Large Animal Focal Spinal Disease Flashcards
what is the tail-pull response with lower motor neuron weakness?
weak standing and walking tail-pull response
what is the stride like with upper motor neuron weakness?
long stride
what are the neurologic features of a C1-5 (high cervical) lesion?
general proprioceptive and upper motor neuron signs to all four limbs (hind>front)
what commonly causes focal spinal disease in horses?
cervical vertebral stenotic myelopathy/cervical vertebral malformation
trauma
what signs are associated with cervical vertebral stenotic myelopathy in young horses?
unsteady when working
may trip/fall when turning quickly, loose gait behind
what is cervical vertebral stenotic myelopathy?
compressive spinal disease in horses
what signs are associated with cervical vertebral stenotic myelopathy in middle-aged horses?
horses with a lot of “wear and tear”
presented for lameness, or neck stiffness
often more subtle/mild
what is the pathophysiological mechanism of cervical vertebral stenotic myelopathy in young horses?
developmental
trauma
what is thee pathophysiological mechanism of cervical vertebral stenotic myelopathy in middle-aged horses?
degenerative +/- trauma
what is developmental orthopedic disease associated with?
excess energy and accelerated bone growth
what is the principle of cervical vertebral stenotic myelopathy?
extramedullary compression of spinal cord
what is the diagnostic approach for cervical vertebral stenotic myelopathy?
minimal sagittal diameter
what is the normal minimal sagittal diameter for thoroughbreds?
MSD>0.5
what is affected by cervical vertebral stenotic myelopathy?
descending motor tracts such as corticospinal tracts
what are the signs with C1-5/high cervical lesions?
general proprioceptive and upper motor neurons signs to all four limbs
what are the signs with C6-T2/low cervical lesions?
general proprioceptive to all four limbs
lower motor neuron signs to forelimb
upper motor neuron signs to hindlimb
what are the signs with L4-caudal segment/lumbosacral lesions?
normal forelimbs
general proprioceptive and lower motor neuron signs to hindlimb
areflexia/analgesia: anus, perineum, tail, penis
what can cause multifocal spinal disease in horses?
equine protozoal myeloencephalitis
viral encephalitis
tick-borne
what causes cervical vertebral stenotic myelopathy in young horses?
malformation with spinal narrowing or instability: dynamic compression
developmental orthopedic disease
fast-growing, often overfed concentrate
what factors are associated with developmental orthopedic disease in horses?
high-grain diets (most common)
macromineral deficiency
trace mineral imbalance
breed genetics
what does it mean that a lesion is static?
malformed bone or proliferative bone that is compressing spinal cord
why are hindlimb deficits usually more severe with cervical vertebral stenotic myelopathy?
rearlimb tracts are more peripheral: external compression of cervical spine
what do you measure for minimal sagittal diameter?
smallest diameter of the cranial aspect of the cervical canal
widest diameter of the cranial aspect of the vertebral body of the same vertebra
what does compression of CNS tissue lead to?
impeded normal axoplasmic flow in axons
reduced blood flow
