What is a Subarachnoid Hemorrhage?
A subarachnoid hemorrhage (SAH) refers to bleeding within the subarachnoid space - the area between the brain and the tissues that cover the brain.
The subarachnoid space is the space where the cerebrospinal fluid circulates, and is responsible for protecting your brain from injury by acting as a cushion. A hemorrhage in this space can result in a coma, paralysis, or even death.
Most often, subarachnoid hemorrhage occurs when a weak area in a blood vessel (aneurysm) on the surface of the brain bursts and leaks. The blood then builds up around the brain and inside the skull increasing pressure on the brain. This can cause brain cell damage, life-long complications, and disabilities.
Causes of Subarachnoid Hemorrhage
The most common cause of subarachnoid hemorrhage is the rupture of an intracranial aneurysm, which is a weakened or bulging area in the wall of an artery in the brain. Other factors that may lead to aneurysms or subarachnoid hemorrhage include:
- Severe head injury or trauma
- Bleeding from a tangle of blood vessels called an arteriovenous malformation (AVM)
- Hypertension
- Drug abuse, especially stimulants like cocaine
- Excessive alcohol consumption
- Smoking
- Heredity
- Bleeding disorders
- Connective tissue disorders, such as Ehlers-Danlos syndrome or polycystic kidney disease
Symptoms of Subarachnoid Hemorrhage
Subarachnoid hemorrhage often presents with sudden and severe symptoms. These include:
- Severe headache
- Nausea and vomiting
- Sensitivity to light (photophobia)
- Changes in vision
- Loss of consciousness
- Seizures
- Dizziness
- Neck stiffness
- Numbness in an area of your body
- Vision changes, including double vision, blind spots, or temporary vision loss in one eye
- Mood and personality changes, including confusion and irritability
- Muscle aches, especially in your neck and shoulders
Diagnosis of Subarachnoid Hemorrhage
If your physician suspects you have a subarachnoid hemorrhage based on your physical exam and symptoms, they may likely order tests, such as:
- CT (Computed Tomography) Scan: A CT scan uses X-rays and a computer to make detailed images of tissues in your body. A CT scan of your brain is an effective way to provide rapid and accurate information about the presence and location of bleeding. However, a CT scan does not always show a small subarachnoid hemorrhage or one that happened a week or more ago.
- MRI (Magnetic Resonance Imaging): MRI uses a large magnet and radio waves to create images of your brain. You might get a contrast dye by IV to enhance the images. It can reveal bleeding that has happened in the recent past.
- CT Angiography (CTA): Another type of CT scan, CT angiography (CTA), visualizes blood vessels using contrast material injected through a vein. This imaging technique may be used to visualize blood vessels in the brain and identify the source of bleeding, such as an aneurysm or arteriovenous malformation (AVM).
- Lumbar Puncture (Spinal Tap): If a CT scan is inconclusive but clinical suspicion for SAH remains, a lumbar puncture or spinal tap may be performed. This involves the insertion of a special needle into the lower back, into the spinal canal to obtain a sample of cerebrospinal fluid (CSF) and analyzing it for the presence of blood or xanthochromia (yellow discoloration indicating the breakdown of red blood cells).
- Cerebral Angiography: This is an invasive procedure that involves injecting a contrast dye into the blood vessels of the brain, allowing for detailed imaging of the blood vessels. Cerebral angiography can help identify aneurysms, AVMs, or other vascular abnormalities.
Treatment of Subarachnoid Hemorrhage
The treatment of subarachnoid hemorrhage involves a combination of supportive care, medical interventions, and, in many cases, surgical procedures to address the underlying cause of the bleeding. The specific treatment plan depends on the severity of the SAH, the location of the bleeding, and the presence of complicating factors. Some of the key aspects of SAH treatment include:
Emergency Care and Monitoring:
- Stabilization: Initial care focuses on stabilizing the patient, ensuring adequate oxygenation and blood flow, and managing any associated complications.
- Neurological Monitoring: Continuous monitoring of neurological status, blood pressure, and other vital signs is essential.
Medical Management:
- Pain Management: Severe headaches are a common symptom, and pain relief is provided to improve patient comfort.
- Blood Pressure Control: Maintaining stable blood pressure is crucial. Blood pressure may be carefully controlled to prevent rebleeding while ensuring adequate cerebral perfusion.
Prevention of Complications:
- Seizure Prophylaxis: Antiseizure medications may be administered to prevent seizures, which can be a complication of SAH.
- Fluid and Electrolyte Management: Maintaining proper fluid balance and electrolyte levels is important for overall patient well-being.
Surgical Interventions:
If you have an aneurysm that has burst, you may need to undergo one of the following procedures to prevent or stop further bleeding.
- Endovascular Coiling: This procedure involves making a tiny surgical cut (incision) in your groin and passing a thin tube called a catheter through the artery in your leg up to the artery in your head that is bleeding. Your physician will place a tiny coiled wire into the aneurysm, where it forms a clot that stops the bleeding.
- Endovascular Stent: In this procedure, instead of a coil, a tiny tube called a stent is placed across the aneurysm. The stent channels the blood away from the aneurysm to prevent it from bursting or leaking.
- Aneurysm Clipping: This procedure involves making an incision in your scalp and removing a section of your skull to access the aneurysm. A special microscope will assist your physician in locating the aneurysm and securing a tiny clip across it, replacing the section of the skull, and stitching up the incision.
Vasospasm Management:
Calcium Channel Blockers: Medications such as nimodipine may be given to manage or prevent cerebral vasospasm, a complication that can happen days after the initial bleeding. A vasospasm occurs when a blood vessel narrows and cuts off oxygen to your brain.
Rehabilitation:
After the acute stage of treatment, rehabilitation may be needed to assist patients to recover and regain functional abilities. This may include occupational therapy, physical therapy, and speech therapy as needed.
Close Monitoring and Follow-up:
Patients are closely monitored for any signs of rebleeding or other complications. Follow-up care is crucial to evaluate long-term results and address any ongoing issues.
