Subarachnoid Hemorrhages (SAH)

What is SAH?

-bleeding in subarachnoid space

-commonly refers to nontraumatic type of hemorrhages eg: ruptures of berry aneurysm and arteriovenous malformation (AVM).

What are the signs and symptoms?

*-sudden onset of a severe headache which often worse near the back of the head.

-nausea and/or vomiting

-symptoms of meningeal irritation (eg, neck stiffness, low back pain, bilateral leg pain. Take several hours to develop.

-photophobia and visual changes

-loss of consciousness (50% of ppl at the time of bleeding onset)

-mood and personality changes

What causes SAH?

-Primary SAH may results from ruptures of: saccular aneurysm**, AVM **, mycotic aneurismal rupture, angioma, neoplasm, cortical thrombosis.

-congenital causes

-head injury

-use of blood thinners

-idiopathic

Risk factors:

-aneurysms in other blood vessels

-Fibromuscular dysplasia (FMD) and other connective tissue disorders associated with aneurysm or weakened blood vessels.

-high blood pressure

-history of polycystic kidney disease

-smoking

Physical examination:

-stiff neck due to irritation by blood of the meninges

-neurological exam may show signs of decreased nerve and brain function (

- eye exam may show decreased eye movement (sign of damage CN).

Investigation:

-head CT scan (immediately if SAH is suspected)

-lumbar puncture (SAH patients will have blood in their spinal fluid)

-CT scan angiography à evidence of aneurism

-cerebral angiography à show small aneurisms or other vascular problems

-tanscranial Doppler ultrasound à blood flow in the arteries

-MRI and magnetic resonance angiography (MRA) can be used.

How to treat SAH?

-treatment aims are to save the life, repair the cause of bleeding, relieve symptoms and prevent complications.

-surgery

References:

http://www.nlm.nih.gov/medlineplus/ency/article/000701.htm

http://emedicine.medscape.com/article/794076-overview