TRAUMATIC BRAIN INJURY Flashcards
What is TBI?
- non-degenerative, non-congenital INSULT to the brain from an EXTERNAL mechanical force
> temporary/permanent impariment of COGNITIVE/PHYSICAL/ PSYCHOSOCIAL fxns
Who is at risk of TBI?
- young men and elderly
- previous head injuries
- inner cities residents
- alcohol and DRUG abuse
- low-income
What political stances made for preventing TBI?
- seatbelt laws (‘83)
- testing for drink driving (‘83)
- helmets
How to manage a pt coming in with a TBI?
- atls managment (ABCs) —-GCS/ PUPILS/ other
- Secondary survey (check for other injuries) –c-spine
- HX (what happened/ when/ age/ PMH/ DRUGS- anticoagulants)
When must CT scans be performed WITHIN 1 hr of head injury?
- GCS <13 at ED
- gcs <15 AT 2HRS after injury
- suspected skull # (open/depressed)
- basal skull #
- post traumatic seizure
- focal NEUROLOGICAL deficit
- more than one episode of VOMITING
- SUSPICION of NAI (non-accidental injury)
Special request for CT scan in pts if they experience LOC or amnesia since the injury?
- > 65y.o
- coagulopathy
- dangerous mechanism of INJURY (MVA/ fall from a height > 1m)
- MORE than 30 mins of RETROGRADE amnesia of events before the injury
What is a sign of BASILAR skull fracture?
BATTLE’S sign
- crescent shaped bruise that appears behind ONE or BOTH ears
What are other signs of basilar skull fracture?
- bruising around the eyes
- anosmia
- hearing problems
- fluid/ blood leaking from ears/nose
What form of posturing is found in cerebral hemorrhage damage?
decorticate posturing –FLEXION of arms in wards (like mummy)
—-as red nucleus is still functioning
(nucleus relays flexor info)
What form of posturing is seen with brain stem damage?
- decerebrate posturing
EXTENSION of arms—no red nucleus fxn
What is subfalcine herniation?
when the Cingulate gyrus HERNIATES under the FALX cerebri
to the OTHER side
How does subfalcine herniation present as?
- ACA compression as the ACA gets dragged to the other side
- c/l hemiparesis of the LEG
What occurs in UNCAL herniation
- medial temporal lobe crosses over the tentorium cerebelli
> COMPRESSES MIDBRAIN
How does an epidural hematoma usually occur?
- # of pterion bone o> rupture of MIDDLE meningeal artery
How does Epidural hematoma present on CT?
- CONVEX shape
(LEMON) - because can’t cross suture lines (dura attached to the sutures)
What is the clinical course of the epidural hematoma?
- Initial loss of consciousness, immediately after the trauma
- temporary recovery of consciousness (LUCID interval)
- Renewed decline in MENTAL status- rapid
SYMPTOMS which may appear AFTER the trauma or after a LUCID interval
- deteriorating GCS
- possible HEMIPARESIS
- u/l FIXED and DILATED pupil
- apnoea and death
How does subdural hematoma occur?
- rupture of BRIDGING veins
- blood b/w DURA and arachnoid mater
How diff. is the onset of symptoms in Subdural hematoma as opposed to extradural?
- SLOW bleed in SUBDURAL hematoma d.t rupture of low pressure veins
Who is at risk of subdural hematoma?
- old age (Brain atrophy)
- alcoholics
- those on BLOOD THINNERS
When is the onset of symptoms in Subdural hemorrhage?
- confusion WEEKS AFTER head injury
What is subarachnoid hemorrhage?
- bleeding between the PIA and ARACHNOID mater
How does subarachnoid hemorrhage present as?
- worst headache of my life
- SUDDEN onset
- FEVER and nuchal rigidity
- Photophobia
- focal neurological deficits
How to confirm dx of subarachnoid hemorrhage?
- CT
- blood stained or xanthochromic (6-48 hrs) CSF spinal tap
What causes subarachnoid hemorrhage?
- ruptured BERRY aneurysm
- –esp. at anterior circle of WILLIS (branch points of AComm artery)
What conditions result in subarachnoid hemorrhage?
- AV malformations
- MARFAN Syndrome
- ADPKD (auto. dominant polycystic kidney disease)
- Ehler-Danlos (connective tissue d.o)
How does UNCAL herniation present as?
- ipsilateral CNIII compression
(BLOWN pupil) and lack of pupillary constriction - CORTICAL blindess/ Homonymous hemianopia (collpased PCA)
- cerebral PEDUNCLE comprssion (c/l PARESIS)—or herniates to opp. side (ipsilateral paresis)
- May have duret hemorrhage of PONs and midbrain
Summarize the signs of uncal herniation.
- dilated pupil at side of lesion
- VISUAL loss
- HEMIPARESIS
What occurs with central transtentorial herniation?
- thalamus/ hypothalamus/ medial parts of temporal lobes HERNIATEs through the tentorium cerebelli
How does central herniation present as?
- LOC
- somnolence
- intially: SMALL, reactive pupils (dilated, fixed pupils)
- LATER: non-reactive
- ——–paralysis of UPWARD eye movement (SUNSET eyes sign)
- POSTURING
What is the danger of TONSILLAR herniation?
- compression of MEDULLA results in depression of centers for RESPIRATION and CARDIAC rhythm control
What occurs with tonsillar herniation?
- CEREBELLAR tonsils HERNIATE down into the FORAMEN magnum
- -> usually d.t post. fossa mass lesion
What are the signs of tonsilar herniation?
- headache and neck stiffness
- LOC > FLACCID paralysis
- CNiii palsy / CN VI palsy
- ATAXIA
- (+)ve BABINSKI
- –irregular breathing
What are the signs of RAISED ICP?
- reduced LOC
- neurological signs
- PAPILLEDEMA
- cushing’s triad= irregular breathing+ Incr. BP+ bradycardia
What is the level of raised ICP?
- > 100mmhg-180mmHg
When is intubation and ventilation recommended?
- when GCS is <9
At what point of a pt with TBI, should the neurosurgeons step in?
- with further deterioration of GCS and neck range of motion
- LARGE extradural or subdural bleed is noted on CT
What are some ddx for SUDDEN onset headache?
- SAH
- Migraine
- benign Coital cephalgia
What focal neurological deficits may a pt present with, in a suspected SAH?
- Dysphasia
- Hemiparesis
- III CN palsy
On fundoscopy, what is seen in suspected SAH?
- retinal or vitreous hemorrhage
How accurate is a CT scan post-SAH?
-if within 48hrs; detects >90% of the bleeds
may be negative if >3days POST-ictus
- negative in 15% of pts who HAVE bled
When is a lumbar puncture safe to perform>
- in alert pt
- no neurological deficit
- NO papilloedema
- after normal CT scan
How to differentiate traumatic tap from SAH + csf tap?
- no. of blood cells would be roughly equal through out the 3 testubes if it is SAH
- in a traumatic tap; the no. reduces
What is the gold standard method of dx for SAH?
- cerebral angiography
(seldinger tech. via the femoral artery)
——though may miss aneursym d.t vasospasm
Other methods of dx for SAH?
- MRI
- CT
What are complications of SAH?
- re-bleeding
- delayed ischaemic deficit
- hydrocephalus
- hyponatremia
- seizures
Duret hemorrhages are seen in which brain herniations ?
- Uncal
- Central
