What neurological feature is characteristic of Sturge-Weber syndrome?

Sturge-Weber syndrome is characterized by the presence of leptomeningeal angiomas, which are abnormal blood vessel formations located on the surface of the brain's protective membranes. This key feature is linked to the neurological manifestations seen in individuals with the syndrome. The presence of these angiomas can lead to a variety of neurological issues, such as seizures, cognitive impairment, and hemiparesis.

The other options, while they can be associated with other neurological conditions, are not defining features of Sturge-Weber syndrome. For instance, agenesis of the corpus callosum and hydrocephalus are more commonly associated with other congenital brain malformations. Spastic paraplegia may occur in various neurological disorders but is not specific to Sturge-Weber syndrome. Therefore, the identification of leptomeningeal angioma is crucial in diagnosing and understanding the implications of Sturge-Weber syndrome.