6.2.2 Acute headache attributed to non-traumatic subarachnoid haemorrhage (SAH)

Identification: Male patient, 48 years old, executive, untreated hypertensive, smoker (20 pack-years), family history of cerebral aneurysm (brother).

History of Present Illness:

Explosive onset of intense bifrontal headache (10/10) during a work meeting, 2 hours ago

Characteristics:

Described as "an explosion inside the head"

Posterior cervical radiation

Worsens with head movements

Associated with:

Projectile vomiting (3 episodes)

Incapacitating photophobia

Initial syncope (≈30 seconds)

No history of primary headaches or recent trauma

Neurological Examination:

General state: GCS 13 (E3V4M6), confused

Meningeal signs:

Marked neck stiffness

Positive Brudzinski's sign

Positive Kernig's sign

Focal signs: Partial paralysis of the right third cranial nerve (partial ptosis, mydriasis)

BP: 200/120 mmHg

Fundoscopy: Subhyaloid hemorrhage (Fisher level II)

Complementary Exams:

Urgent non-contrast cranial CT:

Blood in basal cisterns (Fisher 4)

Localized hematoma in the interpeduncular space

Acute hydrocephalus (Evans index >0.3)

CT Angiography:

Saccular aneurysm (7.8 mm) in the right posterior communicating artery

Moderate vasospasm (Lindegaard scale = 5)

Lumbar puncture (performed after stabilization):

Xanthochromic fluid

15,000 red blood cells/mm³

Bilirubin detected (confirming SAH)