Lecture 5.2: Intro to TBI

TBI definition

disruption in normal function of brain caused by a bump, blow or jolt to the head or a penetrating head injury

types of TBI

1. mild TBI (concussion)

- repeated may lead to a longer recovery or more severe problems, possibly long-term problems

2. moderate TBI

3. severe TBI

survivors of a moderate or severe TBI may lead to...

long-term or life-long health problems

what age has the highest number and rates of TBI related hospitalization and death

75+ years old

who is 2x more likely to be hospitalized and 3x more likely to die from TBI

males

top causes of TBI

- falls are the leading cause

- fire-arm related suicide are the most common TBI related deaths

- MVA and assaults

closed head injury

skull not penetrated (could be fx)

- focal and diffuse axonal damage

open injury

- penetrating wound (gun shot)

- focal axonal damage

deceleration injury

diffuse axonal damage

coup-contracoup injury

focal axonal damage to opposite poles of brain

- diffuse axonal damage

blast injury

rapid pressure shock waves creating kinetic energy that causes deformation of the brain

- diffuse axonal damage + higher incidence of PTSD

which lobes are particularly susceptible to external forces

frontotemporal lobes due to their location in the skull

- may present w/ behavioral and cognitive sx

focal axonal injury

necrotic area is concentrated at the coup w/ compromised blood supply

- will lead to impairments based on neuroanatomy (i.e. frontal lobe will present w/ cognitive deficits, behavioral changes and hemiparesis)

diffuse axonal injury

non-contact forces of rapid deceleration and acceleration cause shearing and stretching injury in cerebral brain tissues

- hallmark feature is extensive damage of axons predominantly in subcortical and deep white matter tissues of brain stem and corpus callosum

what's the most likely outcome for a person of TBI 5 years later?

becomes worse

Glasgow Coma Scale

assesses depth and duration of impaired consciousness and coma following TBI

- assess eyes, verbal and motor

- validity and reliability decrease when given to pt who are intubated or sedated

13-15 Glasgow Score

Mild TBI

- pt is awake

- confused but can follow directions and communicate

9-12 Glasgow Score

Moderate TBI

- pt is drowsy or obtunded

- can open eyes and localize painful stimuli

3-8 Glasgow Score

Severe TBI

- pt is obtunded to comatose

- unable to follow directions

- may exhibit decorticate or decerebrate posturing

decorticate posturing and decerebrate posturing

abnormal responses to noxious stimuli from external or internal source

- indicates a lack of cortex motor function and typically carries a worse prognosis for recovery if underlying cause is not treated immediately

- could be due to increased ICP causing herniation of brainstem or large lesion in midbrain

what is the goal of initial emergency care for TBI

limit development of secondary brain damage while providing best condition for recovery

- establish and maintain a clear airway

- replacement of fluids to ensure good peripheral circulation w/ adequate BV

early medical care for TBI

- coma inducing medications to reduce oxygen demands on brain

- diuretics to reduce fluid in soft tissues to help reduce ICP

- anti-epileptic medication to prevent seizure

surgical interventions for TBI

decompression of injured brain to minimize damage

- craniotomy

- removal of hematoma

- removal of skull fragments or other foreign objects

- ICP monitoring device

- EVD

external ventricular drain (EVD)

drains CSF from ventricles in real time to an external bag

- make sure RN clamps before working

normal ICP

4-15 mmHg

disorders of consciousness (DOC)

1. coma - absent wakefulness or awareness

2. unresponsive wakefulness - wakeful but not aware

3. minimally consciousness state - not fully aware yet

4. healthy awake - awake and fully aware

arousal

eye-opening

- supported by brainstem

awareness

command-following

- cerebral cortex and corticothalamic network

what is consciousness dependent on

interaction between cerebral cortex, thalamus and brainstem

recovery from coma or DOC

- consciousness microcircuits facilitate recovery from coma

- restoration of excitatory neurotransmission along subcortical and cortical pathways

clinical presentation of focal axonal injury

dictated by areas of the brain impacted by injury

clinical presentation of diffuse axonal injury

- altered level of consciousness due to disruption of circuits between brainstem and cortex

- can have many impairments of large volume of axonal damage in cortex and brainstem

Rancho Los Amigos Level of Cognitive Functioning Scale

measures an individual's recovery over time and after brain injury

- recovery can plateau at any level, dependent on severity

- pt can fluctuate between stages especially when fatigued

- typically not performed until the individual is closer to medical stability

Rancho I

no response but awake

- total assist

- appears to be in a deep sleep but unresponsive to any stimuli

Rancho II

generalized response

- total assist

- reacts inconsistently and non-purposefully to stimuli

- usually the same responses

- deep pain evokes response

- gross motor movements, vocalization, physiologic changes

Rancho III

localized response

- total assist

- responds specifically but inconsistently to a direct stimulus

- pt will turn head towards sound or focus on an object when presented

- may follow simple commands and better to some people

Rancho IV

confused agitated

- max assist, may sit, reach or walk

- heightened state of activity w/ a severely decreased ability to process info

- hostility and attempts to climb out of bed

contraindications for PT

- worsening or new neurologic signs

- unstable vital signs or outside of recommendations for mobility

- have an EVD w/o orders from MD

precautions for PT

- surgical precautions (helmet, ICP parameters)

- neck immobilized until spine is imaged

PT exam tips

1. level of consciousness (need to be beyond Rancho II to progress to assess cognition)

2. attention - need to have attention before assessing cognition and function

3. may be ready for cognition and executive function at Rancho IV - V

stimulus-response screen

document level of alertness w/ a specific statement of what the pt did in response to a particular stimuli

- appropriate for Rancho I, II and III

coma recovery scale

examines brainstem, subcortical and cortically-mediated behaviors

- higher score indicates higher arousal state

Rancho I interventions

- PT is not appropriate

- educate family education for PROM and skin care

Rancho II-III interventions

- gentle PROM progress to AAROM

- sit in chair position or cardiac chair -> up to EOB w/ assistance

- position devices to prevent loss of ROM (especially DF) and joint protection

- sensory stimulation

- family education

progression/regression of Rancho II-III

- slowly increase amount of time of sensory stimulation

- increase amount of time spent sitting up

- increase use of multiple sensory stimulation (careful w/ overstimulation)

what causes agitation

1. pathophysiological - neural injury leads to disinhibition of behaviors

2. behavioral - certain people may lead to agitation or calm

3. unmet basic needs - hunger or thirst

4. environmental stress - lights, loud noise, touch

*cognitive analogy w/ money in wallet

warning signs of agitation

- restlessness

- decreased visual contact and verbal output

- increased loudness of voice

- increased distractibility

- negative comments

- chewing

what to do when pt becomes agitated

- remove and decrease stimuli

- call "code-gray"

- don't put pt between yourself and door

- remove yourself if you're in danger

agitated behavior scale

monitors agitation through recover or over course of day

- higher score means worse agitation

ABCs of behavior

Antecedent - event that immediately triggers

Behavior - pt response to antecedent

Consequence - outcome produced by behavior

Rancho IV for PT treatment

- begin functional training w/ neurofacilitation

- impaired based interventions (ROM, strength, behavioral impairments)

- assess for AD or orthotic

- family education about overstimulation and behavior watch

general tips for Rancho IV

- find good motivator for pt

- select interventions that maintain pt and PT safety (avoid agitation)