CC BY 4.0 · Arq Neuropsiquiatr 2024; 82(S 02): S53-S176
DOI: 10.1055/s-0045-1807134
ID: 760
Area: Malformations of the central nervous system
Presentation method: Eletronic Poster

Clinical and neuroimaging features of congenital cystic malformations of the posterior fossa: an illustrated guide

Wallyson Pablo de Oliveira Souza
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
,
Ingrid Brandão Cardoso Paz
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
,
Ayana Saraiva Brito Vitorino de Oliveira
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
,
Nara Lívia Rezende Soares da Paz Oliveira
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
,
Marcelo de Melo Aragão
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
,
Giuliano da Paz Oliveira
1   Centro Universitário UNINOVAFAPI, Teresina PI, Brazil.
2   Universidade Federal de São Paulo, São Paulo SP, Brazil.
3   Universidade Federal do Delta do Parnaíba, Parnaíba PI, Brazil.
› Author Affiliations
 

    *Correspondence: wallyson.pablo@ufpi.edu.br.

    Abstract

    Background: Congenital abnormalities of the posterior fossa, whose diagnosis can be made in the pre- and postnatal periods, represent a spectrum of morphological malformations that occur during embryonic development. Its pathophysiology is related to disorders involving the main components of this brain region, such as the pons, the medulla oblongata, the fourth ventricle, and the cerebellum.

    Objective: To describe the clinical and neuroimaging features of congenital cystic malformations of the posterior fossa through an illustrated guide.

    Methods: To compose the illustrated guide, self-authored drawings were produced. Moreover, using our personal archive, we added neuroimaging exams of children affected by the aforementioned conditions.

    Results: Congenital cystic anomalies of the posterior fossa include Dandy-Walker malformation (DWM), Blake’s pouch cyst (BPC), mega cisterna magna (MCM), arachnoid cyst (AC), and cerebellar vermis hypoplasia (CVH). DWM presents signs and symptoms of increased intracranial pressure. Typical neuroimaging features are a hypoplastic, elevated and rotated vermis, cystic dilatation of the fourth ventricle, and widening of the posterior fossa. BPC can manifest macrocephaly, hydrocephalus, ataxia, seizures, and dizziness. Its radiological findings include presence of a retro or infra cerebellar cyst due to dilation of the fourth ventricle. Most children with isolated MCM are asymptomatic. Radiologically, the cisterna magna and the posterior fossa are enlarged, but the vermis is intact. AC is usually asymptomatic, but it may also present with headache and increased intracranial pressure. On imaging, the cyst frequently presents ovoid with isointense content relative to cerebrospinal fluid. CVH leads to a milder clinical picture, for instance, a mild cognitive impairment. The radiological pattern is partial hypoplasia of the inferior vermis without other notable changes.

    Conclusion: Thus, through an illustrated guide, we summarize the clinical and neuroimaging aspects of cystic congenital malformations of the posterior fossa in order to provide a didactic guide for neurologists and child neurologists.


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    Publication History

    Article published online:
    12 May 2025

    © 2024. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution 4.0 International License, permitting copying and reproduction so long as the original work is given appropriate credit (https://creativecommons.org/licenses/by/4.0/)

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