Overview
This lecture covers the types, anatomy, causes, clinical features, diagnosis, and treatments of traumatic intracranial hemorrhages.
Types of Intracranial Hemorrhage
- Intracranial hemorrhage refers to any bleeding within the skull or brain.
- Two main groups: extra-axial hemorrhages (outside brain tissue) and intra-axial hemorrhages (within brain tissue).
- Extra-axial bleeds: epidural hematoma, subdural hematoma, subarachnoid hemorrhage.
- Intra-axial bleeds: intraventricular hemorrhage, cerebral contusion, intracerebral hemorrhage.
Anatomy of the Meninges
- Meninges are protective membrane layers around the brain and spinal cord.
- Layers: dura mater (outermost, tough), arachnoid mater (middle, spider-like), pia mater (innermost, delicate, on brain).
- Potential spaces: epidural (between skull and dura), subdural (between dura and arachnoid).
- Subarachnoid space (between arachnoid and pia) contains cerebrospinal fluid (CSF).
Extra-Axial Hemorrhages
Epidural Hematoma
- Location: epidural space (between skull and dura).
- Cause: usually blunt trauma or skull fracture tearing middle meningeal artery.
- Presentation: loss of consciousness, lucid interval, rapid deterioration, headache, contralateral hemiparesis, dilated pupil.
- Diagnosis: CT shows biconvex/lens-shaped bleed.
- Treatment: neurosurgical emergency, immediate drainage, manage intracranial pressure (ICP).
Subdural Hematoma
- Location: subdural space (between dura and arachnoid).
- Cause: acceleration/deceleration injury rupturing bridging veins, more common in elderly/alcoholics.
- Presentation: slow progression, headache, confusion, contralateral hemiparesis, dilated pupil.
- Diagnosis: CT shows crescent-shaped bleed, may see midline shift.
- Treatment: neurosurgical emergency, drainage or EVD, manage ICP.
Subarachnoid Hemorrhage (Traumatic)
- Location: subarachnoid space over cerebral surface.
- Cause: blunt trauma causing artery/vein rupture on brain surface.
- Presentation: “thunderclap” headache, vomiting, seizures, decreased consciousness.
- Diagnosis: CT shows high-density areas in sulci/fissures.
- Treatment: no surgery, manage ICP, EVD may help.
Intra-Axial Hemorrhages
Intraventricular Hemorrhage
- Location: within the ventricular system.
- Cause: often secondary to subarachnoid or intracerebral hemorrhage, sometimes primary due to vein tears.
- Presentation: headache, vomiting, seizures, altered mental status, usually minimal focal signs.
- Diagnosis: CT shows blood in ventricles.
- Treatment: no surgery, EVD to manage pressure, manage ICP.
Cerebral Contusion
- Location: cortical tissue, often coup-contrecoup pattern.
- Cause: blunt trauma, usually motor vehicle accidents.
- Presentation: headache, confusion, sleepiness, nausea, seizures, focal signs depend on location.
- Diagnosis: CT shows ill-defined hypodense areas with hemorrhagic foci.
- Treatment: no surgery, EVD if severe, manage ICP.
Intracerebral Hemorrhage
- Location: within brain parenchyma.
- Cause: penetrating trauma, depressed fracture, or severe acceleration injuries.
- Presentation: headache, vomiting, seizures, decreased consciousness, contralateral hemiparesis.
- Diagnosis: CT shows blood within brain tissue.
- Treatment: unclear benefit from surgery, EVD, manage ICP.
Key Terms & Definitions
- Intracranial Hemorrhage — bleeding within the skull or brain.
- Extra-axial — outside brain tissue.
- Intra-axial — within brain tissue.
- Epidural Hematoma — arterial bleed between skull and dura.
- Subdural Hematoma — venous bleed between dura and arachnoid.
- Subarachnoid Hemorrhage — bleed into CSF space between arachnoid and pia.
- Intraventricular Hemorrhage — bleed into brain ventricles.
- Cerebral Contusion — bruising of brain tissue.
- Intracerebral Hemorrhage — bleed within brain tissue itself.
- ICP (Intracranial Pressure) — pressure inside the skull.
- EVD (External Ventricular Drain) — device to relieve intracranial pressure.
Action Items / Next Steps
- Review anatomical diagrams of the meninges and spaces.
- Understand signs/symptoms and CT features of each bleed type.
- Practice differentiating hemorrhage types on sample CT images.