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Aneurysms, Cardiac Arrest and Seizure Disorders

Aneurysms, heart attacks and seizures can each cause serious brain injury.

Read about ANEURYSMS




An aneurysm is a weak area in a blood vessel that usually enlarges. It’s often described as a “ballooning” of the blood vessel. When this occurs in the brain, it is called a cerebral aneurysm. About 1.5 to 5 percent of the general population has or will develop a cerebral aneurysm. About 3 to 5 million people in the United States have cerebral aneurysms, but most are not producing any symptoms. Between 0.5 and 3 percent of people with a brain aneurysm may suffer from bleeding.

People usually aren’t born with aneurysms. Most develop after age 40. Aneurysms usually develop at branching points of arteries and are caused by constant pressure from blood flow. They often enlarge slowly and become weaker as they grow, just as a balloon becomes weaker as it stretches. Aneurysms may be associated with other types of blood vessel disorders, such as fibromuscular dysplasia, cerebral arteritis or arterial dissection, but these are very unusual. They may run in families, but people are rarely born with a predisposition for aneurysms. Some aneurysms are due to infections, drugs such as amphetamines and cocaine that damage the brain’s blood vessels, or direct brain trauma from an accident.

What are the symptoms of an unruptured aneurysm?

Smaller aneurysms usually don’t have symptoms. But as an aneurysm enlarges, it can produce headaches or localized pain. If an aneurysm gets very large, it may produce pressure on the normal brain tissue or adjacent nerves. This pressure can cause difficulty with vision, numbness or weakness of an arm or leg, difficulty with memory or speech, or seizures.

What happens if an aneurysm bleeds?

If an aneurysm ruptures, it leaks blood into the space around the brain. This is called a “subarachnoid hemorrhage.” Depending on the amount of blood, it can produce:

  • a sudden severe headache that can last from several hours to days

  • nausea and vomiting

  • drowsiness and/or coma

The hemorrhage may also damage the brain directly, usually from bleeding into the brain itself. This is called a “hemorrhagic stroke.” This can lead to:

  • weakness or paralysis of an arm or leg

  • trouble speaking or understanding language

  • vision problems

  • seizures

What is the usual damage to the brain after an aneurysm ?

Once an aneurysm bleeds, the chance of death is 30 to 40 percent and the chance of moderate to severe brain damage is 20 to 35 percent, even if the aneurysm is treated. Fifteen to 30 percent of patients have only mild difficulties or almost none. If the aneurysm isn’t treated quickly enough, another bleed may occur from the already ruptured aneurysm.

In 15 to 20 percent of patients, vasospasm (irritation by the leaked blood causing narrowing of the blood vessels) may occur. This can lead to further brain damage. Other problems may include hydrocephalus (enlargement of the spaces within the brain that produce cerebrospinal fluid), difficulty breathing that requires a mechanical ventilator, and infection. Heart and lung problems may result due to extensive brain damage that can affect the body’s normal functions.

Source/Permalink: American Stroke Association

Cardiac Arrest

Cardiac arrest is the abrupt loss of heart function in a person who may or may not have diagnosed heart disease. Cardiac arrest may be caused by almost any known heart condition. Most cardiac arrests occur when the diseased heart's electrical system malfunctions, producing an abnormal rhythm such as ventricular tachycardia or ventricular fibrillation. Some cardiac arrests are caused by extreme slowing of the heart’s rhythm.


The majority of cardiac arrest survivors have some degree of brain injury and impaired consciousness. Some remain in a persistent vegetative state. Determining the survivor’s prognosis and making the decision to treat or to withdraw care is complicated and based on many variables (many of which have not been thoroughly studied).

Factors before cardiac arrest:

  • Age

  • Ethnicity

  • Poor health including diabetes, cancer, infection, kidney disease and stroke

Factors during cardiac arrest:

  • Time between collapse and start of CPR/defibrillation

  • Quality of CPR/defibrillation

  • Whether survivor had any neurological function during or immediately after CPR

Factors after cardiac arrest and resuscitation:

  • Neurological function: Generally, poor function equals poor prognosis but could be complicated by medical instability and treatments. Some patients suffer a stroke after a cardiac arrest.

  • Neurophysiologic function: tests include somatosensory evoked potentials (SSEP) and electroencephalogram (EEG).

  • Neuroimaging and monitoring: to determine structural brain injury — such as cranial CT, MRI, magnetic resonance spectroscopy, positron emission tomography (PET) — mostly to exclude hemorrhage or stroke.

  • Biochemistry: from blood or cerebrospinal fluid

  • Whether therapeutic hypothermia (intentionally lowering the patient's body temperature) was used. 

Source/Permalink: American Heart Association

Seizures and Seizure Disorders after Traumatic Brain Disorder

Seizures happen in 1 of every 10 people who have a TBI that required hospitalization. The seizure usually happens where there is a scar in the brain as a consequence of the injury.

During a seizure there is a sudden abnormal electrical disturbance in the brain that results in one or more of the following symptoms:

  •  Strange movement of the head, body, arms, legs, or eyes, such as stiffening or shaking.

  •  Unresponsiveness and staring.

  •  Chewing, lip smacking, or fumbling movements.

  •  Strange smell, sound, feeling, taste, or visual images.

  •  Sudden tiredness or dizziness.

  •  Not being able to speak or understand others.

  • A seizure in the first week after a brain injury is called an early post-traumatic seizure. About 25% of people who have an early post-traumatic seizure will have another seizure months or years later.

  • A seizure more than seven days after a brain injury is called a late post-traumatic seizure. About 80% of people who have a late post-traumatic seizure will have another seizure (epilepsy).

  • Having more than one seizure is called epilepsy. More than half the people with epilepsy will have this problem for their whole lives.

  • The cause of the brain injury can help doctors figure out how likely the patient is to have seizures.

  • 65% of people with brain injuries caused by bullet wounds have seizures.

  • 20% of people with ‘closed head injuries’ that cause bleeding between the brain and the skull experience seizures. A ‘closed head injury’ means the skull and brain contents were not penetrated in the injury.

  • Over 35% of people who need 2 or more brain surgeries after a brain injury experience late post-traumatic seizures.

  • Over 25% of people with bleeding on both sides of the brain, or who have a blood clot that must be removed by surgery, experience late post-traumatic seizures. 

How are post-TBI seizures treated?

An anti-seizure drug may be given during the first week after a moderate to severe TBI to avoid any additional brain damage that might be caused by a seizure. If seizure does occur, additional medications may be used. Medications that are used to control seizures are called anti-epileptic drugs (AEDs).


Source: “Seizures After Traumatic Brain Injury.” Craig Hospital, Jeffrey Englander MD, David X. Cifu MD, and Ramon Diaz-Arrastia MD, in collaboration with the Model Systems Knowledge Translation Center. PDF:

Please note: The information on this website is not meant to replace the advice of a medical professional. You should consult your health care provider regarding specific medical concerns or treatment.

Cardiac Arrest
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