Natasha Richardson Autopsy: What is Epidural Hematoma?
The New York City medical examiner has said that Natasha Richardson died of an epidural hematoma "due to blunt impact to the head".
The Tony-award-winning actress was injured after a fall on the beginner ski slope at the Mont Tremblant resort in Canada.
An epidural hematoma is a traumatic brain injury in which there is a buildup of blood between the skull and the dura mater, the outer membrane of the central nervous system.
It is most often caused by a severe blow to the head. When this occurs, the brain "bounces" within the skull, which can cause blood vessels around the brain and dura mater to tear.
Blood accumulates in the space between the skull and the dura mater, and when this happens, the brain swells, leading to increased pressure in the intracranial space and compressing delicate brain tissue.
The symptoms of an epidural hematoma can include severe headache, dizziness, vomiting, increased size of one pupil or sudden weakness in an arm or leg.
As the epidural hematoma swells and the brain structures are pushed together, more visible signs can occur. A more dangerous sign of epidural hematoma is a decreased level of consciousness, such as drowsiness, confusion or inability to awaken from a very deep sleep (often called coma). Because the brain controls all functions of the human body, breathing pattern changes also can occur. Shortness of breath, gasping for air or very slow breathing can be a warning sign that the person needs help. An epidural hematoma can be life-threatening; therefore, if any of these signs or symptoms occur, the person should be taken to a medical facility immediately.
Dr Keith Siller of New York University Langone Medical Center said epidural hematoma injuries were treatable if detected early enough:
"This is a very treatable condition if you're aware of what the problem is and the patient is quickly transferred to a hospital," he said. "But there is very little time to correct this."
A CT scan can detect bleeding, bruising or the beginning of swelling after an injury. The challenge is for patients to know whether to seek one.
Treatment of epidural hematoma depends on the size of the clot and area of the brain affected.
As with other types of intracranial hematomas, the blood may be aspirated surgically to remove the mass and reduce the pressure it puts on the brain. The hematoma is neurosurgically evacuated through a burr hole or craniotomy. The diagnosis of epidural hematoma requires a patient to be cared for in a facility with a neurosurgeon on call to decompress the hematoma if necessary and stop the bleed by ligating the injured vessel branches.
Patients' prognosis is generally better if they had a "lucid interval" after the injury - although this is relatively rare. Natasha Richardson was reported to have appeared to be fine after the accident, laughing it off, before her condition worsened.
Fewer than 20% of patients demonstrate the classic presentation of a lucid interval between the initial trauma and subsequent neurological deterioration.