Localising lesions

Question 1

If an animal has:
Ataxia/abnormal gait affecting all limbs,
FL reflexes are normal/increased 
HL reflexes are normal/increased
Which spinal segments could be affected?

Answer 1

C1-C5

Question 2

If an animal has:
Ataxia/abnormal gait affecting all limbs, 
FL reflexes are reduced
HL reflexes are normal/increased
Which spinal segments could be affected?

Answer 2

C6-T2

Question 3

If an animal has:
Ataxia/abnormal gait affecting the HLs only
FL reflexes are normal 
HL reflexes are normal/increased
Which spinal segments could be affected?

Answer 3

T3-L3

Question 4

If an animal has:
Ataxia/abnormal gait affecting the HLs only
FL reflexes are normal
HL reflexes are reduced
Which spinal segments could be affected?

Answer 4

L4-S3

Question 5

If an animal presents in stupor or in a coma, where is the lesion?

Answer 5

Brainstem

Question 6

Forebrain lesions cause blindness - is this ipsilateral or contralateral? Which reflex is affected?

Answer 6

Contralateral blindness
Absent menace (but PLR reserved)

Question 7

Do forebrain lesions affect gait?

Answer 7

No

Question 8

Forebrain lesions may present with circling, head turning, head pressing or pacing. Is the circling towards or away from the lesion?

Answer 8

Towards lesion

Question 9

How do forebrain lesions affect postural responses?

Answer 9

Decreased in CONTRALATERAL limbs

Question 10

An animal presents with behavioural changes. Where is the leson?

Answer 10

Forebrain

Question 11

Cranial nerve deficits suggest the lesion is in the…

Answer 11

Brainstem

Question 12

An animal has decerebrate rigidity. Where is the lesion?

Answer 12

Brainstem

Question 13

How does the brainstem affect postural responses?

Answer 13

Decreased in ipsilateral or all limbs

Question 14

An animal presents with neurological respiratory or cardiac abnormalities. Where is the lesion?

Answer 14

Brainstem

Question 15

An animal presents with normal vision but an abnormal menace on the left eye. Where is the lesion?

Answer 15

Left cerebellum

Question 16

An animal presents blind in the right eye. Where is the lesion?

Answer 16

Left forebrain

Question 17

An animal presents with ataxia, a broad based stance and decerebellate rigidity. Where is the lesion?

Answer 17

Cerebellum

Question 18

How does the cerebellum affect postural responses?

Answer 18

Delayed, but hypermetric

Question 19

An animal presents with abnormal behaviour, circling to the right and blindness in the left eye. Where is the lesion?

Answer 19

Right forebrain

Question 20

Peripheral and central vestibular diseases present similarly. If there is paresis, is the lesion peripheral or central?

Answer 20

Central - +/- paresis

Peripheral - no paresis

Question 21

Peripheral and central vestibular diseases present similarly. If there are proprioceptive defects, is the lesion peripheral or central?

Answer 21

Central - +/- proprioceptive deficits

Peripheral - no deficits

Question 22

What cranial nerves may be affected by central vestibular disease? What about peripheral?

Answer 22

Central - can affect V-XII

Peripheral - VIII (vestibulocochlear) only

Question 23

Peripheral and central vestibular diseases present similarly. If there is Horner’s syndrome present, is the lesion likely to be peripheral or central?

Answer 23

Peripheral

Question 24

Peripheral and central vestibular diseases present similarly. If there is vertical nystagmus, where is the lesion?

Answer 24

Central vestibular system
(Central - verticular, horizontal or rotary
Peripheral - horizontal or rotary)

Question 25

An animal presents alert and with horizontal nystagmus. After a neurological exam showing no proprioceptive deficits, you notice the fast phase of nystagmus is to the left. Where is the lesion likely to be?

Answer 25

Right peripheral vestibular system

Question 26

In peripheral vestibular disease, is the fast phase of nystagmus towards or away from the lesion?

Answer 26

Away from lesion

Towards in central

Question 27

Peripheral and central vestibular diseases present similarly. If there is altered mentation, where is the lesion?

Answer 27

Central nervous system

Question 28

Head tilts may also be seen with cerebellar disease, always in the presence of other cerebellar signs e.g. hypermetria. Is the head tilt ipsilateral or contralateral?

Answer 28

Contralateral

Paradoxical head tilt - cerebellar

Question 29

A dog cannot shut its mouth but is otherwise normal. Which cranial nerve is affected?

Answer 29

Trigeminal

Question 30

A dog has an absent menace response and an absent PLR. Which cranial nerve is affected?

Answer 30

Optic