Sensory testing Flashcards
What is sensory integration
- the ability of the brain to organize, interpret and use sensory information
- it informs and guides motor responses
- requires ability to interpret and discriminate among the senses
Why screen sensation
- determine the need for more detailed screening
- determine if referral to another health care practitioner is needed
- focuses the search for symptom origin
- aids in identification of system related impairments that contribute to activity and participation limitations or disability
Somatosensation
- sensation received from the skin and MSK system
- separate from the 5 senses
Where along the system can deficits occur
- sensory receptors
- peripheral nerves
- spinal nerves
- nerve roots
- spinal cord
- brainstem
- thalamus
- sensory cortex also known as somatosensory cortex
Cutaneous superficial sensory receptors
- mechanoreceptors
- thermoreceptors
- nociceptors
Deep mechnoreceptros
- GTO
- Muscle spindles
- work with superficial to convey the sensory information
Patterns of sensory distribution impairments
- dermatomal
- peripheral nerve
- spinal cord
- brain injury
Dermatomal distribtion
- nerve root radicular neuropathy
Peripheral nerve sensory distribution
- peripheral neuropathy
- sensory, motor, autonomic impairments
spinal cord sensory distribution
- more diffuse, can be complete, or incomplete lesions
brain injury sensory distribution
- diffuse patterns of sensory loss related to area and amount of damaged tissue
Anterolateral spinothalamic pathway
- carry pain, temperature, non-discriminative touch
- activated primarily by mechanoreceptors, nociceptors, thermoreceptors
- crosses over when it enters the SC → medulla → thalamus → somatosensory cortex
- afferent fibers, small diameter, unmyleinated = slow conducting
Dorsal column medial lemniscus DCML
- carry more discriminative sensation
- discriminative touch, kinethesia (movement), proprioception (static) and vibration
- activated by mechanoreceptors in skin, joints, muscles and tendons
- large myleinated fibers, conduct rapidly
- enter SC → cross in medulla→ thalamus → somatosensory cortex
Sensory examinaiton
- start distally on extremity; if intact there is no need to continue
- superficial sensation - more primitive responses (choose one - pain or temperature with dull/sharp or cold/hot)
- followed by deep sensation choose one = prorioception, kinesthesia, vibration
- if deficits are present then can test combined cortical response which use information from both systems as well as higher level thinking
Stereognosis
ability to perceive and recognize the form of an object in the absence of visual and auditory information, by using tactile information to provide cues from texture, size, spatial properties, and temperature
Tactile localization
- reflects internal organization of the hand even early in normal development
- the individual’s ability to perceive where on the skin he/she was touched with a light stimulus
2 point discrimination
- the ability to discern that two nearby objects touching the skin are truly two distinct points, not one.
Double simultaneous stimulation
- examines the ability to perceive a simultaneous touch stimulus on opposite sides of the body;
- proximally and distally on a single extremity; or
- proximally and distally on one side of the body.
Graphesthesia
The ability to recognize letters, numbers, or designs traced on the skin
Barognosis
ability to recognize weight
