Placement of an external ventricular shunt is one of the most common neurosurgical procedures in neuro-resuscitation. However, the modalities of its withdrawal are not, the subject of recommendations but rather of service habits. It has been recently demonstrated that pupillary monitoring by an electronic pupillometer was more reliable than standard clinical monitoring in brain injury patients. This tool provides access to a rich pupillary semiology at the patient's bed.

So the goal is to study the evolution of the various pupillary parameters analyzed by the electronic pupillometer during the external ventricular shunt weaning tests and to highlight the predictive factors of failure.

Inclusion Criteria:

• All patients for whom the doctor orders an external ventricular bypass clamp test
• Neuro-injured patients and non-neuro-injured patients whose state of health requires sedation and mechanical ventilation

Exclusion Criteria:

• Ophthalmological pathology making impossible to carry out measurements by the pupillometer (chemosis, eyelid edema, enucleation, etc.).
• Pregnant woman.

Adult patients who have benefited from an external ventricular bypass, whatever the indication, and for whom the doctor in charge prescribes a clamping test.