Brain Aneurysm Diagnosis: Understanding the Tests and Screening

A sudden, excruciating headache, unlike any you’ve experienced before, or the emergence of other concerning symptoms could signal a serious underlying issue – a ruptured brain aneurysm. Prompt and accurate diagnosis is critical in such situations to determine if bleeding has occurred in the space surrounding your brain, known as a subarachnoid hemorrhage, or to identify other stroke-related conditions. Furthermore, even without rupture, certain symptoms might indicate the presence of an unruptured brain aneurysm, necessitating diagnostic evaluation.

When is Brain Aneurysm Diagnosis Needed?

The need for Brain Aneurysm Diagnosis typically arises in two scenarios: when symptoms suggest a ruptured aneurysm or when symptoms point towards an unruptured aneurysm.

Diagnosing a Ruptured Brain Aneurysm

A ruptured brain aneurysm is a medical emergency requiring immediate attention. The hallmark symptom is a sudden, severe headache, often described as a “thunderclap” headache, which reaches maximum intensity within seconds. This can be accompanied by:

• Nausea and vomiting
• Stiff neck
• Blurred or double vision
• Sensitivity to light
• Seizure
• Loss of consciousness

If you experience these symptoms, especially a sudden and severe headache, it is crucial to seek immediate medical attention. Doctors will employ various diagnostic tests to quickly determine if a subarachnoid hemorrhage has occurred and if a ruptured aneurysm is the cause.

Diagnosing an Unruptured Brain Aneurysm

Sometimes, an unruptured brain aneurysm can press on surrounding brain tissues or nerves, leading to milder, but persistent symptoms. These may include:

• Pain behind or above the eye
• Changes in vision, such as double vision or blurred vision
• Dilated pupils
• Weakness or numbness on one side of the face
• Difficulty speaking

While these symptoms are less dramatic than those of a ruptured aneurysm, they still warrant medical investigation. Diagnostic tests can help identify unruptured aneurysms and allow for proactive management.

Diagnostic Tests for Brain Aneurysms

Several sophisticated imaging techniques and procedures are available to diagnose brain aneurysms, both ruptured and unruptured. These tests help visualize the brain and blood vessels, enabling doctors to detect abnormalities.

CT Scan

A Computed Tomography (CT) scan is often the first-line diagnostic tool, particularly in emergency situations where a ruptured aneurysm is suspected. This specialized X-ray creates cross-sectional images, or “slices,” of the brain.

Alt Text: Radiologist examining a CT scan for brain aneurysm diagnosis, highlighting the importance of medical imaging in identifying cerebrovascular conditions.

A CT scan is highly effective in detecting bleeding in the brain, including subarachnoid hemorrhage, which is a key indicator of a ruptured aneurysm. It can also help rule out other causes of stroke.

For a more detailed view of the brain’s arteries, a CT angiogram may be performed. This involves injecting a contrast dye into a vein, which highlights the blood vessels on the CT images. CT angiography provides enhanced visualization of blood flow and can effectively detect the presence, size, and shape of brain aneurysms.

Lumbar Puncture (Spinal Tap)

If a subarachnoid hemorrhage is suspected based on symptoms, but the initial CT scan is inconclusive (doesn’t show bleeding), a lumbar puncture, also known as a spinal tap, may be performed. This procedure involves extracting a sample of cerebrospinal fluid (CSF), the fluid that surrounds the brain and spinal cord.

The presence of red blood cells in the CSF strongly suggests bleeding in the subarachnoid space. Lumbar puncture can be a crucial diagnostic step when a CT scan is negative but clinical suspicion of a ruptured aneurysm remains high.

MRI

Magnetic Resonance Imaging (MRI) utilizes strong magnetic fields and radio waves to produce detailed images of the brain. MRI scans can create both 2D and 3D images, offering a comprehensive view of brain structures.

MRI is excellent at detecting subtle bleeding in the brain and can provide more detailed information than a CT scan in some cases. Like CT angiography, MR angiography (MRA) is a specialized MRI technique that focuses on the arteries. MRA vividly portrays the blood vessels and is particularly useful in identifying unruptured aneurysms, assessing their size, shape, and precise location within the brain’s vascular network.

Cerebral Angiogram

Cerebral angiogram, also known as cerebral arteriogram, is a more invasive diagnostic procedure. It is typically reserved for situations where other non-invasive tests haven’t provided sufficient information, or when detailed visualization of the blood vessels is needed for treatment planning.

During a cerebral angiogram, a thin, flexible tube called a catheter is inserted into a large artery, usually in the groin or wrist. Guided by real-time imaging, the catheter is carefully threaded through the arteries, past the heart, and into the arteries of the brain. Once in position, a contrast dye is injected through the catheter, flowing into the brain’s arteries. A series of X-ray images are then taken, capturing detailed views of the arteries and revealing any abnormalities, including aneurysms. Cerebral angiography offers the most detailed images of blood vessels and is often considered the gold standard for brain aneurysm diagnosis when less invasive methods are not definitive.

Brain Aneurysm Screening: When is it Recommended?

Routine screening for brain aneurysms in the general population is not typically recommended. This is because most aneurysms remain unruptured and may never cause symptoms. The potential risks and costs of widespread screening are generally considered to outweigh the benefits for the average person.

However, screening may be advisable for individuals at higher risk of developing brain aneurysms. Talk to your healthcare provider to discuss the potential benefits of screening if you have:

• Family history of brain aneurysms: Especially if two or more first-degree relatives (parents, siblings, or children) have had brain aneurysms. This strong familial link significantly increases individual risk.
• Certain genetic disorders: Some inherited conditions are associated with an increased risk of brain aneurysms. These include:
  • Polycystic kidney disease
  • Ehlers-Danlos syndrome
  • Coarctation of the aorta
  • Neurofibromatosis type 1
  • Marfan syndrome

If you fall into these high-risk categories, discussing screening options with your doctor is a proactive step in managing your health. Screening typically involves non-invasive imaging techniques like MRA.

Prognosis Factors Following Aneurysm Rupture

While diagnosis is crucial, understanding the potential outcomes after a ruptured aneurysm is also important. The prognosis, or likely course of the condition, following a rupture is influenced by several factors, including:

• Age and overall health of the individual: Younger and healthier individuals generally have a better prognosis.
• Presence of other medical conditions: Co-existing health issues can complicate recovery.
• Size and location of the aneurysm: Larger aneurysms and those in certain locations may pose a higher risk.
• Amount of bleeding: The severity of the subarachnoid hemorrhage impacts the prognosis.
• Time elapsed before receiving medical care: Prompt medical attention significantly improves outcomes.

It’s important to recognize the seriousness of a ruptured brain aneurysm. Statistics indicate that approximately 25% of individuals who experience a rupture die within the first 24 hours, and another 25% succumb to complications within six months. Early diagnosis and treatment are therefore paramount in improving survival and functional outcomes.

Treatment Options Following Diagnosis (Brief Overview)

While this article primarily focuses on diagnosis, it’s important to briefly touch upon treatment. Once a brain aneurysm is diagnosed, whether ruptured or unruptured, treatment strategies are considered. For ruptured aneurysms, the immediate goals are to stop the bleeding and prevent re-rupture. Treatment options include:

• Surgical clipping: A surgical procedure to place a metal clip at the base of the aneurysm to block blood flow.
• Endovascular coiling: A less invasive procedure where coils are inserted into the aneurysm through a catheter to block blood flow.
• Flow diversion: A newer endovascular technique using stents to redirect blood flow away from the aneurysm.

For unruptured aneurysms, the decision to treat is based on a careful assessment of rupture risk versus treatment risks. Factors like aneurysm size, location, patient age, and overall health are considered.

Lifestyle Changes to Reduce Risk

Even without a diagnosed aneurysm, adopting certain lifestyle modifications can contribute to overall cerebrovascular health and potentially reduce the risk of aneurysm formation or rupture. These include:

• Abstaining from smoking: Smoking is a significant risk factor for aneurysm development and rupture.
• Managing high blood pressure: Controlling hypertension is crucial in reducing aneurysm risk.
• Maintaining a healthy diet and exercising regularly: These habits support overall cardiovascular health.
• Avoiding illicit drug use: Drugs like cocaine and methamphetamine can significantly increase the risk of aneurysm rupture.

Conclusion

Accurate and timely brain aneurysm diagnosis is essential for effective management and improving patient outcomes. If you experience sudden, severe headaches or other concerning neurological symptoms, seeking prompt medical evaluation is crucial. For individuals with a family history or genetic predisposition to brain aneurysms, discussing screening options with a healthcare provider is a proactive step. Understanding the diagnostic process empowers individuals to take charge of their health and seek appropriate medical attention when needed.

References:

1. AskMayoExpert. Unruptured intracranial aneurysm (adult). Mayo Clinic; 2021.
2. Kim B-S. Unruptured intracranial aneurysm: Screening, prevalence and risk factors. Neurointervention. 2021; doi:10.5469/neuroint.2021.00451.
3. Cerebral aneurysms fact sheet. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Cerebral-Aneurysms-Fact-Sheet. Accessed Dec. 14, 2022.
4. Cerebral aneurysm. American Association of Neurological Surgeons. http://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Cerebral-Aneurysm. Accessed Nov. 15, 2021.
5. Jankovic J, et al., eds. Intracranial aneurysms and subarachnoid hemorrhage. In: Bradley and Daroff’s Neurology in Clinical Practice. 8th ed. Elsevier; 2022. https://www.clinicalkey.com. Accessed Nov. 15, 2021.
6. Singer RJ, et al. Unruptured intracranial aneurysms. https://www.uptodate.com/contents/search. Accessed Dec. 1, 2022.
7. Srinivasan J, et al., eds. Subarachnoid hemorrhage. In: Netter’s Neurology. 3rd ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Nov. 15, 2021.
8. Simon RP, et al. Headache and facial pain. In: Clinical Neurology. 10th ed. McGraw Hill; 2018. https://accessmedicine.mhmedical.com. Accessed Dec. 15, 2022.
9. Rinkel GJ. Management of patients with unruptured intracranial aneurysms. Current Opinion in Neurology. 2019; doi:10.1097/WCO.0000000000000642.
10. Chancellor B, et al. Flow diversion for intracranial aneurysm treatment: Trials involving flow diverters and long-term outcomes. Neurosurgery. 2020; doi:10.1093/neuros/nyz345.
11. Daou BJ, et al. Clinical and experimental aspects of aneurysmal subarachnoid hemorrhage. CNS Neuroscience and Therapeutics. 2019; doi:10.1111/cns.13222.
12. Rinaldo L, et al. Natural history of untreated unruptured intracranial aneurysms in the elderly. Journal of Neurosurgical Sciences. 2020; doi:10.23736/S0390-5616.16.03891-1.
13. Dai D, et al. Histopathological findings following pipeline embolization in a human cerebral aneurysm at the basilar tip. Interventional Neuroradiology. 2016; doi:10.1177/1591019915622165.
14. Thielen E, et al. Concomitant coiling reduces metalloproteinase levels in flow diverter-treated aneurysms but anti-inflammatory treatment has no effect. Journal of Neurointerventional Surgery. 2017; doi:10.1136/neurintsurg-2015-012207.
15. Kallmes DF, et al. Aneurysm study of pipeline in an observational registry (ASPIRe). Interventional Neurology. 2016; doi:10.1159/000446503.
16. Brinjiki W, et al. Treatment of ruptured complex and large/giant ruptured cerebral aneurysms by acute coiling followed by staged flow diversion. Journal of Neurosurgery. 2016; doi:10.3171/2015.6.JNS151038.
17. Becske T, et al. Pipeline for uncoilable or failed aneurysms: Results from a multicenter clinical trial. Radiology. 2013; doi:10.1148/radiol.13120099.
18. Wiebers DO, et al. Unruptured intracranial aneurysms: Natural history, clinical outcome and risks of surgical and endovascular treatment. 2003; doi:10.1016/s0140-6736(03)13860-3.
19. Kerezoudis P, et al. Predictors of 30-day perioperative morbidity and mortality of unruptured intracranial aneurysm surgery. Clinical Neurology and Neurosurgery. 2016; doi:10.1016/j.clineuro.2016.07.027.
20. Zhao B, et al. Stent-assisted coiling versus coiling alone of poor-grade ruptured intracranial aneurysms: A multicenter study. Journal of Neurointerventional Surgery. 2017; doi:10.1136/neurintsurg-2016-012259.
21. Sorenson T, et al. Trials and tribulations: An evidence-based approach to aneurysm treatment. Journal of Neurosurgical Sciences. 2016; https://pubmed.ncbi.nlm.nih.gov/27102908/. Accessed Dec. 3, 2021.
22. Brown RD, et al. Screening for brain aneurysm in the Familial Intracranial Aneurysm study: Frequency and predictors of lesion detection. Journal of Neurosurgery. 2008; doi:10.3171/JNS/2008/108/6/1132.
23. Brown RD (expert opinion). Mayo Clinic. Dec. 27, 2022.
24. Thompson BG, et al. Guidelines for the management of patients with unruptured intracranial aneurysms: A guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2015; doi:10.1161/STR.0000000000000070.
25. Quality check. The Joint Commission. https://www.qualitycheck.org/search/?keyword=mayo clinic. Accessed Nov. 21, 2021.
26. Caffes N, et al. Unruptured cerebral aneurysms in elderly patients: Key challenges and management. Annals of medicine. 2021; doi:10.1080/07853890.2021.1990393.
27. Korhonen A, et al. Subarachnoid hemorrhage during pregnancy and puerperium: A population-based study. Stroke. 2022; doi:10.1161/STROKEAHA.122.039235.
28. What you should know about cerebral aneurysms. American Stroke Association. https://www.stroke.org/en/about-stroke/types-of-stroke/hemorrhagic-strokes-bleeds/what-you-should-know-about-cerebral-aneurysms. Accessed Dec. 20, 2022.
29. Brain aneurysm basics. Brain Aneurysm Foundation. https://www.bafound.org/about-brain-aneurysms/brain-aneurysm-basics/. Accessed Dec. 22, 2022.
30. Surgical clipping. Brain Aneurysm Foundation. https://www.bafound.org/treatment/surgical-clipping/. Accessed Jan. 20, 2023.