Hemorrhagic conversion can occur naturally or be a consequence of tissue plasminogen activator (tPA)—the go-to emergency stroke treatment.
This article discusses the causes, symptoms, diagnosis, and treatment of hemorrhagic conversion. It also covers who is most at risk and why there are circumstances under which both using tPA and not using it can cause HC.
Hemorrhagic Conversion Symptoms
Hemorrhagic transformations usually happen one or two weeks after a stroke begins. In about 9% of cases, HC happens within 24 hours.
Bleeding in the brain causes numerous cognitive and physical symptoms, including:
Headache Nausea or vomiting Loss of consciousness Weakness or numbness in the face, arm, or leg, usually on one side of the body Vision loss Seizures: Around 5% to 10% of people will have one within the first two weeks of hemorrhagic conversion.
Depending on how soon after the stroke HC occurs, symptoms may seem like an effect of the original stroke rather than a separate event.
Symptoms often progress gradually over the course of minutes or hours. Other times, the stroke survivor’s condition may suddenly and rapidly decline as the hemorrhagic conversion takes place.
That said, there are many cases in which there are no signs that hemorrhagic conversion is occurring. The bleed may not be detected until a computed tomography (CT) scan of the brain is done.
In a study of 1,789 people who had ischemic strokes, only 1.4% (25 people) experienced HC with symptoms, while 8% (143 people) experienced HC with no symptoms at all.
Complications
During a hemorrhagic conversion, blood pools within the brain and between brain tissues and the skull. This prevents oxygen circulating in the blood from reaching the brain and causes tissue damage.
As blood collects, it also places immense pressure on the brain, heightening the degree of brain damage.
Both of these can have significant effects. Related complications vary from person to person.
Most notably, hemorrhagic transformation carries a significant risk of death. Approximately 40% of people die within one month of their brain hemorrhage and 54% of people die within one year.
Those who survive are likely to have some form of physical or cognitive disability that can last for six months or more.
Possible long-term disabilities following hemorrhagic transformation include:
Communication problems: One may have difficulty speaking or understanding what someone else is saying, a condition known as aphasia. Loss of vision, hearing, or touch: Some senses may be impaired by the brain bleed, which can make performing many tasks especially challenging. Muscle weakness or paralysis: Trouble walking, balancing, or controlling muscles are all possible after a brain hemorrhage. This increases the risk of falling.
Certain disabilities are related to the area of the brain damaged by the bleeding. For example:
If a person’s visual cortex is damaged, they may have vision-related complications. If a person’s forebrain or brainstem are damaged, they may lose bladder control and need a catheter until they can urinate on their own. Brainstem or cortex damage can also paralyze the tongue, resulting in trouble swallowing (dysphagia) and increased risk of choking.
Between 12% and 39% of people maintain long-term functional independence after their brain hemorrhage. This means that they are able to continue their lives without a permanent need for help with everyday-life tasks, such as self-care, communication, movement, and problem-solving.
Research indicates that whether or not HC symptoms were initially present makes no difference in long-term outcomes or survival past one year.
Causes
Stroke quickly destroys brain cells and damages the brain’s blood vessels, making it harder for them to retain blood. The most common form of stroke is ischemic stroke, which is usually caused by a blood clot that clogs an artery, blocking blood flow and oxygen to the brain.
Restoring blood flow (recanalization) is the immediate goal of stroke treatment. It may happen on its own in the hours or days after the stroke as the damaged tissues heal, or with the help of a thrombolytic (namely, tPA).
Thrombolytics are drugs that dissolve the blood clot that is causing the stroke. They quickly get blood flowing to the brain to prevent as much brain damage as possible.
Unfortunately, damaged blood vessels can rupture and bleed into the brain when blood starts to pour back in. This is hemorrhagic conversion.
Between 10% and 15% of people who have an ischemic stroke develop hemorrhagic conversion.
How soon HC occurs following an ischemic stroke depends on several factors, including:
How much brain tissued was damaged by the strokeWhat treatment was given, if any, and whenHow soon blood flow was restored
Risk Factors
Your risk of hemorrhagic conversion increases with your risk of ischemic stroke. You are more likely to have an ischemic stroke if you have one or more of the following conditions:
High blood pressure Diabetes Heart disease Vascular disease High LDL cholesterol
Not everyone who has an ischemic stroke develops HC, though. The older you are, the more likely you are to develop HC. Your risk is also higher if:
Your stroke damaged a large amount of brain tissue You have high blood pressure You have high blood sugar You have a low platelet count in your blood, which puts you at greater risk for uncontrolled bleeding
Lastly, the risk of hemorrhagic conversion is especially high in the hours and days following thrombolysis—the process in which blood flow to the brain is restored using a thrombolytic drug.
Doctors must weigh risk factors quickly and carefully to keep the risk of hemorrhagic conversion as low as possible when treating a stroke patient.
Window for Using tPA
Tissue plasminogen activator is the mainstay of emergency treatment for ischemic stroke. It is highly regarded as a life-saving treatment that restores blood flow and prevents further tissue damage.
Activase (alteplase) is the only tPA approved by the U.S. Food and Drug Administration (FDA) to treat ischemic stroke. This potent blood thinner is given through an IV in the arm. It is capable of dissolving 75% of a stroke-causing blood clot within eight minutes.
One study found that people who were given alteplase were 37% less likely to die from stroke-related complications than people who weren’t. Researchers also found that those who received the treatment were more independent and experienced less disability in the five years after their stroke than those who did get the drug.
Furthermore, approximately 15% of ischemic stroke survivors who are not given thrombolytic treatment develop hemorrhagic conversion within 14 days of their stroke.
The benefits are impressive. But there is a catch: Alteplase is only safe and effective when given within three hours of the first stroke symptoms appearing.
Beyond that time, blood vessels are likely too fragile and can more easily rupture when blood flow suddenly returns, heightening the risk of hemorrhagic conversion. The brain tissue damage caused by the stroke is also likely too extensive for the treatment to help.
Note that risk factors for uncontrolled bleeding in the brain can also make you ineligible to receive tPA treatment. These include:
Being older than 75 History of internal bleeding Uncontrolled high blood pressure Blood sugar that is too high or too low Use of blood-thinning medication, like warfarin Severe head trauma, stroke, or heart attack within the previous three months Major surgery, such as coronary bypass surgery, within the previous three months
Diagnosis
According to the American Heart Association, those who are given alteplase should be closely monitored for at least 24 hours in the ICU or stroke unit.
During this time, doctors will keep close tabs on the patient’s blood pressure and routinely check for nausea or vomiting, vision changes, trouble speaking, confusion, or other signs that their neurological state is worsening.
Should any such changes occur, the patient will immediately be taken for a CT scan to check for a brain hemorrhage.
And because hemorrhagic transformations do not always cause symptoms, all patients who receive alteplase should be given several CT scans throughout the first 24 hours to monitor for the condition.
If a patient returns to the hospital with HC symptoms, doctors will follow the same protocol that was used to monitor for HC in the first 24 hours after their stroke.
Hemorrhagic Conversion Treatment
Hemorrhagic conversion is treated like any other brain hemorrhage, with the primary focuses being:
Stopping the bleeding Controlling blood pressure Addressing neurological changes Reducing pressure around the brain Treating any complications that arise, such as seizures
As soon as the hemorrhagic conversion is diagnosed, doctors will likely begin by giving a IV transfusion of cryoprecipitate—a fluid derived from plasma that stops bleeding by clotting blood.
Next, the focus turns to lowering blood pressure and stopping the pool of blood (hematoma) from expanding.
If blood flow has already returned, doctors will try to keep their patient’s blood pressure below 180/105. Blood pressure-lowering (antihypertensive) medications that may be used to accomplish this include angiotensin-converting enzyme (ACE) inhibitors, beta blockers, and calcium channel blockers.
If complete recanalization has not occurred, blood pressure will need to be kept slightly higher to ensure enough oxygen reaches the brain. Doctors may use a blood vessel-narrowing medication like norepinephrine to raise blood pressure at a controlled rate.
To relieve pressure on the brain, a type of surgery called hematoma evacuation may be necessary to suction up the blood. How the surgeon performs this procedure depends on the size of the hematoma.
For smaller hematomas, the surgeon may suction the blood through small burr holes that they will make in the skull. For larger hematomas, the surgeon may perform a hemicraniectomy, in which a large flap of the skull is removed to suction the blood and relieve pressure.
The portion of the skull that is removed during a hemicraniectomy may either be replaced at the end of the surgery or in a separate surgery months later, when the patient has recovered. This separate surgery is known as a cranioplasty.
Throughout the treatment process, doctors and their patients will need to carefully weigh the risks and benefits of each treatment and only proceed with those that improve the patient’s chance of survival.
While some people may be able to return home within days of their hemorrhagic conversion, others may need care (short- or long-term) in a rehabilitation facility.
Summary
Hemorrhagic conversion occurs when blood vessels in the brain rupture after blood flow is restored to the brain after a stroke. HC can cause stroke-like symptoms, as well as complications that can have lasting effects, including disability and death.
The risk of hemorrhagic conversion increases drastically the longer stroke treatment is delayed. But while it can happen to people who are not given tPA—the standard emergency drug treatment—it can also happen to those who get it too late (i.e., more than three hours after their stroke started).
Doctors carefully monitor for HC while stroke patients are in the hospital, and patients who experience symptoms in the week or two after their stroke—even if while back at home—should seek immediate medical attention.
A Word From Verywell
“Time is brain” is a phrase meant to convey that every minute that passes during a stroke, more brain cells die and the risk of brain hemorrhage increases.
Know the signs of stroke and call 911 if you notice or even suspect them. Never drive yourself to the hospital.
Medics will be able to start treatment immediately, and some mobile stroke units can even take a CT scan of your brain and begin tPA treatment en route to the hospital.
