Bleeding into the cerebrospinal fluid space due to trauma or ruptured aneurysm describes which type of hemorrhage?

• A. Intracerebral hemorrhage
• B. Subarachnoid hemorrhage
• C. Subdural hematoma
• D. Epidural hematoma

Answer: (B)

The idea being tested is bleeding that fills the cerebrospinal fluid spaces surrounding the brain. When vessels rupture into this space, blood leaks into the subarachnoid space, which lies between the arachnoid and pia mater. This is called a subarachnoid hemorrhage and commonly results from a traumatic injury or a ruptured aneurysm.

Clinically, a subarachnoid hemorrhage often presents with a sudden, severe headache—sometimes described as the worst headache of life—along with neck stiffness, photophobia, or signs of meningeal irritation. In the field or emergency department, rapid assessment and stabilization are crucial, with attention to airway, breathing, and circulation and avoidance of procedures or positions that could raise intracranial pressure.

Diagnosis is usually confirmed with a CT scan of the head. If the CT is negative but suspicion remains high, a lumbar puncture can reveal blood in the CSF or bilirubin/hemoglobin breakdown products (xanthochromia), confirming bleeding in the subarachnoid space.

Other types of head bleeding involve different spaces and have distinct features: bleeding into brain tissue itself is an intracerebral hemorrhage; bleeding into the space between dura and arachnoid is a subdural hematoma; bleeding between the skull and dura is an epidural hematoma. Each has characteristic causes, presentations, and imaging findings, which helps guide treatment decisions.