Head Trauma

Head Trauma: Basics - Skull Cracker Intro

• Epidemiology: Road Traffic Accidents (RTAs) are a major cause of head trauma.
• Injury Types:
  • Primary: Direct, irreversible damage at impact.
  • Secondary: Delayed, potentially preventable (e.g., hypoxia, edema, ↑ICP).
• Monro-Kellie Doctrine: Skull is a rigid box. Intracranial volume ($V_{brain} + V_{blood} + V_{CSF}$) is constant. If one component volume ↑, others must ↓ to maintain normal Intracranial Pressure (ICP).

⭐ Falls are the most common cause of Traumatic Brain Injury (TBI), particularly in pediatric and geriatric populations.

Head Trauma: GCS & Severity - Brain Scoreboard

• GCS: E+V+M. Total 3-15.
• GCS Scoring:

  Comp.	Max	Responses
  E (Eye)	4	Spont (4), Speech (3), Pain (2), None (1)
  V (Verb)	5	Orient (5), Conf (4), Inapp (3), Sounds (2), None (1)
  M (Mot)	6	Obeys (6), Local (5), Withdraw (4), Flex (Decorticate) (3), Ext (Decerebrate) (2), None (1)

• TBI Severity: Mild 13-15; Mod 9-12; Sev 3-8 (GCS ≤8 intubate).

⭐ GCS drop ≥2 pts: urgent reassessment.

Head Trauma: Fractures & Hematomas - Crack & Bleed Atlas

• Fractures:
  • Linear: Simple break.
  • Depressed: Bone fragment pushed inwards.
  • Basilar: Skull base. Signs: Battle's (postauricular ecchymosis), Raccoon eyes (periorbital ecchymosis), CSF otorrhea/rhinorrhea.
• Hematomas:

  Type	Source	CT Appearance	Key Feature(s)
  EDH	MMA (Middle Meningeal A.)	Lentiform 📌 Lemon	Lucid interval
  SDH	Bridging veins	Crescentic 📌 Banana	Gradual; elderly/alcoholics
  SAH	Aneurysm/Trauma	Blood in cisterns	Thunderclap headache

  • ICH (Intracerebral): Bleeding within brain parenchyma.

⭐ The Middle Meningeal Artery (MMA) is the most common source of Extradural Hematoma (EDH).

Head Trauma: ICP & CPP - Pressure Cooker Control

• Normal Intracranial Pressure (ICP): 5-15 mmHg.
• Cerebral Perfusion Pressure (CPP) is $CPP = MAP - ICP$. Maintain CPP >60 mmHg.
• Signs of raised ICP (↑ICP):
  • Cushing's Triad: Systemic Hypertension, Bradycardia, Irregular respirations.

⭐ Cushing's Triad (systemic hypertension, bradycardia, irregular respirations) is a late, ominous sign of severely raised ICP.

• Management of raised ICP:
  • Elevate head of bed to 30° (promotes venous outflow).
  • Hyperosmolar therapy: Mannitol (0.5-1 g/kg IV), Hypertonic Saline.
  • Controlled hyperventilation (Target PaCO₂ 30-35 mmHg; temporary).
  • Surgical decompression (craniectomy) for refractory cases.

Head Trauma: Imaging & Interventions - Scan & Fix Guide

• CT Head Indications:

  Rule Component	Finding
  Key Adult Signs	GCS <15, Focal deficit, Fracture signs
  Key Pediatric Signs	PECARN: AMS, LOC, Fracture signs

  ⭐ NCCT Head: Initial imaging of choice in acute head trauma.

• MRI: For DAI, subacute/chronic bleeds, posterior fossa.
• Surgical Fix Criteria:
  • EDH: >30ml vol, >15mm thick, midline shift >5mm.
  • Acute SDH: >10mm thick, midline shift >5mm.
  • Depressed Fx: >cranial thickness, dural tear.
• Interventions: Craniotomy (flap replaced), Craniectomy (flap out).

Head Trauma: Complications - Aftermath Alert

• Early:
  • Seizures (prophylaxis: 7 days for severe TBI)
  • Hydrocephalus
  • Infection (meningitis)
  • Cerebral Salt Wasting (CSW)
• Late:
  • Post-Concussion Syndrome (PCS)
  • Post-Traumatic Epilepsy (PTE)
  • Cognitive deficits
  • Chronic Traumatic Encephalopathy (CTE)

⭐ Post-concussion syndrome is a common long-term sequela, even after mild TBI.

High‑Yield Points - ⚡ Biggest Takeaways

• GCS (Glasgow Coma Scale) is key for initial assessment and predicting outcome in head trauma.
• EDH (Extradural Hematoma) often shows a lucid interval; typically a middle meningeal artery bleed.
• CT scan is the undisputed investigation of choice for any acute head injury.
• Cushing's triad (↑BP, ↓HR, irregular breathing) indicates critically raised ICP (Intracranial Pressure).
• Diffuse Axonal Injury (DAI) can present with minimal CT findings but carries a grave prognosis.
• Management priorities: ABCDE protocol, and crucially, prevent secondary brain injury.
• Basilar skull fracture indicators include Battle's sign (postauricular ecchymosis) and Raccoon eyes (periorbital ecchymosis).