3.1 Sensory Loss

Question 1

General schema of the sensory pathways

Answer 1

Receptor -> peripheral nerve -> spinal root -> sensory tract -> thalamus -> sensory cortex

Question 2

Merkel’s disk and free nerve fibers are examples of ______ receptors

Answer 2

Non-encapsulated

Question 3

Represent the surface innervation of the sensory nerve roots

Answer 3

Dermatomes

Question 4

Dermatome: T6

Answer 4

Xiphoid process

Question 5

Dermatome: C6

Answer 5

Thumb

Question 6

Dermatome: L4

Answer 6

Knee, big toe

Question 7

Dermatome: genitalia

Answer 7

S2 - S3

Question 8

General sensory modalities include:

Answer 8

Pain
Light touch
Temperature
Vibration
Position sense
Deep pressure

Question 9

Sensory changes due to interruption of ______: vary depending on whether the nerve involved is predominantly muscular, cutaneous or mixed. Deep pain and perception is intact.

Answer 9

Single peripheral nerve

Question 10

Sensory changes due to interruption of _______: sensory impairment is bilaterally symmetrical. The longest and largest fibers are most affected, glove and stocking distribution of sensory loss

Answer 10

Multiple nerves (polyneuropathy)

Question 11

Sensory changes due to interruption of _______: follows dermatomal distribution, intensified by movement of the spine and radiate in proximal distal fashion ( shooting or lancinating pain)

Answer 11

Nerve roots/ radiculopathy

Question 12

Sensory changes due to interruption of _______: widespread dse may produce the same sensory defects as of the posterior nerve roots, proximal areas of the body also show pronounced sensory loss

Answer 12

Sensory ganglia/ neuronopathy/ ganglionopathy

Question 13

Paraneoplastic, connective tissue dses ( sjogren syndrome), toxic exposure and idiopathic inflammation are examples of what type of sensory change:

Answer 13

Sensory changes due to involvement of sensory ganglia

Question 14

All forms of sensation below a level that corresponds to that lesion

Answer 14

Complete spinal sensory syndrome

Question 15

Affectation of the pain and thermal sensation on the side contralateral to the lesion, ipsilateral proprioceptive affectation, associated spastic motor paralysis on the ipsilateral side

Answer 15

Hemisection/ brown sequard syndrome

Question 16

Abolition of pain and temperature on one or both sides over several segments but with sparing of tactile sensation

Answer 16

Syringomyelic syndrome

Question 17

Vibration and position senses are most affected. Paresthesias may be common complaints, seen in MS, tabes dorsalis and HIV patients

Answer 17

Posterior dorsal column syndrome

Question 18

Loss of pain and temperature sensation below the level of the lesion but relative or absolute sparing of proprioceptive sensation, spastic paralysis is a prominent feature

Answer 18

Anterior myelopathy/ anterior spinal artery syndrome

Question 19

Examination sometimes include overtly hysterical findings like ipsilateral reduced hearing, smell and taste

Answer 19

Sensory loss due to suggestability and hysteria

Question 20

Disturbance of discriminative sensory function without impairment of the primary modalities of sensation

Sensory inattention, extinction and neglect

Answer 20

Sensory loss due to lesions of the parietal lobe

Question 21

Loss or diminution of all forms of sensation on the opposite side of the body

Spontaneous pain discomfort may appear on the affected side of the body (thalamic pain)

Answer 21

Hemisensory loss d/t a lesion of the thalamus / syndrome of dejerine-roussy

Question 22

May cause crossed sensory disturbance

Answer 22

Medullary lesions

Question 23

Crossed trigeminothalamic and lateral spinothalamic tracts run together; lesions at this level may cause loss of pain and temp on the opposite half of the face and body

Answer 23

Upper medulla, pons and midbrain lesion

Question 24

Increase in sensibility to pain, pain in response to a stimulus not normally painful

Answer 24

Allodynia, hyperalgesia, hyperpathia

Question 25

Abnormal spontaneous sensations experienced in the absence of stimulation

Answer 25

Paresthesia

Question 26

Vibration sense

Answer 26

Pallesthesia

Question 27

Unpleasant or painful sensation, either spontaneous or after a normally non painful stimulus

Answer 27

Dysesthesias