system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A pediatric patient with progressively developing degenerative neurologic disease/disorder has an elevated CSF antibody titer to measles virus. You should suspect which of the following?
assistant
The correct answer is  SSPE is thought to be caused by a measles-related virus present in the central nervous system. Most SSPE patients show elevated measles virus antibodies in serum and CSF. In patients with MS, lower CSF antibody titers have been observed, suggesting a possible etiologic role for measles virus in MS.