The cohort will be constituted of patients treated for a stroke suspicion after calling emergency medical services of the Rhone and presenting a symptom-onset (the last time the patient was seen without deficit) less than 6 hours.

Tests from Cincinnati prehospital stroke severity scale (CPSSS) will be carried out by the physician at emergency medical services on telephone call with firemen, paramedics or the emergency medical services team for any stroke suspicion that meets the criteria for inclusion. Emergency department physician will have to follow a standardized questionnaire to complete the different items of the score. The score will not be calculated by emergency department physician and will not influence the orientation and management of patients.

The final diagnosis will be the presence or absence of a large vessel occlusion. This diagnosis will be done on cerebral imaging by a neurologist.

The Cincinnati prehospital stroke severity scale is composed of 3 items: 2 points if the patient has a deviation of the gaze, 1 point if the patient is not able to give the date and answer to a simple order such as closing the eyes or clenching the fist and 1 point if the patient presents a hemiplegia. The CPSSS score ranges from 0 to 4, highest value indicating the worst score. It will be considered positive if it is equal to 2 or more.

Performances will be evaluated in terms of sensitivity, specificity, positive and negative predictive values.