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) – cases per 100,000 i.e. 600,000 new cases per year (Tennant 1995) Fatal 10% GCS - Mild – %, 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 ºLaceration ºConcussion 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 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 opening 4 – spontaneously 3 – to verbal commands 2 – to pain 1 – No response Best Motor response 6 – obeys commands 5 – Localizes to pain 4 – flexion withdrawal 3 – abnormal flexion 2 – extension 1 – no response Best Verbal response 5 – 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