Intracranial haemorrhages

1. Overview

• Intracranial hemorrhage within the skull occurs in a variety of locations, each with specific causes.
• General causes:
  • Hypertension or other pressure alterations.
  • Vascular malformations (rupture).
  • Trauma (only subdural + epidural hemorrhages).

2. Apoplexia (Intraparenchymal Hemorrhage)

Definition

• Bleeding into the brain parenchyma, related to hypertension.
• BP > 200 mmHg = risk for vessel rupture.

Sites

• Intraparenchymal vessels: basal ganglia (putamen #1), thalamus, pons, cerebellum.

Pathogenesis

• Hypertension causes small aneurysms in small penetrating vessels = Charcot-Bouchard aneurysms.
• Hyaline arteriolosclerosis → protein deposition in vessel walls → fragile → rupture.

Consequences

• Bleeding → ↑ ICP → brain stem compression → tonsillar herniation → respiratory + cardiovascular failure → death.

3. Subarachnoid Hemorrhage (Hematoma Subarachnoideale)

Definition

• Bleeding into subarachnoid space.
• Non-traumatic rupture of saccular (berry) aneurysm of cerebral arteries.

Pathogenesis

• Branching vessels of the Circle of Willis are prone to berry aneurysms.
• Most common site: anterior communicating artery.
• Rupture → arterial “jet-stream” bleeding → acute ↑ ICP.

Clinical Features

• Sudden, excruciating headache (“worst headache of life / thunderclap headache”).
• Loss of consciousness, meningismus, photophobia.
• “Ticking time bomb” — unpredictable.
• Onset typically 40–50 years, when HTN ↑.
• Associations: ADPKD, Ehlers-Danlos type IV, Marfan syndrome, smoking, HTN.
• Complications: rebleeding, vasospasm, hydrocephalus.

4. Subdural Hematoma (Hematoma Subdurale)

Definition

• Bleeding into subdural space.
• Tearing of bridging veins between cortex + dural sinuses.

Pathogenesis

• Rapid acceleration/deceleration of the brain → tears bridging veins.
• Brain atrophy in elderly → bridging veins stretched → more sensitive to rupture (even minor trauma).

Types

• Acute SDH: car accidents, sudden trauma; rapid neurological deterioration.
• Chronic SDH: long-term trauma (boxing) or elderly + atrophy.
  • Repeated bleeding → fibrosis → fibrotic tissue around meninges → progressive neurological symptoms (confusion, gait changes).

Morphology

• Crescent-shaped (concave) hematoma on CT.
• Crosses cranial sutures but not falx/tentorium.

5. Epidural Hematoma (Hematoma Epidurale)

Definition

• Bleeding into the epidural space between dura + skull.
• Associated with skull fracture.

Pathogenesis

• Dura normally tightly applied to inside of skull (fused with periosteum).
• Rupture of middle meningeal artery (between dura + skull) typically from temporal bone fracture at pterion.
• → Accumulation of blood separates dura from periosteum → hematoma compresses brain surface.
• Alcoholic patients more susceptible (impaired reflexes → dangerous falls).

Lucidum Intervallum (Lucid Interval)

• Conscious phase between two unconscious phases.
• Sequence: unconscious (impact) → conscious recovery → bleeding inside skull (↑ ICP) → unconscious 2nd time.
• Classic for epidural hematoma.

Morphology

• Biconvex (lens-shaped) hematoma on CT.
• Does NOT cross sutures (dura is fused there).
• Can cross falx + tentorium.

6. Comparison Table

Type	Cause	Vessel	Shape on CT	Clinical
Apoplexia (intraparenchymal)	HTN	Charcot-Bouchard aneurysms	Within parenchyma	Basal ganglia/thalamus/pons; ↑ ICP, herniation
Subarachnoid	Berry aneurysm rupture	Circle of Willis (anterior communicating)	Star-shaped, around brainstem	“Worst headache of life”; ADPKD, Ehlers-Danlos
Subdural	Bridging vein tear	Veins	Crescent-shaped; crosses sutures, not falx	Elderly, boxers; slow venous bleed
Epidural	Skull fracture (temporal)	Middle meningeal artery	Biconvex (lens-shaped); doesn’t cross sutures	Lucid interval → deterioration

💡 High-yield: Intraparenchymal (apoplexia) = HTN; Charcot-Bouchard aneurysms in basal ganglia/thalamus/pons/cerebellum. Subarachnoid = ruptured berry aneurysm at Circle of Willis (anterior communicating most common); “thunderclap/worst headache of life”; ADPKD/Ehlers-Danlos. Subdural = bridging veins, crescent shape, crosses sutures, elderly/alcoholics/boxers, chronic in atrophy. Epidural = middle meningeal artery (temporal bone fracture/pterion); biconvex lens shape, doesn’t cross sutures; lucid interval (unconscious → conscious → unconscious).