is a common associated anomaly.
Purpose of the Study:
- To document the intracranial imaging findings on early postnatal MRI in infants who underwent fetal repair for spinal dysraphisms.
- To correlate these findings with Chiari II malformation features.
Main Methods:
- Retrospective analysis of 29 infants.
- Review of fetal and postnatal MRI scans.
- Evaluation for specific Chiari II malformation imaging features.
Main Results:
- 55% of infants showed resolution of tonsillar ectopia.
- 62% had a dorsal outpouching near the foramen magnum.
- Persistent Chiari II features included prominent massa intermedia (93%), tectal beaking (93%), towering cerebellum (55%), flattened fourth ventricle (90%), hypoplastic tentorium (97%), and tonsillar hypoplasia (59%).
Conclusions:
- The most common presentation was normally positioned or minimally descended, often hypoplastic tonsils with a Chiari II posterior fossa configuration.
- A dorsal thecal sac outpouching was also frequently observed.
Objective:
Our objective is to document the imaging appearance in the intracranial compartment at the time of the infants' first postnatal brain MR imaging after fetal repair for spinal dysraphisms.
Methods:
Twenty-nine patients were evaluated on fetal and postnatal magnetic resonance imaging for a series of features of Chiari II malformation.
Results:
Of the 29 infants, 55% had resolution of tonsillar ectopia, and 62% showed a dorsal outpouching of the near the foramen magnum on postnatal magnetic resonance imaging. The majority had persistence of Chiari II features including: prominent massa intermedia (93%), tectal beaking (93%), towering cerebellum (55%), flattening of the fourth ventricle (90%), hypoplastic tentorium (97%), and tonsillar hypoplasia (59%).
Conclusions:
Normally positioned or minimally descended, oftentimes hypoplastic tonsils in the presence of a posterior fossa configuration typical of Chiari II, was the most common presentation. An additional documented feature was an outpouching of the dorsal thecal sac between the opisthion and the posterior arch of C1.
