Neurology · Year 3 · from Neurology

Case 1: Severe Traumatic Brain Injury

Patient Demographics

• Age: 23 years old
• Sex: Male
• Mechanism: Motorcycle accident, not wearing helmet

Prehospital Information

EMS called to scene of motorcycle vs. car collision. Patient found unresponsive with obvious head trauma. GCS at scene: Eye 1, Verbal 1 (intubated), Motor 3 = GCS 5T. Right pupil 5mm and sluggish; left pupil 3mm and reactive. Intubated in field. Transported as trauma code.

Emergency Department Assessment

Primary Survey:

• Airway: Secured (intubated in field)
• Breathing: Bilateral breath sounds, SpO2 99% on ventilator
• Circulation: HR 58, BP 168/92 (Cushing response)
• Disability: GCS 5T (E1V1TM3)

Secondary Survey - Neuro:

• GCS Breakdown:
• Eyes: 1 (no opening)
• Verbal: 1T (intubated)
• Motor: 3 (abnormal flexion to pain)
• Pupils:
• Right: 6mm, fixed
• Left: 3mm, sluggish
• Motor Response: Abnormal flexion (decorticate posturing) bilaterally

Other Injuries:

• Scalp laceration, right temporal
• Right clavicle fracture
• No other significant injuries

Clinical Image

Image: CT head showing acute subdural hematoma with midline shift, demonstrating the crescent-shaped hyperdense collection conforming to the brain surface with mass effect.

Image Source: Wikimedia Commons Attribution: Radiology case, CC BY-SA 3.0 URL: https://commons.wikimedia.org/wiki/File:Subdural_hematoma.jpg

CT Head (Non-contrast)

Findings:

• Right acute subdural hematoma - crescent-shaped, 12mm maximal thickness
• Midline shift: 10mm to the left
• Right uncal herniation: Effacement of ipsilateral ambient cistern
• Diffuse cerebral edema: Loss of gray-white differentiation
• No epidural hematoma
• No skull fracture

Assessment

1. Severe traumatic brain injury (GCS ≤8)
2. Acute subdural hematoma requiring emergent evacuation
3. Right uncal herniation - dilated right pupil from CN III compression
4. Elevated intracranial pressure

Signs of Herniation

Immediate Management (ED)

Airway/Ventilation:

• Confirm ETT placement
• Target: PCO2 35-40 mmHg (avoid hypocapnia unless herniating)
• Target: SpO2 >94%

Blood Pressure:

• SBP target: >100 mmHg (age 50-69) or >110 mmHg (age 15-49)
• Avoid hypotension - single episode of SBP <90 associated with worse outcomes
• This patient hypertensive (Cushing response) - no treatment of HTN (reflects ICP elevation)

ICP Management - Emergent:

• Head of bed elevated 30 degrees
• Midline head positioning (avoid jugular compression)
• Hypertonic saline 23.4% - 30mL bolus (or mannitol 1g/kg if HTS unavailable)
• Brief hyperventilation to PCO2 30-35 (temporary bridge to OR)
• Sedation with propofol

Seizure Prophylaxis:

• Levetiracetam 1000mg IV (reduces early post-traumatic seizures)

Other:

• Normothermia (avoid fever)
• Glucose control (avoid hypoglycemia and severe hyperglycemia)

Neurosurgical Intervention

Decision: Emergent surgical evacuation

Indications for SDH evacuation met:

• Thickness >10mm: YES (12mm)
• Midline shift >5mm: YES (10mm)
• GCS drop: N/A (already severe)
• Neurological deterioration: YES (herniation)

Procedure: Right frontotemporoparietal decompressive craniectomy with SDH evacuation

Operative Findings:

• Large acute subdural hematoma evacuated
• Brain swollen, not replaced bone flap (decompressive craniectomy)
• ICP monitor placed

ICU Management Post-Operatively

Neuroprotective Targets:

ICP Monitoring:

• Initial ICP post-op: 18 mmHg (improved)
• CPP maintained at 65 mmHg

Tiered ICP Management Protocol:

Tier 1 (General measures):

• Head of bed 30 degrees
• Avoid fever, pain, agitation
• Sedation with propofol/fentanyl
• Maintain euvolemia

Tier 2 (If ICP remains elevated):

• CSF drainage (if EVD in place)
• Osmotic therapy:
• Hypertonic saline (3% continuous or 23.4% bolus)
• OR Mannitol 0.25-1 g/kg boluses
• Brief hyperventilation (if acutely herniating)

Tier 3 (Refractory ICP elevation):

• Barbiturate coma (pentobarbital)
• Decompressive craniectomy (already done)
• Hypothermia (controversial)

Clinical Course

Day 1-3:

• ICP controlled 15-20 mmHg on tier 1 measures
• Sedation weaned on day 3
• Opened eyes to voice, localized to pain
• Right pupil improved to 4mm, sluggishly reactive

Day 7:

• Off sedation
• Following simple commands
• Moving all extremities (left weaker than right)
• Tracheostomy and PEG placed

Day 14:

• Transferred to acute rehabilitation
• GCS 11T (E4VTM6)
• Cranioplasty planned in 6-8 weeks

Teaching Points

1. GCS ≤8 defines severe TBI and mandates airway protection (intubation)

1. Avoid secondary brain injury:

• Hypotension (SBP <90) dramatically worsens outcomes
• Hypoxia (SpO2 <90%) worsens outcomes
• Fever increases metabolic demand
• Hyperglycemia and hypoglycemia are harmful

1. Subdural hematoma surgical indications:

• Thickness >10mm
• Midline shift >5mm
• GCS drop of ≥2 points
• ICP >20 mmHg

1. Signs of uncal herniation:

• Ipsilateral pupil dilation (CN III compression)
• Contralateral hemiparesis (or ipsilateral - Kernohan's notch)
• Declining consciousness

1. ICP management is tiered - start with basic measures, escalate as needed

1. Target ICP <22 mmHg and CPP 60-70 mmHg

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