Neurology
Summary
A subdural hematoma is a collection of blood between the dura and arachnoid space secondary to the rupture of bridging veins. This trauma commonly occurs in cases such as falls in the elderly and alcoholics, non-accidental injuries in pediatric patients (such as shaken baby syndrome), or iatrogenic causes like a CSF leak following a lumbar puncture or epidural placement. The use of anticoagulants, cocaine abuse, or having diagnosis of a meningioma, brain metastasis, platelet disorders, vascular abnormalities or dural venous thrombosis can place patients at higher risk for a spontaneous subdural hematoma.
The clinical presentation of a subdural hematoma can be acute (with symptoms occurring within 3 days of the inciting event) or chronic (with more insidious symptoms that may take over 3 weeks to appear). Subdural hematomas may present with symptoms such as headaches, nausea, vomiting, focal neurologic deficits, seizures, or may even be asymptomatic. The first most appropriate test is a CT scan without contrast, which may show a concave area of blood that does not cross the midline. The treatment for subdural hematomas involves the immediate reversal of anticoagulation, potential neurosurgical intervention or decompression of the cranium, and close observation possibly requiring repeat CT scans.
Lesson Outline
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FAQs
A subdural hematoma is a collection of blood between the dura and arachnoid space due to the tearing of bridging veins. This can occur due to several reasons, the most common being trauma secondary to falls especially in elderly and alcoholics. Non-accidental injuries (like shaken baby syndrome) in pediatric patients is also another cause. Some iatrogenic causes-- like a CSF leak following a lumbar puncture or epidural placement-- can lead to decreased intracranial pressure which can direct stress the bridging veins and cause them to tear as a result.
Risk factors for a spontaneous subdural hematoma include persons on antithrombotic therapy, those with cerebral atrophy, platelet disorders, or the presence of a meningioma or metastasis. Individuals with vascular abnormalities such as aneurysms or arteriovenous malformations, or patients with dural venous thrombosis, are also at higher risk.
Acute subdural hematoma symptoms usually appear within 3 days of the inciting event and are more common in young adults. Chronic subdural hematomas, on the other hand, have an insidious onset generally lasting greater than 3 weeks and are more common in the elderly population.
Patients with a subdural hematoma may present with a variety of neurologic symptoms including headache, confusion, nausea, dizziness, hemiparesis, hemisensory deficit, aphasia, altered level of consciousness, seizures, or even coma.
A subdural hematoma is typically diagnosed with a CT scan of the head without contrast. This scan will often show a crescent-shaped, concave area of blood that does not cross the midline but can cross suture lines. Treatment often includes reversal of anticoagulation, and all patients should be closely observed with frequent neurologic exams and serial CT scans. Depending on the clinical status, size of the hematoma, and the presence of any midline shift, neurosurgical intervention may be required.
