What Is It?
A subdural hematoma is a mass of blood below the dura mater (the leathery outer covering of the brain and spinal cord) and above the arachnoid membrane (the middle of three coverings of the brain and spinal cord).
Subdural hematomas generally occur after a traumatic brain injury. With head trauma, veins that traverse the subdural space can be torn, leading to bleeding into this normally empty space.
In younger patients, subdural bleeds generally occur with quite severe head trauma and present acutely as an acute subdural. They often occur along with other intracranial injuries.
In elderly patients, whose brains are atrophied somewhat, a subdural can occur from relatively minor trauma, often unnoticed by the patient. In these cases, the patients often do not present to medical care until days or even weeks after the initial bleed. These delayed presentations are often referred to as subacute or chronic subdurals.
In any cause or age group, a subdural hematoma, if large enough, can cause pressure on the underlying brain, even shifting the brain part-way from one side of the head to the other.
What Types of Symptoms Are Typical?
The presenting symptoms of subdural hematoma vary greatly. In the case of younger patients who have sustained a major head trauma, they generally present emergently to a trauma center with multiple traumatic injuries. These patients often have a depressed level of consciousness, usually in some level of coma. The level of consciousness and coma in an acutely head injured patient is often described by clinicians with the Glasgow Coma Scale
. Like other masses that cause shift of the brain, they can cause abnormal pupils in the eyes, referred to as a "blown" pupil or a fixed and dilated pupil.
In the case of elderly patients with a subacute or chronic bleed, they can present with changes in their level of consciousness as the hematoma expands. However, more commonly these patients present with headache, mood and personality changes and/or hemiparesis (weakness on one side of the body, opposite the side of the hematoma). The diagnosis in this case can be confused with depression, dementia and/or stroke.
How Is The Diagnosis Typically Made?
While a careful neurological examination can often indicate a mass in the head causing pressure on the brain, the definitive diagnosis is often made when a CT scan
or MRI scan
of the brain is obtained. These imaging studies can reveal the hematoma and help to characterize it as acute, subacute or chronic. The specific location and shape of the bleed can usually aid in differentiating a subdural from other hematomas that can occur in similar locations, such as an epidural hematoma
. These studies can also help to confirm the diagnosis and rule out other non-traumatic causes of the patient's symptoms.
What Are Some Common Treatments?
While the treatment plan for subdural hematoma varies depending on several factors, most symptomatic patients will undergo surgery. In acute trauma, a large craniotomy (an opening in the skull) is often needed to remove the large subdural bleed. In the case of older bleeds in elderly patients, sometimes smaller procedures such as bur holes or a drain can help to decompress the old blood.
These and other treatment decisions are variable depending on the specifics of each case. In the case of acute trauma, these decisions are often made on an emergent basis and the patient may be taken to the operating room immediately. Otherwise, these treatment decisions should be discussed with each patient's treating physician team.
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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.