In clinical practice, hospital admission of patients with altered level of consciousness ranging from drowsiness to decreasing response states or coma is extremely common. This clinical condition demands effective investigation and early treatment. Imaging and laboratory tests have played increasingly relevant roles in supporting clinical research. One of the main causes of coma is intracranial hypertension (IH), with traumatic brain injuries (TBI) and cerebral hemorrhages being the major contributors to its development. IH increases the risk of secondary damage in these populations, and consequently, morbidity and mortality. Clinical studies show that adequate intracranial pressure (ICP) control in TBI patients reduces mortality and increases functionality. Unfortunately, the most accurate way to measure and evaluate the ICP is through a catheter located inside the skull, and its perforation is required for this purpose. Several studies have attempted to identify noninvasive solutions for ICP monitoring; however, to date, none of the techniques gathered sufficient evidence to replace invasive monitors. Recently, an extensometer device has been developed, which only maintains contact with the skull's skin and therefore eliminates the need for its perforation, being able to obtain recordings of cranial dilatation at each heartbeat and consequently reflecting brain compliance. In vivo studies have identified excellent qualitative correlation with catheter ICP recordings. However, this device was evaluated only in a limited number of clinical cohorts and the correlations between the information provided by this device with patients outcomes is still poor. Therefore, this project aims primarily to evaluate the use of this noninvasive brain compliance monitoring system in a cohort of TBI patients.

Inclusion Criteria:

• Moderate to severe traumatic brain injury with less than 24 hours.

Exclusion Criteria:

• Primary decompressive craniectomy
• Brain death signs at admission
• Severe hemodynamic instability

Patients of any gender, older than 18 years, with very acute moderate or severe TBI will be included just after stabilization and any surgical evacuation procedure performed.

Possibly some anonymous data can be shared with other researchers upon reasonable request.