quiz 2: Sensory Flashcards
Most subjective aspect of neurologic exam
sensory examination
sensory exam
- most subjective
- diff ways to explain sensory system/sensory loss
- sensory loss explains neuro system
- impairment of sensory affect function
Critical parts of sensory system
- Transduction (mechanical E convert to electric E)
- Transmit electrical E via PNS to higher centers
- higher centers perceive impulse
- interpret perception
- motor output based on sensory input
Sensory Input –> Motor output
to make motor choices
sensory: how would diminished sensation affect motor performance?
aware of body proprioception
sensory: how are the various sensory modalities used for mobility?
feel the ground bumps in walking
sensory: does selective loss of one modality lead to unique functional limitations?
if do not know location of legs then cannot walk
sensory: grading of movement dependent on accurate sensory information
hold paper cup without squishing it: sensory –> motor
Potential Sources of Sensory Problems
3
- Receptor –> Sensory
- Nerve –> dorsal root –> spinal
- cord –> cortical sensors
Localization sensory pattern: Receptor
focal, dermatome otherwise intact (no sensation at that area but dermatome intact elsewhere)
Localization sensory pattern: Peripheral Nerve
median, ulnar, musculocutaneous etc.
Localization sensory pattern: Dermatomal
nerve root, cord (area of skin supplied by a single spinal nerve)
Localization sensory pattern: Cortical
diffuse, large area, non dermatomal
Localization sensory pattern: association cortex
difficulty with sensory interpretation
What are Localization sensory patterns
- receptor
- peripheral nerve
- dermatomal
- cortical
- association cortex
What are primary sensations?
- where are they processed?
- what are they mediated by?
- superficial light touch, sharp and dull
- deep proprioception, vibration
processed at: the primary somatosensory cortex
mediated by: anterolateral system and dorsal column; medial meniscus
What are cortical sensations?
- where are they processed?
- what are they mediated by?
- 2-point discrimination
- graphesthesia
- stereognosis
- double simultaneous extinction
processed in the association cortex in the parietal lobe
What do you do for a sensory exam?
- tools
- instructions
- document
Tools: cotton tip, safety pin/paper clip, tuning fork
Instructions are clear: “teach the test” and say what you will do so no ambiguity
Document: many descriptors, stay consistent
Sensory exam rules
6
- expose the part
- compare bilaterally (should be equal)
- by systematic (between size, but do randomly)
- “random testing”
- patient eyes closed
- patient responds YES or NO (ask, can you feel this?)
Documenting sensory exam (5)
Intact—-YAY
Absent (no response)
Diminished
Inconsistent- (sometimes correct, sometimes not)
Delayed (after touch takes time to answer)
Abnormal Sensory Findings
- Paraesthesia: tingling
- Dysesthsia: painful
- Analgesia: unable to distinguish pain
- Hyperaesthesia: excessive
- Hypoaesthesia: diminished
- Anaesthesia: absent
- Allodynia: non-noxious stimuli elicit pain