Sub Arachnoid Hemorrhage (SAH) is a public health concern because of its high incidence (7/100 000 inhab.), its mortality rate (25%), and its morbidity rate (50%).~Prognostic tools are indispensable in guiding and optimizing the care of these patients.~Some diagnostic factors have been identified (e.g. age, comorbidities, ACSOS , GCS, ICP, occurrence of complications) as well as some classification schemes used for grading seriousness of the disease (Hunt and Hess, World Federation of NeuroSurgery).~A tool that is simple, reliable, reproducible, non costly, non invasive, and simple to perform (including remote methods and without changing planned patient care) would be ideal.~The measurement of the Optic Nerve Sheath Diameter (ONSD,) correlated by MRI and ultrasound in previous studies, with intra-cranial pressure (ICP: a fundamental prognostic factor for SAH) could be one of these tools.~This measurement, previously demonstrated using ultrasound, could be carried out at the time of the patient's initial cerebral scan.~In practice, at admission each patient undergoes a cerebral CT scan much more often than an ultrasound (faster, less costly, less technical training required).~Two preliminary studies seem to suggest that this measurement of ONSD on CTc is a predictive factor for morbi-morbidity in patients having serious traumatic skull fractures.The measurement is reliable, reproducible, non invasive, and non costly, with good sensitivity and specificity.~Proving that it is also applicable to SAH could be particularly useful.
Sub Arachnoid Hemorrhage (SAH) is a public health concern because of its high incidence (7/100 000 inhab.), its mortality rate (25%), and its morbidity rate (50%).