Subdural hematoma is defined as a collection of blood outside the brain below the dura mater.
Confusion and headache appears to be the most common presenting features as it is seen in as much as 90% to 56% of cases.
Following any form of head trauma, medical assessment including complete neurological examination should be conducted on the individual . Most of the time, a CT scan or MRI scan will usually show significant subdural hematomas.
Subdural hematomas are seen mostly around the sides and tops of the parietal and frontal lobes. They are also seen in the posterior cranial fossa as well as near the falx cereberi and tentorium cerebeli. Subdural hematomas can expand along the skull unlike epidural hematomas.
Following a CT scan, subdural hematomas appear crescent-shaped with a concave surface away from the skull. However, they can have a convex appearance especially in the early stage of bleeding.
Mortality for cases of subdural hematoma has been put at 36 to 79% . Most of the time, survivors are not able to regain previous levels of functionality especially following acute subdural hematoma that is serious enough to warrant surgical drainage. Positive outcomes in cases of subdural hematoma is seen 14 to 40% of the time.
Studies show that outcome is often favourable in younger patients .
The main causes of acute subdural hematoma may include any of the following :
The main causes of chronic subdural hematoma include the following:
Risk factors for chronic subdural hematoma include the following:
Acute subdural hematomas have been noted to occur in 5 to 25% of patients that have severe head injuries with annual cases reported to be 1 to 5.3 cases per 100,000 population . Some of the more recent studies show a higher incidence but this may be as a result of better imaging techniques.
There is sexual preponderance as SDH is seen more in men than in women. Male to female ratio is approximately 3:1. Men equally have a higher incidence of chronic subdural hematoma. The male to female ratio for chronic subdural hematoma is 2:1.
The incidence of chronic subdural hematoma is believed to be at its peak within the fifth to seventh decades of life.
Most of the time, the torn blood vessel is a bridging vein which connects the cortical surface of the brain to a dural sinus. In elderly individuals, the dural sinus may already be stretched due to brain atrophy.
Alternatively, a direct injury or laceration can damage a cortical vessel which may be a vein or artery. Acute subdural hematoma as a result of a ruptured cortical artery may be associated with only a minor head injury possibly without any associated cerebral contusion. Arterial injury may result in rapid neurological decline. In some instances, the ruptured cortical arteries were found located around the sylvian fissure. Generally, low-pressure venous bleeding from bridging veins occurs along the convexity.
The head trauma may equally also cause associated brain hematomas or contusions as well as subarachnoid hemorrhage or diffusing axonal injury. Secondary brain injuries can include secondary haemorrhage, brain herniation, infarction or edema.
Chronic subdural hematomas develop over a time of days to weeks, often after minor head injury. They may not be discovered until they present clinically after a while.
A subdural hematoma (SDH) refers to the collection of blood outside the brain below the dura mater . This condition is generally occurs due to severe head injuries and causes increased bleeding and pressure on the brain. This makes it a life-threatening condition. Subdural hematomas often require surgical drainage but in many cases, they resolve and stop without any external interventions.
Subdural hematoma refers to a situation where a vessle get ruptured between the brain and the dura matter. The dura matter refers to one of the three membrane layers that cover your brain. The leaking blood forms a kind of clot which compresses the tissues of the brain. If the clot (hematoma) continues to enlarge, a progressive decline in consciousness often follows and this often leads to death when untreated. Treatment is mostly via surgery.