Somatosensory Lesions

Question 1

Anesthesia

Answer 1

Complete loss of touch sensation

Question 2

Hypesthesia

Answer 2

. Hypoesthesia

. Partial loss of touch sensation

Question 3

Hyperesthesia

Answer 3

. Abnormal inc. sensitivity of skin when touched

Question 4

Paresthesia

Answer 4

. Spontaneous sensations (burning, tingling, pins and needles)

Question 5

Dysesthesia

Answer 5

. Impaired touch sensation short of anesthesia
. Disagreeable sensation is produced by ordinary stimuli
. Abnormal sensations experienced in absence of stimuli
. Allodynia is condition in which ordinarily non-painful stimuli evoke pain

Question 6

Analgesia

Answer 6

. Complete loss of pain appreciation

Question 7

T/F all anesthetics are analgesics, but all analgesics are not anesthetics

Answer 7

T

Question 8

Hypalgesia

Answer 8

. (Hypoalgesia)

. Partial loss of pain appreciation

Question 9

Hyperalgesia

Answer 9

. Hyperpathia

. Abnormal inc. sensitivity to painful stimuli

Question 10

Radicular pain

Answer 10

Shooting pain in a dermatome

Question 11

Causalgia

Answer 11

. CRPS
. Severe burning pain persistent and related to trauma
. Radiates to areas outside affected nerve
. Associated w/ RSD

Question 12

Mononeuropathy

Answer 12

. Sensory loss restricted to one area of body

Question 13

Polyneuropathy

Answer 13

Pattern of sensory loss symmetric for both side of body

. Multiple peripheral nn. Affected

Question 14

Dissociated sensory loss

Answer 14

. Spinal cord lesions
. No other level of CNS level will cause this
. Brown-Sequard syndrome: one leg losses pain, one leg loss touch and proprioception

Question 15

Spinal n. Lesions

Answer 15

. Ipsilateral loss or reduction of sensation in area of distribution of that spinal n./ receptor
. May affect all sensations being transmitted through particular n.

Question 16

DCML lesion

Answer 16

. Loss or diminished sensations related to this system are noticeably distally
. Difficulty in localizing tactile cues and diminished sense of 2-point discrimination
. Diminished vibratory sense
. Diminished sense of direction (difficulty perceiving what direction object moves on skin)
. Impairments of conscious proprioception

Question 17

Unilateral lesion of dorsal columns in spinal cord or dorsal nuclei

Answer 17

. Lost or diminished sensation in all ipsilateral dermatomes at and below spinal cord level of lesion
. Lost or diminished sensations on ipsilateral body if lesion is in dorsal column nuclei

Question 18

Unilateral lesion of medial lemniscus, VPL thalamic nucleus, fibers of internal capsule or cerebral cortex

Answer 18

. Lost or diminished sensations seen contralateral to the lesion

Question 19

DCML impairments of conscious proprioception

Answer 19

. Direction and extent of movements not well-perceived
. Passive movements felt as touch or pressure sensations
. Loss of conscious proprioception greatly impairs performance of voluntary motor movements (positive rhomberg, dorsal ataxia)

Question 20

Dorsal column ataxia

Answer 20

. Poor coordination of voluntary movements
. Seen in neurosyphilis
. Degeneration of dorsal columns in lumbosacral levels of spinal cord

Question 21

. Loss of secondary modalities (stereognosia) w/o loss of primary modalities is a sign of what lesion?

Answer 21

. Lesion of post. Parietal lobe
. Area 3,1,2 in postcentral gyrus perceives basic stimuli
. Area 5 and 7 of parietal lobe receives inputs from 3,1,2 and visual, auditory, limbic motor systems to assign meaning to stimuli

Question 22

Effects of posterior parietal lobe lesions

Answer 22

. Inability to recognize object by touch alone (astereognosia)
. Inability to detect nu,bears or letters written on skin (agraphesthesia)

Question 23

Extinction phenomenon

Answer 23

. Tactile or visual stimulus perceived normally when presented to 1 side only
. When stimulus is presented on side opposite lesion simultaneously w/ identical stimulus on normal side, the patient neglected the stimulus on opposite side of lesion
. Type of hemineglect

Question 24

Unilateral lesions of STT in spinal cord

Answer 24

. Los or diminished pain, temp, and crude touch sensations in contralat. Dermatomes below spinal cord lesion

Question 25

Unilateral lesion of STT in brainstem, VPL, fibers of internal capsule or cerebral cortex

Answer 25

. Lost or diminished pain, temp, and crude touch sensations contralat. To lesion

Question 26

Lesion localized in VPL of thalamus

Answer 26

. Initial loss of all sensations from contralat. Side of body (including pain)
. Overtime patient may experience pain in all or part of constralat. Side of body
. Used to be called thalamic pain syndrome/Dejerine-Roussy syndrome but now called central post-stroke pain (CPSP)
. Pain described as spontaneous burning
. Sudden onset of intense pain set off w/ innocuous stimuli
. Pain due to SRTT still being intact carrying slow pain info

Question 27

Clinical symptoms seen after lesions to ALS

Answer 27

. Inability to recognize pain and temperature sensations (analgesia and thermoanesthesia)
. Diminished ability to recognize touch sensations (hypesthesia/hypoesthesia)

Question 28

Peripheral lesions of trigeminal system

Answer 28

. Ipsilateral loss or diminished sense of pain, temp., discriminative abilities, conscious proprioception, and vibration in distribution of trigeminal division that is damaged
. Ipsilateral flaccid paralysis and profound atrophy of mm. Of mastication if V3 is affected
. Trigeminal neuralgia

Question 29

Unilateral lesion of trigeminal motor nucleus or fibers

Answer 29

. Ipsilateral flaccid paralysis and profound atrophy of mm. Of mastication

Question 30

Unilateral lesion of trigeminal sensory nuclei

Answer 30

. Lost or diminished sensation ipsilateral to lesion (spinal = pain/temp, chief = discriminative sensation)

Question 31

Unilateral lesion of VTTT or higher neural structures (VPM, internal capsule fibers, cerebral cortex)

Answer 31

. Lost or diminished sensations contralat. To lesion
. Usually all forms of sensation affected if lesion is at or above level of chief sensory nuclei
. Only pain and temperature senses affected if lesion is at level of spinal trigeminal nucleus