“…One long-acting steroid preparation, methylprednisolone acetate (Depomedrol, Upjohn Co.) has been used intrathecally to provide a high CSF concentration in non-infectious inflammatory diseases of the arachnoid membrane-adhesive arachnoiditis, nerve root fibrosis, etc. (Smith and Ross, 1959;Sehgal et al, 1962;Mack, 1964;Kulick, 1965). Since the arachnoid villi are actually extensions of the arachnoid membrane, the treatment in similar fashion of an inflammatory disease of the villi caused by blood in the CSF would seem to be a logical adjunctive measure in an attempt to prevent symptomatic hydrocephalus after SAH.…”