Dandy-Walker syndrome, also known as Dandy-Walker anomaly or Dandy-Walker malformation, presents with a series of abnormalities in the posterior cranial fossa, including the fourth ventricle, the medullary pool of the cerebellum, and the cerebellar earthworm, with some patients having dilated lateral ventricles and about 1/3 having hydrocephalus. Clinical symptoms and signs: The classic Dandy-Walker malformation mainly presents with hydrocephalus, increased cranial pressure, cerebellar ataxia, neurological palsy, mental retardation, inability to hold the head erect, difficulty sitting and standing, spastic paralysis, seizures, and in severe cases, a spastic state, positive bilateral pathological signs, and death due to compression of the medulla oblongata respiratory center, which may also lead to respiratory failure. Variant and enlarged cerebellar medullary pools with indeterminate clinical manifestations. Typology Fourth ventricle cerebellar medullary pool cerebellar earthworms Lateral ventricle dilatation Classic Dandy-Walker dilatation Dilatation Complete or partial absence Mostly present Variant Dandy-Walker normal Dilatation Lower earthworm absence May be present Cerebellar medullary pool dilatation Normal Dilatation Normal Mostly absent Diagnosis: 1. Fourth ventricle dilatation; 2. Cerebellar earthworm absence; 3. Cerebellar medullary pool dilatation; 4. Lateral ventricle Dilatation; 5. Combined anomalies: 50%-70% of patients with Dandy-Walker anomalies are combined with other anomalies, commonly: dilated lateral ventricles, agenesis of the corpus callosum, total forebrain, cerebral bulge, polycystic kidney, cleft lip and palate, cardiac malformation, etc. Treatment: The disease needs to be treated surgically, and the following surgical methods are currently available: 1) simple cystectomy for patients without ventriculocephalus; 2) shunts, including lateral ventricular shunts or cystic shunts; 3) double shunts for lateral ventricles and cysts, and about 16% to 92% of patients need to undergo such surgical treatment. Many authors believe that early recurrence is easy after simple cyst removal; simple lateral ventricular cerebrospinal fluid shunt cannot effectively reduce the pressure in the posterior cranial fossa, and supratentorial herniation may also occur; while dual lateral ventricular, cyst-abdominal shunt allows simultaneous decompression of posterior cranial fossa cyst and lateral ventricle, and is the preferred surgical method for Dandy-Walker malformation.