Localization of Spinal Cord Lesions

Question 1

LMN involvement means

Answer 1

LMN involvement means SPINAL CORD INVOLVEMENT or root or nerve

Question 2

C4 dermatome

Answer 2

clavicle **

Question 3

C5 dermatome

Answer 3

shoulder

Question 4

C6 dermatome

Answer 4

thumb

Question 5

C7 dermatome

Answer 5

middle finger

Question 6

C8 dermatome

Answer 6

little finger

Question 7

T4 dermatome

Answer 7

nipple line **

Question 8

T10 dermatome

Answer 8

umbilicus **

Question 9

L1 dermatome

Answer 9

inguinal crease **

Question 10

L5 dermatome

Answer 10

lateral calf **

Question 11

S4-S5 dermatome

Answer 11

perianal area **

Question 12

biceps brachii myotome

Answer 12

C5 (C6)

Question 13

triceps myotome

Answer 13

C7 (C6-C8)

Question 14

intrinsic hand muscles myotome

Answer 14

C8, T1

Question 15

quadriceps femoris myotome

Answer 15

L3 (L2-L4)

Question 16

gastrocnemius myotome

Answer 16

S1

Question 17

spinothalamic tract crosses in ________

Answer 17

spinothalamic tract crosses in SPINAL CORD

Question 18

dorsal columns cross in _________

Answer 18

dorsal columns cross in medulla

Question 19

a lesion on one side of the spinal cord will cause loss of ____________________ on the side of the lesion, and loss of ______________ on side opposite the lesion

Answer 19

a lesion on one side of the spinal cord will cause loss of POSITION and VIBRATORY SENSE on the side of the lesion, and loss of PAIN and TEMPERATURE on side opposite the lesion

Question 20

Brown-Sequard Syndrome

Answer 20

Hemisection of spinal cord.

Deficits in dorsal column, spinothalamic, and corticospinal tracts.

Ipsilateral loss of position and vibration sense.

Contralateral loss of pain and temperature sense (slightly below level of lesion due to movement of spinothalamic fibers up thru lissauer’s tract before decussation).
Ipsilateral paralysis.

Question 21

a lesion in the central part of the spinal cord can affect ___________, leaving ______ and ______ tracts unaffected.

Answer 21

a lesion in the central part of the spinal cord can affect PAIN and TEMPERATURE, leaving DORSAL COLUMN and CORTICOSPINAL tracts unaffected.

Question 22

suspended sensory loss for pain and temperature means

Answer 22

spinal cord disease

only ventral white commisure is affected

Question 23

lesion of ventral white commisure

Answer 23

Only fibers that cross at level of lesion will be affected. (lose pain/temp at level of lesion)

Pain and temperature will be normal above and below the lesion.

Question 24

syringomyelia

Answer 24

• affects ventral white commisure
• suspended sensory loss for pain and temperature
• starts small, gets bigger: next affected is burning fingers w/o realizing, LMN weakness

Question 25

ALS

Answer 25

Amyotrophic Lateral Sclerosis - motor disease only - combined UMN and LMN disease [LMN signs predominate, fasciculations] - affects corticospinal tract, LMNs - does NOT affect sensory - rare - elderly - progressive - 2-3 yr survival - death from infection

Question 26

ALS - LMN lesions vs UMN lesions

Answer 26

LMN lesions: fasciculations UMN lesions: clonus, babinski sign

Question 27

variants of ALS

Answer 27

Spinal muscular atrophy - LMN Primary lateral sclerosis - UMN Bulbar ALS - LMN cranial nerves

Question 28

tabes dorsalis

Answer 28

Predominant DORSAL COLUMN deficits - loss of position/vibration sense - difficulty maintaining erect posture - Romberg sign - patchy loss of pain/temp - affects dorsal roots/ganglia -form of tertiary neurosyphilis

Question 29

Romberg sign

Answer 29

Patient can stand with eyes open, but cannot stand with eyes closed Seen with Tabes Dorsalis

Question 30

what is needed for balance?

Answer 30

2 of the following: - visual - vestibular - posterior column

Question 31

subacute combined degeneration posterolateral sclerosis

Answer 31

Dorsal columns and corticospinal tract deficits - Romberg sign - UMN signs - vitamin B12 deficiency - pernicious anemia

Question 32

poliomyelitis

Answer 32

Anterior horn cells affected. LMN syndrome. -viral infection with predilection for anterior horn cells -acute febrile illness

Question 33

post-polio syndrome

Answer 33

- new weakness years after acute polio (stress to system) | - often in same distribution as original weakness

Question 34

anterior spinal syndrome

Answer 34

Spinothalamic and Corticospinal affected. Dorsal column preserved. (due to loss of anterior spinal artery, providing blood to anterior 2/3 of spinal cord) Loss of pain/temperature, motor function

Question 35

extrinsic cord compression

Answer 35

osteophytes, herniations, tumors, abcesses - commonly presents with pain (from root compression) - early involvement of sacral segments (from compression of lateral aspects of spinothalamic tracts and lateral corticospinal tracts) - localized LMN lesion from compression of ventral root