The Circle of Willis is an important vascular confluence inside the head. It lies at the base of the brain and four major arteries that supply blood to the brain branch out from it. These in turn form many branches and smaller arteries to distribute the blood efficiently.
As a result, there are various artery junctions in the brain with a constant flow of blood at different blood pressures. Some of the artery joints become weak over a period of time due to constant wear and tear. This causes blood to rush and accumulate in abnormal ways near the weak points creating a brain aneurysm.
Types
- Saccular: This is the most common type. Here, the weak point causes a sac or bulge to form on the artery that soon gets filled with blood. The sac is similar to a balloon, with a broad body and a narrow neck near the base of the artery. These sacs, if not treated in time, can grow to become as big as a berry.
- Fusiform: Here, there is no sac created. Instead, the weak point causes the artery to bulge all around.
- Dissecting: Here, a tear forms on the inside wall of the artery, causing the blood to pool between layers of arterial walls.
The sac in the saccular aneurysm can develop perforations, causing the blood to leak into surrounding tissues. Alternatively, the sac can grow steadily with time and rupture one day. Both of these are dangerous conditions that require emergency treatment. These possibilities have created 3 more types of aneurysms: un-ruptured, bleeding, and ruptured.
Causes and Risk Factors
There is no clear reason as to why an aneurysm develops in the first place. However, there are various risk factors:
- Adults and seniors are more at risk than children and adolescents
- Men are more at risk than women
- Cigarette smoking
- Hypertension or high BP
- Drug abuse involving cocaine and amphetamines
- Excessive alcohol consumption
- Inherited conditions such as Ehlers-Danlos syndrome and polycystic kidney disease
- Cardiovascular conditions such as cerebral arteriovenous malformation and coarctation of the aorta
- A family history of brain aneurysms
- Atherosclerosis or plaque deposition in coronary arteries
- Trauma or injury to the head
- Tumours in the head or neck region
- Certain infections in the blood
Symptoms
Symptoms of Unruptured Aneurysms
- The headache of different intensities at different times during the day
- Problems with vision such as blurry or double vision
- Dilated pupils, pain around the eyes
- Drooping eyelids
- Difficulty in speaking or understanding others
- Weakness and numbness on one side of the face
Symptoms of a Leaking Aneurysm
- Sudden and intense headache that feels like the worst headache you have ever had
Symptoms of Ruptured Aneurysms
- An intense and sudden headache
- Loss of consciousness
- Seizures
- Nausea and vomiting
- Drowsiness
- Loss of balance while walking and lack of coordination while doing simple activities
- Stiff neck
- Dilated pupils, drooping eyelids, sudden blurred or double vision
- Sensitivity to light
- Confusion and lack of awareness of one’s surroundings
Complications from Brain Aneurysms
- Re-bleeding: Aneurysms that have ruptured or leaked and have been treated, are at risk of bleeding again. This second bout of bleeding causes further damage to brain tissues.
- Vasospasm: A ruptured aneurysm can cause some blood vessels in the brain to narrow down causing what is called a vasospasm. Narrowed blood vessels result in reduced blood flow to cells; they could trigger an ischemic stroke and cause additional damage to brain tissue.
- Hydrocephalus: Within the skull, the brain is suspended in a fluid called the cerebrospinal fluid. A ruptured aneurysm can cause bleeding into this fluid. This increases the volume of fluid and hence the pressure on the brain increases over time. This again causes damage to brain tissue.
- Hyponatremia: When an aneurysm ruptures, it can cause bleeding in the space between the brain and surrounding tissue. This is called a subarachnoid hemorrhage. This can disturb the balance of sodium in the blood leading to swelling of brain cells and damage to brain tissue.
Diagnosis
Brain aneurysms are detected by various tests:
- CT Scan and CT Angiography: These are imaging tests used to detect bleeding anywhere in the brain.
- MRI Scan: Similar to a CT scan, an MRI scan provides detailed 2D and 3D images of the brain which make it easy to detect bleeding.
- Cerebrospinal Fluid Test: The fluid is tested for the presence of red blood cells, indicating a ruptured aneurysm.
- Cerebral Angiogram: When none of the above tests provide conclusive evidence of an aneurysm but the symptoms continue, the doctor may order a cerebral angiogram. This is a minimally-invasive procedure in which a catheter is inserted into one of the large arteries in the brain. A special dye is inserted into the catheter and released. X-ray images are then taken to map the flow of blood in the arteries of the brain.
Treatment Options
- Medical Therapy: Quitting smoking and managing BP.
- Surgical Clipping: A clip is inserted around the neck of the bulge to cut off blood flow into it.
- Endovascular Coiling: A thin coil of wire is inserted using a catheter into the aneurysm. The coil sits tightly inside the aneurysm thereby blocking blood flow into it.
- Flow Diverter Surgery: When the aneurysm is big and neither clipping nor coiling will work, a stent is fixed at the weak point in the artery thereby cutting off blood flow into the aneurysm.
Conclusion
Brain aneurysms are serious health conditions that require quick and comprehensive treatment. If you or any of your dear ones are showing any of the symptoms listed above, rush to a reputed hospital. Such hospitals have some of the best neurologists and neurosurgeons on their rolls. These specialists will diagnose your condition precisely and choose the best treatment option for quick recovery and rehabilitation.
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.
Chennai – 044 4000 6000 • Trichy – Cantonment – 0431 4077777 • Trichy – Heartcity – 0431 4003500 • Trichy – Tennur – 0431 4022555 • Hosur – 04344 272727 • Salem – 0427 2677777 • Tirunelveli – 0462 4006000 • Bengaluru – 080 6801 6801