Subdural hematoma

A type of bleeding in the brain

Subdural hematoma
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Headache, confusion, vomiting, slurred speech, coma
Complications	Brain herniation, seizures
Onset	Acute or chronic
Duration	N/A
Types	N/A
Causes	Head injury, anticoagulant use
Risks	Elderly, alcohol use, anticoagulant therapy
Diagnosis	CT scan, MRI
Differential diagnosis	N/A
Prevention	N/A
Treatment	Surgery, observation
Medication	N/A
Prognosis	Varies depending on severity and treatment
Frequency	Common in head injuries
Deaths	N/A

A subdural hematoma (SDH) is a type of intracranial hemorrhage where blood collects between the dura mater and the arachnoid mater of the brain. This condition can be life-threatening and requires prompt medical attention.

Pathophysiology

Subdural hematomas occur when there is a rupture of the bridging veins that traverse the subdural space. This can happen due to traumatic brain injury or spontaneously in individuals on anticoagulant therapy. The bleeding leads to increased intracranial pressure, which can cause brain tissue to shift, resulting in brain herniation.

Classification

Subdural hematomas are classified based on the timing of their presentation:

• Acute subdural hematoma: Develops within 72 hours of injury. It is often associated with severe head trauma and has a high mortality rate.
• Subacute subdural hematoma: Develops 3 to 7 days after the injury.
• Chronic subdural hematoma: Develops over weeks to months, often with minor or no known trauma, and is more common in the elderly.

Symptoms

Symptoms of a subdural hematoma can vary depending on the size and rate of bleeding. Common symptoms include:

• Severe headache
• Confusion
• Drowsiness or lethargy
• Nausea and vomiting
• Slurred speech
• Weakness or numbness
• Seizures
• Loss of consciousness

Diagnosis

Diagnosis is typically made using imaging studies such as a CT scan or MRI of the brain. These imaging modalities can reveal the presence of a hematoma and help assess its size and effect on surrounding brain structures.

Histological image of a subdural hematoma

CT scan showing a subdural hematoma

Treatment

Treatment depends on the size and symptoms of the hematoma. Options include:

• Observation: Small, asymptomatic hematomas may be monitored with serial imaging.
• Surgical intervention: Larger or symptomatic hematomas often require surgical evacuation. Techniques include:

 * Burr hole trephination: Drilling small holes in the skull to drain the hematoma.
 * Craniotomy: Removing a section of the skull to access and remove the hematoma.

Post-operative image of a chronic subdural hematoma after burr hole drainage

Prognosis

The prognosis of a subdural hematoma varies widely. Acute subdural hematomas have a higher mortality rate, especially if not treated promptly. Chronic subdural hematomas have a better prognosis, particularly if treated early.

Prevention

Preventive measures include:

• Using protective headgear during activities with a risk of head injury.
• Careful management of anticoagulant therapy.
• Fall prevention strategies in the elderly.

Also see

• Epidural hematoma
• Traumatic brain injury
• Intracranial hemorrhage
• Neurosurgery