Dandy-Walker Malformation

Excerpt

Dandy-Walker malformation (DWM) or syndrome is a posterior fossa anomaly characterized by:

1. Agenesis or hypoplasia of the vermis

2. Cystic enlargement of the fourth ventricle with communication to a large cystic dilated posterior fossa

3. Upward displacement of tentorium and torcula (torcular-lambdoid inversion)

4. Enlargement of the posterior fossa

The first description of DWM dates back to 1887 by Sutton. Dandy and Blackfan described this deformity in 1914, and Taggart and Walker expanded on it in 1942. Bender first described the condition as DWM in 1954.

The "Dandy-Walker complex" and "Dandy-Walker spectrum" are 2 of the most often used radiological entities proposed by Barkovich et al. in 1989. Most patients have hydrocephalus at the time of diagnosis. DWM is the most common posterior fossa malformation, and it typically occurs sporadically.

Keeping the development of cerebellar vermis as the standard, the Dandy-Walker spectrum can be divided into:

1. Dandy-Walker malformation

2. Dandy-Walker variant

3. Simple posterior fossa cistern widening

Dandy-Walker variant is characterized by cerebellar vermian hypoplasia, cystic fourth ventricular dilatation, and normal posterior fossa volume. This terminology is currently going out of favor as it generates a lot of confusion. Rather, individual physical abnormalities should be mentioned.

Many patients remain clinically asymptomatic for years, while others may present with a variety of comorbidities leading to earlier diagnosis. Treatment is generally focused on alleviating hydrocephalus and posterior fossa symptoms, often including surgical interventions like ventriculoperitoneal and cystoperitoneal shunting.