Lesion localization

What makes up the CNS

• brain

• spinal cord

What are the 3 divisions of the brain

• Forebrain/thalamocortex

• brainstem

• cerebellum

What are the parts of the brain stem

• midbrain

• pons

• medulla

What makes up the PNS

• nerves

• muscle

• Neuromuscular junction

Upper motor neurons remain in the ________ or ___________ and control all limbs

• brain

• spinal cord

Lower motor neurons originate from the ________ in the spinal cord and end in ______

• gray matter

• muscle

What are the important function of upper motor neurons

• facilitate flexor muscle movement

• inhibit extensor muscle movement

What are the important functions of lower motor neurons

• final common pathway

• manifest motor activity in the form of reflexes

In a dog with an UMN lesion you see ___________ muscle tone, ____________ reflexes and ________ atrophy

• normal

• normal

• slow

In a dog with an LMN lesion you see___________ muscle tone, ____________ reflexes and ________ atrophy

• decreased

• decreased

• fast

Dogs with either a UMN or LMN lesion will both exhibit characteristic signs of what?

paresis or paralysis

A dog with an UMN lesion but with both UMN and LMN signs means they might have a lesion in one of the ______ regions

plexus regions

What are the 4 spinal cord regions

• c1-5

• c6-t2

• t3-l3

• l4-s3

A lesion in what spinal cord regions will cause tetraparesis/plegia

• c1-5

• c6-t2

A lesion in what spinal cord region will cause only paraparesis/plegia

• T3-L3

• L4-S3

A lesion in what spinal cord regions will cause UMN deficits to appear

• c1-5

• T3-L3

In any spinal cord lesion there will be ________ present

ataxia

An animal with ataxia presents with tetra paresis, Increased extensor tone in all 4 limbs, but normal to increased flexor reflex in pelvic limbs. When you move to test the thoracic limbs you note decreased flexor reflex while still having increased extensor tone this leads you to believe the lesion is where and affecting what nerve?

• c6-c8

• musculocutaneous

At which vertebral level does the spinal chord end?

L5

the L5 vertebrate contains what part of the spinal cord

• s1

• s2

• s3

Trauma at L5 generally leads to ________ due to loss of control of the _____ nerve

• incontinence

• pudendal

Generally lumbosacral disease does not cause _________ but can cause ___________

• paraplegia

• flexor weakness

Exceptions to the lumbosacral disease rule include ______ and ________

• spinal shock

• Schiff Sherrington syndrome

A dog hit with a car exhibits severe paraparesis with decreased- absent tone and reflex on initial inspection but after an hours is back to normal you would consider this what and localize the lesion to what area of the spinal cord

• spinal shock

• T3-L3

A dog presents with a stiff neck and thoracic limbs, but has a lesion visualized at T2-L5 this is representative of __________ and is caused in part by it affecting the __________

• shiff Sherrington syndrome

• propriospinal tract

If a dog presents with all 4 limbs affected with LMN signs what is most likely

the lesion is not in the spinal cord

Diseases that cause LMN signs in all 4 limbs do not cause what?

proprioceptive ataxia

what three areas can lesions be in the brain

• thalamocortex

• brainstem

• cerebellum

A dog presents with marked mentation changes like being particularly sleepy, cranial nerve deficits, and tetraparesis and ataxia where in the brain is this lesion occurring

the brainstem

What cranial nerves are located in the brainstem

CN3-12

from caudal to rostral what are the areas of the brainstem

• caudal medulla

• rostral medulla

• pons

• mesencephalon

A dog has a lesion localized to the brainstem, the animal is presenting particularly with ocular paralysis and mydriasis(pupil dilation) what area of the brainstem is the lesion in

mesencephalon

A cat has a lesion localized to the brainstem, the animal is presenting with atrophy of masticatory muscles what area of the brainstem is the lesion in

pons

a dog has a lesion localized to the brainstem, the animal is is particularly presenting with head tilt, facial paralysis and an absence of the palpebral reflex what area of the brainstem is the lesion in?

Rostral medulla

A cat has a lesion localized to the brainstem, the animal is presenting with dysphonia, dysphagia, and tongue paralysis what area of the brainstem is the leison in

Caudal medulla

A central vestibular lesion is present in the __________ while a peripheral vestibular lesion is present in the __________

• brain

• ear

Unlike a central vestibular lesion a peripheral lesion will have no _______ changes

proprioceptive

what clinical signs are consistent with central vestibular disease

• vertical nystagmus

• proprioceptive deficits

A dog presents with whole body tremors and hypermetria, but no proprioceptive deficits, and no weakness what area of the brain does this dog have a lesion in

cerebellum

A cat presents for circling to the right, and generalized seizures. When testing the cat has absent menace response on the left side, proprioceptive deficits in the left limb, and lost nasal sensation in the left nostril where in the brain does the dog have a lesion?

right forebrain lesion

what tests would you perform to specifically test thalamocortical function

• menace

• nasal sensation

• postural reactions

• mental status