NOTE: This work is an extension of "Clinical Rules of Perry et al for Identifying a Patient with Acute Headache Who Should Be Evaluated for Subarachnoid Hemorrhage" (above)
Patient selection:
(1) age > 15 years
(2) headache new and severe
(3) headache nontraumatic
(4) maximum intensity within 1 hour
(5) normal neurologic exam
Exclusions:
(1) new neurologic deficit
(2) history of previous aneurysm
(3) history of subarachnoid hemorrhage
(4) history of brain tumors
(5) history of recurrent headaches (>= 3 headaches in a period of >= 6 months)
High risk parameters:
(1) age >= 40 years
(2) neck pain or stiffness
(3) limited neck flexion on physical exam
(4) witnessed loss of consciousness
(5) onset during exertion
(6) thunderclap onset (instantly peaking pain)
The presence of 1 or more of the high risk findings is an indication for further testing.
Performance:
• The rule is reported to have a sensitivity of 100%.
