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Medical Author:

Benjamin Wedro, MD, FACEP, FAAEM

Benjamin Wedro, MD, FACEP, FAAEM

Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.

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Medical Editor:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Brain Aneurysm Diagnosis

Brain Aneurysm Exams and Tests

When a patient who has a headache presents for medical care, the concern in the back of the physician's mind is whether an aneurysm exists and has ruptured. Because up to half of aneurysms have a sentinel leak prior to completely rupturing, the first headache presentation is an opportunity to intervene and potentially prevent that rupture.

If the patient is awake, alert, and oriented, there is time to ask questions and learn about when the headache started, where it is located, and if there are any other associated symptoms like nausea, vomiting, change in vision or hearing, weakness, numbness, and neck pain.

If the patient is lethargic or not completely awake, initial steps will include evaluation of the ABCs of resuscitation (or CABs, according to new resuscitation guidelines) -- airway, breathing, and circulation -- to make certain that the patient is stable before proceeding any further.

The Glasgow Coma Scale is a quick test that is done to assess the basic wakefulness of a patient. It can also help document the level of coma if the patient is not completely awake. This scoring system focuses on eye opening, speech, and movement.

The physical exam will focus on the neurologic status of the patient and usually includes the following:

• evaluation of the pupils to see if they are round and reactive;
• assessment of the cranial nerves that help the face, mouth, and tongue move and feel;
• evaluation of the eyes via a fundoscopic exam;
• examination of the back of the eyes with a light to view the optic nerve (It is the one nerve that leaves the brain that can be directly visualized and may give clues as to whether there is increased pressure within the brain.);
• assessment of the movement, sensation, and reflexes of the extremities; and
• assessment of balance and coordination.

The doctor will also check for neck stiffness and meningismus, a condition that features meningitis-like symptoms without inflammation of the meninges (the membranes that cover the brain and spinal cord). When blood leaks from a cerebral aneurysm, it enters the subarachnoid space and causes the tissues that surround the brain to become inflamed. This causes involuntary stiffness of the neck. The patient does not complain about soreness when moving the neck; instead, the stiffness makes it difficult for the doctor to flex or bend the neck because it is being held rigid by the surrounding muscles.

Patients often describe the symptoms of a leaking brain aneurysm and subarachnoid hemorrhage as “the worst headache of their life”. While this compliant is of concern, the decision to pursue that diagnosis requires that the findings of the physical examination be consistent with an ill appearing patient who is at risk for brain aneurysm.

A CT scan of the head without contrast is the first test to look for leaking blood in the brain. The CT is 95% sensitive for detecting a leaking aneurysm, although it cannot tell exactly where the bleeding comes from.

If the suspicion remains high that a brain aneurysm is present, the next test to be performed is a lumbar puncture (LP). With the patient either lying on their side or sitting up, a small needle is inserted through the skin in the lower part of the back between the vertebrae of the lumbar spine and into the subarachnoid space. A few drops of cerebrospinal fluid (CSF) is withdrawn and analyzed in the laboratory. The CSF surrounds the spinal cord and brain and provides them with nutrients. The CSF normally contains no red or white blood cells. If the analysis shows a significant numbers of red blood cells, it may indicate that bleeding has occurred and that the aneurysm has leaked, even though the bleeding could not be seen on a CT scan. The fluid is also checked for white blood cells and bacteria to exclude meningitis and encephalitis as potential causes of the symptoms.

Angiography is the definitive test to make the diagnosis of a leaking brain aneurysm. A small tube is threaded into the arteries of the neck and dye is injected to outline the arteries of the brain to look for abnormalities in the anatomy, including a brain aneurysm. Other tests may be needed to help stabilize and assess the patient.

EKGs and monitors may help look for changing heart rhythms. Increased pressure in the brain can cause changes in the blood pressure, heart rate, heart rhythm, and alterations in the electrical conduction of the heart. Routine blood tests are often done to check for anemia, blood clotting, electrolyte levels, and kidney function. An EEG may be done if the patient has a seizure, which is sometimes a complication of a bleeding brain aneurysm.

While most cerebral aneurysms are due to weakness of a blood vessel wall in the brain, others may be due to an infection or cancer (rarely). Should that be the case, other tests might be necessary.