Any process that decreases blood-brain barrier permeability, the quality of the blood-brain barrier that allows for a controlled passage of substances (e.g. macromolecules, small molecules, ions) into and out of the brain.
Synonyms:
exact_synonym:
down-regulation of BBB permeability; down-regulation of blood-brain barrier permeability; downregulation of BBB permeability; downregulation of blood-brain barrier permeability; negative regulation of BBB permeability
narrow_synonym:
inhibition of maintenance of permeability of BBB; inhibition of maintenance of permeability of blood-brain barrier