The myelin sheath is damaged by an autoimmune mechanism with various neurologic consequences.

In Multiple Sclerosis, microglia phagocytose and degrade myelin debris by receptor-mediated phagocytosis and lysosomal activity.

In addition, AIDS dementia complex is caused by HIV-1 infection of the CNS

Microglia are infected by HIV-1

A number of cytokines, such as interleukin-1 and tumor necrosis factor, activate and enhance HIV replication in microglia.
 - common demyelinating disease.
- in multiple sclerosis, microglia become phagocytic.
- Characterized by the destruction of oligodendroglia.
- Medial longitudinal fasciculus syndrome is a muscular disorder associated with multiple sclerosis.
- Random asymmetric lesions in mostly white matter of the cervical region are seen in multiple sclerosis.