Severe Traumatic Brain Injury

Severe Traumatic Brain Injury (TBI) is one of the most devastating forms of trauma, frequently resulting in high mortality, permanent neurological disability, and significant socioeconomic burden. It occurs when an external mechanical force — such as a road traffic crash, fall, physical assault, or sports injury — causes structural damage and dysfunction of the brain. Severe TBI is defined physiologically by a Glasgow Coma Scale (GCS) score ≤ 8 after resuscitation, or by imaging evidence of structurally significant injury.

The injury sets in motion a dynamic cascade of primary injury (direct parenchymal disruption) and secondary injury (neuroinflammation, cerebral edema, ischemia, raised intracranial pressure), which can exponentially worsen neurological outcome without timely and specialized care. The multidisciplinary approach involving trauma, neurosurgery, critical care, rehabilitation, and long-term support is critical to improve survival and functional outcomes.1–4

Pathophysiology

Severe TBI involves two broad phases:1. Primary injury: Direct damage at the moment of impact resulting in contusions, lacerations, diffuse axonal injury, hematomas (epidural, subdural), skull fractures, and hemorrhage within the brain parenchyma.2. Secondary injury: A multifactorial process involving increased intracranial pressure (ICP), blood–brain barrier disruption, excitotoxicity, inflammation, ischemia, cerebral edema, and hypoxia — all of which contribute to progressive neuronal loss and worsened outcomes.1,5

Epidemiology

• Globally, TBI accounts for millions of emergency admissions annually and is a leading cause of death and disability in young adults.12

• The greatest incidence is among persons aged 15–24 and the elderly (≥ 65 years) due to falls, traffic collisions, and high-risk activities.

• Motor vehicle crashes are a major contributor to severe TBI worldwide.12

Clinical Presentation

Patients with severe TBI may present with a combination of:

Neurological

• Decreased level of consciousness (GCS ≤ 8)

• Pupil abnormalities (unequal or fixed dilated pupils)

• Motor deficits (weakness/paralysis)

• Posturing (decorticate/decerebrate)

• Seizures

Systemic

• Hypotension

• Hypoxia

• Bradycardia

• Respiratory depression

Associated injuries

• Facial trauma

• Cervical spine injury

• Thoracoabdominal trauma

• Long bone fractures

Diagnostic Criteria

Severe TBI is diagnosed clinically and supported by imaging when:

• Glasgow Coma Scale (GCS) score ≤ 8 after resuscitation

• Presence of structural injury on brain CT (hematoma, contusion, swelling)

• Signs of raised intracranial pressure (altered pupillary response)

• Focal neurological deficits suggesting localized injury

Investigations

Imaging

• Non-contrast CT scan of the head — gold standard for acute assessment

  • Detects hemorrhage, contusions, skull fractures, mass effect

• MRI brain — useful for diffuse axonal injury (subacute/chronic phase)

• CT angiography/venography when vascular injury is suspected

Monitoring

• Intracranial pressure (ICP) monitoring

  • Indicated in severe TBI when CT abnormalities or clinical evidence of raised ICP are present

• Continuous EEG — if seizures are suspected

Laboratory

• Full blood count, electrolytes, coagulation profile

• Arterial blood gas (oxygenation/ventilation status)

• Blood glucose

• Toxicology screen if indicated

Management

A. Initial Resuscitation (Trauma ABCDE + Neuroprotection)

Airway

• Secure airway with cervical spine protection

• Endotracheal intubation if GCS ≤ 8

Breathing

• Ensure adequate oxygenation (SpO2 ≥ 94%)

• Correct hypoxia and hypercapnia

Circulation

• Maintain perfusion (SBP ≥ 100 mmHg)

• Avoid hypotension to preserve cerebral perfusion pressure (CPP)

B. Early Neurocritical Care

Patients with severe TBI require intensive care unit (ICU) admission with strict monitoring:

• ICP monitoring, aiming for ICP < 22 mmHg

• Cerebral perfusion pressure (CPP) target 60–70 mmHg

• Head elevation (30°) to reduce ICP

• Normothermia

• Normoglycemia

• Avoidance of hypoxia and hypotension

• Sedation and analgesia to minimize ICP spikes

C. Surgical Intervention

Craniotomy / Decompressive craniectomy may be indicated for:

• Large epidural or subdural hematomas with mass effect

• Refractory intracranial hypertension despite medical therapy

• Cerebral herniation

D. Pharmacological Therapy

There is no specific neuroprotective drug proven to improve mortality in severe TBI, but supportive pharmacotherapy includes:

• Analgesia and sedation

• Antiepileptics for seizure control or prophylaxis (typically for 7 days)

• Osmotic therapy (e.g., mannitol, hypertonic saline) for raised ICP

• Antibiotics if open fractures or infection suspected

• Venous thromboembolism prophylaxis once safe

• Stress ulcer prophylaxis

E. Rehabilitation

Early and multidisciplinary rehabilitation is essential:

• Physical therapy

• Occupational therapy

• Speech and cognitive rehabilitation

• Psychological and social support

• Long-term follow-up for disability and quality of life

Rehabilitation should begin as soon as the patient is medically stable and often continues for months to years.

Complications

Acute

• Intracranial hypertension

• Seizures

• Central diabetes insipidus

• Infections (pneumonia, meningitis)

• Multi-organ dysfunction

Long-term

• Motor deficit

• Cognitive impairment

• Behavioral disorders

• Persistent vegetative state or minimally conscious state

• Post-traumatic epilepsy

Outcome and Prognosis

Outcomes vary based on:

• Severity and location of injury

• Age and comorbidities

• Speed and quality of emergency and neurocritical care

Best outcomes are seen with rapid airway stabilization, avoidance of secondary insults, and comprehensive rehabilitation.1–4

Prevention

• Road safety measures (helmets, seatbelts)

• Occupational safety

• Fall prevention strategies in elderly

• Enforcement of laws against drunk driving

• Community education and awareness