What is a subdural hematoma?

A subdural hematoma is a collection of blood that develops beneath the skull, over the surface of the brain. It usually occurs as a result of a strike to the head, often from a fall. It is very common in the elderly, especially in patients who are taking blood thinners such as aspirin, clopidogrel (Plavix), warfarin (Coumadin), and apixaban (Eliquis), among others.

What are the symptoms?

The symptoms and severity of a subdural hematoma vary depending on the size (thickness) and location of the bleeding, along with how quickly it develops. Small subdural hematomas may have no symptoms. Larger hematomas can cause headaches, nausea, vomiting, weakness or numbness on one side of the body, balance problems, and seizures. If a subdural hematoma develops quickly and is large, it can be life-threatening; these hematomas can cause the symptoms above along with lethargy (sleepiness) and even coma.

How are subdural hematomas diagnosed and treated?

Subdural hematomas are diagnosed by a clinical history, physical examination, and a CT or MRI scan of the brain.

Treatment depends on the size and location of the hematoma as well as the patient's symptoms. All patients are prescribed a short course of anti-seizure medication (commonly 7 days of levetiracetam). This medication is needed because the hematoma can be irritating to the surface of the brain, temporarily raising the risk of a seizure. If a patient does not have seizures, the medication is stopped after a week.

Small subdural hematomas, particularly those with few or no symptoms, can often be observed and allowed to dissolve away on their own. This process usually takes several weeks. Your doctor may order a repeat CT scan to confirm that the hematoma has dissolved.

If a patient has severe symptoms and/or if a subdural hematoma is large, surgery may be needed. Two common forms of surgery are burr holes and craniotomy.

Craniotomy involves removing a part of the skull; we select this when the hematoma is relatively fresh and has a thick consistency. The piece of skull is plated back in place at the end of the operation.

Burr holes are dime-sized holes drilled into the skull to wash out a subdural hematoma. This procedure is less invasive than a craniotomy, but it is reserved for cases in which the subdural hematoma is older and therefore has a liquid consistency.

What can a patient expect after surgery for a subdural hematoma?

Surgery for a subdural hematoma is always performed as an inpatient, meaning you will stay overnight at least one or two nights in the hospital. Outcomes after surgery depend on many factors, including the size and location of the hematoma, the patient's overall health, and, most importantly, the patient's neurologic condition before surgery. The main risk of surgery is that the subdural hematoma can come back, especially if the patient has another head injury or resumes blood thinner medications. Fortunately, if treated promptly, most patients with subdural hematomas can make an excellent recovery.