Veterinary Neurology: Localizing Lesions

Front 1

List 5 motor unit components

Back 1

LMN
Peripheral nerves
Neuromuscular junction
Skeletal muscle fibers
Sensory nerves

Front 2

Damage to these motor neurons causes:
Paresis or paralysis
Rapid atrophy
Altered sensation
Diminished or absent spinal reflexes

Back 2

Lower motor neuron

Front 3

Unconscious response to stimulation, requiring a receptor, afferent neuron, efferent neuron, neuromuscular junction, and skeletal muscles.

Back 3

Spinal reflex

Front 4

True or false: Spinal reflexes do not require higher centers to be processed.

Back 4

True

Front 5

The triceps reflex evaluates this nerve.

Back 5

Radial nerve (C7-T1)

Front 6

The biceps reflex evaluates this nerve.

Back 6

Musculocutaneous (C6-C8)

Front 7

The extensor carpi radialis reflex evaluates this nerve.

Back 7

Radial (C7-T2)

Front 8

Describe a normal withdrawal response.

Back 8

Flexion of limb and conscious perception of pain

Front 9

The patellar reflex evaluates this nerve.

Back 9

Femoral (L4-S2)

Front 10

The cranial tibial reflex evaluates this nerve

Back 10

Peroneal branch of the sciatic nerve (L6-S2)

Front 11

The gastrocnemius reflex evaluates this nerve.

Back 11

Tibial branch of the sciatic nerve (L6-S2)

Front 12

The pelvic withdrawal reflex evaluates these nerves.

Back 12

Sciatic nerve
Cranial and caudal gluteal nerves

Front 13

The perineal reflex evaluates this nerve.

Back 13

Pudendal nerve (S1-S3)

Front 14

How is the sciatic response evaluated?

Back 14

Percuss thumb in the sciatic notch. Normal response is jerk of entire limb.

Front 15

Grey matter of spinal cord contains these 2 components.

Back 15

LMN
Interneurons

Front 16

White matter in the spinal cord contains these two components.

Back 16

Ascending sensory axons
Motor axons from upper motor neurons

Front 17

Injury to these motor neurons causes:
Paresis or paralysis
Disuse atrophy over time
Altered sensation
Exaggerated/abnormal spinal reflexes

Back 17

Upper motor neurons

Front 18

Injury to these motor neurons causes ataxia: Upper or lower?

Back 18

Upper motor neurons

Front 19

List two abnormal spinal reflexes.

Back 19

Babinski
Crossed extensor

Front 20

This abnormal spinal reflex causes involuntary extension of one limb when the contralateral limb's digits are pinched.

Back 20

Crossed extensor

Front 21

In this abnormal spinal reflex, moderate pressure is applied to the plantar surface of the hock in a sweeping motion, and the digits extend.

Back 21

Babinski

Front 22

Localize this spinal cord injury:
-Rear limb paresis
-Bilateral hypotonia in rear limbs
-Diminished/absent spinal reflexes in rear limbs
-No changes in thoracic limbs

Back 22

L4-S2

Front 23

Localize this spinal cord lesion:
-Rear limb weakness
-Disuse atrophy of rear limbs
-Exaggerated spinal reflexes in rear limbs
-Absent panniculus response caudal to injury
-No change in thoracic limbs

Back 23

T2-L4

Front 24

The panniculus reflex evaluates these nerves.

Back 24

Dorsal branches of each spinal nerve

Front 25

Localize this spinal cord lesion:
-Quadriparesis/quadriplegia
-UMN signs in rear limbs
-LMN signs in front limbs
-Absent panniculus reflex
-Horners syndrome

Back 25

C6-T2

Front 26

Why does Horner's syndrome appear when C6-T2 is injured?

Back 26

Sympathetic innervation to the face and eye emerges fromt he spinal cord at T1-T2 and travels up the vagosympathetic trunk.

Front 27

What is Horner's syndrome?

Back 27

Loss of sympathetic innervation to the eye, causing miosis, ptosis, and enopthalmus

Front 28

Localize this spinal cord lesion:
-Quadriparesis/quadriplegia
-Some tone remaining in muscles
-UMN signs in all four limbs
-Potentially may affect respiratory muscles

Back 28

C1-C6

Front 29

This is the best test to differentiate between neurologic and orthopedic diseases.

Back 29

Postural reactions

Front 30

Do postural reactions evaluate upper or lower motor neurons?

Back 30

Both

Front 31

This postural reaction is less sensitive on the front limbs because the shoulder is engaged and allows the animal to "cheat."

Back 31

Conscious proprioception

Front 32

In this proprioceptive test, knuckle the foot over and observe how long it takes the animal to right itself.

Back 32

Conscious proprioception

Front 33

Intracranial lesions in these regions of the brain will create ipsilateral postural reaction deficits.

Back 33

Midbrain, pons, medulla

Front 34

Intracranial lesions in these regions of the brain will create contralateral postural reaction deficits

Back 34

Midbrain, diencephalon, cerebrum

Front 35

This structure in the brain extends from the caudal diencephalon to the medulla and recieves input from sensory systems, transmitting it on to other regions of the nervous system.

Back 35

Reticular formation

Front 36

Autonomic functions such as inspiration,expiration, normal breathing rhythm, heart rate, and blood pressure are controlled by this structure in the brain.

Back 36

Reticular formation

Front 37

This brain formation controls consciousness.

Back 37

Reticular formation

Front 38

Cranial nerve associated with the Telencephalon/cerebrum

Back 38

CN I

Front 39

Cranial nerve associated with the Diencephalon (thalamus/hypothalamus)

Back 39

CN II

Front 40

Cranial nerves associated with the Mesencephalon (midbrain)

Back 40

CN III and IV

Front 41

Cranial nerves associated with the metencephalon/pons and myelencephalon/medulla.

Back 41

CN V- XII

Front 42

After crossing the brain at the optic chiasm, visual signals synapse at this ganglion before going to the visual cortex.

Back 42

Lateral geniculate ganglion

Front 43

Explain the consensual pupilary light response.

Back 43

Not all visual fibers cross at the optic chiasm. Additionally, some of the efferent constriction signals cross over at the parasympathetic nucleus of III.

Front 44

Is pupillary constriction parasympathetic or sympathetic?

Back 44

Parasympathetic

Front 45

Is pupillary dilation parasympathetic or sympathetic?

Back 45

Sympathetic

Front 46

If an animal shows no pupillary response whatsoever when a light is shone in the left eye but normal bilateral response when light is shone in the right eye, the lesion is likely in the...

Back 46

L optic nerve

Front 47

An animal is non-visual in the left eye but has normal pupillary light reflexes in both eyes. The lesion is likely in the...

Back 47

R visual cortex

Front 48

If a patient has normal direct and consensual PLR on the right eye but no PLR activity in the left eye, there is likely a lesion...

Back 48

Left oculomotor nerve

Front 49

This reflex is tested by moving the head side to side and watching for eye movement or nystagmus.

Back 49

Oculocephalic reflex

Front 50

The oculocephalic reflex evaluates these nerves.

Back 50

CN III, IV, and VI

Front 51

If an animal has ptosis of the upper eyelid, ventrolateral strabismus, and a dilated pupil, this cranial nerve is affected.

Back 51

CN III

Front 52

If a cat has rotational deviation of the globe, which cranial nerve is affected?

Back 52

CN IV

Front 53

If an animal has ventromedial strabismus this cranial nerve is affected.

Back 53

CN VI

Front 54

This cranial nerve supplies sensation to the face

Back 54

CN V

Front 55

This cranial nerve is motor to muscles of facial expression and supplies sympathetic innervation to the lacrimal glands.

Back 55

CN VII

Front 56

This cranial nerve is motor to the muscles of mastication

Back 56

CN V

Front 57

An animal presents with ptosis of the upper eyelid, inability to close the eye, inability to retract the lip, loss of tear production, and a loss of taste to the rostral 2/3 of the tongue, all on the right side of the head. Which CN is likely affected?

Back 57

Right CN VII

Front 58

Nystagmus and strabismus are two hallmarks of problems with this cranial nerve.

Back 58

CN VIII

Front 59

Describe the positional strabismus typically seen with vestibular disease.

Back 59

Ventral deviation of the globe on affected side when the head is extended

Front 60

A dog presents with a head tilt, a consistent nystagmus, and Horner's syndrome on the R side. Postural reactions are normal. There is facial drooping on the right side. Classify the vestibular disease.

Back 60

Peripheral

Front 61

A dog presents with a right head tilt and a dynamic nystagmus that changes direction with position. Postural reactions are decreased on the R side, and the right side of the face is drooping and has diminished sensation. Classify the vestibular disease.

Back 61

Central

Front 62

The gag response evaluates these cranial nerves.

Back 62

CN IX, X, and XI

Front 63

Tongue movement evaluates this cranial nerve

Back 63

CN XII

Front 64

How does tongue deviation change with chronicity of a CN XII injury?

Back 64

Acutely deviates to normal side
Chronically atrophy occurs on affected side

Front 65

Do cranial nerve deficits occur on the same side or opposite side from a CN injury? Why?

Back 65

Same side, because cranial nerves are lower motor neurons

Front 66

Gait deficits on R
Deficits in R CN V-XII
Head tilt to R
Altered consciousness
Abnormal respiratory rate and heart rate

Localize the brain injury

Back 66

R pons/medulla

Front 67

Goal directed tremor and ataxia are associated with injury to this brain region.

Back 67

Cerebellum

Front 68

Decerebrate rigidity (opisthotonus and rigidity of all 4 limbs) and abnormal PLR are associated with injury to this region of the brain.

Back 68

Midbrain

Front 69

Injury to this region of the brain may result in gait deficits either ipsilateral or contralateral to the lesion, depending on the precise location of the lesion.

Back 69

Midbrain

Front 70

Injury to these regions of the brain result in behavioral changes, blindness, autonomic and endocrine dysfunction, and seizures.

Back 70

Telencephalon and Diencephalon

Front 71

With injury to the forebrain, will there be postural reaction deficits ipsilateral or contralateral to the lesion?

Back 71

Contralateral

Front 72

When an animal circles as the result of an intracranial injury, is the circling usually toward or away from the lesion?

Back 72

Toward

Front 73

Head tilt indicates that neurologic injury has occured in this region of the CNS.

Back 73

Intracranially

Front 74

Postural reactions can differentiate between neurologic and...... disease.

Back 74

Musculoskeletal