Sensation Flashcards

Question

What is somatotopic arrangement?

Answer 1

- Information is received and organized somatotopically in primary somatosensory cortex - High innervation density are highly sensitive and have proportionately larger representation area with somatosensory are of cortex - Cerebral cortex receives information about the type and location of sensory stimulation by conscious relay pathways - Three neuron pathway = discriminative touch, conscious proprioception, and stereognosis: 1) Receptors to medulla 2) Medulla to thalamus 3) Thalamus to cerebral cortex Cerebral cortex = motor movement

Answer 2

- Tongue - Lips - Hands - Face (eyes, ears, nose)

Answer 3

- Any interruptions along the ascending sensory pathway or in the sensory areas of the cortex may result in decreased or loss of sensation - Can result in impaired tactile and proprioceptive sensation, astereognosis, increased pain, etc.

Answer 4

- Effects of CVA on sensation depends on specific disruption of blood supply - 60% of people with strokes in carotid artery system have sensory deficits - Patterns of sensory loss in head trauma are less predictable

Answer 5

1) Quickly screen areas of body where sensation is likely to be intact 2) Assess more thoroughly areas most likely to be affected (usually contralateral side) 3) If fine touch and proprioception are intact then there is no need to assess temperature or pain 4) If pain and temperature are absent, there is no need to assess fine touch or proprioception

Answer 6

Specific sensory tests

Answer 7

Perception: Tactile Main receptor: Merkel cell Evaluates sensory receptor innervation density Normal distance: 6 mm

Answer 8

Perception: Vibration | Main receptor: Pacinian corpuscle

Answer 9

Perception: Vibration | Main receptor: Meissner

Answer 10

Perception: Pressure Main receptor: Merkel Reliability comparable to monofilament test

Answer 11

Perception: Temperature | Main receptor: free nerve endings

Answer 12

- Plasticity of brain allows for topographical reorganization of cerebral cortex - influenced by sensory input, learning, and experience - Use of body part will improve functional sensibility - Use of tasks stimulating localization, graded stimulus, and recognition

Answer 13

The choice of an intervention depends on: the diagnosis, the prognosis, and the evaluation results Loss of Protective Senses - Risk for serious injury because person cannot feel pinprick, hot, or cold - Education includes: 1) Try to soften amount of force used when gripping an object 2) Visually examine skin for edema, redness, cuts etc. 3) Protect from being exposed to sharp items or hot or cold items

Answer 14

- Protective sensation is intact but not able to localize 1) Interventions include: grading of objects from grossly dissimilar to more similar objects 2) Involves training in localization and graded discrimination

Answer 15

- Localization of moving touch tends to return before constant touch - Hand grid

Answer 16

- Grading from gross to fine discrimination - Sequencing of 3 categories: 1) Same or different 2) How are they the same or different? 3) Identification of material or object - stereognosis

Answer 17

- Used for hypersensitivity - Usually observed when there is nerve trauma, soft tissue injuries, burn, or amputations - Increased use of textures, weight bearing, or mirror visual feedback

Answer 18

Premise: functional use of the body part with reduced sensation is possible but spontaneous use is limited. Reeducation techniques are not well defined - Carr and Shepard (1998) stated reorganization seems related to frequency of use 1) Enlargement of sensory receptive areas within cortex is result of increased participation of the body part in activities requiring tactile sensations 2) Therapists may alter the cortical map by directing sensory experiences of patient 3) Use of meaningful and relevant sensory and motor experiences early in rehab - Dannenbaum and Jones (1993) feel appreciation of tactile stimulation and basic motor skills are prerequisites: 1) 100 Hz stim with vision and w/o vision 2) Early incorporation into functional activities and prevention of abnormal of grasp and movement 3) Textures

Answer 19

1) Cortical reorganization in response to repetitive stimulation 2) Extensive repetitive stim applied to impaired site and patient does not participate 3) Evidence is not strong at this time for passive sensory training. This training is not sustainable because the therapist has to administer intervention to patient

Answer 20

1) Active participation of patient 2) Identification of number of touches 3) Graphesthesia tests 4) "find your thumb" without looking 5) Identification of shape, weight, and texture 6) Passive drawing and writing

Answer 21

1) Place unaffected arm in front of mirror, and then therapist gives commands to move both hands/arms 2) Requires full concentration 3) Research is not conclusive at this time

Answer 22

1) Compensatory techniques: use vision to compensate for decreased sensation 2) Education on risk factors: water temperature or potential for burns (sun, heat) 3) Emphasize consistent skin care: skin inspections and weight shifts

Answer 23

Complete SCI is total loss of sensation in dermatomes below level of lesion Sensory losses for incomplete SCI are related to damage within specific tracts

Answer 24

1) Use a test with a strong stimulus 2) Know key sensory points within each dermatome to utilize when assessing 3) Bilateral testing is necessary 4) If patient has a known complete lesion there is no need to test multiple sensory modalities 5) Incomplete or unknown lesions = test for multiple sensory modalities