Which disorder is defined by bilateral vestibular schwannomas and relatively preserved cognition?

• A. Sturge-Weber syndrome
• B. Tuberous sclerosis
• C. Neurofibromatosis type 2
• D. Neurofibromatosis type 1

Answer: (C)

Neurofibromatosis type 2 is characterized by bilateral vestibular schwannomas, which typically cause hearing loss and balance problems, while cognition is relatively preserved. This pattern—tumors on both vestibular nerves with preserved intellectual function—is the hallmark that sets NF2 apart from other similar conditions. The genetic basis involves mutations in the NF2 gene encoding merlin, and patients can also develop other CNS tumors such as meningiomas and ependymomas. In contrast, Sturge-Weber involves facial port-wine stains and leptomeningeal vascular malformations; tuberous sclerosis includes cortical tubers with seizures and facial angiofibromas; Neurofibromatosis type 1 features neurofibromas, café-au-lait spots, and possible learning difficulties. Thus the combination of bilateral vestibular schwannomas and relatively preserved cognition points to Neurofibromatosis type 2.