Acute Subdural Hematoma

An acute subdural hematoma is an accumulation of blood, or a hematoma, inside the skull. It is located between the dura, the fibrous covering of the brain, and the brain itself. An acute subdural hematoma occurs when blood leaks into the space between the dura and the brain. There is very little extra room within the skull, so the build-up of blood puts pressure on the brain.

What are the causes and risks of the injury?

Persons traveling at any increased speed are at risk for hematoma whenever the head is struck. During impact, the brain moves around inside the skull. Veins may tear, spilling blood into the subdural space. As people age, brains shrink slightly, so veins are stretched. Thus, the elderly are more susceptible to this type of injury. Other conditions that put people at risk for subdural hematoma include:

What are the signs and symptoms of the injury?

An acute subdural hematoma causes a quick decrease in the level of consciousness after head injury. As the hematoma gets larger, the pupil of one eye will dilate, or become wider. The eye on the side of the head with the injury is the eye affected. This dilation happens almost at the same time as increasing body weakness. The weakness is usually on the side of the body opposite the hematoma.

If consciousness continues to decrease, the pulse begins to slow. Breathing becomes difficult. The body gets weaker and less responsive to stimulation. Both pupils of the eyes become dilated and unresponsive to light. Finally, breathing ceases and death occurs.

How is the injury recognized?

Diagnosis of acute subdural hematoma begins with a history and physical exam. The healthcare provider may order additional tests, such as:

What can be done to prevent the injury?

Proper medical treatment of diseases that affect consciousness and balance can help reduce the number of subdural hematomas. Other measures that can reduce head injuries include:

What are the treatments for the injury?

A craniotomy, or brain surgery, is the treatment for acute subdural hematoma. The skull is opened, and the hematoma is removed. The bleeding vein is clotted if it is still bleeding. Often where there is swelling of the brain, the piece of bone is left out. It may be replaced later if the individual recovers enough. This practice can relieve the increased pressure inside the skull that frequently occurs.

Breathing is often controlled with a ventilator, or artificial breathing machine. Fluids and medicines are used to control blood flow in the brain. Anticonvulsant medicines are often used to prevent seizures. Those who recover from surgery may be mildly or severely neurologically impaired. If so, long-term rehabilitation may be necessary. Some survivors are so neurologically impaired that long-term nursing care in a skilled nursing facility may be necessary.

What are the side effects of the treatments?

After surgery, many individuals have neurological impairments. They may have changes in consciousness level, motor skills, and activities of daily living. Seizure disorders are common, requiring medicines for control. The death rate following even the best treatment has been reported to be as high as 80%.

What happens after treatment for the injury?

After treatment, many individuals experience impaired motor coordination. They are at risk for future injuries. Many individuals may have problems with memory, judgment, and attention span. Some of these changes may be permanent. Psychological counseling may be helpful for both the individual and the family. Any new or worsening symptoms should be reported to the healthcare provider.

Author:James Warson, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:06/01/01
Reviewer:Adam Brochert, MD
Date Reviewed:06/01/01