Q 2.20. Subarachnoid hemorrhage

LAYERS OF THE BRAIN

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A subarachnoid hemorrhage (SAH) is a medical emergency that occurs when there is bleeding into the space between the arachnoid membrane and the pia mater, which are the layers that cover the brain. This space is called the subarachnoid space, and it contains cerebrospinal fluid.

CAUSES

Causes	Description
Cerebral Aneurysm	Weakness or bulging of a blood vessel in the brain wall.
Arteriovenous Malformations (AVMs)	Abnormal tangle of blood vessels in the brain.
Head Trauma	Injury to the head leading to bleeding in the subarachnoid space.
Bleeding Disorders	Conditions affecting blood clotting, leading to spontaneous bleeding.
Tumors	Brain tumors can cause pressure on blood vessels, leading to rupture.
Cocaine or Stimulant Abuse	Increased blood pressure and vessel damage from substance abuse.
Infections	Inflammatory conditions causing vessel damage and bleeding.
Use of Blood Thinners	Medications that interfere with clotting may increase the risk.
Familial or Genetic Factors	Some individuals may have a genetic predisposition to aneurysm formation.
Hypertension	High blood pressure can weaken blood vessel walls.

 

SYMPTOMS

Symptoms	Description
Sudden Severe Headache	Often described as the worst headache of one’s life. Severe headache with acute onset is a red flag and it is the most important sign of SAH.
Nausea and Vomiting	Feeling nauseous and vomiting.
Stiff Neck	Difficulty or pain when trying to move the neck.
Sensitivity to Light (Photophobia)	Discomfort or pain when exposed to light.
Changes in Vision	Blurred or double vision, visual disturbances.
Loss of Consciousness	Some individuals may experience a loss of consciousness.
Seizures	Uncontrolled electrical activity in the brain, leading to convulsions.
Altered Mental Status	Confusion, disorientation, or changes in awareness.
Focal Neurological Deficits	Weakness, numbness, or difficulty moving specific body parts.
Loss of Balance or Coordination	Difficulty maintaining balance or coordinating movements.
Syncope (Fainting)	Loss of consciousness.
Meningismus	Symptoms suggesting irritation of the meninges, including neck stiffness and headache.

 

DIAGNOSIS

The diagnosis of subarachnoid hemorrhage (SAH) typically involves a combination of medical history, clinical examination, and imaging studies. The goal of the diagnostic process is to identify the cause of subarachnoid hemorrhage and determine the most appropriate treatment plan. Early diagnosis and intervention can significantly impact outcomes.

Here are the key steps in the diagnosis:

1.  Clinical History and Examination:

·       A detailed medical history is obtained, focusing on the onset and nature of symptoms, such as the sudden and severe headache.

·       A neurological examination is performed to assess cognitive function, coordination, reflexes, and other neurological signs.

2.  Imaging Studies:

·       Non-Contrast CT Scan (NCCT): This is often the initial imaging study performed when a subarachnoid hemorrhage is suspected. A CT scan can quickly detect blood in the brain and is highly sensitive in the first 6-12 hours after the onset of symptoms.

·       Computed Tomography Angiography (CTA): CTA involves injecting a contrast dye into the blood vessels to visualize the arteries in the brain. This study can help identify the source of bleeding, such as an aneurysm or arteriovenous malformation (AVM).

·       Lumbar Puncture (Spinal Tap): In cases where the initial CT scan is inconclusive but clinical suspicion remains high, a lumbar puncture may be performed to analyze the cerebrospinal fluid (CSF) for the presence of blood.

3.  Angiography:

·       Cerebral Angiography (Digital Subtraction Angiography – DSA): This is a more detailed imaging study that allows visualization of blood vessels in the brain. It is often used to identify the source of bleeding, such as an aneurysm or arteriovenous malformation (AVM).

4.  MRI (Magnetic Resonance Imaging):

·       An MRI may be used in some cases, especially if further details about the brain and blood vessels are needed. Magnetic resonance angiography (MRA) can provide images of blood vessels without the need for contrast dye.

5.  Electroencephalogram (EEG):

·       In some cases, an EEG may be used to assess electrical activity in the brain, especially if seizures are present.

TREATMENT 

Patient’s care starts immediately (prior to performing any laboratory and imaging tests) and depends on the clinical symptoms. After the detection of bleeding in subarachnoid hemorrhage (SAH), the treatment plan is reviewed promptly to address the underlying cause, manage symptoms, and prevent complications.

1.   Emergency Medical Care:

·       Stabilization: Ensure patient’s airway, adequate breathing, and stable circulation.

·       Monitoring: Continuous monitoring of vital signs, neurological status, and other relevant parameters.

2.   Blood Pressure Control:

·       Hypertension Management: Careful control of blood pressure is crucial to reduce the risk of rebleeding. Medications may be administered for blood pressure control.

3.   Pain Management:

·       Analgesics: Administer pain medications to alleviate headache and other associated pain.

4.   Nimodipine Administration:

·       Calcium Channel Blocker: Nimodipine is often administered to prevent vasospasm, a complication that can occur after SAH, which may lead to reduced blood flow to the brain.

5.   Surgery or Endovascular Treatment:

·       Clipping or Coiling: If an aneurysm is identified, surgical intervention may be required. This can involve clipping the aneurysm or endovascular coiling to block blood flow to the aneurysm.

6.   Ventriculostomy or Lumbar Drain:

·       CSF Drainage: In cases of elevated intracranial pressure, a ventriculostomy or lumbar drain may be placed to drain cerebrospinal fluid and reduce pressure within the skull.

7.   Seizure Prophylaxis:

·       Antiepileptic Drugs: Prophylactic use of antiepileptic drugs may be considered to prevent seizures, which can be a complication of SAH.

! Keep in mind that every person has headaches but severe headache with acute onset, with or without meningismus, nausea, vomiting which cannot be managed as usual and increase in intensity within hours is allarming and requires a CT scan.

CASE STUDY

Hyperintense fluid in all pulse sequences seen filling and expanding the left sylvian fissure and adjacent sulci.

A small middle cerebral artery saccular aneurysm is identified in post contrast study.

Diagnosis: Subarachnoid haemorrhage due to rupture aneurysm

 

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