DANDY WALKER SYNDROME ( DWS )

What is Dandy Walker Syndrome?

Dandy Walker syndrome ( DWS ) represents a congenital malformation characterized by agenesis or hypoplasia of the cerebellar vermis, cystic dilation of the fourth ventricle, and enlargement of the posterior fossa with or without hydrocephalus.

Who first described this condition?

First autopsy descrpition  in 1887 by Sutton.

First to realize an association between hydrocephalus and cystic fourth ventricular dilation were Dandy & Blackfan in 1914

Dandy in 1921 & Taggart & Walker in 1942 related it to congenital atresia of the fourth ventricular exit foramina.

Benda in 1954 first used the term DWS.

Studies by D'Agostino in 1963 and Hart et al in 1972 further defined the characteristic triad of Dandy-Walker malformation, as follows:

• Complete or partial agenesis of the vermis
• Cystic dilatation of the fourth ventricle
• An enlarged posterior fossa with upward displacement of lateral sinuses, tentorium, and torcular herophili.

What is the etiopathogenesis?

Cerebellum development  begins in the 9^th week of gestation when the genesis of the cerebellar hemispheres occurs from the rhombic lips. Subsequently , the hemispheres fuse to form the rhombic lips . Subsequently, the cerebellar  hemispheres fuse to form vermis. The abnormal development at this stage may lead to non regression of posterior medullary velum, absence of vermis, failure of development of foramen of Magendie.

What are the clinical features?

DWS occurs in 1 in 30,000 newborns with the highest incidence in infants. The presentation may me delayed . Usually presents with macrocrania, delayed milestones. It is one of the differential diagnosis of pediatric hydrocephalus.

What are the radiological features?

Elevated torcular Herophili  on Plain radiography ( Bucy’s sign)

Featal ultrasound, or post natal ultrasound or MRI or CT scan

Enlarged fourth ventricle and posterior fossa, elevated location of the transverse venous sinuses and their confluence.

Absence of cerebellar vermis and hypoplasia of the cerebellar hemispheres.

 

What is the treatment?

Diversion of CSF through shunting. Options include (1) shunting the supratentorial compartment(ventriculoperitoneal shunt) , (2) shunting the cerebellar cyst ( Cysto peritoneal shunt) ,or (3) shunting both compartments.

 

Sources:
Chapter DWS, Authors; Ondrej Choutka & Francesco T.Mangano.  Youman’s Neurological Surgery, H.Richard Winn,  6^th Edition( Elsevier Saunders)
Wikipedia
Medscape reference