Large Animal Focal Spinal Disease

Question 1

what is the tail-pull response with lower motor neuron weakness?

Answer 1

weak standing and walking tail-pull response

Question 2

what is the stride like with upper motor neuron weakness?

Answer 2

long stride

Question 3

what are the neurologic features of a C1-5 (high cervical) lesion?

Answer 3

general proprioceptive and upper motor neuron signs to all four limbs (hind>front)

Question 4

what commonly causes focal spinal disease in horses?

Answer 4

cervical vertebral stenotic myelopathy/cervical vertebral malformation
trauma

Question 5

what signs are associated with cervical vertebral stenotic myelopathy in young horses?

Answer 5

unsteady when working
may trip/fall when turning quickly, loose gait behind

Question 6

what is cervical vertebral stenotic myelopathy?

Answer 6

compressive spinal disease in horses

Question 7

what signs are associated with cervical vertebral stenotic myelopathy in middle-aged horses?

Answer 7

horses with a lot of “wear and tear”
presented for lameness, or neck stiffness
often more subtle/mild

Question 8

what is the pathophysiological mechanism of cervical vertebral stenotic myelopathy in young horses?

Answer 8

developmental
trauma

Question 9

what is thee pathophysiological mechanism of cervical vertebral stenotic myelopathy in middle-aged horses?

Answer 9

degenerative +/- trauma

Question 10

what is developmental orthopedic disease associated with?

Answer 10

excess energy and accelerated bone growth

Question 11

what is the principle of cervical vertebral stenotic myelopathy?

Answer 11

extramedullary compression of spinal cord

Question 12

what is the diagnostic approach for cervical vertebral stenotic myelopathy?

Answer 12

minimal sagittal diameter

Question 13

what is the normal minimal sagittal diameter for thoroughbreds?

Answer 13

MSD>0.5

Question 14

what is affected by cervical vertebral stenotic myelopathy?

Answer 14

descending motor tracts such as corticospinal tracts

Question 15

what are the signs with C1-5/high cervical lesions?

Answer 15

general proprioceptive and upper motor neurons signs to all four limbs

Question 16

what are the signs with C6-T2/low cervical lesions?

Answer 16

general proprioceptive to all four limbs
lower motor neuron signs to forelimb
upper motor neuron signs to hindlimb

Question 17

what are the signs with L4-caudal segment/lumbosacral lesions?

Answer 17

normal forelimbs
general proprioceptive and lower motor neuron signs to hindlimb
areflexia/analgesia: anus, perineum, tail, penis

Question 18

what can cause multifocal spinal disease in horses?

Answer 18

equine protozoal myeloencephalitis
viral encephalitis
tick-borne

Question 19

what causes cervical vertebral stenotic myelopathy in young horses?

Answer 19

malformation with spinal narrowing or instability: dynamic compression
developmental orthopedic disease
fast-growing, often overfed concentrate

Question 20

what factors are associated with developmental orthopedic disease in horses?

Answer 20

high-grain diets (most common)
macromineral deficiency
trace mineral imbalance
breed genetics

Question 21

what does it mean that a lesion is static?

Answer 21

malformed bone or proliferative bone that is compressing spinal cord

Question 22

why are hindlimb deficits usually more severe with cervical vertebral stenotic myelopathy?

Answer 22

rearlimb tracts are more peripheral: external compression of cervical spine

Question 23

what do you measure for minimal sagittal diameter?

Answer 23

smallest diameter of the cranial aspect of the cervical canal
widest diameter of the cranial aspect of the vertebral body of the same vertebra

Question 24

what does compression of CNS tissue lead to?

Answer 24

impeded normal axoplasmic flow in axons
reduced blood flow