HIV meningitis
In a HIV/AIDS patient what is the most common CNS presentation. The answer is AIDS dementia complex. In this type the cortex is spared with only subcortical involvement.
Histological examination of the subcortical areas shows the following features
Microglial nodules- these are basically collections of macrophages which form the microglial nodules. Giant cells may also be present in these nodules
Patchy areas of White mater necrosis
In addition there is Vacuolar myelopathy of spinal cord
What are the things that are never seen in HIV meningitis?
Remember there are no viral inclusions in HIV meningitis. There is no vasculituis also. There may be perivascular inflammation but there is no vasculitis.