Subdural empyema

Subdural Empyema is a form of intracranial infection characterized by the accumulation of pus between the dura mater and the arachnoid mater, the outer and middle layers of the meninges that surround the brain. It is a rare but serious condition that requires prompt medical attention to prevent potentially life-threatening complications.

Causes

Subdural empyema is most commonly caused by the spread of a bacterial infection from another location in the body, such as the sinuses, ears, or teeth. The bacteria can reach the subdural space through the bloodstream or by direct extension from an adjacent infected area. The most common bacteria involved include Streptococcus spp., Staphylococcus aureus, and various anaerobes.

Symptoms

The symptoms of subdural empyema can develop rapidly and may include severe headache, fever, nausea and vomiting, lethargy, and seizures. As the condition progresses, neurological deficits such as hemiparesis (weakness on one side of the body), aphasia (difficulty with speech), and changes in consciousness may occur.

Diagnosis

Diagnosis of subdural empyema involves a combination of clinical assessment, laboratory tests, and imaging studies. Magnetic resonance imaging (MRI) or computed tomography (CT) scans are crucial for visualizing the extent of the infection and guiding treatment. Lumbar puncture is generally avoided as it may lead to brain herniation due to the pressure differential.

Treatment

Treatment of subdural empyema requires a two-pronged approach: surgical intervention to drain the pus and antibiotic therapy to eradicate the infection. Surgical options include burr hole drainage or craniotomy, depending on the size and location of the empyema. Antibiotic therapy is typically broad-spectrum initially, tailored based on culture results.

Complications

If not treated promptly, subdural empyema can lead to serious complications, including brain abscess, seizures, hydrocephalus (accumulation of fluid in the brain), and meningitis. Long-term neurological deficits may persist even after treatment.

Prevention

Preventing subdural empyema involves treating sinus, ear, and dental infections promptly and effectively to prevent the spread of infection to the brain. Vaccination against common pathogens like Streptococcus pneumoniae and Haemophilus influenzae type b can also reduce the risk.

Prognosis

The prognosis for subdural empyema depends on the speed of diagnosis and treatment. Early intervention can lead to full recovery, but delays in treatment can result in permanent neurological damage or death.