Definition of Subdural Hematoma (SDH) Disease
A subdural hematoma (SDH) is an accumulation of blood that forms between the dural and arachnoid membranes covering the brain. This accumulation is usually caused by a tear in the veins in this space, but can sometimes involve an arterial source. The SDH often appears crescent-shaped on medical images, as the bleeding follows the contour of the dura mater. It can occur along the cerebral convexities, between the cerebral and cerebellar hemispheres, or around the brainstem.
Symptoms
Clinical manifestations:
The symptoms of a subdural hematoma vary depending on its severity and location. Common symptoms include:
- Weakness: Decreased muscle strength.
- Numbness: Reduced sensation in certain parts of the body.
- Visual disturbances: Altered vision or loss of vision.
- Seizures: Convulsions or fits.
- Coma: In severe cases, especially with severe head trauma.
An SDH can also be asymptomatic and discovered incidentally during imaging for other reasons.
Causes of Subdural Hematoma
Etiology of SDH:
- Head trauma: The most common cause of SDH, often related to road accidents, falls, or assaults.
- Arterial causes: Intracerebral hemorrhage, rupture of a cerebral aneurysm, arteriovenous malformation, or vasculopathy.
- Neoplasms: Brain tumors, particularly metastases from the breast, prostate, lungs, or lymphomas.
- Intracranial hypotension: Decrease in cerebrospinal fluid pressure due to a leak, for example after a lumbar puncture or neurosurgical intervention.
Treatment
The treatment of subdural hematoma depends on its severity, origin, and the symptoms presented by the patient:
- Surgery: In severe cases or when the SDH causes significant neurological symptoms, surgical intervention may be necessary to drain the hematoma.
- Observation: For asymptomatic or small SDHs, close monitoring may be sufficient.
- Conservative treatment: Administration of anticoagulants or other treatments depending on the origin of the SDH.
Use of Medical Imaging
Medical imaging is crucial for diagnosing subdural hematoma, assessing its severity, and planning the most appropriate treatment.
- Non-contrast brain computed tomography (CT): This is the imaging test of choice for diagnosing a subdural hematoma. CT allows for rapid visualization of the presence of blood in the subdural space and determination of the size and location of the hematoma.
- Magnetic resonance imaging (MRI): Although more time-consuming and less accessible, MRI is useful for detecting small chronic subdural hematomas and identifying potential underlying causes. It is also useful for patients with contraindications to CT or for follow-up examinations.
Source: UpToDate