Table 3.

Imaging and clinical details for the seven patients with false negative clinical decision rules.

Age	Neck pain or stiffness	Onset with exertion	Loss of consciousness	CT results	Angiography findings
32	No	Unknown	No	Positive	5mm right ACA aneurysm
39	No	No	No	Positive	6mm left MCA aneurysm
27	No	No	No	Positive	7mm left ACOM aneurysm
32	No	Unknown	No	Positive	6mm right PCOM aneurysm
39	Unknown	No	No	Positive	ACOM aneurysm (unknown size/location)
25	No	No	No	Positive	2mm right ICA aneurysm
29	Unknown	No	No	Positive	Right MCA aneurysm (unknown size)

Seven patients presenting with aneurysmal SAH had false negative results using the clinical decision rule (age >40, presence of neck pain or stiffness, headache onset with exertion, loss of consciousness at headache onset) for subarachnoid hemorrhage. Diagnosis of SAH was made by computed tomography in each case. Details of the decision rule elements and formal cerebral angiography are presented for each case.

ACA, anterior cerebral artery; ACOM, anterior communicating artery; CT, computed tomography; ICA, internal carotid artery; MCA, middle cerebral artery; PCOM, posterior communicating artery; SAH, subarachnoid hemorrhage