Head Injury (TBI) M K Alam, MS; FRCSEd

Head Injury (TBI) The most common cranial condition. Decline in mortality: 50% 1970s to 36% 1980s to 27% 1990s to 15% 2000s EMS, Critical Care, CTs USA: brain injury occurs every 7s, result in death every 5 min TBI: 1/3 of all trauma related deaths Motor vehicle accidents: 50% Incidence : M:F 2:1 2

Outcome of TBI Death : % Severe Disability : 15% Moderate Disability : 14 – 20% Persistent vegetative state : < 5% Good Outcome : 25%

Causes of trauma RTA or MVA Pedestrian trauma Fall from height Assault Industrial accidents Natural disasters Explosions Firearm injuries Knife

Pre-hospital care Delivery to the hospital for definitive care as rapidly as possible- scoop and run Only critical interventions at the scene Airway established, hard collar, spine board, control any external hemorrhage Infusion on way to the hospital

Hospital care ATLS approach A well defined order Primary survey- initial assessment and management Treat the greatest threat to life Immediate intervention as the threat to life is identified Detailed history not essential Re-evaluation of initial management Secondary survey- a head to toe evaluation

Primary survey A B C D E Airway & cervical spine protection Breathing Circulation Disability (neurologic assessment) Exposure and Environmental control

Disability Neurologic evaluation Level of consciousness measured by the Glasgow Coma Scale (GCS) If the GCS is used in intubated and paralyzed patients, record should be made Pupillary response can still be assessed in a paralyzed patient

CLASSIFICATION OF TBI 9

Glasgow Coma Scale (GCS), Total = 15 Eye responseVocal responseMotor response Spontaneous 4Oriented 5Obeys commands 6 To voice 3Confused 4Purposeful movement to pain 5 To pain 2Inappropriate words 3Withdraw from pain 4 None 1Incomprehensible words 2Flexion to pain 3 ***None 1Extension to pain 2 *** None 1

PUPILS Unilateral Dilated: CN III compression secondary to tentorial herniation Traumatic Mydriasis Bilateral Dilated: Inadequate brain perfusion, bilateral CN III compression Bilateral Miotic: Drugs, metabolic encephalopathy, Pontine lesion Unilateral Miotic: Injured sympathetic pathway ( e.g. carotid sheath injury)

Head injury severity Mild GCS ≥ 13 Moderate GCS 9- ≤ 12 Severe GCS ≤ 8

Secondary Survey Only after completion of primary survey All life threatening injuries dealt, normalization of vital signs Secondary Survey: A head to toe evaluation Detailed history and examination Continuous reassessment of vital signs Additional laboratory/ radiological tests. Additional tubes, lines and monitoring devices Priorities and plan definitive management of all injuries

Head injury Traumatic brain injury (TBI)- the leading cause of death in trauma patients. Upto 50% of all traumatic deaths. Primary injury- the anatomic and physiologic disruption that occurs as a direct result of trauma Secondary injury- extension of the primary injury, result from local swelling, increased ICP, hypoperfusion, hypoxemia, or other factors. Aim- detection and treatment of primary injury and prevention of secondary injury

MILD TBI 80% of all TBI ( GCS ≥ 13) 3% of pts with mild TBI deteriorate How could I know if my patient is in the 3%? Classification of mild TBI: – Admission GCS – Duration of LOC – Post traumatic amnesia – Focal neurological deficits 15

MODERATE TBI 10% of all TBI pts seen in ER ( GCS 9- ≤ 12) 10% will deteriorate CT head in all Admission F/U CT 16

SEVERE TBI GCS ≤ 8 Will typically be evident by CT ICU required The worse the GCS the worse the prognosis In this regard the motor component of GCS is more important than the other 2 17

SKULL FRACTURES Fracture patterns depend on: – Thickness – Morphology – Composite nature of the bone Types – Linear – Depressed (open or closed) – Basilar or Basal 18

LINEAR FRACTURES Most common Direct impact to the cranium From a broad surface Separation of the # edges (diastasis) Thinnest areas of the skull Squamous portion of temporal bone & damage of middle meningeal artery - epidural hematoma 19

DEPRESSED FRACTURES Small surface area of the object Punched inwards CSF leakage Open (laceration of scalp) Infection Seizures 20

DEPRESSED FRACTURES Surgical intervention when: – > 8-10 mm depression (or > than the thickness of skull) – Deficit related to underlying brain – CSF leak – Compound fractures – Cosmetic region

BASAL FRACTURES Direct trauma to Mastoid (Battle’s sign) Occipital Supraorbital (Raccoon eyes) Indirectly to Cribriform plate CSF leak Rhinorrhea Otorrhea Cranial nerves Carotid artery 22

Subdural hematoma More common than EDH Acute form is associated with other significant brain injuries Cerebral contusion (67%) Highest Mortality rate: 60-70%. (acute SDH) Can be subdivided into Acute - less than 3 days Subacute - 3 days to 3 weeks Chronic - after 3 weeks 23

Subdural hematoma Surgical intervention when … – Symptomatic – SDH thickness > 1cm (5mm in Peds) – Midline shift > 5mm Positive Displacement Factor or shift out of proportion – Midline shift > SDH thickness Timing of Surgery: – Early : 0 – 4 Hrs from injury – Late : > 4 Hrs

Epidural hematoma An acute lesion Commonly seen in frontal or temporal region 75-90% of patients with epidural hematomas will have fractures. Middle meningeal artery (85%) “Lucid interval” Surgery: > 5mm midline shift, symptomatic, detoriation of GCS 25

Epidural Subdural Hematoma Hematoma

TRAUMATIC SAH Most common lesion from closed head injury. Significant SAH always associated with cortical contusions. Block arachnoid villus causing hydrocephalus. 27

DAI (Diffuse axonal injury) Rotational injury forces (angular acceleration) can disrupt axons. DAI shows minimal gross alteration. SEVERITY: – Mild: coma 6 – 24 Hrs – Moderate: coma >24 Hrs without decerebrate posturing – Severe: coma > 24 Hrs + decerbrate posturing & flaccidity – CLINICAL HALLMARK – prolonged loss of consciousness. – occurs immediately after the injury. – no correlation with external trauma or skull fractures. 28

Intracranial hypertension Surgical intervention when: – Progressive neurological deterioration – Refractory high ICP – GCS 6 – 8 – Frontal or temporal contusions >20 cm 3 – Midline shift > 5mm – Any lesion >50 cm 3

Late complications of TBI Posttraumatic seizures Communicating Hydrocephalus Post-concussive syndrome – Cluster of Symptoms (organic / psychological) Dizziness, visual disturbance, anosmia, hearing difficulty Difficulty concentrating Emotional difficulties, insomnia

Head injury- management summary Maintain BP >90 mmHg, PaO2 >60 mmHg Assess GCS and lateralizing signs- pupil and motor function Pupillary asymmetry >1 mm suggests intracranial injury Larger pupil is on the side of the mass lesion Extremity weakness- detected by testing motor power CT scan head- accurate localization of the lesion Epidural or subdural hematoma: evacuated Intracerebral hematoma & contusion Diffuse axonal injury: maintain brain perfusion & prevent rise in ICP.