Acute Headache: Helping to Rule Out a Subarachnoid Hemorrhage

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Subarachnoid hemorrhage is a life-threatening situation that needs an urgent treatment.  Acute headache is the key symptom, but only 1-3% of them are due to a subarachnoid hemorrhage in the Emergency Department. A good anamnesis and a complete  physical examination are basic for a correct diagnosis, but more than 12% of patients have a misdiagnosis in the Emergency Department.

CLINICAL CASE: A previous healthy  40-year-old man started with an acute and intense headache, worsening with  exercise and the Valsalva maneuver. He had two previous visits to a GP who detected a high blood pressure (HBP) to a value of 175/100 and he started treatment. Because he has no improvement he went to another doctor who asked for a thoracic CAT scan where a constricted superior cava vein was observed. Two days later he started with high fever and vomiting and the doctor decided to send him to the hospital.

CLINICAL EVOLUTION: A thoracic vascular malformation and fever make  the doctor to think  in a pulmonary problem. But the persistence of headache centered the problem in the central nervous system. A CAT scan showed a lesion located in the right frontal area with edema. An angioCAT identified a sacular  aneurysm (9×6 mm) in the anterior communicating arteria with a right frontobasal hemorrhage.

ANALYSIS: this patient has signs and symptoms that can be present in several pathological entities, HBP, fever, headache. The high index of suspiction, a reevaluation of the case and intuition , were the key elements to reach the diagnosis.

FINAL DIAGNOSIS: Subarachnoid Hemorrhage anterior communicating artery. Differential: -cerebral venous sinus thrombosis -pituitary apoplexy – arterial dissection

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COMMENTS: In difficult clinical situations is common in Medicine to develop rules to facilitate a correct diagnosis. There are 3 clinical decision rules for the diagnosis of a subarachnoid hemorrhage:


FROM: Perry JJ et al. Clinical Decisions Rules to Rule Out Subarachnoid Hemorrhage for Acute Headache. JAMA 2013; 310:1248-1255