TBI & Glasgow Coma Scale Mandy Freeman March 2010.

TBI & Glasgow Coma

Scale

Mandy Freeman

March 2010

Aims

Highlight types of traumatic brain injuries (TBI)

Highlight the importance of Glasgow Coma

Scale

Aetiology Annual incidence (US) – 180-220 cases per

100,000 i.e. 600,000 new cases per year (Tennant 1995)

Fatal 10% GCS - Mild – 75-80 %, moderate – 10%,

severe – 10% Permanent disability

100% in severe, 66% in moderate Male to female ratio – 2:1 (Sosin et al 1996) Age Range ?

Most common causes??

(Royal College of Surgeons of England 2007)

Pathophysiology

Skull – rigid, inelastic container = Vol (Brain) + Vol (CSF) + Vol (Blood) = 80% + 10% + 10% Monro-Kellie Doctrine – states that total

intracranial volume is fixed because of the inelastic nature of the skull

Intracranial compliance – change in the pressure due to the change in volume

Cushings Triad -Sign of ICP

ºLaceration ºBOS # ºContusion ºAbrasion SKULL ºLacerationºConcussion ºContusions ºEDH – ºSubdural: ºCranial # ºICH ºSAH

EDH

Extradural hematomas Between inner table of skull and dura Biconvex Arterial injury – enlarge rapidly Venous in around 10% Classic example – temporal EDH by fracture

through course of middle meningeal artery Lucid interval before deteriorating If tackled early – good prognosis for isolated

lesion

SDH

Subdural hematoma Between dura and brain Outer edge – convex, inner – concave Not limited by suture lines Usually venous – bridging veins (cortex to

dura) In elderly brain more common due to

cerebral atrophy

Management

Mild Head Injury 3% will progress to more serious injuries Concussion – majority have concussion –

physiological injury to brain without structural alteration

Monitored Would require neurological observations When discharged instructed to seek medical

attention if severe headache, persistent nausea and vomiting, seizure,

confusion, unusual behaviour, watery discharge from ear or nose

Contusions

Most common and evident in minor and major head injuries

Can present with GCS 15/15 worsening over day 3 to 5

Strict fluid balance 2 litre restriction

4hrly Observations

Diffuse Axonal Injury

Neuronal injury in subcortical gray matter or brain stem due to rotation or deceleration injury

Patients with severely depressed level of consciousness

CT – no significant injury ICP – within reference range Prognosis - poor

GCS

Severity of Head Injury Mild head injury – GCS 15 - 13 Moderate head injury – GCS 12 – 9 Severe head injury – GCS 8 and below

Developed by Jennett and Teasdale (1974)

Assess level of consciousness 3 categories

Eye opening – E Motor response – M Verbal response – V

Glasgow Coma Scale

Eye opening4 – spontaneously3 – to verbal

commands2 – to pain1 – No response

Best Motor responseBest Motor response6 – obeys commands6 – obeys commands5 – Localizes to pain5 – Localizes to pain4 – flexion withdrawal4 – flexion withdrawal3 – abnormal flexion3 – abnormal flexion2 – extension 2 – extension 1 – no response1 – no response

Best Verbal response5 – oriented and converses

4 – disoriented and converses

3 – inappropriate words

2 – incomprehensible sounds

1 – No response

Best – 15

Worst - 3

Poor Outcome

Age older than 60 years GCS of <5 Presence of fixed pupil Prolonged hypotension or hypoxia Presence of surgical treatable mass

lesion

NAI Children

Child with head injury – NAI must be excluded

HI is most common cause of morbidity and mortality in NAI

Multiple bilateral skull fractures, subdural hematomas of different ages, cortical contusions and shear injuries, cerebral ischaemia, retinal haemorrhages

Dunn L, Henry J, Beard D. Social deprivation and adult head injury: a

national study. (2003) J Neurol Neurosurg Psychiatry. 74:1060–1064 National Institute for Clinical Excellence. (2007) Triage, assessment

Investigation and early management of head injury in infants, children and adults Clinical Guidelines CG56. NICE;

Swann IJ, Walker A. (2001) Who cares for the patient with head injury now? Emerg Med.18:352–357.

Sosin DM, Sniezek JE, Thurman DJ. (1991) Incidence of mild and moderate brain injury in the United States. Brain Injury. 1996;10:47–54.

Thornhill S, Teasdale G, Murray GD, McEwen J, Yoy CW, Penny KI. Disability in young people and adults one year after head injury: prospective

cohort study. BMJ. 2000;320:1631–5

Tennant A. Epidemiology of head injury. (1995) In: Chamberlain MA, Neumann VC, Tennant A, editor. Traumatic Brain Injury Rehabilitation: Services, treatments and outcomes. London: Chapman & Hall