Acute Subdural Hematoma

A 34-year-old driver was hit from behind at approximately 25 mph. He hit his head, but did not lose consciousness and did not seek care. Approximately 12 hours later, he developed a headache and confusion, and was taken to the emergency department by a family member. He was found to have an acute subdural hematoma . (Picture shown below). He was hospitalized, and a neurosurgeon was consulted for surgical management.

CT scan of an acute subdural hematoma (arrow) seen as a hyperdense clot with an irregular border. There is a midline shift from the mass effect of the accumulated blood.

Case Discussion

Subdural hematomas (SHs) can occur at any age, but are most common in infants and older adults. Most SHs are caused by trauma.

SHs by definition occur in the subdural space, most commonly seen in the parietal region

Clinical features: The clinical features are often nonspecific, making the diagnosis difficult in the absence of known trauma.
• Infants may present with drowsiness, irritability, poor tone, poor feeding, or new seizures.
• Older adults may present with headaches, confusion, subtle changes in mental status, gait disturbances, hemiparesis, or other focal neurologic signs.

Diagnosis: Acute Subdural Hematomas are seen easily on a non contrast CT scan (as in picture above). Subacute and chronic SHs can be similar in color to the brain parenchyma and may be easier to see on a contrast CT or an MRI.

Differential Diagnosis: Other causes of nonspecific symptoms seen with SH can be differentiated by neuroimaging and include the following:

• Infections such as sepsis or meningitis—Fever, elevated white blood cells, positive blood cultures, and cerebral spinal fluid consistent with meningitis.
• Hemorrhagic or ischemic stroke or transient ischemic attacks—Consider risk factors for stroke such as hypertension, diabetes, atrial fibrillation, and smoking
• Dementia or depression—Less acute onset, advanced age, and other symptoms consistent with depression.
• Primary or metastatic brain neoplasms—History of cancer and risk factors for cancer.

Other causes of intracranial bleeding can also be differentiated by neuroimaging and include the following:
• Epidural hematoma —Well-defined biconvex bright white density that resembles the shape of the lens of the eye.
• Subarachnoid hemorrhage —Bright white blood outlines cerebral sulci.
• Hemorrhage in brain parenchyma—Bright white lesion apart from dura.

Management:  Most SHs are managed surgically, and there is little evidence about
conservative management.
• Determine the Glasgow Coma Scale in patients with serious head trauma and consider airway protection in patients with a score less than 12.
• Obtain an urgent non contrast CT scan on any patient suspected of having an SH.
• If the non contrast CT scan is non revealing, obtain a contrast CT or MRI, particularly if the traumatic event occurred 2 to 3 days prior.
• Emergently refer patients with an SH and deteriorating neurologic status or evidence of brain edema or midline shift to a hospital with neurosurgeons.
• Consult a neurosurgeon expediently in patients with an SH and stable focal neurologic signs.
• Consider neurosurgical consultation in asymptomatic patient or patients with only a headache and a small acute SH without brain edema or midline shift. These patients may be followed by serial CT scans without surgical treatment, but this should be done in consultation with experts in CT interpretation and management of SHs.
• Evaluate any infant with an SH for child abuse or neglect.