Summary about Disease
A subdural hematoma (SDH) is a collection of blood between the dura mater (the tough outer membrane covering the brain) and the arachnoid mater (the next membrane layer covering the brain). It is usually caused by a head injury, where small veins that bridge the subdural space tear and bleed. SDHs can be acute (developing rapidly after a severe injury), subacute (developing over days or weeks), or chronic (developing over weeks or months after a relatively minor injury). They can put pressure on the brain, leading to neurological symptoms. SDHs are a serious condition and can be life-threatening.
Symptoms
Symptoms can vary depending on the size and location of the hematoma, as well as how quickly it develops.
Headache (can be persistent or fluctuating)
Confusion
Drowsiness
Change in behavior or personality
Nausea and vomiting
Slurred speech
Weakness or numbness on one side of the body
Seizures
Vision changes (e.g., blurred vision, double vision)
Difficulty walking or balancing
Loss of consciousness
Pupil asymmetry (one pupil larger than the other)
Causes
The primary cause of subdural hematomas is head trauma. This trauma can tear bridging veins that run between the surface of the brain and the dura. Other less common causes include:
Blood clotting disorders
Use of blood-thinning medications (anticoagulants, antiplatelet agents)
Alcoholism (may increase the risk of falls and also affect clotting)
Brain aneurysm or arteriovenous malformation (rare)
Spinal fluid leak (rare)
Medicine Used
Medications are not typically used to treat the hematoma itself, but may be used to manage symptoms or underlying conditions.
Antiseizure medications: To prevent or control seizures.
Pain relievers: To manage headache pain.
Medications to reduce brain swelling: Such as mannitol or hypertonic saline.
Medications to reverse anticoagulation: If the patient is on blood thinners, medications such as vitamin K or protamine sulfate may be used to reverse the effects of the medication.
Desmopressin (DDAVP) may be used to improve platelet function in patients taking antiplatelet agents. It is important to note that in many cases, surgery is the primary treatment for subdural hematomas.
Is Communicable
No, subdural hematomas are not communicable. They are caused by physical injury or underlying medical conditions and cannot be transmitted from person to person.
Precautions
Prevent Head Injuries: Wear helmets during activities that carry a risk of head injury (e.g., biking, skateboarding, skiing, contact sports). Seatbelts in vehicles.
Medication Management: If you are on blood-thinning medications, follow your doctor's instructions carefully and get regular checkups.
Fall Prevention: Take steps to prevent falls, especially if you are elderly or have balance problems. Remove hazards in the home, use assistive devices if needed, and ensure adequate lighting.
Limit Alcohol Consumption: Excessive alcohol consumption can increase the risk of falls.
Prompt Medical Attention: Seek immediate medical attention if you experience a head injury or symptoms suggestive of a subdural hematoma.
How long does an outbreak last?
Since subdural hematomas are not communicable, the concept of an "outbreak" does not apply. Each case is an individual event related to a specific injury or condition. However, the time it takes for a subdural hematoma to resolve or for symptoms to improve can vary greatly, from weeks to months, depending on the size and type of hematoma, the treatment received, and the individual's overall health.
How is it diagnosed?
Neurological Examination: Assesses mental status, reflexes, motor strength, sensation, and cranial nerve function.
CT Scan: The primary imaging study used to diagnose subdural hematomas. It can quickly and accurately show the presence, size, and location of the hematoma.
MRI Scan: May be used for more detailed imaging, especially in chronic subdural hematomas or when the CT scan is inconclusive.
Blood Tests: May be ordered to assess clotting factors and rule out bleeding disorders, especially if no obvious trauma is present.
Timeline of Symptoms
The timeline of symptom development depends on the type of SDH:
Acute SDH: Symptoms develop rapidly, usually within hours of the injury. These can include severe headache, loss of consciousness, and neurological deficits.
Subacute SDH: Symptoms develop over days or weeks after the injury. Symptoms may include headache, confusion, drowsiness, and mild neurological deficits.
Chronic SDH: Symptoms develop gradually over weeks or months after a minor head injury (often so minor that the person doesn't even remember it). The initial injury may not cause any immediate symptoms. Symptoms are often subtle and may include headache, cognitive impairment, personality changes, and gait disturbances. Symptoms may fluctuate over time.
Important Considerations
Early Diagnosis and Treatment: Early diagnosis and treatment are crucial to improve outcomes.
Underlying Medical Conditions: It's essential to address any underlying medical conditions that may contribute to the development of SDHs, such as bleeding disorders or anticoagulant use.
Surgical Intervention: The decision to operate depends on the size of the hematoma, the severity of symptoms, and the patient's overall condition. Not all SDHs require surgery.
Potential Complications: Complications of SDHs can include permanent brain damage, seizures, stroke, coma, and death.
Monitoring: Patients with SDHs require close monitoring for changes in neurological status.
Recurrence: Subdural hematomas can recur, particularly in individuals with underlying risk factors. Follow-up appointments are important.
Age: Elderly individuals are at higher risk for chronic subdural hematomas due to brain atrophy, which makes the bridging veins more susceptible to tearing.