Test 1: Sensory Screen and Evaluation Flashcards
describe how a sensory pathway works
sensory info enters SC through dorsal roots
carried to higher pathways via ascending pathways
interprets sensation within primary somatosensory cortex
2 main afferent sensory pathways
anterolateral spinothalamic pathway
-nondiscriminitive/crude touch/pain/temp
-more primitive
dorsal column medial lemniscus (DCML)
-precise location/discriminative touch
the anterolateral spinothalamic pathway recieves signals from what
mechanoreceptors
nociceptors
thermoreceptors
what fibers relay info from the anterolateral spinothalamic path
C fibers (peripheral n)
small unmyelinated
3 tracts for the anterolateral spinothalamic tract
anterior spinothalamic = crudely localized, light touch, pressure
lateral spinothalamic tract = pain and temp
spinoreticular = deep/diffuse/chronic pain
DCML is primary sensation for
discriminitive touch
combined cortical sensations (stereogenesis, tactile pressure, barogenesis, texture, kinesthesia, etc)
DCML receives signals from
specialized mechanoreceptors
fine graduations of intensity and precise location on a body surface
fibers involved with the DCML
A beta and A delta
large myelinated
rapid conduction
what type of info is perceived in the somatosensory cortex cortical areas
location
shape
texture
size
describe sensory receptors
nerve endings located at distal ends of afferent n fiber
specific/sensitive to type of stimulus they are designed for
tactile sensations recieved when specific receptors are stimulated
what are teh 3 divisions of sensory receptors
superficial
deep
combined (cortical) sensations
** also the 3 types of sensations**
what is superficial sensation/type of receptors
exteroreceptors recieve stimuli from environment via skin/subcutaneous tissue
responsible for perception of pain, temp, light touch, and pressure
what is deep sensation/type of receptors
proprioceptors recieve stimuli from muscles, tendons, ligaments, joints, and fascia
responsible for sense and awareness of joints at rest, movement awareness, and vibration
what is combined cortical sensation/type of receptors
combo of superficial and deep
require info from exteroceptive and proprioceptive receptors as well as intact function of cortical sensory association areas
2 point discrimination, barognosis, graphesthesia, tactile localization, etc
what is a mechanoreceptor
respond to mechanical deformation fo receptor/surrounding area
what are thermoreceptors
respond to change in temp
what are nociceptors
respond to noxious stimuli and result in perception of pain
what are chemoreceptors
respond to chemical substances and are responsible for taste, smell, oxygen levels, etc
what are photic receptors
respond to light within the visible spectrum
what is a merkel’s disc
found abundantly in fingertips
responsible for 2 pt discrimination
what is a free nerve ending
found throughout body
sense pain, temp, touch, and pressure
what are the types of muscle receptors
muscle spindles
golgi tendon organs
free nerve ending
pacinian corpuscles
what do muscle spindle fibers do
monitor changes in muscle length and velocity of these changes
vital role in position and movement and in motor learning
types of joint receptors
golgi type endings
free nerve endings
ruffini endings
paciniform endings
what is a sensory screen and the 5 primary categories
screen that identifies need for further investigation of the neuro/MSK systems
light touch
pin prick
temp
joint position/awareness
vibration
what is a gross sensation screening
part of neurologic evaluation which examines a patients somatosensation
what does somatosensory mean
sensation received from the skin and MSK system
what is sensory integrity
how clearly a sensation is being perceived
determines pts ability to interpret and discriminate among incoming somatosensory information
what does a sensory exam/screen include
gross sensation screening
part of systems review
somatosensory exam
tests sensory integrity
includes assessing anterolateral spinothalamic and DCML pathways
testing order for sensory exam
superficial sensations (pain/light/crude touch/pressure/temp)
deep/proprioceptive sensation (DCML path)
combined cortical sensation
logical because if there is a superficial impairment there will also be a deep one
performance considerations for sensory exam
apply stimuli randomly
perform distal to proximal
avoid desensitized surface areas
block patients vision
cater verbal cuing for accurate responses
common elements that need to be documented for sensory screening
type of sensation
area of body being tested
degree of involvement
localization of the exact boundaries of sensory impairment
patient position
tools used
grading scale for sensation
2 = normal
1 = impaired/delayed
0 = absent
NT = not testable (amputation, cast, etc)
dermatome chart used to graphically display findings
how to test pain perception
sharp/dull discrimination
indicates function of protective sensation
apply uniform pressure and avoid summation of impulses
how to test temperature awareness
distinguish between warm and cool
use 2 test tubes with different temps
touch pt skin with side of test tube
how to test touch awareness
determines perception of tactile input
use piece of cotton/monofilament device
touch pts skin with instrument; can combine with tactile location (where do you feel touch)
how to test pressure perception
determines deeper perception of tactile input
cotton swab/tongue depressor
apply firm pressure on skin
how to test kinesthesia awareness
join tmoved passively through small ROM
move in small increments
have pt describe the direction of motion
how to test proprioceptive awareness
examines joint position sense and awareness
joint moved pssively and repositioned statically
held in static position
patient asked to describe static position
what is pronator drift
pt holds arms out in front for 30 sec with eyes closed
positive test is if the pts more affected side begins to droop or pronate back to neutral
how to test vibration perception
tuning fork (DCML)
place on bony prominence while vibrating and still
pt can distiguish between 2 conditions
what is steregnosis perception
ability to recognize the form of objects by touch
