What is the typical presentation of a patient with Chiari II malformation?

Chiari II malformation, also known as Arnold-Chiari malformation, is characterized by the herniation of cerebellar tissue through the foramen magnum and is often associated with spinal cord abnormalities and hydrocephalus. The typical presentation in affected patients includes an array of neurological symptoms resulting from these structural anomalies.

Hydrocephalus occurs due to obstruction of cerebrospinal fluid flow, leading to increased intracranial pressure. Such hydrocephalus can cause an array of symptoms including headaches, vomiting, and developmental delays in children. Spinal cord abnormalities, particularly related to the tethering of the spinal cord, can lead to neurological deficits and motor issues.

In contrast, while absent gag reflex, severe headaches, ataxia, and loss of consciousness may be related to various neurological disorders, they are not the hallmark features of Chiari II malformation. The unique combination of hydrocephalus and structural changes in the spinal cord effectively distinguishes this malformation from other conditions. Thus, identifying hydrocephalus and spinal abnormalities is crucial for diagnosing Chiari II malformation.