Spinal Cord Lesions

Front 1

In what areas do sensory findings appear in spinal cord lesions?

Back 1

1. Restricted to one dermatome

Front 2

What are the muscular signs of a spinal cord lesion?

Back 2

1. Weakness

2. Paralysis

3. Reduced/absent DTRs

4. All in a single muscle or muscle group

Front 3

What are the signs of a lower motor neuron lesion?

Back 3

1. Everything is LOW

2. Weakness, paralysis, fasciculations, areflexia, atrophy

Front 4

What is degraded in ALS?

Back 4

1. Upper motor neurons

2. Lower motor neurons

3. In corticospinal tracts

Front 5

What is destroyed in polio myelitis?

Back 5

1. Lower motor neurons

Front 6

What does destruction/loss of the fasciculus gracilis/cuneatus produce?

Back 6

1. Loss of fine touch, vibratory sensation, and conscious proprioception

2. IPSILATERAL to lesion

3. Gracilis=lower body

4. Cuneatus=upper body

Front 7

What will lesions to the upper thoracic/cervical cuneatus and gracilis lead to?

Back 7

1. Involvement of both the cuneatus and gracilis

Front 8

What will result from damage to the ventral funicular?

Back 8

1. Loss of pain and temperature sensation below the level of the lesion

2. CONTRALATERAL

Front 9

What is syringomyelia?

Back 9

1. Pathological expansion of the central canal of the spinal cord

2. Ssx: loss of pain and temperature sensation at the level of the central canal

Front 10

What is the result of injury to the lateral corticospinal tract?

Back 10

1. IPSILATERAL loss of voluntary movement below the level of the lesion

Front 11

What are the ssx of an upper motor neuron injury?

Back 11

1. Everything is UP

2. Increased tone, hyperreflexia, clonus, positive Babinski

Front 12

What leads to pathological motor signs in an upper motor neuron injury?

Back 12

1. Loss of excitatory corticospinal input to spin cord interneurons that normally inhibit muscle contraction

Front 13

What would result from unilateral damage to one ventral corticospinal tract?

Back 13

1. Not likely to produce weakness

2. Other ventral corticospinal tract also supplies the motor neurons of axial and limb muscles

Front 14

What would result from bilateral damage to both ventral corticospinal tracts?

Back 14

1. Weakness

2. Spasticity

Front 15

What occurs in the acute phase of spinal cord injuries due to vascular accident or trauma?

Back 15

1. Voluntary movement below lesion is lost

2. DTRs absent

3. Sensation lost

4. Possible autonomic outflow disruption

Front 16

What occurs in the chronic phase of spinal cord injuries due to vascular accident or trauma?

Back 16

1. Upper motor neuron ssx emerge

2. Residual sensory functions resume if pathways are intact

Front 17

What functions usually return following a spinal cord injuriy due to vascular accident or trauma?

Back 17

1. Intrinsic spinal cord autonomic reflexes--- urination, defecation

2. Voluntary control usually lost

Front 18

What occurs in complete transection of the spinal cord?

Back 18

1. Complete loss of all conscious sensation

2. Complete loss of voluntary movement

3. Spasticity

Front 19

What ssx would emerge in hemisection of the spinal cord?

Back 19

1. Loss of fine touch, vibratory sensation, and conscious proprioception IPSILATERAL to lesion

2. Loss of pain and temperature sensation CONTRALATERAL to the lesion

3. Acute and/or choric upper motor neuron signs IPSILATERAL to lesion

Front 20

What is the result of destruction of the corticospinal tracts above the spinal cord?

Back 20

1. Loss or weakness of voluntary movement

2. Pathological motor signs

3. CONTRALATERAL

Front 21

What is the result of lesions in the motor cortex or internal capsule?

Back 21

1. Destruction of corticospinal fibers

2. Rubrospinal and reticulospinal fibers intact

Front 22

Why does increased extensor tone result from a lesion to the motor cortex?

Back 22

1. Excitatory reticulospinal inputs to the gamma motor neurons serving extensor muscles

Front 23

What results from lesions below the midbrain?

Back 23

1. Destruction of corticospinal fibers and rubrospinal fibers

2. Reticulospinal pathways intact

Front 24

What are the ssx of a lesion below the midbrain?

Back 24

1. Decerebrate posturing: spastic tone increase in extensors of upper limb, lower limb, and trunk