<prompt> A patient with neurological problems has an elevated cerebrospinal fluid CSF antibody titer to measles virus. You would most likely suspectFifth diseaseSusceptibility to chickenpoxPossible subacute sclerosing panencephalitis SSPEPossible hepatitis B infection  <response>: C Possible subacute sclerosing panencephalitis SSPE 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 CSE In patients with multiple sclerosis MS, lower CSF antibody titers have been observed, suggesting a possible etiologic role for measles virus in MS. 