Pupillar diameter variation to predict success or failure of external ventricular derivation clamping.

Pupillometry utilisation as a diagnostic tool in external ventricular clamping test in neurological ICU should improve patients care in several ways :

• earlier use of ventriculo-peritoneal or ventriculo-atrial shunts to shorten the external ventricular treatment duration and thus reduce risks of infection and hospital stay duration
• limit the medical imagery prescription and radiation exposition
• avoid neurological deterioration linked to the external ventricular drain clamping in case of the pupillometric parameters variation would be earlier than clinical signs

Inclusion Criteria:

• Neurologic ICU hospitalization
• Traumatic brain injury
• External ventricular drain

Exclusion Criteria:

• Legal protection
• refusal
• therapeutics limitation
• craniectomy
• pupillar anomaly

Any patient with an external ventricular drain in neurologic ICU can be recruited in the study if all the eligibility criteria are met.