Pupillary examination, and in particular pupillary reactivity to light, is fundamental to the monitoring and follow-up in intensive care units of patients with acute brain injury. A pupillometric index combining different parameters of pupillary light reflex has been described as predictive of intracranial hypertension and the neurological outcome of the patient.

Pupillary examination, and in particular pupillary reactivity to light, is fundamental for the monitoring and follow-up in intensive care units of patients with acute brain injury. Intracranial pressure monitoring and pupillometry measurement are thus part of the routine practice of intensive care unit management of brain injured patients. Furthermore, elevated intracranial pressure in brain injured patients admitted to the ICU is associated with a poor prognosis, and very high intracranial pressure is a life-threatening situation.

A pupillometry index combining different parameters of pupillary light reflex has been described as having predictive value of intracranial hypertension and neurological outcome of the patient: the "NPi". Another manufacturer IdMed, Marseille, France proposes an index: the QPI (Quantitative Pupillometry Index), based on a statistical classification of the amplitude of the light reflex.

The aim of this study is to show that :

• QPI is equivalent to NPI
• An abnormal value of the pupillometry indexes (NPI/QPI) is predictive of high intracranial pressure.
• An abnormal value of pupillometry indexes (NPI/QPI) is predictive of a poor neurological outcome at 6 months.

Inclusion Criteria:

• Patients ≥ 18 years of age
• Patients admitted for any brain injury: traumatic, intracranial hemorrhage, subarachnoid hemorrhage
• Pupillometry available as a standard assessment tool.
• Patient intubated/ventilated for neurological reasons for more than 12 hours

Exclusion Criteria:

• Non-intensive care patients
• Facial and or ocular trauma not allowing pupillometry evaluation
• Patients admitted to the ICU with a life expectancy of < 24 hours
• Protected persons (under guardianship, curators, pregnant or breastfeeding women, persons deprived of liberty, persons not subject to a psychiatric measure)
• Patients not affiliated to a social security system
• Patients who object to the use of their data for research purposes

patient admitted for a traumatic brain injury, intracranial hemorrhage, or subarachnoid hemorrhage and for whom a pupillometry indication is retained

Because of the observational/exploratory nature of the study, no formal sample size calculation has been performed. However, it is planned to recruit a total of at least 30 patients (traumatic brain injury, intracranial hemorrhage, subarachnoid hemorrhage), over a 12-month period.

Data will be described in numbers and percentages for qualitative data, and in quartiles and means/standard deviation for quantitative characteristics.