This is the high-dose steroid (30 mg/kg intravenous bolus followed by 5.4 mg/kg/hour for 23 hours if it is started within 3 hours and for 47 hours if between 3 to 8 hours after injury). It should not be started more than 8 hours after injury.
Clinical trials have shown that this treatment improves recovery by about 20% when given within 8 hours after injury but does not help when started more than 8 hours after injury. While methylprednisolone is not a cure, every little bit helps. Complications are minimal.