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Dandy–Walker syndrome (DWS)

Congenital brain malformation encompassing a continuum of disorders characterized by cystic posterior fossa anomalies.

On the sagittal T1 weighted image, there is absence of the inferior vermis with a large cystlike structure communicating between the cisterna magna and fourth ventricle. This is a case a Dandy-Walker malformation which is the most common posterior fossa malformation. Features include hypoplasia of the vermis with cephalic rotation of the vermian remnant, cystic dilatation of the fourth ventricle extending posteriorly, and an enlarged posterior cranial fossa with torcular lambdoid inversion. There are numerous associations in both the nonsyndromic and syndromic setting. Some of the CNS associations include cortical migration anomalies and dysgenesis of the corpus callosum. Non-CNS anomalies include cleft palate, low set ears, and cardiac anomalies. | Dandy-Walker Malformation—Neuro MR Case Studies—CTisus CT Scanning. (n.d.). CTisus. Retrieved November 7, 2021, from https://www.ctisus.com/redesign/teachingfiles/neuro-mr/359956

Congenital brain malformation encompassing a continuum of disorders characterized by cystic posterior fossa anomalies.

History:

DWS, also known as Dandy–Walker malformation or Dandy–Walker complex, was originally described by Sutton in 1887 in a case of hydrocephalus, posterior fossa cyst, and hypoplasia of the cerebellar vermis. This triad entity was then confirmed by Dandy and Blankfan in 1914. In 1942, Taggart and Walker reported three cases of congenital atresia of foramina of Luschka and Magendie. They proposed a hypothesis that this condition may be due to damage of the fourth ventricle and cerebellar vermis hypoplasia during embryonic development. The nomenclature “Dandy–Walker syndrome” was first introduced by Benda in 1954. Currently, DWS is considered to be the result of maldevelopment in the region of the fourth ventricle, but is not limited to foraminal atresia.

Etiology

Associated conditions:

  • Hydrocephalus
  • Spina bifida
  • Genetic ciliopathies:
    • Primary ciliary dyskinesia
    • Bardet-Biedl syndrome
    • Polycystic kidney
    • Liver disease
    • Nephronophthisis
    • Alstrom syndrome
    • Meckel-Gruber syndrome
    • Some forms of retinal degeneration

Pathoanatomy

Classic anatomic hallmarks:

Partial/complete congenital failure to develop the cerebellar vermis which blocks the CSF circulation
  • Hypoplasia of cerebellar vermis
  • Anterior-posterior enlargement of the posterior fossa
  • Upward displacement of the torcula and transverse sinuses
  • Cystic dilatation of the fourth ventricle
Schematic view of the brain's interior of the child with Dandy-Walker syndrome
Schematic view of the brain’s interior of the child with Dandy-Walker syndrome | Study of Genetics Mutations ZIC1, ZIC2 and ZIC4 Genes in Dandy-Walker Syndrome Human – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/Schematic-view-of-the-brains-interior-of-the-child-with-Dandy-Walker-syndrome_fig1_324030185 [accessed 22 May, 2018]

Presentation

The clinical manifestations of DWS are non-specific, and are related to cerebellar structural defects and intracranial hypertension caused by hydrocephalus and an enlarged posterior fossa cyst.

Congenital hydrocephalus:

  • Bulging fontanelle
  • Persistent downward gaze (“sun-setting” eyes)
  • Macrocephaly (manifesting as rapidly increasing head circumference)
  • Irritability, vomiting, poor feeding, seizures, and lethargy

Cerebellar defects:

  • Motor deficits: Delayed motor development, hypotonia, and ataxia
  • Mental retardation (50% cases)

Rare features:

  • Diplopia, myasthenia gravis, sensorineural deafness, and neurocutaneous melanosis.
Child with Dandy-Walker syndrome
Child with Dandy-Walker syndrome with severe hydrocephalus | Study of Genetics Mutations ZIC1, ZIC2 and ZIC4 Genes in Dandy-Walker Syndrome Human – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/Child-with-Dandy-Walker-syndrome-with-severe-hydrocephalus-Materials-and-Methods_fig3_324030185 [accessed 22 May, 2018]

Diagnosis

MRI:

First choice of investigation
  • Dilated fourth ventricle or huge posterior fossa cyst communicating with the fourth ventricle, and the cyst showing isointensity to cerebrospinal fluid
  • Cerebellar hypoplasia or/and absence of the cerebellar vermis
  • Enlargement of the posterior fossa with upward displacement of the lateral sinuses, sinus confluents, and tentorium
  • Supratentorial hydrocephalus
  • Agenesis of corpus callosum
  • Other intracranial malformations.
MRI image of the person with Dandy-Walker syndrome (DWM)
MRI radiologic image of the person with Dandy-Walker syndrome (DWM) compared with those with cerebellar viremia hypoplasia (CVH) and cerebellar mega cysterma (MCM). | Study of Genetics Mutations ZIC1, ZIC2 and ZIC4 Genes in Dandy-Walker Syndrome Human – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/MRI-radiologic-image-of-the-person-with-Dandy-Walker-syndrome-DWM-compared-with-those_fig13_324030185 [accessed 22 May, 2018]

Management

Surgical management:

Mainstay of treatment of DWS.
  • Cystoperitoneal shunting
  • Ventriculoperitoneal shunting

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