Ans. is 'a' i.e., Toxoplasmosis Neurological manifestations of H.I.V. AIDS dementia complex (HIV encephalopathy) is a result of direct effects of HIV on CNS (not an oppounistic disease). It is subcoical dementia. Most common cause of seizures --> Toxoplasma Most common cause of meningitis --> Cryptococcus M.C. cause of focal neurological deficit --> Toxoplasma Toxoplasmosis is the most common CNS infection in AIDS. CNS lymphoma and prograssive multifocal leukoencephalopathy may occur.