Response of chronic experimental cerebral vasospasm to methylprednisolone and dexamethasone.

The authors have previously demonstrated that high-dose methylprednisolone (30 mg/kg intravenously every 8 hours) prevents severe chronic vasospasm in dogs. In the present study, lesser doses of methylprednisolone (15 mg/kg intravenously every 8 hours) and dexamethasone (0.1 mg/kg intravenously every 8 hours), although better than no treatment at all, were significantly less effective than the higher dose of methylprednisolone. These data suggest that methylprednisolone can prevent chronic experimental vasospasm from occurring only when given in high doses (30 mg/kg).