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The following lecture has been approved for University Undergraduate Students This lecture may contain information, ideas, concepts and discursive anecdotes that may be thought provoking and challenging It is not intended for the content or delivery to cause offence Any issues raised in the lecture may require the viewer to engage in further thought, insight, reflection or critical evaluation [email protected] Introduction to Brain Injury Dr. Craig Jackson Senior Lecturer in Health Psychology School of Health and Policy Studies Faculty of Health & Community Care University of Central England What was Michael Angelo’s Hidden Message? Michelangelo. The Creation of Adam (detail, Sistine Chapel). 1510. Fresco. Sistine Chapel, Vatican, Rome. Objectives List major structures and function of nervous system Name types of head and spine injuries; describe clinical features Describe mechanisms of neurological injury Describe assessment of head injuries Describe functional affects and symptoms Describe imaging techniques Neurological Injuries Responsible for 50+% of trauma deaths Approx. 1,000,000 patients in UK attend A&E with head injury per year Can be prevented (some extent) by helmets and PPE Major cause of chronic disability Mostly from Falls, RTAs and Assaults Flannery & Buxton, 2001 Anatomy Principles Neuron specialized nerve cell Dendrites and Axons short and long processes of neurons Peripheral neurons sheathed with myelin Impulses transmitted from synapses to dendrites Anatomy Principles 2 Central Nervous System = brain, spinal cord Peripheral Nervous System = nerves, branches Meninges = protective triple layer cover Dura matter Arachnoid Pia matter = = = outer layer middle layer inner layer Cerebral Spinal Fuid (CSF) circulates in middle layer Anatomy Principles 3 Cerebrum (hemispheres) Cerebellum, brainstem Cranial nerves originate at base of brain Sensory / motor supply to head and face Motor nerves = brain to muscle units Sensory nerves = skin back to brain Somatic Nervous System = voluntary action Automatic Nervous System = involuntary action Anatomy Principles 4 Traumatic Brain Injury Physical force causes nerve cells to stretch, tear and pull apart Unable to relay messages through brain Force causes brain to slam against skull interior: “Traumatic Brain Injury” Injury to brain cells affects processing: thinking remembering seeing control & coordination mood Traumatic Brain Injury TBI ranges from mild to severe: degree of force multiple trauma neurological complications speed of assistance Head Injuries Severity depends on amount of Primary and Secondary brain injury Main cause of Secondary injury = hypoxia Categories: Open or Closed Forces: Shearing and Compression Non Loss of Function 41 yr old Mike Hill Attacked from behind Full recovery after removal No infection Left hospital 1 week after removal Epileptic medication and some memory problems Functional Status SPECT image with Technetium (T99) Pathophysiological Disturbance Involve scalp, cranium, or underlying brain Depends on mechanism of injury Scalp: lacerations, contusions, abrasions Skull fractures: vault / base, simple or compound, depressed or planar Primary Brain Injury: Focal (intra-cranial haematoma, contusion) Diffuse (diffuse axonal injury) Categories: Open or Closed Forces: Shearing and Compression “Closed” or “Open” Head Injury Closed Head Injury (CHI): No penetration of the skull Usually a TBI Not always though Open head Injury (OHI): Bullet, Knife, or Fracture Skull breeched Brain injury depends on power of physical force injury If great enough, forces radiates through skull, causes sudden brain movement Results in damaged nerve cells May result in “soft tissue” injury - cervical strain myofascial trauma “Mild” Traumatic Brain Injury Head injury graded on: (i) length of unconsciousness (ii) length of amnesia Both caused by sudden trauma and nerve cell tearing Brain cannot maintain functioning and shuts down either: fully (unconsciousness) or partially (dazed) MBI refers to loss of consciousness for 30 mins or less Unconscious Amnesia Altered consciousness neurological deficits Any of these indicates MBI MBI can result in life changing consequences Diffuse Axonal Injury Diffuse Axonal Injury Thinking slows down Memory poor Mild Brain Injury Processing slower Concentration haphazard “Roadblocks of damaged unconnected neurons” Individual feels: Incomplete Unconfident Frustrated Irritable Struggling emotional problems Described as “ mental fog” cognitive problems Brain Injury without Direct Trauma Whiplash & Shaking Sudden movement inside cranium damages neurons Acceleration – Deceleration RTAs – even with airbag deployment –can cause brain injury Brain is torn, squashed, bruised Rollercoasters Types of Head Injuries Concussion: Temporary alteration in neurological function or LOR Cerebral Contusion: Bruised brain Cerebral Haemotoma or bleed epidural sub-dural sub-arachnoid intra-cerebral Signs and Symptoms Headache Dizziness Nausea / Vomiting Amnesia Decreased responsiveness Confusion Combativeness Loss of responsiveness Assessment First impression: Responsive or Unresponsive Urgent Survey: LOR ABC’s Open airway with C-spine Check breathing: Ventilate; Oral airway; O2 when available Check carotid artery pulse – CPR if indicated Control any major bleeding Assessment continued Rapid Body Survey Sample, DCAP-BTLS Stabilize head between knees Call for equipment, assistance, transport Maintain body temp. Transport (head uphill) Non-Urgent Survey Ongoing Survey – seizures, vomiting, change in LOR Assessment continued Brain Swelling Increased Intracranial Pressure (ICP) Hypoxia Further Secondary Brain Injury More Swelling Increased ICP Localised Neurological Signs (ICP) GENERAL SIGNS + PLUS + Change in pupil size / light reactivity Slowing pulse Rising BP. Change in respiration Unilateral weakness Incontinence Seizure Urgent Interventions - ATLS Presume C-Spine injury Immobilize neck Open airway: administer oxygen Treat bleeding and shock Prevent aspiration of vomit / secretions Transport immediately Elevate head 6” Transport head uphill Imaging Xray, MRI and CT cannot show traumatic brain injury Techniques rely on tissue density Diffuse damage will not show on these techniques SPECT or PET measure brain cell metabolism Can detect changes in function due brain injury Behavioural Changes Speech Cognition Memory Mood Mental health psychoses delirium Tremor Gait Symmetry of function Visual Auditory Positive and negative symptoms Gross over-simplification Other Causes of Brain Injury Drug effects Tumor Metastases Physical assault Surgery Traumatic birth Hypoxia Glasgow Coma Scale Scores 8 or less = needs urgent anaesthetic assessment. Danger of airway compromise 13-15 = mild 9-12 = moderate 3-8 = severe Queen’s Medical Centre Cerebral Asymmetry of Function Hemispheric asymmetry of function is relative Asymmetries have been overblown by popular media into fads (e.g. golf with your right brain) Anterior-posterior differences far outweigh left-right differences Asymmetry is not uniquely human Cerebral Asymmetry of Function LEFT HEMISPHERE Convolutions mature more rapidly Extends further posteriorly Higher in density (more gray matter; more neurons) Planum temporale larger on left (in 60-90%) of cases Larger insula Longer Sylvian fissure (gentler slope) Double cingulate gyrus Larger lateral posterior nucleus (to parietal cortex) Wider occipital lobe Larger total area of frontal operculum (much buried in sulci) Larger inferior parietal lobule Cerebral Asymmetry of Function RIGHT HEMISPHERE Convolutions mature less rapidly Extends further anteriorly Larger and heavier Primary auditory (Heshl's gyrus) larger on right Shorter (steeper slope) Single Larger medial geniculate nucleus Narrower Larger area of convexity in frontal lobe; wider frontal lobe Cortical Lesions Human cognitive and sensory dysfunction different following lesions (due to strokes, surgery, accident, etc.) Differences noted in lesions to left and right hemispheres Lesions can provide clues about brain organization Do specific areas possess special unique functions? Does a lesion to a specific area demonstrate a dysfunction + Lesions to other brain locations do not cause a similar dysfunction Dissociation Lesion site Reading Writing Speaking 100 normal normal impaired 102 impaired normal normal 104 normal impaired normal Allows understanding of specific sites and impairments Hemispherical Function Left Vision linguistic stimuli Audition language sounds rhythm Somatosensation Right patterns faces steropsis tactile recognition Motor complex movement spatial movement Memory verbal memory non-verbal memory Language speech reading writing arithmetic prosody Emotion social emotions primary emotions Spatial processes geometry spatial images orientation Split Brain and Commissurotomy Corpus Callosum joins hemispheres Sever corpus callosum Two hemispheres cannot communicate Brain Injury - Summary 1. The main cause of secondary damage to the brain is _ _ _ _ _ _ _ ? 2. Head injury alone rarely causes damage. T / F? 3. Temporary loss of consciousness or function from a head trauma is a __________? 4. Brain injury can occur without any impact trauma. T / F 5. Axons being damaged / shredded is the simple reason for cognitive problems in head injury patients. T / F Hemispherical test I always wear a watch 1 Hemispherical test I keep a journal 2 Hemispherical test I believe there is a right and wrong way to do everything 3 Hemispherical test I hate following directions 4 Hemispherical test The expression "Life is just a bowl of cherries" makes no sense to me 5 Hemispherical test I find that sticking to a schedule is boring 6 Hemispherical test I'd rather draw someone a map the tell them how to get somewhere 7 Hemispherical test If I lost something, I'd try to remember where I saw last 8 Hemispherical test If I don't know which way to turn, I let my emotions guide me 9 Hemispherical test I'm pretty good at math 10 Hemispherical test If I had to assemble something, I'd read the directions first 11 Hemispherical test I'm always late getting places 12 Hemispherical test Some people think I'm psychic 13 Hemispherical test Setting goals for myself helps keep me from slacking off 14 Hemispherical test When somebody asks me a question, I turn my head to the left 15 Hemispherical test If I have a tough decision to make, I write down the pros and the cons 16 Hemispherical test I'd make a good detective 17 Hemispherical test I am musically inclined 18 Hemispherical test If I have a problem, I try to work it out by relating it to one I've had in the past 19 Hemispherical test When I talk, I gesture a lot 20 Hemispherical test If someone asks me a question, I turn my head to the right 21 Hemispherical test I believe there are two sides to every story 22 Hemispherical test I can tell if someone is guilty just by looking at them 23 Hemispherical test I keep a to do list 24 Hemispherical test I feel comfortable expressing myself with words 25 Hemispherical test Before I take a stand on an issue, I get all the facts 26 Hemispherical test I've considered becoming a poet, a politician, an architect, or a dancer 27 Hemispherical test I lose track of time easily 28 Hemispherical test If I forgot someone's name, I'd go through the alphabet until I remembered it 29 Hemispherical test I like to draw 30 Hemispherical test When I'm confused, I usually go with my gut instinct 31 Hemispherical test I have considered becoming a lawyer, journalist, or doctor 32 Hemispherical test 1. L 2. L 3. L 4. R 5. L 6. R 7. R 8. L 9. R 10. L 11. L 12. R Hemispherical test 13. R 14. L 15. R 16. L 17. L 18. R 19. R 20. R 21. L 22. R 23. R 24. L Hemispherical test 25. L 26. L 27. R 28. R 29. L 30. R 31. R 32. L