quiz 5 Flashcards
what are the different categories of TBI
open
closed
- acceleration-decceleration
- diffuse axonal injury (DAI)
- combat related blast injury
open tbi
when the scalp, skull, and meninges are penetrated (ie gunshot wound)
closed tbi
typically from mechanical forces
- acceleration-deceleration
acceleration-deceleration
the moving head suddenly stops but the brain continues to move in the original direction
- coup: point of initial impact
- contrecoup: wwhen the brain rebounds in the opposite direction and impacts another surface of the skull
(closed head tbi)
can cause DAI
diffuse axonal injury (DAI)
jerking/twisting motion of brain during acceleration and deceleration resulting in axonal stretching, shearing, and tearing
- results in disrupted neuronal communication among various brain regions
combat-related blast injury
may result in injury from one or more of 4 mechanisms:
- primary mechanism results from rapid pressure changes from the blast wave in organs with air-fluid interfaces
- secondary injury occurs when debris, set in motion by the blast, strikes th body, resulting in focal damage
- third mode is when the body is thrown against a surface which causes injury
- fourth includes other processes, like inhalation of toxic agents or radiation
what is the difference between primary and secondary damage in a TBI?
primary= focal and diffuse lesions
secondary= things like infection, oxygen deprivation, brain swelling, and elevation of intracranial pressure
what populations are at highest risk (highest incidence) for TBI?
- ages 15-24 (typically associated with motor vehicle crashes)
- then over age 65 and under age 5 (mostly from falls)
- males twice as likely as females
- those with previous tbi are 3x as likely to have another tbi
basic structure of the glasgow coma scale (GCS) and 3 major areas of function assessed
- assesses severity of injury by rating (1) the degree of eye opening, (2) best verbal response, and (3) best motor response
severe: 3-8; coma over 6 hrs; PTA over 24 hrs
moderate: 9-12; coma less than 6 hrs; PTA 1-24 hrs
mild: 13-15; coma 20 min or less; PTA 60 min or less
numbers are the glasgow coma score
define coma
condition where a patient displays minimal, if any, purposeful respose to the external environment
- believed to result from damage to the central portions of the brainstem
persistent vegetative state (PVS)
people who survive but never regain any degree of consciousness in the sense of higher cortical function
- don’t speak or follow commands, but do regain the alerting mechanism
- called PVS after they have been in this condition for a month
define minimally conscious state (MCS)
minimal but definitive evidence of self- or environmental awareness
- reflects transitional stage showing an improvement in consciousness or (as with a neurodegenerative disease) progressive decline
- consistent evidence of one or more of the following behaviors:
- following simple commands
- intelligible verbalization
- recognizable yes/no responses to relevant environmental stimuli not attributable to reflexive activity
4 spheres of personal orientation that may be disturbed by a TBI
1. person: autobiographic memory (usually returns first)
2. place: knowledge of familiar places
3.** time**: requires ability to take in, store, and recall new info presented after injury
4. circumstance: recalling this usually returns before place & time
describe the pragmatic difficulties commonly encountered by individuals with a prefrontal cortex TBI
- difficulties with the formulation of discourse (not attributable to aphasia)
- inappropriate social interactions (interpreting social cues, abstract language/irony-sarcasm)