Inclusion Criteria:  Physical status ASA I and ASA ll. Males and females between the ages of 21 and 55. Patients undergoing posterior fossa Surgeries. Patients with GCS ≥14 Patients undergoing operation in prone position  Exclusion Criteria:  Patient refusal. Patients with a history of allergy to opioids or local anesthetics GCS (Glasgow coma score) ≤13 upon emergence from anesthesia. Patients who will need post-operative ventilation Patients who had previous craniotomies Patients with contraindication to regional anaesthesia e.g.: local sepsis, Patients with pre-existing peripheral neuropathies and coagulopathy. Patients who will develop intraoperative surgical complications Operations lasting more than 5 hours.