The prognosis is first and foremost dependent on the early and successful treatment of hydrocephalus, if present. The other significant factor affecting prognosis is the presence of a comorbid genetic condition or brain anomaly. Mortality rates from DWM are roughly 15%. In a study of<unk><unk><unk>  variant (DWV), a mortality rate of 12.5% was observed. The most common cause of death is complications from hydrocephalus or its treatment. Untreated hydrocephalus can lead to increased intracranial pressure and brain damage. Shunts used to treat DWM have a moderate-to-good success rate, but they have a higher-than-average failure rate, which can result in failure to reduce the intracranial pressure or infection, such as meningitis. Complications from overdrainage such as subdural haematomas are also possible and can lead to mortality. Shunts in the fourth ventricle (cystoperitoneal shunts, or CP shunts) have a generally high rate of successful cyst and ventricle size reduction, especially in the cyst (at least 80%). With a shunt in the lateral ventricles (ventriculoperitoneal shunt, or VP shunt), studies have generally found a roughly 50% successful cyst size reduction rate, with successful ventricle size reduction roughly two thirds of the time. Other systemic or genetic conditions are often present with DWM, and each have their own significant effect on prognosis.
Dandy–Walker malformation
Glial tumor
Subdural hygroma
Schizencephaly
Chiari malformation
Hemimegalencephaly
Subependymoma
Hydranencephaly