Methylprednisolone for Moderate to Severe Traumatic Brain Injury

The goal of this clinical trial is to learn if standard-dose methylprednisolone sodium succinate can improve neurological recovery and safety in adults with moderate to severe traumatic brain injury (TBI). The main questions it aims to answer are: 1. Does adding a 5-day course of methylprednisolone improve overall long-term neurological outcome compared with placebo? 2. Does methylprednisolone reduce 6-month mortality or increase the proportion of patients with good neurological recovery? 3. What medical problems do participants experience when receiving methylprednisolone? Researchers will compare methylprednisolone sodium succinate (2 mg/kg/day intravenously for 5 days) with a matching placebo to see if the steroid improves outcomes beyond standard TBI care. Participants will: 1. Receive either methylprednisolone or placebo once daily for 5 days, added to guideline-directed standard care. 2. Undergo CT scans and neuro-examinations during hospitalization. 3. Return for follow-up visits at 1 month and 6 months after injury for neurological assessments, safety checks, and questionnaires.