What Proportion of Emergency Department Headache Patients with Normal Neurology Have a Serious Secondary Headache Cause? A HEAD Study Report

Kelly, A.M., Chu, K.H., Kuan, W.S., Keijzers, G., Kinnear, F.B., Cardozo‐Ocampo, A., HEAD Study and HEAD Colombia Investigators, Lunter, C., Facer, R., Thomson, D. and Day, R.