What's the Diagnosis? By Lesley Walinchus-Foster
A 50 yo M presents to the ED w/ sudden onset severe headache. Symptom onset was 20 hours ago while hunting. His neuro exam in non-focal. CT head without contrast is done. What's the diagnosis? (scroll down for answer)
Answer: Subarachnoid Hemorrhage
- 75% caused by ruptured cerebral aneurysm
- Sensitivty of noncontrast CT for diagnosis of SAH is highest shortly after symptom onset and is estimated to be 98% within 6 hours- decreases to 91-93% at 24 hours
- CT followed by CTA can exclude SAH with 99% posttest probability
- Consider LP if clinical suspicion high and above imaging negative
- Patients can decompensate quickly due to respiratory depression, hypercapnia- intubate early if lethargic, altered MS, focal neuro deficit
- Remember pain management and sedation post intubation to prevent increased ICP
- General recommendation is SBP < 160 using titratable IV antihypertensive (labetolol, nicardipine)
- Start nimodipine even if patients normotensive- 60mg PO or via NG
- Seizure prophylaxis remains controverisal, discuss w/ NSG
Hackman JL, Nelson AM, Ma O. Hackman J.L., Nelson A.M., Ma O Hackman, Jeffrey L., et al.Spontaneous Subarachnoid and Intracerebral Hemorrhage. In: Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM. Tintinalli J.E., Stapczynski J, Ma O, Yealy D.M., Meckler G.D., Cline D.M. Eds. Judith E. Tintinalli, et al.eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 8e New York, NY: McGraw-Hill; 2016.
McCormack RF, Hutson A. Can computed tomograph angiography of the brain replace lumbar puncture in the evaluation of acute-onset headache after a negative noncontrast cranial computed tomography scan? Academic Emergency Medicine. 2010 April 17. (4) : 444-451.