<prompt> Most common viral cause of acquired aqueductal stenosis is:RubellaMumpsToxoplasmaEnterovirus  <response>: b. MumpsRef: Nelsons 20e p 1552-1553, Ghai 8e p 217-218CNS complications of Mumps include Meningoencephalitis, transverse myelitis, aqueductal stenosis facial palsy. 