Subarachnoid Haemorrhage: Causes, Symptoms, Risk Factors, Diagnosis and Treatment
Nov 14, 2023
A subarachnoid haemorrhage is the term for bleeding in the subarachnoid space, which is the space between the brain and the surrounding membrane. The main complaint is a sudden, severe headache. Some people say it's the worst headache they've ever had. Apart from a headache, certain individuals might additionally suffer:
Usually, bleeding happens when a brain aneurysm or an irregular blood vessel protrusion bursts. Bleeding can occasionally be caused by trauma, an arteriovenous malformation (a tangle of blood vessels in the brain), or other problems relating to the health of blood arteries.
If a subarachnoid haemorrhage is not treated, it may result in death or permanent brain damage.
What Is The Cause Of Subarachnoid Haemorrhage?
Head trauma from a serious fall or auto accident is the most common cause of subarachnoid haemorrhage. Exploding brain aneurysms are another common cause of SAH.
Brain aneurysms are enlargements of brain arteries that may rupture and spill blood into the space between the brain and the skull.
Another cause of SAH that may not involve head trauma is a spontaneous rupture of a brain aneurysm. Blown-out brain aneurysms account for approximately 85% of non-traumatic SAH occurrences.
Several uncommon reasons for SAH include the following:
Haemorrhage is caused by an entangled blood artery known as an arteriovenous malformation (AVM).
Subarachnoid haemorrhages (SAHs) can happen to anyone, however, the age range of 40 to 60 is the most commonly afflicted.
The most common population affected by an injury-related SAH is older people who have fallen and hit their heads. The most frequent injury among younger people that causes subarachnoid haemorrhage is a car crash.
The subsequent variables heighten the likelihood of experiencing a subarachnoid haemorrhage:
An intact aneurysm in your body, either in the brain or another area.
History of ruptured cerebral aneurysms.
High BP, often known as hypertension.
Fibromuscular dysplasia (FMD) and other connective tissue disorders; Ehlers-Danlos syndrome.
History of polycystic kidney disease.
Use of cocaine or methamphetamine.
Excessive use of alcoholic beverages.
A substantial aneurysm family history.
Diagnosis Of Subarachnoid haemorrhage
To determine whether you have a subarachnoid haemorrhage, your doctor may likely recommend:
CT scan: This imaging test can be used to detect brain haemorrhage. When performed appropriately, a CT scan is a very useful test; nevertheless, the scan could miss the bleed if you have a low red blood cell count (anaemia) and only a small amount of blood is spilt during the procedure. Your doctor may administer a contrast dye injection for a more thorough examination of your blood arteries (CT angiography).
MRI: This imaging method can also be used to detect brain haemorrhage. Your healthcare provider may inject a dye into a blood artery for an MR angiography, which emphasises blood flow and provides a more detailed view of the arteries and veins. Rarely, there may be indicators of a subarachnoid haemorrhage when the symptoms are not obvious on a CT scan.
Brain angiography: Your medical practitioner will place a catheter, a long thin tube into an artery and your brain. The blood arteries in your brain are injected with dye to make them visible on X-ray imaging. Your doctor might recommend cerebral angiography for more accurate imaging. They may also recommend the test in cases where a subarachnoid haemorrhage is suspected but the reason is unknown or does not appear on other imaging. You could need a second cerebral angiography if the first one indicated that there was likely to be an aneurysm but did not show one.
Lumbar puncture: Sometimes the initial imaging results from aneurysmal subarachnoid haemorrhages do not reveal the bleeding. If there is no evidence of bleeding on the first CT scan, your doctor might recommend a lumbar puncture. A needle is inserted into the lower back to extract a small amount of the cerebrospinal fluid, which surrounds the brain and spinal cord. Should blood be observed in the liquid, this may suggest that you are experiencing a subarachnoid haemorrhage.
If you have an aneurysm, treatment focuses on treating it, stabilising your health, and avoiding consequences.
Your blood pressure, blood flow, and respiration are all monitored by your physician.
If your bleeding is the result of a burst brain aneurysm, your doctor may advise:
Surgery: The brain aneurysm is located by the surgeon after making a scalp incision. To stop the blood flow to the aneurysm, a metal clip is placed on it.
Endovascular embolization: A catheter is threaded into an artery and inserted into your brain by the surgeon. After being inserted through the catheter, detachable platinum coils are positioned into the aneurysm. Blood clots as a result of the coils filling the aneurysm and decreasing blood flow into the aneurysm sac.
Available endovascular therapy: Certain aneurysms can be treated with endovascular embolisation, which uses more modern technologies such as devices that obstruct blood flow or coiling that is supported by a stent or balloon.
Problems must be avoided as they raise the danger of recurrent bleeding, insufficient blood supply to the brain, low blood salts (sodium), excessive brain fluid accumulation, and abnormally high or low blood sugar. It has been shown that nimodipine (Nymalize), a medication, reduces problems with cerebral circulation after a subarachnoid haemorrhage.
One common outcome is post-aneurysmal subarachnoid haemorrhage delayed cerebral vascular spasm.
A stroke may occur if blood flow is reduced below a certain threshold. When this problem occurs, strokes can be avoided by using intravenous medication to raise blood pressure or medicines to dilate blood vessels in the brain.
Hydrocephalus, or accumulation of fluid in the brain's inner areas, is another common outcome. This problem can be addressed by drains inserted into the head (ventriculostomy catheter) or lower back (lumbar drains).
Sometimes, procedures need to be repeated. To track any changes, your physician will arrange for regular follow-up consultations with you. It might also be necessary to receive speech, occupational, and physical therapy.
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