Which of the following is not seen in HIV involvement of CNS -
CNS involvement in AIDS

Involvement of C.N.S. is a common and important manifestation of AIDS.
In addition to the lymphoid system, the nervous system is a major target of HIV infection.
Macrophages 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.
It is widely believed that HIV is carried into the brain by infected monocytes.
Ninety percent of patients demonstrate some form of neurological involvement at autopsy.
C.N.S. involvement in AIDS usually produces AIDS dementia complex.
The pathology associated with AIDS-related cognitive-motor complex sometimes called subacute encephalitis is located mainly in subcortical areas with relative sparing of the cerebral cortex.

Microscopic changes include :

Diffuse white matter pallor
Perivascular infiltrates of lymphocytes and macrophages.
Foci of necrosis, gliosis and/or demyelination
Microglial nodules, macrophages and multinucleated cells.

Remember,
Vasculitis is characteristically absent in CNS involvement in AIDS

Spinal cord involvement in AIDS

The 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.
Involvement of the posterior column gives symptoms similar to subacute combined degeneration of the cord (Vit B12 deficiency).
Perivascular giant cell
Vacuolar degeneration of posterior column
Microglial nodule formation
Inclusion bodies