Ottawa SAH Rule Last edited and medically reviewed by Alaric Steinmetz on 10.10.2022 Synonyms Ottawa SAH Rule, Ottawa Subarachnoidalblutungsregel The Ottawa SAH Rule provides guidance for the evaluation of patients with headache1: Age > 40 years Neck pain or stiffness Witnessed loss of consciousness Onset during exertion Thunderclap headache Limited neck flexion on examination References Book: Neurosurgical Knowledge Update - A comprehensive review. Robert E. Harbaugh et al. Thieme Verlag. ↩ ↩