9S Moderate/Severe TBI

what are the 4 MOIs?

• closed head injury

• severe acceleration/deceleration

• blast injuries

• penetrating injuries

External forces/objects hitting the head or hitting head hard enough to cause brain movement.

May see coup/contrecoup injury

closed head injury

May cause injury without head strike.

ex) whiplash, shaken-baby syndrome

severe acceleration/deceleration

Explosion resulting in fast moving pressure wave affecting skull and brain parenchyma

blast injuries

Object/s breaching skull cavity cause direct cellular and vascular damage

penetrating injuries

what are the 2 stages of TBI pathophysiology?

primary and secondary damage

patho of closed head TBI

• skull moves faster than brain

• skull strikes brain

• if skull comes to a stop then brain rebounds

• contre-coup lesions, axonal shearing

patho of penetrating TBI

• object breaches skull, penetrates dura

• if supersonic, air rushes in track, causing it to cavitate

• object creates brain jury track of destroyed parenchyma

• cavitation stretches vasculature and axons compresses neurons/glia

patho of 1st degree explosive blast TBI

• explosion create fast moving pressure wave

• pressure waves impact skull causing transient deformation

• pressure waves pass through brain, stretching axons and vasculature and compress neurons/glia

“bruise” within brain, can occur in any region

contusion

can occur in areas where the skull surface is irregular or to brain vasculature, can cause CSF leak

laceration

Tearing of meningeal vessels causes blood to collect between skill and dura

Highly associated with skull fx.

epidural hematoma/hemorrhage

Result of tears to bridging veins, often due to acceleration/deceleration injury, including falls

subdural hematoma

What is a Diffuse Axonal Injury (DAI), and why does it occur?

shearing injury, occurs when brain tissues with different structures or weights respond differently to acceleration, deceleration, or rotational forces during trauma, leading to compromise of cellular membranes.

Why is Diffuse Axonal Injury considered "diffuse"?

affects widespread areas of the brain due to shearing forces

What type of brain injury involves direct damage to tissues that are physically contacted?

Penetrating injuries.

What additional effect can high-velocity penetrating injuries, like bullets, have on the brain?

cause damage to remote areas of the brain due to shock waves.

What causes blast injuries to the brain?

high-pressure wave (overpressure) followed by a low-pressure wave (underpressure), leading to compression and shearing of brain tissue.

Are blast injuries typically focal or diffuse?

Diffuse

Why does increased intracranial pressure (ICP) occur, and what are its potential consequences?

occurs due to swelling or hematoma

Since the skull cavity is fixed, increased pressure can distort brain tissue (e.g., cause midline shift) or result in herniation.

What is the normal range for intracranial pressure (ICP)?

5–20 cm H₂O

How can cerebral ischemia or hypoxia develop after a brain injury?

result from compressed or ruptured blood vessels, limiting oxygen and nutrient delivery to brain tissue.

How do electrolyte imbalances and acid/base disturbances affect neurons after injury?

leads to cell death by necrosis or apoptosis

How can infections develop in the brain after a traumatic injury?

due to open wounds or from invasive monitoring devices

What are common causes of seizures after a brain injury?

Tissue damage, increased pressure, or scarring

what are some components of secondary damage?

• increased ICP from swelling or hematoma

• cerebral ischemia or hypoxia

• electrolyte imbalance and acid/base balance

• infection

• seizures

what are the types of primary damage that can occur?

diffuse axonal injury, penetration, blast injuries

Elevated sympathetic nervous system activity occurs following injury and can become sustained resulting in…

• Increased HR/RR

• Increased BP

• Diaphoresis

• Excessive salivation, tearing

• Hyperthermia

• Dilated pupils

• Vomiting

• increased medical complexity of these patients

Elevated _______ activity occurs following injury and can become sustained

sympathetic nervous system

what happens when there is a lesion above the red nucleus?

decorticate posture - flexor tone is left unchecked leading to sustained UE flexion

what happens when there is a lesion below the red nucleus?

decerebrate posturing due to inhibition of flexor tone leading to dominate extensor tone

what is the lowest level of consciousness?

coma

Complete paralysis of cerebral function or a state of unresponsiveness.

Eyes closed, no response to painful stimuli, no obvious sleep/wake cycles, usually ventilator-dependent.

No pupil rxn to light.

coma

Wakeful, reduced responsiveness with no evident cerebral cortical function.

The difference between coma and UW is that there are intermittent periods of wakefulness in UW.

Brainstem usually mostly intact.

unresponsive wakefulness

Clear but minimal or inconsistent awareness.

Can demonstrate motor responses reproducibly and respond to 1 step commands (even if inconsistently).

Sleeps a lot, exhibits reduced alertness, disinterest in the environment, and slow responses to stimulation

minimally conscious state

the time lapse between the injury and when memory functions are restored

post-traumatic amnesia (PTA)

deficit in memory retrieval with inability to recall events that occurred prior to the injury

retrograde amnesia

inability to form new memories after the injury

anterograde amnesia

Behavioral changes closely linked to cognitive changes.

These include:

• Low frustration tolerance

• Agitation and Irritability

• Disinhibition

• Apathy

• Emotional lability

• Mental inflexibility

• Aggression

• Impulsivity

______ changes closely linked to cognitive changes.

behavioral

what are secondary complications that can occur from TBI?

• iatrogenic injuries

• infections

• issues associated with prolonged bed rest

• surgical complications

• post-traumatic epilepsy

• depression

what are some iatrogenic injuries that can occur from TBI?

pts pulling them out - catheters, NG tubes, tracheotomies

what are some infections that can occur from TBI?

UTI, pneumonia, others related to tx

what are some issues from bed rest that can occur from TBI?

contractures, skin breakdown, heterotrophic ossification, DVT

how is TBI categorized?

mild, moderate, severe

the categorizations of mild, moderate, severe are based on what scales?

glascow coma scale and duration of LOC and PTA

Ranchos Los Amigos Levels of Cognitive Functioning Scale (LOCF) measures?

consciousness, cognition, and behaviors

Ranchos Los Amigos Levels of Cognitive Functioning Scale (LOCF) is often used to track?

progress through various stages of medical care and rehab

Ranchos Scale: no response to visual, verbal, tactile, auditory, or noxious stimuli

I

Ranchos Scale: generalized response

II

Ranchos Scale: localized response

III

Ranchos Scale: confused and agitated

IV

Ranchos Scale: confused and inappropriate

V

Ranchos Scale: confused and appropriate

VI

Ranchos Scale: automatic and appropriate

VII

Ranchos Scale: purposeful and appropriate

VIII

how many Ranchos levels are there?

8

pt appears to be in a deep sleep and is complete unresponsive to any stimuli

Ranchos I - no response

• pt reacts inconsistently and nonpurposefull to stimuli in a nonspecific manner

• responses are limited and often the same regardless of stimulus presented

• responses may be physiological changes, gross body movements, and/or vocalization

Ranchos II - generalized response

• pt reacts specifically but inconsistently to stimuli

• responses are directly related to the type of stimulus presented

• may follow simple commands in an inconsistent, delayed manner

Ranches III - localized response

• pt is in a heightened state of activity, lacks short- long- recall

• behavior is bizarre and nonpurposeful relative to immediate environemtn

• does not discriminate among persons or objects, unable to cooperate direction with tx efforts

• verabalizations are incoherent and/or inappropriate to the environment, confabulation may be present

• gross attention of environment is brief, selective attention is often non-esistent

Ranchos IV - confused-agitated

• pt is able to respond to simple commands fairly consistently

• increased complexity of commands or lack of any external structure, responses are non purposeful, random, fragmented

• demonstrates gross attention to the environment but is highly distractible and lacks ability to focus attention on specific task

• with structure, may be able to converse on a social automatic level for short periods of time, verbalization is often inappropriate and confabulatory

• memory is severely impaired, often shows inappropriate use of objects

• may perform previously learned tasks with structure but is unable to learn new information

Ranchos V - confused-inappropriate

• pt shows goal-directed behavior bu is dependent on external input or direction

• follows simple directions consistently and shows carryover for relearned tasks

• responses may be incorrect d/t memory problems, but they are appropriate to the situation

• past memories shows more depth and detail than recent memory

Ranchos VI - confused appropriate

• pt appears appropriate and oriented within the hospital and home settins

• goes through daily routine automatically, but robot-like

• pt shows minimal to no confusion and has shallow recall of activities

• shows carryover for new learning but a decreased rate

• with structure is able to initiate social or recreational activities, judgement remains impaired

Ranchos VII - automatic appropriate

• patient is able to recall and integrate past and recent events and is aware of and response to environment

• shows carryover for new learning and needs no supervision once activities are learned

• may continue to show a decreased ability relative to premorbid abilities, abstract reasoning, tolerance for stress, and judgement in emergencies or unusual circumstances

Ranches VIII - purposeful appropriate

what is hyperosmolar therapy?

to reduce cerebral edema and ICP

Large portion of the skull removed to allow the brain to swell

decompressive craniectomy

Catheter fed into lateral ventricle to monitor ICP and drain CSF

external ventricular drain

what are the prognostic indicators?

• age

• clinical severity

• initial CT scan

• secondary insults

• lab values

• duration of coma and PTA

Prognostic indicators: Age

older age = poorer outcomes and increased mortality

Prognostic indicators: Clinical Severity

lower GCS = poorer outcomes and increased mortality

Prognostic indicators: initial CT scan

presence of subarachnoid hemorrhage

Prognostic indicators: secondary insults

ex) hypoxia or hypotension

Prognostic indicators: lab values

high glucose concentrations, coagulopathy

Prognostic indicators: duration of coma and PTA

longer coma or period of PTA leads to worse outcomes

what are TBI-specific considerations for examination/evaluation?

• Level of consciousness

• Cognitive status- Ability to participate in examination

• Behavioral functioning

• Medical interventions (EVD, craniectomy, etc)

• Seizure risk/history

in systems review, considerations are based on?

mix of findings available from other disciplines and directly measured by PT

coma recovery scale assist with?

DDx, prognosis, and tx planning in pts with disorders of consciousness

what tools can be used to examine consciousness?

coma recovery scale or LOCF scale

what tool can be used to examine cognition?

montreal cognitive assessment (MoCA)

how many items and subscales in coma recovery scale?

23 and 6