SAH is bleeding into the subarachnoid space, which is the area between the brain and the arachnoid membrane.
Causes:
1. Traumatic causs of SAH – Head injury, Fracture of skull
2. Non traumatic causes of SAH –
Aneurysm rupture: A common cause where a bulging blood vessel in the brain bursts.
Arteriovenous malformations: Abnormal connections b/w arteries and veins can also lead to SAH.
Other causes: Conditions like hypertension, blood disorders, or certain infections.
Symptoms:
1. Severe Headache: Often described as the worst headache of a person's life (Thunderclap headache)
2. Nausea and Vomiting: Common due to increased intracranial pressure.
3. Loss of consciousness: Can occur immediately after the bleed.
Neck Stiffness: Due to irritation of the meninges.
4. Seizures
Diagnosis:
1. CT Scan: Often the first imaging test used to detect bleeding.
2. MRI: Can be used for more detailed imaging.
3. Lumbar Puncture: Used to detect blood in the cerebrospinal fluid if CT is inconclusive.
4. Angiography: To identify the source of bleeding, such as an aneurysm.
NOTE: Normal CSF is colorless clear fluid and in the case of subarachnoid haemorrhage CSF appears yellow.
NOTE: Xanthochromia is the yellowish discoloration of cerebrospinal fluid (CSF) that occurs when blood mixes with CSF, often due to subarachnoid hemorrhage (SAH).