SAH -subarachnoid haemorrhage (A letter to The Editor)

The Skeptik, 2017, Vol. 3, pgs. 4, 5

Kukanová B. St. Helens and Knowsley Teaching Hospitals NHS Trust

SAH should be considered in any "worst ever" headache or sudden onset headache (1, 2).

Atraumatic SAH can occur in any age and is an important cause of sudden death or collapse. More than 2/3 of patients present with RAPID ONSET or "WORST HEADACHE EVER" (2).

SAH is classically described like a BLOW TO THE BACK OF THE HEAD accompanied by neck pain, photophobia and vomiting (3).

In 1/4 of patients headache is precipitated by exertion."Warning headache" may precede SAH and UNILATERAL EYE PAIN may occur.

NECK STIFFNESS is often ABSENT in Emergency department presentations.Kernig's sign takes 6 hours to develop.CT head is the most sensitive within12h from the onset of the headache. If CT is negative, Lumbar puncture should be done after 12h from the onset of headache .  Suspicious is ANY SUDDEN HEADACHE especially WITH NECK or BACK PAIN (1-3).

In PRIMARY CARE only 1/4 of patients who present with sudden headache have SAH. Differentials include meningitis,migraine, intracerebral bleed and cortical vein thrombosis. Patients with SAH may earlier have experienced sentinel headache perhaps due to a small warning leak from the offending aneurysm (4, 5).

In patients with known aneurysm the relative risk of rupture increases with the diameter size of the aneurysm with relative risk 17 in aneurysm bigger than 12mm (6).

REFERENCES

1. Edmeads J. Headache in cerebrovascular disease. A common symptom of stroke. Postgrad Med. 1987 Jun;81(8):191-3, 196-8.

2. Bø SH, Davidsen EM, Gulbrandsen P, Dietrichs E. Acute headache: a prospective diagnostic work-up of patients admitted to a general hospital. Eur J Neurol. 2008 Dec;15(12):1293-9.

3. Welty TE, Horner TG. Pathophysiology and treatment of subarachnoid hemorrhage. Clin Pharm. 1990 Jan;9(1):35-9. Review.

4. Mark DG, Kene MV, Vinson DR, Ballard DW. Outcomes following possible undiagnosed aneurysmal subarachnoid hemorrhage: a contemporary analysis. Acad Emerg. Med. 2017 Jul 4. doi: 10.1111/acem.13252. [Epub ahead of print]

5. Chu KH, Howell TE, Keijzers G, Furyk JS, Eley RM, Kinnear FB, Thom O, Mahmoud I, Brown AF. Acute Headache Presentations to the Emergency Department: A Statewide Cross-sectional Study. Acad Emerg Med. 2017 Jan;24(1):53-62. doi: 10.1111/acem.13062.

6. Awaji K, Inokuchi R, Ikeda R, Haisa T. Nontraumatic Pure Acute Subdural Hematoma Caused by a Ruptured Cortical Middle Cerebral Artery Aneurysm: Case Report and Literature Review. NMC Case Rep J. 2016 May 12;3(3):63-66. doi: 10.2176/nmccrj.cr.2015-0151. eCollection 2016 Jul.