1. Department of Anesthesiology, Division of Neuroanaesthesia, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
2. Department of Anesthesiology and Critical Care Medicine, Amrita Institute for Medical Sciences, Cochin, Kerala, India.
3. Department of Anaesthesia and Intensive Care Postgraduate Institute of Medical Education and Research, Chandigarh, India.
4. Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India.