head injury Flashcards
how many types of brain injury are there?
2, primary and secondary
explain primary HI
- caused by impact or initial insult
Include diffuse axonal injury and the focal lesions of laceration, contusion
and hemorrhage
○ Focal / Polar / Diffuse
○ Intracranial hematomas
what is focal in primary HI>
particular spot in the brain
what is polar in primary HI?
brain shift within the skul and meninges, injuries at 2 opposite poles
what is diffuse in primary Hi?
widespread neuronal damage
examples of intracranial haemorrhage in primary HI
➢ Epidural, Subdural Subarachnoid
explain secondary HI
Progressive damage resulting from a physiologic response to an initial insult
○ Damage results from the subsequent brain swelling, infection, and cerebral hypoxia.
○ Often diffuse or multifocal, including concussion, infection, and hypoxic brain injury
what causes brain injury? (5)
Trauma, tumours, stroke, metabolic derangements, degenerative disorders
explain the different score band for GCS
3 - 8: Coma
9 - 12: Moderate head injury
15: fully conscious
Score >11: 85% chance of recovery
what are the symptoms of HI?
Changes in level of consciousness - may fluctuate; RAS
dependent
○ Confusion, delirium, obtundation, stupor, coma
● Alterations in sensory & motor functions
● Alterations in cranial nerve reflexes
what is RAS?
Reticular Activating System
what is obtundation?
less than full alertness with decrease interest, slower reaction to stimulus
what is stupor?
near unconsciousness
what is decorticate posture? score 3 for motor
Abnormal flexor response of arms and wrist
➢ Leg and feet extend and internally
what is decerebrate posture (score 2 for motor)
extensor
what parts of the brain does the pupil reflex test, tests on
Function of the brainstem and CN II & III
what does it indicate if the patient’s pupil reflex test is abnormal?
of brain herniation
how does increasing ICP affect the eye?
Increasing ICP may impair eye movements controlled by CN III, IV, VI
what does the oculovestibular reflex test on. how do u do it?
brainstem dysfunction.
caloric water test or dolls eye. test/
what is the corneal reflex?
test if u blink to stimulus.
what does abnormal result in corneal reflex test indicates?
Absence of blink response, indicator of severely impaired brain function
how many types of primary injury are there?
- focal, polar, diffuse, intracranial hematomas
what is a characteristic of linear fracture?
Lucent lines, it indicate bone separation and dense lines, overlap
what does linear fracture cause?
● Causes rupture of meningeal vessels
how many types of depressed fracture are there? please list them
3 in total
● Stellate:
● Eggshell:
● Open fractures associated with infections
how do you identify a stellate fracture? what does it mean?
starburst shaped, multiple fracture points that radiate outward from a central point.impact by blunt objects. Underlying brain injury
how do u identify eggshell fracture and in which scenarios is it commonly seen?
fine delicate cracks in thin brittle bones such as elderly and children, child abuse
is it easy to identify eggshell fracture on xray?
no :(
how many types of skull fracture are there in terms of category?
3, linear depressed, basal skull fracture
is it easy to detect basal skull fracture?
DIFFICULT in view of irregular dense bones
how do you identify a basal skull fracture without the use of diagnostic machines? (4)
1) hemotympanum - blood in middle ear
2)CSF rhinorrhea and otorrhea
3)postauricular ecchymoses ( battle’s sign)
4) periorbital ecchymoses ( raccon’s eyes)
what are the usual symptoms associated with a HI?
scalp wound
lOC
fracture
swelling, bruising
nasal discharge
stiff neck
what are fractures at the base of skull associated with.
cranial nerve injuries.
anosmia,
nystagmus,
partial loss of vision,
facial palsy
vertigo
how many types of intracranial lesions are there?
6
concussions, contussion
extradural haematoma
subdural haematoma
subarachnoid haematoma
intracerebral haematom
what is concussion?
immediate transient LOC
- dazed, star struck situation
what are the causes of a concussion?
Rotation of the cerebral hemispheres on the relatively fixed brainstem
➢ Electro-physiological dysfunction of the reticular activating system
➢ No structural lesion & residual sequelae
what are the clinical features of concussion? (3)
Amnesia may occur after injury
➢ Retrograde amnesia
● Memory loss for events before the injury
● May indicate severity of the lesion
➢ Antegrade amnesia
● For events after, very brief
how many types of amnesia are there?
2 retrograde
● Memory loss for events before the injury
● May indicate severity of the lesion
antegrade
● For events after, very brief
what is contussion?
Head injury resulting in haemorrhage into brain tissue
what are the causes of contussion?
➢ Due to deceleration of the brain against the skull rupturing the blood vessels on the surface of
the brain
➢ Frontal and occipital poles affected
➢ Coup injury
● Directly under point of impact
➢ Contrecoup injury
● At a point opposite to the point of impact
what is coup injury?
● Directly under point of impact
what is contrecoup injury?
At a point opposite to the point of impact
what are the clinical features of contussion? (5)
Hemiparesis or gaze paralysis may occur with frontal injuries
➢ Visual defect in occipital injuries
➢ Cranial nerve dysfunction - commonly olfactory
➢ More severe injury causes cerebral edema, decorticate or decerebrate rigidity
➢ If cerebral lesions are bilateral ⇒ coma
what is extradural haematoma?
Bleeding is between skull & dura Due to direct trauma causing # temporal bone and damage to middle meningeal artery
➢ As the bleeding is arterial, there is rapid worsening of the patient’s condition
what is the clinical features of a extradural haematoma? (4)
➢ Brief LOC (due to concussion) followed by a short “lucid interval” then, coma again
(progressive neurological deterioration due to herniation)
➢ Carries a bad prognosis
➢ Usually requires surgical evacuation
➢ Untreated: decerebrate rigidity, coma, death
how does the duration of LOC differes between extradural haematoma and acute SDH?
EDH is short, SDH is long
what is SDH
Bleeding is between dura mater and arachnoid membrane
May not be associated with any surface injuries on the scalp
● Follows severe head injury – change in velocity
● Due to rupture of surface cerebral veins that join the dural venous sinuses
● Twice as common as extradural hematoma
what are the symptoms of SDH (4)
Brief LOC (due to concussion) followed by a relatively longer “lucid interval” then,
coma again (progressive neurological deterioration due to herniation)
● Carries a bad prognosis if associated with cerebral injury due high velocity
● Usually requires surgical evacuation
● Untreated: decerebrate rigidity, coma, death
what are the causes of chronic SDH?
➢ Cause
● Common in elderly > 60 y/o
● minor injuries which may not be remembered
● Due to shrinking of the brain coupled with fragility of blood vessels
what are the clinical features of chronic SDH? (7)
Signs & symptoms appear months to years after trivial injury
● Due to slow accumulation of venous blood around atrophied brain
● Symptoms and signs may be absent, non-specific, non-localising
● Commonly experience minor headaches over a period of time because of slow
bleeding
● Other symptoms: personality changes, fluctuating drowsiness, confusion, weakness,
seizures
● Can be confused with stroke, dementia
● Potentially treatable
what should u assess for HI patients? (7) and not do.
● Vital signs – ABC
● Secure airway and IV line
● Protect cervical spine in collar
● No morphine or depressants!
● Hourly vital signs, GCS
● Arrange for urgent CT scan head
● Neurological assessment for severity of head
injury
