Damage to the brain or spinal cord is followed by the growth of capillaries and gliosis (i.e., the proliferation of astrocytes and microglia). Gliosis in the central nervous system is the equivalent of scar formation elsewhere; once established, it remains permanently. In spinal cord injuries, axonal regeneration can be seen up to 2 weeks after injury. After 2 weeks, gliosis has taken place and attempts at axonal regeneration end. In the central nervous system, axonal regeneration occurs only in the hypothalamohypophysial region, where glial and capillary barriers do not interfere with axonal regeneration. Axonal regeneration seems to require contact with extracellular fluid containing plasma proteins Diagnosis: Cerebral contusion, gliosis