Subarachnoid hemorrhage is bleeding in the area between the brain and the thin tissues that cover the brain. This area is called the subarachnoid space.
Hemorrhage - subarachnoid
Causes, incidence, and risk factors
Subarachnoid hemorrhage can be caused by:
Subarachnoid hemorrhage caused by injury is often seen in the elderly who have fallen and hit their head. Among the young, the most common injury leading to subarachnoid hemorrhage is motor vehicle crashes.
A strong family history of aneurysms may also increase your risk.
The main symptom is a severe headache that starts suddenly (often called thunderclap headache). It is often worse near the back of the head. Many persons often describe it as the "worst headache ever" and unlike any other type of headache pain. The headache may start after a popping or snapping feeling in the head.
Other symptoms that may occur with this disease:
Signs and tests
A physical exam may show a stiff neck
A brain and nervous system exam may show signs of decreased nerve and brain function (focal neurologic deficit
An eye exam may show decreased eye movements -- a sign of damage to the cranial nerves (in milder cases, no problems may be seen on an eye exam)
If your doctor thinks you have a subarachnoid hemorrhage, a head CT scan
(without contrast dye) will be done right away. In some cases, the scan is normal, especially if there is only been a small bleed. If the CT scan is normal, a lumbar puncture (spinal tap
) must be done.
Other tests that may be done include:
The goals of treatment are to:
Surgery may be done to:
If the patient is critically ill, surgery may have to wait until the person is more stable.
Surgery may involve:
(cutting a hole in the skull) and aneurysm clipping -- to close the aneurysm
-- placing coils in the aneurysm and stents
in the blood vessel to cage the coils reduces the risk of further bleeding
If no aneurysm is found, the person should be closely watched by a health care team and may need more imaging tests.
Treatment for coma or decreased alertness includes:
A person who is is conscious may need to be on strict bed rest. The person will be told to avoid activities that can increase pressure inside the head, including:
Treatment may also include:
Medicines given through an IV line to control blood pressure
Nimodipine to prevent artery spams
Painkillers and anti-anxiety medications to relieve headache and reduce pressure in the skull
Phenytoin or other medications to prevent or treat seizures
Stool softeners or laxatives to prevent straining during bowel movements
How well a patient with subarachnoid hemorrhage does depends on a number of different factors, including:
Older age and more severe symptoms can lead to a poorer outcome.
People can recover completely after treatment. But some people die even with treatment.
Repeated bleeding is the most serious complication. If a cerebral aneurysm bleeds for a second time, the outlook is much worse.
Changes in consciousness and alertness due to a subarachnoid hemorrhage may become worse and lead to coma
Other complications include:
Complications of surgery
Medication side effects
Calling your health care provider
Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of a subarachnoid hemorrhage.
Identifying and successfully treating an aneurysm can prevent subarachnoid hemorrhage.
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Tateshima S, Duckwiler G. Vascular diseases of the nervous system: intracranial aneurysms and subarachnoid hemorrhage. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 51C.
Zivin J. Hemorrhagic cerebrovascular disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 415.
Luc Jasmin, MD, PhD, Department of Neurosurgery, Cedars Sinai Medical Center, Los Angeles and Department of Anatomy, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.