HEAD INJURIES
Normal intracranial pressure
1-15mmHg
2 neuropsychologic factors that are associated with a decreased prognosis following a head injury
1. Being over the age of 30 2. Less education
2 categories of focal brain injuries
1. Contusion 2. Hematoma
8 principal symptoms of temporal lobe damage
1. Disturbance auditory sensation and perception 2. Disturbance of selective attention of auditory and visual input 3. Disorders of visual perception 4. Impaired organization and categorization of verbal material 5. Disturbance of language comprehension 6. Impaired long-term memory 7. Altered personality and affective behavior 8. Altered sexual behavior
3 main factors contributing to the overall severity of a head injury
1. Edema 2. Increased intracranial pressure 3. Poor circulation of blood to the brain
2 main goals of the acute phase of treatment for a head injury
1. Monitor ICP 2. Treat if an increase in ventilation, swelling, hematoma
4 classifications used in describing a TBI
1. Penetrating vs. Nonpenetrating (mechanism) 2. Severity (mild/mod/severe) 3. Pathophysiology (primary [impact], secondary [swelling etc.]) 4. Patho-anatomical (diffuse, focal, mixed)
In terms of a head injury, a CT scan will be used to assess what 3 residual affects of the injury
1. Swelling 2. hematoma 3. Infarction
A persistent vegetative state is most often due to what 2 types of head injuries
1. anoxia (severe deficiency of oxygen 2. DAI
3 descriptions for forces in context to head injuries
1. coup (primary impact) 2. contracoup (secondary impact) 3. shearing (rotational)
Name a few of the cytologic changes that occur secondary to brain injury
1. demyelination 2. Pro-apoptotic cascade 3. Apoptosis 4. cerebral edema 5. Inflammatory cytokines 6. Vasogenic edema 7. etc. etc. etc.
2 categories of diffuse brain injuries
1. diffuse axonal injury 2. hypoxic-ischemic injury
4 major sequelae associated with a brain contusion
1. disinhibition 2. apathy 3. amnesia 4. aphasia
2 common causes that lead to CNS infection as a secondary neurologic complication
1. evacuation of fluid from the CNS space, such as with a hemorrhage 2. introduction of blood borne pathogens crossing the blood brain barrier
3 factors following a head injury that lead to a poor prognosis
1. loss of pupillary function 2. Long duration of post traumatic amnesia 3. Diffuse axonal injury
When examining a person whose suffered an injury what 2 general S/S are you looking for that might indicate an epidural hematoma
1. pupillary changes 2. bleeding of the skull
Name the order of meningeal layers starting from the skin to the brain
1. skin 2. periosteum 3. skull 4. dura mater 5. arachnoid 6. pia mater
4 mechanisms of force to cause injury to the axon in a DAI
1. twist 2. compressed 3. sheared 4. stretched
Cerebral perfusion of < __ mmHg will lead to cell death in brain tissue
10mmHg
A mild head injury is scored between what range on the GCS
13-15
Most concussions score at what range on the GCS
14-15
Normally you would notice a subdural hemorrhage in what general time frame
24-72 hours
Normal volume of blood needed per 100g of brain tissue
25cc
__-__% of athletes will experience concussion
5-10%
Females playing soccer have a __% chance of acquiring a concussion
50% chance
___% - ___% of DAI injuries can have normal CT
50-80%
Normal cerebral perfusion should be __ mmHg
60 mmHg
Males playing football have a __% chance of acquiring a concussion
75% chance
A severe head injury is scored between what range on the GCS
8-3
A moderate head injury is scored between what range on the GCS
9-12
what is the mortality rate % for a person with bilateral loss of pupillary function
95% mortality rate
A subdural hematoma is most often due to hemorrhaging of what vessel type
venous
An intraparenchymal hematoma would be forming where
within the brain tissue
T/F - A DAI is often missed on a CT & MRI scan
True
A person who is awake though responses to stimuli are reduced and movements are without purpose is said to be at what level on the Glasgow outcome scale
Vegetative state
What are the 4 levels (not including the 5th death) of the Glasgow Outcome Scale
Vegetative state Severe disability Moderate disability Good recovery
A typical time frame for a person to be in a coma, as stated by the PPT
a few days to about several weeks
Residual sequelae associated with hypoxic-ischemic injury
amnesia, dementia, persistent vegetative state (PVS), persistent cognitive deficits including memory deficits and bradyphrenia (slowness of thoughts)
An epidural hematoma is most often due to hemorrhaging of what vessel type
arterial
An epidural hemorrhage can be generally described as what shape on a CT scan?
biconvex
Contusions tend to be more often cortical or sub-cortical
cortical
Term used to describe as a certain level of consciousness defined as: disorientation, fear & agitation
delirium
Focal contusion in the skull typically affect what lobes of the brain
frontal and temporal
2 most common sites of hypoxic-ischemic injury
hippocampus, neocortex
The initial sequelae associated with diffuse axonal injury (DAI)
initial coma and amnesia
What cranial nerve is the least likely to be damaged with a head injury
CN IV - trochlear nerve
In this level of consciousness a patient experiences no sleep/wake cycles
Coma
The lowest level of consciousness
Coma
This level of consciousness is characterized by being unaraousable and unresponsive
Coma
This state of consciousness is typically the result of widespread, diffuse damage to the brain
Coma
In order from most to least severe, list the levels of consciousness following a head injury
Coma -> Vegetative state -> Stupor -> Obtundity -> Delirium -> Clouding of consciousness
Why might elderly individuals show S/S of a subdural hemorrhage days to weeks after injury
Generally smaller brain mass, takes more blood to apply pressure needed to present with S/S
What scale is used to determine severity of head injury
Glasgow Coma Scale
A person who has recovered from a brain injury and is living a normal social life, able to return to work, though may have some residual motor deficits is said to be where on the Glasgow Outcome Scale
Good Recovery
What are the major S/S of subdrual hemorrhage
Headache, altered mental status, incontinence
4 major sequelae associated with posterior cerebral artery occlusion
Hemianopsia, blindness, alexia (inability to understand print), visual agnosia (impaired recognition of objects)
A pt. chart reads "when they arrived to the ER their GCS was 8." From this information, what do we know about the patients condition
They were most likely in a comatose state
As secondary neurologic complications to head injury, brain edema causing hypoxia will lead to _______, which then leads to _______?
As secondary neurologic complications to head injury, brain edema causing hypoxia will lead to vasospasm, which then leads to increased intracranial pressure?
A Glasgow Coma Scale (GCS) score of 3/15 indicates what?
Totally unresponsive
An subdural hemorrhage can be generally described as what shape?
Concave
MRI as an adjunct scan to a CT, would be used to check for what residual affect of a head injury
Deep hemorrhages
This type of head injury is considered a hallmark of non-penetrating TBI
Diffuse axonal injury
Deficient ability to have foresight/ planning and flexibility of behavior are both associated with a frontal lobe lesion at what site on the frontal lobe
Dorsolateral
Executive function deficits are associated with a frontal lobe lesion at what site on the frontal lobe
Dorsolateral
Perseveration is associated with a frontal lobe lesion at what site on the frontal lobe
Dorsolateral
Poor problem-solving skills with resistance to interference is a behavior associated with a frontal lobe lesion at what site on the frontal lobe
Dorsolateral
Stimulus-bound behavior (behavior initated by external stimulus despite its appropriatness) is associated with a frontal lobe lesion at what site on the frontal lobe
Dorsolateral
Name the 3 behavior response categories for the Glasgow Coma Scale?
Eye opening response Best verbal response Best motor response
3 major sequelae associated with intracerebral hemorrhage
Initial coma residual aphasia hemi-neglect
What events are the most often cause of DAI
MVA
What is Mannitol used for?
Mannitol is used clinically in osmotherapy to reduce acutely raised intracranial pressure until more definitive treatment can be applied, e.g., after head trauma
Apathy/abulia is associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
Impersistence is a behavior associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
Lack of spontaneity and initiation are behaviors associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
Lower extremity paresis is associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
Mutism or transcortical motor aphasia are behaviors associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
The diminished or absent of will to act is associated with a frontal lobe lesion at what site on the frontal lobe
Medial-frontal
What GCS score range has the most unpredictable prediction for recovery
Moderate 9-12
A person who is presenting some evidence of a focal brain injury and is independent though disabled is considered to be at what level on the Glasgow Outcome Scale
Moderate disability
Term used to describe as a certain level of consciousness defined as: slow response to stimuli
Obtundity
Anosmia (decreased sense of smell) is associated with a frontal lobe lesion at what site on the frontal lobe
Orbital frontal
Disinhibition is associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
Distractibility is associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
Impaired judgment and insight are associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
Inappropriate affect is associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
Intermittent explosive disorder is associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
Irritable, labile, euphoria are associated with a frontal lobe lesion at what site on the frontal lobe
Orbital-frontal
What areas of the brain are most often affected by DAI
Parasagital white matter, gray-white junctions, corpus callosum, brainstem, thalamus
Actions of a patient in this level of consciousness would be none purposeful movements and groans
Persistent vegetative state
There is no evidence of cortical function even though the patient is wakeful during this level of consciousness
Persistent vegetative state
2 common sequelae associated with Duret hemorrhage (small lineal areas of bleeding in the midbrain and upper pons of the brainstem)
Progressive stupor, coma
3 types on amnesia common as post head injury complications
Retrograde amnesia (forget their past) Post-traumatic amnesia (unable to remember immediately following injury) Anterograde amnesia (Inability to form new memories)
Equation for measuring cerebral perfusion
SBP - ICP = cerebral perfusion (normal = 60mmHg)
A person who is conscious with spastic paralysis of most limbs, dysphasia and/or imparied mental activity and dependent is at what level on the Glasgow outcome scale
Severe disability
The GCS score that is most predictive is the one taken at what point of a persons trip to the hospital
The GCS score taken in the ER
Two major S/S of hydrocephalus
mental status change and urinary incontinence
What changes to MRI imaging allow DAI to be detected?
more powerful magnets 1.5T vs. 3T vs. 7T
Seizure occurs as a secondary neurologic complication most often with a(n) open/closed head injury
open, skull fracture
What layer of the meninges is closest to the brain?
pia mater
With severe injury, a traumatic subarachnoid hemorrhage increases risk for _______ _________
post-traumatic hydrocephalus
