Other names : Subdural hemorrhage or intracranial hematoma. More broadly, it is also a type of traumatic brain injury (TBI).
Description:
A subdural hematoma (SDH) is a type of bleeding in which a collection of blood—usually associated with a traumatic brain injury—gathers between the inner layer of the dura mater and the arachnoid mater of the meninges surrounding the brain. It usually results from tears in bridging veins that cross the subdural space.
Subdural hematomas may cause an increase in the pressure inside the skull, which in turn can cause compression of and damage to delicate brain tissue. Acute subdural hematomas are often life-threatening. Chronic subdural hematomas have a better prognosis if properly managed.
In contrast, epidural hematomas are usually caused by tears in arteries, resulting in a build-up of blood between the dura mater and the skull. The third type of brain hemorrhage, known as a subarachnoid hemorrhage, causes bleeding into the subarachnoid space between the arachnoid mater and the pia mater.
Types:
Acute: This is the most dangerous type of subdural hematoma. Symptoms are severe and appear right after a head injury, often within minutes to hours. Pressure on the brain increases quickly as the blood pools. If not diagnosed and treated quickly, you could lose consciousness, become paralyzed or even die.
Subacute: Symptoms usually appear hours to days or even weeks after the head injury. A subacute subdural hematoma can occur with a concussion.
Chronic: This type of hematoma is more common in older people. Bleeding occurs slowly and symptoms may not appear for weeks or months. Even minor head injuries can cause chronic subdural hematomas. Due to the delay in developing symptoms, an older person may not even recall how their head injury happened. Also, the changes can be so subtle and occur so slowly that symptoms may not be noticed by the older person or their friends or family.
Symptoms:
*Headache that doesn’t go away. (Headache is usually severe in the case of acute subdural hematoma.)
Confusion and drowsiness.
*Nausea and vomiting.
*Slurred speech and changes in vision.
*Dizziness, loss of balance, difficulty walking.
*Weakness on one side of the body.
*Memory loss, disorientation, and personality changes, especially in older adults with chronic subdural hematoma.
*Enlarged head in babies, whose soft skulls can enlarge as blood collects.
As bleeding continues and the pressure in the brain increases, symptoms can get worse. Symptoms, at this point, include:
*Paralysis.
*Seizures.
*Breathing problems.
*Loss of consciousness and coma.
Sometimes people have no symptoms immediately following a head injury. This is called a lucid interval. They develop symptoms days later. Also, it’s important to know that subdural hematomas that develop more slowly (the chronic type) might be mistaken for other conditions, such as a brain tumor or stroke.
Special note about head injury and symptoms in seniors: Some of the symptoms of subdural hematoma in older people, like memory loss, confusion, and personality changes, could be mistaken for dementia. The older person may not remember hitting their head. Sometimes, people forget because they are disoriented. Other times, the injury was minor and may have occurred weeks before symptoms appeared. They should still see their healthcare provider for evaluation.
Causes:
Subdural hematomas are most often caused by head injury, in which rapidly changing velocities within the skull may stretch and tear small bridging veins. Much more common than epidural hemorrhages, subdural hemorrhages generally result from shearing injuries due to various rotational or linear forces. There are claims that they can occur in cases of shaken baby syndrome, although there is no strong scientific evidence for this.
They are also commonly seen in the elderly and in people with an alcohol use disorder who have evidence of cerebral atrophy. Cerebral atrophy increases the length the bridging veins have to traverse between the two meningeal layers, thus increasing the likelihood of shearing forces causing a tear. It is also more common in patients on anticoagulants or antiplatelet medications, such as warfarin and aspirin, respectively. People on these medications can have a subdural hematoma after a relatively minor traumatic event. Another cause can be a reduction in cerebrospinal fluid pressure, which can reduce pressure in the subarachnoid space, pulling the arachnoid away from the dura mater and leading to a rupture of the blood vessels.
Risk factors:
Factors increasing the risk of a subdural hematoma include very young or very old age. As the brain shrinks with age, the subdural space enlarges and the veins that traverse the space must cover a wider distance, making them more vulnerable to tears. The elderly also have more brittle veins, making chronic subdural bleeds more common. Infants, too, have larger subdural spaces and are more predisposed to subdural bleeds than are young adults. It is often claimed that subdural hematoma is a common finding in shaken baby syndrome, although there is no science to support this. In juveniles, an arachnoid cyst is a risk factor for subdural hematoma.
Other risk factors include taking blood thinners (anticoagulants), long-term excessive alcohol consumption, dementia, and cerebrospinal fluid leaks.
Diagnosis:
First, the doctor will do a thorough physical and neurological exam. Then the patients will be asked about the head injury (when and how it occurred, review the symptoms and other medical problems, review about the medications the patients are taking and ask about other lifestyle habits). The neurology exam will include blood pressure checks, vision testing, balance and strength testing, as well as reflex tests and a memory check.
If the doctor thinks the patients may have a subdural hematoma, they will order a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan of their head. These imaging tests allow doctor to see clear pictures of the brain and determine the location and amount of bleeding or other head and neck injuries.
Treatment:
Doctors treat larger hematomas with decompression surgery. A surgeon drills one or more holes in the skull to drain the blood. Draining the blood relieves the pressure the blood buildup causes on the brain. Additional surgery may be needed to remove large or thick blood clots if present. Usually, the doctors leave a drain in place for several days following surgery to allow the blood to continue draining.
Sometimes hematomas cause few or no symptoms and are small enough that they don’t require surgical treatment. Bed rest, medications and observation may be all that is needed. The body can absorb the small amount of blood over time, usually a few months. The doctor may order regular imaging tests (such as an MRI) to monitor the hematoma and make sure it is healing.
Preventions:
Although it may not be possible to prevent a hematoma as a result of an accident,one can reduce the risk by:
*Protecting one’s head: Use your seatbelt and always wear a helmet when riding a bike or a motorcycle. If you play high-impact or contact sports, always wear a helmet. Use safety gear if one works off the ground or at a job with a high risk of head injury.
*Resting after a head injury: If one hve had a concussion, rest and allow the brain time to recover. The doctor will tell how long to rest before returning to work or previous activities. One should remember, a chronic subdural hematoma may not show symptoms for days, weeks and even months.
*Removing tripping hazards from your home – especially if you are elderly. Get rid of throw rugs; make sure electrical cords are tucked out of the way; add handrails to all stairs; add lights to stairways, hallways and dark areas; and position furniture so one always have something to hold on to as needs to walk through home. Use a cane or walker if the walking is unstable.
*Having vision checked regularly to prevent falls and accidents.
The doctor or pharmacist do a medication review. These professionals can check the side effects of medications to make sure they don’t cause dizziness or loss of balance. If they do, doses can be changed or a different drug may be able to be prescribed.
Drinking responsibly: Excessive alcohol consumption makes your brain more likely to bleed when injured. Avoid drinking more than two alcoholic beverages per day.
Being careful when taking blood thinners: Even minor head injuries can cause a subdural hematoma in people who take blood thinners. Talk to the doctor about needed precautions if one is on these medications. Examples include aspirin, warfarin, heparin and newer blood thinners like dabigatran (Pradaxa®), rivaroxaban (Xarelto®), apixiban (Eliquis®) and edoxaban (Savaysa®).
Prognosis:
Prognosis depends on the patient’s age, the severity of his or her head injury and how quickly received treatment. About 50% of people with large acute hematomas survive, though permanent brain damage often occurs as a result of the injury. Younger people have a higher chance of survival than older adults.
People with chronic subdural hematomas usually have the best prognosis, especially if they have few or no symptoms and remained awake and alert after the head injury.
Older adults have an increased risk of developing another bleed (hemorrhage) after recovering from a chronic subdural hematoma. This is because older brains cannot re-expand and fill the space where the blood was, leaving them more vulnerable to future brain bleeds with even minor head injuries.
Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.
Resources:
https://en.wikipedia.org/wiki/Subdural_hematoma
https://my.clevelandclinic.org/health/diseases/21183-subdural-hematoma
