What is Berry Aneurysm?
Berry aneurysms, also known as saccular aneurysms, are the most common type of brain aneurysm, accounting for 90% of all brain aneurysms. Simply put, this is a situation where a specific area in the blood vessel wall in the brain becomes weak and starts to balloon outward. Depending on the size of this bulge, the resulting symptoms can range from no symptoms at all to a severe brain bleed, specifically a subarachnoid hemorrhage, in the most extreme cases.
The term ‘berry aneurysm’ is an older term that has mostly been replaced by ‘saccular aneurysm’. However, both names refer to the same condition. The shift in terminology is primarily because medical experts prefer not to compare the condition to various fruits. The word ‘aneurysm’ itself comes from the Greek word ‘aneurysma’, which means ‘dilation’ or ‘expansion’.
What Causes Berry Aneurysm?
There are many factors that may increase your risk of developing an aneurysm – a bulge or “ballooning” in the wall of an artery. These include:
Genetic Factors:
* Certain conditions that weaken the walls of your arteries.
* A disease called polycystic kidney disease.
* Arteriovenous malformations, which are tangled blood vessels.
* Having two or more close relatives who’ve had an aneurysm.
Other Factors:
* High blood pressure that isn’t managed.
* Smoking cigarettes.
* Abusing drugs, like cocaine and amphetamines, which can greatly increase your blood pressure. Certain drugs can cause a type of aneurysm that’s linked to infection.
* Drinking alcohol heavily.
* Consuming a lot of caffeine.
Less Common Factors:
* Trauma to your head.
* Infections in your blood that reach the wall of an artery, causing an aneurysm.
There are also factors that can increase the risk of an existing aneurysm rupturing (or bursting):
* Smoking: This not only increases the risk of developing an aneurysm, but it can also lead to aneurysm growth and rupturing.
* High blood pressure: Over time, this can weaken the arteries, increasing the risk of aneurysms and making them more likely to rupture.
* Size: Larger aneurysms are more likely to rupture.
* Location: Aneurysms located in certain parts of the circulation system in the back of the brain are more likely to rupture.
* Growth: If an aneurysm grows over time, even if it’s small, there’s a higher risk of rupture.
* Family history: If aneurysms run in your family, your risk of rupture is higher.
People who’ve previously had an aneurysm rupture or bleed in the brain are at the highest risk of rupture. Other factors like irregular shape, the presence of multiple lobes, and other specific conditions can also increase the risk.
Risk Factors and Frequency for Berry Aneurysm
Cerebral aneurysms are medical conditions that affect between 3 to 5 percent of people. They are slightly more common in women and tend to be diagnosed around the age of 50. About 1 to 2 percent of these aneurysms rupture, leading to subarachnoid hemorrhage, a type of bleeding in the brain. Around 20 to 30 percent of people with aneurysms have more than one, and 85 percent of aneurysms are located in the front part of the brain’s blood circulation system, particularly in the circle of Willis, a network of arteries.
- Cerebral aneurysms occur in 3 to 5 percent of people.
- They are found in around 3.2 percent of people when looked for during an X-ray or autopsy.
- About 0.7 to 1.9 percent of aneurysms rupture, leading to a subarachnoid hemorrhage.
- The average age of diagnosis is 50.
- Aneurysms are more common in females.
- Twenty to thirty percent of patients with aneurysms actually have more than one.
- Most aneurysms, around 85 percent, are found in the anterior circulation, primarily in the circle of Willis.
Common locations for aneurysms in the anterior circulation are:
- The junction of the anterior communicating artery with the anterior cerebral artery.
- The junction of the posterior communicating artery with the internal carotid artery.
- The bifurcation of the middle cerebral artery.
In the posterior circulation, aneurysms are often found at:
- The top of the basilar artery, known as the basilar apex.
- The junction of the basilar artery and the superior or anterior inferior cerebellar arteries.
- The junction of the vertebral artery and the posterior inferior cerebellar artery.
Signs and Symptoms of Berry Aneurysm
Berry aneurysms are a medical condition that can present in a variety of ways, from severe manifestations like major rupture leading to a type of bleed known as subarachnoid hemorrhage, to minor bleeding events, or even situations where there are no symptoms and the issue is discovered by accident.
In the most severe cases, patients may be brought in for treatment in a critical state. In this situation, priority is given to the basics: securing the patient’s airway and breathing, and establishing good IV access. Amidst a trauma setting, the first priority is to assess the overall state of the patient without getting side-tracked by extensive extremity injuries. Once the patient is stable, the next step is immediate brain imaging.
Some patients may present less dramatically and need a detailed history and examination. This should focus on key elements including:
- Type of headache – if it’s a ‘worst headache of my life’ scenario or a thunderclap headache, it can suggest a subarachnoid hemorrhage. Even a headache that differs from usual ones should be seen as a possible warning sign.
- Level of consciousness – if the patient appears confused or less alert, this might be a sign of increased pressure within the skull impeding the brain’s oxygen supply.
- Seizures – these occur in about 25% of aneurysmal subarachnoid hemorrhage cases and can be either focal or generalized.
- Meningeal signs – these include neck pain or stiffness suggesting irritation of the meninges.
- Focal neurological deficits – any changes in strength, sensation, speech, or memory needs attention.
- Visual symptoms – blurred or double vision, or defects in the field of vision.
The physical examination should thoroughly assess various key aspects:
- A comprehensive neurological examination checking cranial nerves, limb and facial strength, sensations, speech, and possible meningeal irritation through Kernig’s and Brudzinski’s signs.
- An assessment of the head region, checking for signs of trauma like cuts, bruises, depressions or fractures in the skull. The ears should be examined for any blood behind the eardrum or cerebrospinal fluid leaks. The eyes should be checked for pupil response and for signs of trauma.
- The nose should be examined for fractures or any leak of cerebrospinal fluid.
Testing for Berry Aneurysm
Imaging
If the doctor suspects a certain condition, they could use several different options for scanning your head. One common scan is called a non-contrast CT (NCCT), which is a type of CT scan that doesn’t use a contrast dye to help visualize the body’s structures. CT angiography can also be used, especially if the first CT scan doesn’t reveal anything unusual. If these are not available or don’t provide clear enough images, MRI/MRA (different types of magnetic resonance imaging) scans can be used. In some circumstances, a formal cerebral catheter angiogram might be necessary. This is a more involved procedure where a tiny tube (catheter) is inserted into a blood vessel in the groin and threaded up to the blood vessels in the head for closer inspection.
Lumbar Puncture
In situations where a CT scan of the head doesn’t show anything unusual, a lumbar puncture might be necessary. A lumbar puncture is a procedure where a needle is inserted into the lower part of the spine to collect a sample of cerebrospinal fluid (CSF), which surrounds your brain and spinal cord. You might need a lumbar puncture if you have a strong family history of aneurysms, or ruptured aneurysms.
A lumbar puncture can also help diagnose other causes of a headache, such as meningitis or a condition called idiopathic intracranial hypertension. Among other things, the doctor will be looking for something called xanthochromia and a high red blood cell count in the CSF. Xanthochromia happens when blood has broken down and is leaking a substance called bilirubin into the CSF, causing it to take on a yellowish appearance.
Treatment Options for Berry Aneurysm
When a patient arrives in the emergency department with certain medical conditions, it’s crucial to manage their symptoms promptly. For example, within the first 24 hours, there’s an increased risk of serious complications like internal bleeding. We can reduce this risk by closely monitoring and controlling the patient’s blood pressure, aiming for a top number (systolic pressure) less than 140 mmHg.
Medications like Labetalol and Nicardipine are often selected as first-line treatments because they work effectively and quickly to lower blood pressure. We avoid certain drugs like Nitroglycerin and Nitroprusside, because these can actually increase the pressure inside the person’s skull.
Palette relief is another important aspect of patient care. Not only is it the compassionate thing to do, but managing pain can also help to control blood pressure, as high pain levels can cause blood pressure to rise.
If a patient feels nauseous, we can provide them with anti-nausea medication to keep them comfortable.
Another drug that may be used in this context is Nimodipine. Within the first four days of treatment, this medication can help decrease the constriction of blood vessels, which in turn improves blood flow.
To prevent seizures, which can further complicate the patient’s condition, medical professionals also begin treatment with an anti-seizure medication.
Overall, these initial actions in the emergency department aim to manage symptoms, stabilize the patient, and prevent further health complications.
What else can Berry Aneurysm be?
When a person has saccular aneurysms, a variety of health conditions could be causing their headaches. These conditions include:
- Tension, migraine, or cluster headaches
- Meningitis – an inflammation of the brain and spinal cord membranes
- Encephalitis – an acute inflammation of the brain
- Space-occupying lesions, such as tumors
- Pituitary masses, which are related to endocrine disorders
- Metabolic disturbances – changes in the body’s chemical processes
- Cerebral venous thrombosis – a blood clot in the brain’s venous sinuses
- Idiopathic intracranial hypertension – high pressure in the brain with no clear cause
- Temporal arteritis – an inflammation of the blood vessels
What to expect with Berry Aneurysm
Many aneurysms don’t cause patients any discomfort or health problems. However, if an aneurysm does burst, the severity of the situation depends on several factors. These include the patient’s previous neurological conditions, age, other medical conditions they may have, where the aneurysm is located, how long it took to see a doctor after the rupture, the severity of bleeding or hemorrhage and if they bleed again, whether the treatment for the aneurysm was successful, if spasms in the blood vessels occured after a few days, and finally, if the patient developed a build-up of fluid in their brain (hydrocephalus) or seizures.
Sadly, 25% of patients who have a ruptured aneurysm do not survive the first 24 hours. Of those who do initially survive, 25% pass away within the following 6 months due to other complications.
Possible Complications When Diagnosed with Berry Aneurysm
- Rebleeding: This refers to a condition where bleeding starts again after it had initially stopped.
- Hyponatremia: This is a condition characterized by low levels of sodium in your blood. Sodium is essential for many body functions including the maintenance of fluid balance, regulation of blood pressure, and normal function of the nervous system.
- Vasospasm: This is a condition where blood vessels tighten, reducing blood flow.
- Hydrocephalus: This is an abnormal buildup of fluid in the brain.
- Seizures: These are sudden, uncontrolled disturbances in the brain. They can cause changes in your behavior, movements, and levels of consciousness.
- Cardiac stress: This refers to strain on the heart. It can be caused by various factors such as high blood pressure or a heart attack.
Preventing Berry Aneurysm
It’s important for patients to understand how to use the emergency medical services (EMS) that are available to them, like emergency rooms. If a patient experiences a severe headache or a headache that is different from the ones they typically have, they should not hesitate to use the EMS to get expert advice from an emergency doctor.
