A patient presents with bulging fontanelle, cranial nerve deficits, and nystagmus. What condition might they have?

The presentation of a bulging fontanelle, cranial nerve deficits, and nystagmus in a patient is indicative of increased intracranial pressure and possible brainstem involvement. Dandy Walker malformation is a congenital brain malformation characterized by the enlargement of the fourth ventricle, cyst formation in the posterior fossa, and agenesis or hypoplasia of the cerebellar vermis, which can lead to such neurological signs.

The bulging fontanelle suggests elevated intracranial pressure, which is a common feature in individuals with Dandy Walker malformation due to the associated cystic changes and potential obstruction of cerebrospinal fluid (CSF) flow. Cranial nerve deficits can also occur due to the anatomical disruptions and pressure on the brainstem and surrounding structures. Nystagmus is often seen with abnormalities in the cerebellum or brainstem, which can occur in Dandy Walker malformation due to its effects on cerebellar function.

Other options present different conditions that do not directly correlate with the triad of symptoms outlined. Myelomeningocele primarily involves defects in the spinal column and presents with neurological deficits lower in the body, rather than cranial nerve involvement. Chiari II malformation indeed