Traumatic Subarachnoid Hemorrhage

What Is It?

Traumatic subarachnoid hemorrhage is a type of bleeding that occurs around the brain following some head injuries. Subarachnoid hemorrahge (SAH) is bleeding into the fluid-filled space around the brain called the subarachnoid space. The subarachnoid is formed by the arachnoid membrane, one of the coverings of the brain and spinal cord, and is filled with cerebrospinal fluid, the watery liquid that bathes the brain and spinal cord. Bleeding into this fluid-filled space can be caused by injury or rupture of the blood vessels that supply blood to the brain.

Traumatic subarachnoid hemorrhage is the most common cause of SAH overall. A large percentage of traumatic brain injuries involve some component of this type of bleeding. However, SAH can occur from other causes as well. Most notably, spontaneous subarachnoid hemorrhage (without any trauma) can occur with the rupture of an intracranial aneurysm. These balloon-like, weakened outpouchings of the blood vessels that supply the brain have a tendency to bleed in some patients. They can rupture spontaneously and cause bleeding into the subarachnoid space. Aneurysm rupture is less common than trauma.

What Types of Symptoms Are Typical?

While spontaneous, isolated subarachnoid hemorrhage from an aneurysm is classically associated with the sudden onset of a severe headache, traumatic subarachnoid hemorrhage occurs in the setting of a moderate or severe head trauma. Therefore, these patients often have other injuries which complicate their presentation. They can present anywhere from relatively asymptomatic to comatose. This presentation all depends on the mechanism of injury, the severity of the overall injury and other associated traumatic injuries to the brain.

How Is The Diagnosis Typically Made?

As with most other traumatic injuries of the brain, this bleeding is most often recognized on CT scan of the head. After initial stabilization and assessment, trauma patients usually undergo extensive CT scanning to assess their internal injuries. On this imaging study, significant bleeding into the subarachnoid space can usually be seen clearly and has a unique appearance when compared to other types of intracranial bleeds, such as epidural hematoma or subdural hematoma.

What Are Some Common Treatments?

The treatment of traumatic brain injury is complex and highly variable depending on specifics of each patient and their injury characteristics. Generally, traumatic subarachnoid hemorrhage does not require any specific treatment other than the general treatments that are used for trauma victims of any type. Whereas other types of traumatic hemorrhages, such as epidural hematoma or subdural hematoma, often require surgical removal, bleeding into the subarachnoid space spreads out into the cerebrospinal fluid and thus does not cause a mass that requires evacuation.

Each trauma patient should be evaluated and their treatment plan decided by their own personal physicians. Generalizations should not be made.

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Important Note: This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.

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