zil; 2 Laboratório Municipal de Novo Hamburgo, RS,

S100B is a 21-kDa calcium-binding protein produced and released primarily by astrocytes in the central nervous system (CNS), where it exerts neurotropic and gliotropic actions (1). Several studies have investigated the potential role of S100B as a peripheral biochemical marker of neural injury, including reactive gliosis, astrocytic death, and/or blood-brain barrier dysfunction (2). Increased cerebrospi-nal fluid (CSF) and/or serum S100B has been reported in several acute and chronic injuries, including traumatic brain injury (3), stroke (4), Alzheimer disease (5), schizo-phrenia (6), HTLV-I-associated myelopathy (7), and sys-temic lupus erythematosus (8). Previous neurodevelopmental studies have demon-strated age-related changes in S100B tissue expression and distribution in the CNS in mammals, which may b