Subarachnoid Hemorrhage

What is a Subarachnoid Hemorrhage?

subarachnoid hemorrhage occurs when blood travels into the subarachnoid space inside the brain. This space contains cerebrospinal fluid and it shields the brain from becoming injured when there is trauma to the head. When blood flows into this space, it can cause individuals to go into a coma or become paralyzed.

This condition can also be fatal, especially if the individual does not have prompt medical care. Causes of a  subarachnoid hemorrhage include head injuries, blood thinning medications and a cerebral aneurysm. Risk factors include high blood pressure, polycystic kidney disease and disorders of connective tissues in the body. Individuals who have family members who have previously suffered aneurysms are also at a higher risk.

What are the Symptoms of Subarachnoid Hemorrhage?

Individuals who have experienced a subarachnoid hemorrhage will immediately have an immense headache that is especially painful in the back portion of their head. The pain often radiates down to the shoulder and neck region.

Parts of the body may feel numb and seizures may occur. Vision problems are common and individuals may have blind spots, double vision, sensitivity to bright lights and short-term loss of vision in one of their eyes. Other people may notice that the individual has contrasting pupil sizes and a droopy eyelid. Some individuals become confused and lose awareness of their surroundings.

Subarachnoid Hemorrhage Causes

The most common cause of subarachnoid hemorrhage is a brain aneurysms, which is a bulge in a blood vessel in the brain. This is especially true when it is a berry aneurysm, which looks like a berry due to its cluster of sac-like pouches affecting a cerebral vessel. A clot occurs when the aneurysm eventually erupts, with smokers, women, and high blood pressure sufferers being more likely to acquire one.

A cause of bleeding within the subarachnoid space – which is between the brain and the enclosing tissues – can be the result of some intense head trauma, such as that which a person might experience during a car crash or during a fall. Because of their fall risk and general increased fragility, the elderly are more at risk.

Bleeding disorders and the use of blood thinners have also sometimes been seen as related to a spontaneous subarachnoid hemorrhage, along with bleeding from a arteriovenous malformation (AVM).

How is a Subarachnoid Hemorrhage Treated?

Immediate treatment of a subarachnoid hemorrhage is essential to prevent potential brain damage or death. Surgeons will open the individual’s skull and seal the aneurysm to prevent the occurrence of bleeding. If the individual is in a coma, life support measures are initiated.

Various medications may be prescribed to reduce headache pain, halt the onset of seizures, manage safe blood pressure levels and avert spasms in the arteries. During the recovery period, individuals must get proper rest. To prevent unnecessary compression on the brain, individuals will be instructed to avoid stooping over and engaging in strenuous activities.

Subarachnoid Hemorrhage Prevention

As the most common cause of subarachnoid hemorrhage is a brain aneurysm, and these are hard to prevent, preventing the hemorrhages themselves is also difficult. Some risk factors for brain aneurysms have been identified, including high blood pressure, smoking, consuming excessive amounts of alcohol, genetics and family history, and some other medical conditions. Reducing these risk factors can thus be helpful.

It is very important that brain aneurysms be detected early enough so that there might be some intervening treatment which could help to avoid further complications leading to a subarachnoid hemorrhage. An MRI with MRA (magnetic resonance imaging with angiography) as well as a CT with CTA (computed tomography with angiography) are the two of the safest and quickest ways for people to undergo the proper screening which can detect the aneurysms before trouble magnifies.

When brain aneurysms have been detected, they can undergo a procedure to prevent subarachnoid hemorrhages.

Last Reviewed:
October 09, 2016
Last Updated:
November 28, 2017