Astrocytic edema in CNS trauma.

The occurrence of astrocytic swelling in response to CNS trauma is reviewed. This response occurs rapidly and appears earlier than the reactive astrocytic response to neuronal and axonal injury. Astrocytic swelling is viewed as an exaggerated pathologic extension of normal astrocytic functions, such as regulation of extracellular ion levels and brain pH. Potential deleterious consequences of swelling, such as failure of ion homeostasis mechanisms, impaired uptake of neurotransmitters, and release of excitotoxic amino acids, are discussed. Possible pharmacologic interventions are reviewed showing that inhibition of such swelling or prevention of some of its potential deleterious consequences by an anion transport inhibitor, L-644,711, may have beneficial effects in head trauma.