Kapitel 26 (Tobias) - Neurologic examination

Question 1

Which 6 parts can the neurologic examination be divided into?

Answer 1

1) Sensorium and behavior
2) Posture and gait
3) Postural reactions
4) Spinal reflexes, muscle mass and muscle tone
5) Cranial nerves
6) Cutaneous sensation

Question 2

Define “sensorium”

Answer 2

The cognitive or mental state of a patient

Question 3

Normal sensation depends on the function of the cerebrum and the reticular activating system - what is the reticulate activating system?

Answer 3

A collection of nuclei located throughout the brainstem - from the thalamus to the medulla

Question 4

Define “Obtundation”

Answer 4

A state of decreased arousal with response to voice or touch

Question 5

Define “Stupor”

Answer 5

Arousal to vigorous stimuli, but response is incomplete or inadequate

Question 6

Define “coma”

Answer 6

Sustained unresponsiveness to stimuli

Question 7

Name examples of changes in quality of sensorium vs level of sensorium

Answer 7

Quality:
Aggression, hyperactivity, hysteria, propulsive movement, loss of housebreaking

Level:
Depression, Obtundation, Stupor, Coma

Question 8

Recumbency is associated with 3 neurological localizations. Which?

Answer 8

1) Brainstem
2) Cervical spinal cord
3) Diffuse neuromuscular disease (Lower motor neuron)

Question 9

Which neurologic localization does headtilt suggest?

Answer 9

Vestibular disease

Question 10

A head or bodyturn suggests which neurologic localization?

Answer 10

Prosencephalon or forebrain

Question 11

Name 2 neurologic localizations resulting in a lowered head position

Answer 11

1) Neck

2) Diffuse neuromuscular disease

Question 12

Describe “Decerebrate rigitidy”

Which neurologic localization does this imply?

Answer 12

• Opisthotonus
• Extensor tonus of all limbs
• Midbrain or rostral cerebellar

Question 13

Describe the impact on mentation in patients with decerebrate vs. decerebellate rigidity

Answer 13

Decerebrate: Always severe impact on mentation and menace response

Decerebellate: Does not always affect mentation

Question 14

Describe “Decerebellate rigidity”

Neurologic localization?

Answer 14

1) Opisthotonus
2) Extensortonus of limbs
3) Flexion of hip joint

Question 15

Describe “Pleurothonus”

neurologic localization?

Answer 15

• Deviation of the head and neck to one side

- Mid to rostral brainstem or cerebral lesions.

Question 16

Define “Paresis”

Answer 16

• Reduced ability to support weight or a deficiency in the ability to generate a gait
• Also implies the presence of voluntary motor function

Question 17

Define the suffix “-plegia”

Answer 17

The absence of voluntary motor function.

Question 18

What caracterizes a “lower motor neuron peresis or plegia”

Answer 18

• Decrease in muscular tone (flaccidity)
• Reduced or absent reflexes
• Pronounced muscular atrophy may be seen

Question 19

What caracterizes an “upper motor neuron peresis or plegia”

Answer 19

• Increased muscular tone (spasticity)
• Normal to exaggerated reflexes
• Relative preservation of muscle mass

Question 20

Name the 3 clinical forms of ataxia

Answer 20

1) General proprioceptive ataxia
2) Vestibular ataxia
3) Cerebellar ataxia

Question 21

Describe General Proprioceptive Ataxia

Answer 21

1) Crossing of the limbs
2) Scuffing or dragging of the digits
3) High stepping
4) Overreaching stride
5) Standing or landing on the dorsal aspect of the paws 6) and sometimes a delay in initiation of the swing phase of the gait

Appears “drunk”

Question 22

Describe Vestibular Ataxia

Answer 22

1) Headtilt
2) Circling
3) Loss of balance
4) Nystagmus

5) Loss of CN V and CN VII - central (Ipsilateral to lesion)
6) Loss of CN V and sympathetic innervation (Horners´s syndrome) - peripheral (Ipsilateral to lesion)

• CN V = Trigeminus = Motor -> chewing muscles
• CN VII = Facialis = Motor -> Face

Question 23

How can you differentiate central and peripheral vestibular disease?

Answer 23

Central:

1) +/- loss of proprioception
2) +/- Ipsilateral upper motor neuron paresis
3) +/- Deficits in CN V and CN VII function

Peripheral:
1) Deficits in CN VII and loss of sympathetic innervation to the head (as evidenced by Horner syndrome)

• CN V = Trigeminus = Motor -> chewing muscles
• CN VII = Facialis = Motor -> Face

Question 24

Describe Cerebellar Ataxia

Answer 24

• Hypermetric gait
• “High stepping, overreaching”
• Intention tremor
• Wide base stance
• May sway or stumble forward and back, as well as from side to side

*Because of the close connection between the cerebellum and the vestibular system, head tilt, loss of balance, and abnormal nystagmus may be present

Question 25

What is necessary for a normal postural reaction?

Answer 25

1) Intact major sensory (generel proprioceptive) pathways of CNS and PNS
2) Intact motor pathways (UMN and LMN) of CNS and PNS

Question 26

Pelvic limbs: Paraparesis with general proprioceptive ataxia. Normal to exaggerated muscle tone and spinal reflexes.

Neurologic localization?

Answer 26

Spinal segment T3-L3

Question 27

In a dog or cat with deficits in proprioception - how do you differentiate a prosencephalic lesion from a lesion caudal to the midbrain?

Answer 27

• Cranial nerve deficits

- Changes in sensorium

Question 28

The patellar tendon reflex is mediated by which nerve and spinal cord segment?

Answer 28

Femoral nerve - segment L4-L6

Question 29

A deficit in the withdrawal reflex of the thoracic limb indicates a leison in which spinal segment?

Answer 29

C6-T2

Question 30

A deficit in the withdrawal reflex of the pelvic limb indicates a leison in which spinal segment?

Answer 30

L6-S1

Question 31

What can you say about the location of the lesion if a dog or cat has deficits in the cutaneus trunci reflex at a certain point?

Answer 31

The lesion is located 1 or 2 vertebral bodies cranial to the deficit

Question 32

Describe “the clasped knife reflex”, when we see this and the function of this reflex

Answer 32

in patients with upper motor neuron deficits and
cponsequent extensor tone.

Analogous to closing a pocket knife, the limb shows increased extensor tone preventing forced flexion until
a certain point where it suddenly gives away and flexes.

This reflex is aimed at protecting from overstretch of the muscle. It is mediated through Golgi tendon organs embedded in tendons; when stimulated, there is a reflex inhibition of the muscle.

Question 33

How can an upper motor neuron deficit result in hypertonia?

Answer 33

Much of the descending upper motor neuron influence provides for inhibition of extensor musculature. With lesions disrupting the upper motor neuron pathways, the lower motor neurons may be released from inhibition, leading to overactivity of the extensors, resulting in hypertonia of the limb.

Question 34

What is “Neurogenic atrophy”?

Answer 34

Muscle atrophy secondary to disturbance of the lower motor neuron innervations of the muscle