Traumatic Brain Injury Flashcards
Definition of traumatic brain injury
damage to brain resulting from external mechanical forces
Epidemiology of traumatic brain injury
trauma most common cause of death 1-45 yo; 50% are deaths from head injury
20% of head injuries cause brain injury
Etiology of traumatic brain injury
direct impact, rapid acceleration, blast waves, penetration by projectile (bullets, knifes, etc.)
intra-axial vs extra-axial brain injury
intra-axial = acceleration/deceleration injury (shearing, coup/countrecoup); in brain parenchyma
extra-axial = direct force; in epidural, subdural, subarachnoid
coup-countrecoup
- head strikes fixed object, causing brain to collide with inside of skull at impact site and opposite side of site
- result in cerebral contusions (bruising)
Primary vs secondary traumatic brain injury
Primary: immediate injury effects
Secondary: molecular cascade of neurochemical reactions in brain post-injury; last for hours to days
epidural injury mechanism
direct trauma, usually with skull fracture, min to hours
Important history information with traumatic brain injury
mechanism, LOC, HA, visual changes, focal neural complaints, neck pain, seizures
Leading cause of brain injuries
falls
where contusions likely to occur?
basilar temporal area
subdural injury mechanism
lower force (eg. fall), less likely skull fracture, veins, hrs to days
subarachnoid injury mechanism
spontaneous/high force, small vessels rupture, secs-mins
Secondary brain injury can result in
neuronal cell death, cerebral edema, increased ICP
PE of traumatic brain injury
Neuro exam Glasgow Coma Scale External findings (hematoma, depressions, lacerations) Signs of increased ICP Signs of basilar skull fracture
Signs of increased ICP
fixed/dilated pupils
decorticate/decerebrate posturing
Cushing response (bradycardia, HTN, less respiratory drive)
Signs of basilar fracture
- Battle sign
- Raccoon eyes
- Hemotympanum, otorrhea, rhinorrhea (may be CSF)
galea
periosteum on top region of skull
decorticate vs decerebrate posturing
decorticate is abnormal flexion rigidity and decerebrate is abnormal extension rigidity
Glasgow Coma Scale classes
Mild = 13-15 Mod = 9-13 Severe = 8 or less
Tx according to Glasgow Coma Scale?
GCS < 8 = intubate
GCS 14 or less = CT
What does Glasgow scale 3 or less indicate?
70-100% mortality
First line diagnostic studies for head injury
1) CT
2) Lumbar Puncture
ER tx and dx of traumatic brain injury
- Maintain vitals
- Neuro exam GCS
- Assess for systemic trauma
- Check labs (CBC, lytes, glucose, coags, etoh, urine drug screen)
For severe TBI - head elevation, Mannitol or IV hypertonic saline
What greatly effects accuracy of Glasgow Coma Scale?
alcohol
Different ways to treat increased ICP
Mannitol, hyperventilation, sedation
Why monitor glucose?
too high - osmotic (water to brain, worsening edema)
too low - seizures
Definition of concussion
trauma-induced alteration in mental status
Definition of mild TBI
- injury to brain caused by contact and/or acceleration/deceleration forces
- GCS score 13-15 measured at ~30 min post-injury
Etiology of mild TBIs
most common MVA and falls
others - occupational accidents, recreation accidents, assaults
Hallmark sx of concussion
confusion, amnesia, +/- LOC
Sx hours to days after concussion
mood and cognitive disturbances, sensitivity to light and noise, sleep disturbances
PE of concussion/mild TBI
should be normal
- Eval head for hematomas, lacerations, or ecchymosis
- Neck and C-spine exam
- Full neuro exam
Most sensitive and specific concussion assessment
SAC (standardized assessment of concussion)
Decisions to CT a mild head injury patient
dangerous mechanism, severe HA, vomiting, seizures, LOC, altered mental status
Concussion Grading Scale
Grade 1, 2, 3 (mild, mod, severe) based upon presence and duration of LOC
But LOC doesn’t predict clinical course and long-term cognitive impairment
SHOULD NOT BE USED! for young athletes
Discharge criteria for concussion
GCS = 15
No ongoing symptoms
Normal exam and CT
No predisposition to bleeding
Admission criteria for concussion
GCS < 15 Seizures Abnormal CT Coagulopathy No responsible person available
Treatment of concussion
- Tylenol prn HA (not NSAIDs or narcotics)
- Physical/cognitive rest for 24-48 hrs with gradual return to work/school/play
Discharged concussion patient should return to ED if…
- Inability to awaken the patient
- Severe/worsening headaches
- Somnolence or confusion
- Restlessness, unsteadiness, or seizures
- Difficulties with vision
- Vomiting, fever, or stiff neck
- Urinary or bowel incontinence
- Weakness/numbness of any part of body
Complications of concussions
postconcussion syndrome (resolve in wks to months)
chronic traumatic encephalopathy (neuropsycho deficits from repeated injury)
Post-traumatic HA, epilepsy, vertigo
Definition of post-concussion syndrome
common symptom complex sequela of mild TBI
Epidemiology of post-concussion syndrome
30-80% of mild TBIs
Severity of TBI doesn’t correlate
Pathophysiology of post-concussion syndrome
Theories:
1) Structural/Biochemical: global atrophy, regional volume loss, white matter abnormalities
2) Psychogenic: symptoms similar to somatization seen in psych disorders
Treatment of post-concussion syndrome
- Simple reassurance; most improve 1-3 months
- Symptomatic tx (dizziness, HA, insomnia)
- Education of family, teachers, employers, etc.
Prognosis of post-concussion syndrome
First 7-10 days: sxs and disabilities greatest
1 month: sxs improved and in many cases resolved
3 months: vast majority of patients have largely recovered
1 year: 10-15% have ongoing sxs
Clinical features of Chronic Traumatic Encephalopathy
Cognitive impairment: memory loss, dementia
Neuropsych sx: behavior and personality changes, depression, suicidal
Neurodegenerative sx: Parkinson’s and other speech and gait abnormalities
Dx of Chronic Traumatic Encephalopathy
Typically on autopsy: cerebral atrophy, fenestrated cavum septum pellucidum, tau protein
Advanced neuroimaging studies (SPECT, PET and fMRI): white matter abnormalities, new radiopharmaceutical that binds to tau proteins but need further studies
Prevention of Chronic Traumatic Encephalopathy
Better helmets
Changed return to play rules
↓ number of contact practices
Rules changes
