What condition is suspected in a patient with port wine stain following trigeminal nerve involvement, seizures, and an ocular defect?

The condition suspected in a patient exhibiting a port wine stain associated with trigeminal nerve involvement, seizures, and an ocular defect is Sturge-Weber syndrome. This is a neurocutaneous disorder characterized by the presence of a facial capillary malformation (the port wine stain), typically located in the distribution of the trigeminal nerve.

The association of a port wine stain with neurological symptoms, including seizures, arises due to the possibility of underlying leptomeningeal angiomas that may lead to cortical dysplasia and calcifications in the brain. These angiomas can disrupt normal brain function and may result in seizures. Additionally, ocular defects are often present as a result of increased intraocular pressure and other vascular complications associated with the condition.

Sturge-Weber syndrome is thus a classic triad consisting of facial port wine stains, neurological disturbances (such as seizures), and ocular issues, making it the most fitting diagnosis in this scenario.