Exam 3

Question 1

Lecture 1

Answer 1

Neurological exam

1. Learn how to perform a neurological examination on horses and foals
2. Develop a flow that helps establish efficiency to be able to perform the examination in practice
   Generally focused on the gait
3. The neurologic examination seeks to establish
   a. Does a neurologic problem exist?
   b. Wha tis the neuroanatomic localization?
4. Where is the lesion, what is the cause?

Question 2

How to do a good neurological exam?

Answer 2

Use all your senses
-Tell differences how they are dragging their toes
-Write what you see

Principles of the Neurological Diagnosis

1. Localize the lesion: review neuroanatomy
2. Characterize the signs: Identify distinctive features
3. Determine the cause: create a differential list, decide what test to perform, interpret results

Start by looking at the horse from the distance

Question 3

What are some signs of ForeBrain and diencephalon lesions?

Answer 3

Obtundation
-Central blindness
-Loss of menace response - contralateral to where the lesion is
-Narcolepsy: falling asleep while standing - musculoskeletal problem
-Head pressing
-Circling
-Unusual aggression
-Maniacal behavior

Question 4

What are the two most common Brainstem lesions seen in horses?

Answer 4

1. Facial head paralysis and
2. Head tilt

Question 5

Spinal cord lesions

What is the hallmark of LMN disease?

Answer 5

Propioceptive tracts peripherally in the cord

-Faciculus gracilis: hindlimb
-Faciculus cuneatus: forelimb

Horses
# 1 cause of spinal ataxia = Stenosis, compressive myelopathy
-Loss of awareness from where their feet are
-Weakness
-Muscle atrophy, eventually

LMN disease Hallmark

-Weakness followed by
-Muscle atrophy

Limb reflexes mostly foals
Hopping sometimes with adults

UMN disease Hallmark

-Ipsilateral weakness of the trunk and limbs
-Loss of inhibition of myotonic reflexes results in SPASTIC movement
-Ataxia: pacing when they walk
-If LMN not affected, then “exaggerated” on the side of the spinal cord lesion

Question 6

UMN between C1-C2

Answer 6

-Neurological signs in all four limbs

1. Weakness: knuckling, stumbling, dropping, dragging leg.
   2.Ataxia: abnormal sway of the limb in the air, trunkal say and pacing
2. Elasticity: hypermetric gait, locking of the patella.
3. Dysmetria

Question 7

UMN lesion between T3-S2

Answer 7

-Affect only the pelvic limbs

Question 8

External compression of the cervical spine lesions

Answer 8

Wobblers
-Cervical vertebral stenotic myelopathy
-Worse signs in pelvic limbs than in thoracic limbs

Question 9

Spinal Cord Reflexes - Cervical Responses

Answer 9

-Take ballpoint pen pricking the neck, normal horses smile
-Slap test: opposite side arythanoid ABducts

Question 10

Spinal cord and urination

Answer 10

-Parasympathetic LMN to bladder smooth muscle (detrusor) originates in intermediate column of gray matter S2-S4
-Sympahttic LMN to the bladder begins in gray matter L1-L4 exit and course caudally to the pelvic plexus

Question 11

Spinal cord localization

Answer 11

Tail-pull test

Weakness while standing still = pelvic lesion or lumbar spinal cord problem

Weakness while walking = cervical problem spinal cord

-At rest - horse initially leans toward the direction of the pull, but then resists: tests myotactic reflex L3-L5

-At walk - pull sideways on tail while walking in a straight line
examine during multiple phases of the stride, lack resistance during walking is consistent with ipsilateral spinal cord lesion affecting descending UMN C1-S1 (but typically a cervical spinal cord lesion)

Question 12

Spinal Cord C1-C6

Answer 12

Signs

-Pelvic limb will be affected more than forelimb sings

Question 13

Spinal cord C6 to T2

Question 14

Spinal cord T3-L3