Neuro: Lecture 11- Spinal Cord

Question 1

Lesion of the right dorsal column at L1 produces what impairment?

Answer 1

Will cause the absence of light touch, vibration, and position sensation in the right leg.
Only fascicles gracilis exists bellow T6
-Common causes include MS, penetrating injuries, and compression from tumours
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Question 2

Lesion of the right fasciculus cuneatus at C3 produces what impairment?

Answer 2

Damage to the right fasciculus cuneatus at c3 causes the absence of light tough, vibration and position sensation in the right arm and upper trunk.
slide 12

Question 3

Lesion of the right lateral corticospinal tract at L1 would produce why impairment?

Answer 3

-causes upper motor neurone signs (weakness or paralysis, hyperreflexia and hypertonia) in the right leg
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Question 4

Lesion of the right lateral spinothalmic tract at L1 produces what impairment?

Answer 4

-Causes the absence of pain and temp sensation in the left leg
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Question 5

Damage to the anterior gray and white commissures (central cord syndrome) at c5-c6 produces what impairment?

Answer 5

-causes absence of pain and temp sensation in the c5 and c6 dermatome in both upper extremities.
-common causes: Posttraumatic contusion and syringomyelia and intrinsic spinal cord tumours
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Question 6

Complete transection of the right half of the spinal cord (hemicord or brown-sequard syndrome) at L1 produces what impairments?

Answer 6

Damage to the right dorsal columns at L1 causes the absence of light touch, vibration, and position sense in the right leg. Damage to the lateral corticospinal tract causes upper motor neuron signs in the right leg (Monoplegia), and damage to the lateral spinothalamic tract causes the absence of pain and temperature sensation in the left leg.
Common causes include penetrating injuries, lateral compression from tumors, and MS.

Question 7

Complete transection of the spinal cord (transverse cord lesion) at L1 would produce what impairments?

Answer 7

-Damage to the dorsal columns, bilaterally, causes the absence of light touch, vibration, and position sense in the both legs.
-Damage to the lateral corticospinal tracts, bilaterally, cause upper motor neuron signs in the both legs (Paraplegia), and -damage to the lateral spinothalamic tracts, bilaterally, cause the absence of pain and temperature sensation in the both legs.
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Question 8

Complete transection of the dorsal columns, bilaterally (posterior cord syndrome) in the cervical region would produce what impairments?

Answer 8

-damage to the dorsal columns (fasciculus gracilis and cuneatus) bilaterally causes the absence of light touch, vibration, and position sense, bilaterally from the neck down (below the lesion level)
common causes: trauma, compression from posteriorly located tumours, and MS
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Question 9

Complete transection of the lateral corticospinal tracts with sparing of the dorsal solumns, bilaterally (anterior cord syndrome) in the cervical region would produce what impairments?

Answer 9

Damage to the lateral corticospinal tracts cause upper motor neuron signs, bilaterally, below the lesion level. Damage to lower motor neurons in the ventral horns cause lower motor neuron signs, bilaterally, at the lesion level. Damage to the lateral spinothalamic tracts cause absence of pain and temperature sensation, bilaterally, below the lesion level. Sparing of the dorsal columns leaves light touch, vibration, and position sense intact throughout.

Question 10

Patient case 1:
The patient complains of “clumsiness” of her left leg due to uncertainty of the limb’s position in space. Active and passive ROM and strength are within normal limits (WNL) throughout. Light touch, two-point discrimination, proprioception, and vibration sense are intact in the right lower extremity but absent in all dermatomes below the umbilicus in the left lower extremity. She is able to distinguish sharp from dull WNL in lower extremities, bilaterally.

Damage to what system(s) is causing this patient’s problems?

Answer 10

answer:
Lesion of the left dorsal column (fasciculus gracilis) at approximately T10.

Lateral corticospinal tracts are intact, bilaterally: AROM and strength are WNL
Lateral spinothalamic tracts are intact, bilaterally: sharp/ dull is WNL
Dorsal column is intact on the right: light touch, two-point discrimination, proprioception, and vibration are WNL
Dorsal column is absent on the left: light touch, two-point discrimination, proprioception (limb position in space), and vibration are absent in all dermatomes below the umbilicus
Lesion level, T10: the umbilicus is located in the T10 dermatome

Left dorsal column lesion slide 32

Question 11

Case 2:
After a fall from his horse, the patient was alert and oriented but unable to move anything but his head. He was unable to sense light touch or pain from the neck down. He could turn his head but shoulder shrug was weak. Speech was normal but respiration was labored and required a respirator.

Damage to what system(s) is causing this patient’s problems?

Answer 11

Complete transection of the spinal cord (transverse lesion ) at approximately C3 (Tetroplegia, Christopher Reeve)

Lateral corticospinal tracts absent, bilaterally, below C3: unable to move any body part except head and shoulder shrug (C3-5)
Dorsal columns absent , bilaterally, below C3: unable to sense light touch below neck
Lateral spinothalamic tracts absent, bilaterally, below C3: unable to sense pain below neck
Lesion level, C3: patient was alert and oriented (cortex and reticular activating system intact), he could turn his head (spinal accessory nerve), shoulder shrug and respiration were weak (shoulder elevator and respiratory muscles C3-5)
Transverse cord lesion
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Question 12

Case 3
Following surgical repair of a knife wound the patient is unable to stand or walk because he is unable to move or bear weight on his right leg. Light touch, position and vibration sense are WNL in the left lower extremity but absent in the right below the crest of the ilium. Active range of motion and strength are normal in the left lower extremity but absent in the right (hip, knee, and ankle). Pain and temperature sensation are intact in the right lower extremity but absent in the left below T12.
Damage to what system(s) is causing this patient’s problems?

Answer 12

Hemisection of the spinal cord on the right at approximately L1

Dorsal column is intact on the left but absent on the right: light touch, position and vibration sense are WNL in the left lower extremity but absent in the right
Lateral corticospinal tract is intact on the left but absent on the right: active range of motion and strength are normal in the left lower extremity but absent in the right
Lateral spinothalamic tract is intact on the left but absent on the right: pain and temperature sensation are intact in the right lower extremity but absent in the left
Lesion level, approximately L1: hip flexion absent on right (L2), pain and temperature sense absent below T12
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