Decompressive craniectomy (DC) is the third most common neurosurgical procedure for treating TBI in India. Cranioplasty is one of the common neurosurgical procedures usually performed post decompressive craniectomy, to protect the underlying cerebral structures. The purpose of cranioplasty is not only to improve cosmesis but also to prevent neurological deterioration. Post-DC patients with large cranial defects are prone to develop the “syndrome of Trephined” also known as the “Sinking skin flap syndrome” which is manifested as dizziness, headache, seizures, motor deficits and language disturbances. The aim of this prospective, observational study is to compare the changes in ICP (derived

by Pulsatility Index of ipsilateral MCA) before and after cranioplasty using transcranial ultrasound.

TCCD examinations will be performed before induction using a phased array 1-5 MHz probe (GE LOGIQ machine) through the transtemporal window. The transducer probe will be placed over the temporal area just above the zygomatic arch in front of the tragus of the ear with the pointer facing medially. Before the examination, TCD will be performed under the same physiological conditions including the heart rate, blood pressure, temperature, and hematocrit pre- (before induction) and post-cranioplasty (1 hour after surgery). The Doppler spectrum of all the cerebral arteries will be obtained by 0 0-degree angle of insonation.