General Medicine Neuroconcepts Part 2

Front 1

What is the number one question to ask yourself if contemplating leg amputation due to a mass in the brachial plexus?

Back 1

Do the pelvic limbs should any neurological deficits?
-if has grown on spinal cord can look for conscious proprioception deficits on same side of hind leg to see if it has affected the UMNs

Front 2

If you shine a light in the left eye and there's no constriction in the right or left eye, where is the lesion?

Back 2

CN 2, optic nerve

Front 3

If you shine a light in the right eye and there's no constriction in the right eye, but constriction in the left eye, where's the lesion?

Back 3

Right oculomotor (CN3)

Front 4

What is the pathway of pupillary constriction?

Back 4

Shine light, it goes in through optic nerve, goes to midbrain to the pretectal area and stimulates the oculomotor nucleus---> out CN3 then goes to ciliary ganglion in eye socket and pupils constrict

Front 5

What is the pathway of pupillary dilation?

Back 5

Goes out optic n. runs all the way down spinal cord, decreased light stimulates rostral coliculi of midbrain and goes down spinal cord to T1-T3**** and comes out and goes up vagosympathetic trunk to cranial cervical ganglion behind jaw goes through **middle ear then goes to postganglionic sympathetic nerves on CN 5 and then get dilation

Front 6

What does it mean if an animal with head trauma has one dilated eye and one constricted eye? What's the prognosis?

Back 6

Unilateral oculomotor nuclear or nerve contusion or compression
-guarded prognosis

Front 7

What does it mean if an animal with head trauma has two pinpoint pupils that are non-responsive to dark? Prognosis?

Back 7

Means oculomotor nerve is working but have compression of midbrain
-guarded prognosis

Front 8

What does it mean if an animal with head trauma has two dilated eyes that are non responsive to light? Prognosis?

Back 8

means bilateral oculomotor nerve contusion or compression
-grave prognosis

Front 9

Blind animals can also have dilated pupils, so how can you determine b/w a blind animal and an animal with bilateral oculomotor nerve contusion?

Back 9

Do a menace response
-blind animals don't respond

Front 10

What are the signs of Horner's syndrome in dogs and cats?

Back 10

the symptoms generally include a sunken in eye (enophthalmia) with a small pupil (miosis), a droopy upper eyelid (ptosis) and a prominant third eyelid.

Front 11

*What is different about horses with Horner's syndrome?

Back 11

When get disruption of sympathetic innervation to the head they have sweating on the effected side
-dogs don't sweat, dry & hot from vasodilation

Front 12

Why do horses with Horner's syndrome sweat?

Back 12

Horses the receptors are Nepi receptors instead of acetylcholine so normal circulating epi and Nepi will sweat when lose sympathetic to one side of the body- get hypersensitivity of these sweat receptors bc they have been deinnervated so get sensitized to NT that should be there

Front 13

***Explain the progression of signs as the spinal cord is compressed.

Back 13

-1st loss: Proprioception
first conscious then unconscious
-2nd loss: Voluntary motor --> paresis, paralysis
3rd loss: touch & superficial pain ---> loss of cutaneous sensation
4th loss: deep pain: loss of deep pain
*comes back in opposite order

Front 14

What is a withdrawl or flexion reflex?

Back 14

Withdraws limb
-no other response

Front 15

What is a pain response?

Back 15

1. withdraws (flexes) limb
2. turns head and or
3. threatens to bite and/or
4. Tries to move away and/or
5. Whines or barks and/or
6. Interrupts respiratory pattern

Front 16

What is the difference b/w a reflex (Withdrawl reflex) and a pain response?

Back 16

-Reflex only depends on the reflex arc being intact
-pain response requires intact spinal cord and goes to the brain for perception

Front 17

What does it mean if you pinch a limb and there's no withdrawl in that one limb only?

Back 17

Localizes lesion to the reflex arc right where the lesion is

Front 18

What does it mean if there's no withdrawl on the front and hind limbs when you pinch a dogs foot but can whimper and cry?

Back 18

diffuse LMN disease, they still feel it but paralyzed

Front 19

What does it mean if there's no pain response?

Back 19

Interference with ascending massage
-can be either LMN or UMN lesion

Front 20

what part of the spinal cord could be damaged if there's no pain response?

Back 20

L4, L5, T13
-just means didn't get to brain

Front 21

What is the prognosis of pain loss?

Back 21

Means last to go in spinal cord: Dogs may walk again and never regain deep pain, but often incontinent (Exception not rule)

Front 22

What has been reports as the first indicator post surgery or treatment that a dog will walk again after spinal injury?

Back 22

VOLUNTARY wagging of the tail

Front 23

What are 4 clinical signs of an animal with a peripheral vestibular disorder?

Back 23

1) Head tilt
2) Weakness of ipsilateral extensor muscles
3) NO conscious prop deficits
4) Nystagmus

Front 24

What are 4 clinical signs of an animal with a central vestibular disorder?

Back 24

1) Head tilt
2) Weakness of ipsilateral extensor muscles
3) Loss of CP ipsilateral****
4) Nystagmus

Front 25

**What are 2 ways to differentiate b/w a peripheral and central vestibular disorder?

Back 25

1) Peripheral has a constant and unvarying nystagmus, central is inconstant and varying
2) Central has a loss of CP ipsilateral, peripheral doesn't

Front 26

Does an animal with a central vestibular disorder have a normal menace response? Peripheral?

Back 26

Both will be normal menace

Front 27

What is paradoxical vestibular?

Back 27

Where have lesion on right side but head tilts to the left and everything said left but conscious proprioception said right

Front 28

Where is the conscious proprioception loss with paradoxical vestibular disease?

Back 28

Ipsilateral side
-but head tilt to contralateral

Front 29

How can you determine if circling is due to a vestibular disorder or cerebral cortex disorder?

Back 29

Vestibular: menace present, weakness of ipsilateral extensors, CP deficits only if central brain lesion -ipsilateral
Cerebral cortex: NO menace, increased extensor tone
*CP deficits contralateral

Front 30

What should come to mind when an animal is circling?

Back 30

Vestibular or cortical

Front 31

**What is the pathway for the menace response?

Back 31

(threat) Optic nerve---> optic chiasm---> optic tract---> rostral colliculli--> lateral geniculate----> occipital cortex----> association cortex---> cerebellum---> motor cortex--> facial nerve (blink)