This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Which of the following is not seen in HIV involvement of CNS - \nSelect and explain. \nA. Perivascular giant cell, B. Vacuolar degeneration of posterior column, C. Microglial nodule formation, D. Inclusion bodies', 'role': 'user'}, {'content': 'Answer: D \nExplanation: CNS involvement in AIDS\n\nInvolvement of C.N.S. is a common and important manifestation of AIDS.\nIn addition to the lymphoid system, the nervous system is a major target of HIV infection.\nMacrophages and microglial cells in the central nervous system that belongs to the monocyte and macrophages lineages are the predominant types in the brain that are infected with HIV.\nIt is widely believed that HIV is carried into the brain by infected monocytes.\nNinety percent of patients demonstrate some form of neurological involvement at autopsy.\nC.N.S. involvement in AIDS usually produces AIDS dementia complex.\nThe pathology associated with AIDS-related cognitive-motor complex sometimes called subacute encephalitis is\xa0located mainly in subcortical areas with relative sparing of the cerebral cortex.\n\nMicroscopic changes include :\n\nDiffuse white matter pallor\nPerivascular infiltrates of lymphocytes and macrophages.\nFoci of necrosis, gliosis and/or demyelination\nMicroglial nodules, macrophages and multinucleated cells.\n\nRemember,\nVasculitis is characteristically absent in CNS involvement in AIDS\n\nSpinal cord involvement in AIDS\n\nThe spinal cord involvement in AIDS leads to vacuolar myelopathy. This change consists of white matter vacuolation in the posterior and lateral column and is mainly due to swelling within myelin sheaths.\nInvolvement of the posterior column gives symptoms similar to subacute combined degeneration of the cord (Vit B12\xa0deficiency).', 'role': 'assistant'}]