Lecture 5

Question 1

What are the components of spinal cord anatomy?

Answer 1

-gray matter on inside (butterfly)
-white matter on outside
-dorsal and ventral horns of gray matter
-dorsal, lateral, and ventral funiculi of white matter

Question 2

What is an intumescence?

Answer 2

swelling/enlargement of the spinal cord to account for the increased number of neurons going to the limbs

Question 3

Where is the thoracic limb intumescence?

Answer 3

C6 to T2

Question 4

Where is the pelvic limb intumescence?

Answer 4

L4 to S3

Question 5

What are the four main segments in which a spinal cord lesion is classified?

Answer 5

-C1 to C5
-C6 to T2 (thoracic intumescence)
-T3 to L3
-L4 to S3 (pelvic intumescence)

Question 6

How can a lesion be localized within the spinal cord?

Answer 6

-lower motor neuron deficits at level of lesion
-upper motor neuron deficits caudal to lesion
-sensory deficits at level of and caudal to lesion

Question 7

What are the deficits seen with a focal lesion at L4 to S3?

Answer 7

-normal cranial to L4
-lower motor neuron deficits at L4 to S3 level

Question 8

What are the deficits seen with a focal lesion at T3 to L3?

Answer 8

-normal cranial to T3
-upper motor neuron deficits at L4 to S3 level

Question 9

What are the deficits seen with a focal lesion at C6 to T2?

Answer 9

-normal cranial to C6
-lower motor neuron deficits at C6 to T2
-upper motor neuron deficits caudal (L4 to S3)

Question 10

What are the deficits seen with a focal lesion at C1 to C5?

Answer 10

upper motor neuron deficits caudal (C6 to T2 and L4 to S3)

Question 11

What is the difference between an upper motor neuron and a lower motor neuron?

Answer 11

-UMN has cell bodies in the brain
-LMN has cell bodies in the spinal cord

Question 12

What are the signs of an UMN lesion?

Answer 12

-paresis or paralysis
-normal or exaggerated spinal reflexes
-increased muscle tone/spasticity
-mild, disuse muscle atrophy

Question 13

What are the signs of a LMN lesion?

Answer 13

-paresis or paralysis
-weak or absent spinal cord reflexes
-decreased muscle tone/flaccidity
-marked, early muscle atrophy

Question 14

What are the questions answered by a neurologic examination?

Answer 14

-is there a neuro lesion?
-where is the lesion?
-how severe is the lesion?

Question 15

What is examined during a neurologic examination?

Answer 15

-gait and posture
-postural reactions
-spinal cord reflexes
-palpation of spine
-behavior and cranial nerves

Question 16

What are the characteristics of ataxia?

Answer 16

-swaying, staggering gait
-“no axis”
-base wide stance
-scuffing
-loss of proprioception

Question 17

What are the characteristics of paraparesis?

Answer 17

-partial loss of voluntary movement in both pelvic limbs
-animal could be ambulatory or non-ambulatory
-indicates a lesion caudal to T2

Question 18

What are the characteristics of paraplegia?

Answer 18

-complete loss of voluntary movement in both pelvic limbs
-indicates a lesion caudal to T2

Question 19

What are the characteristics of tetraparesis/tetraplegia?

Answer 19

-decreased/absent voluntary movement in all limbs
-indicates a lesion cranial to T2 or a generalized peripheral lesion