S100B in the Care of Non-traumatic Headaches in the Emergency Department

The main objective of this pilot study is to make a first assessment of the discriminating ability of a dosage of S100B protein for differential diagnosis between primary headaches and secondary headaches. For this, the investigators will compare serum S100B protein between two groups of headache patients presenting at the emergency department: 1 group of primary headache patients and 1 group of secondary headache patients. If the difference between the two groups proves potentially discriminating, the investigators will seek to determine the discriminating ability of the S100B protein by calculating the area under the ROC curve. The reference diagnostic will be set at one month across the entire clinical picture and imaging by an expert committee composed of a neurologist, a radiologist and an emergency physician.