Cerebellar Disease

Question 1

What is the cerebrocerebellum responsible for?

Answer 1

takes information from cerebral cortex and contributes to FINE MOTOR CONTROL

Question 1

what are the 3 areas of the cerebellum?

Answer 1

1. cerebrocerebellum (dorsolateral hemispheres + caudal vermis)
2. spinal cerebellum (ventrolateral hemispheres + rostral vermis)
3. vestibulocerebellum (flocculonodular lobe)

Question 2

what is the spinal cerebellum responsible for?

Answer 2

takes information from the spinal cord and facilitates GENERAL MOVEMENTS

Question 3

T/F: the cerebellum has only 2 deep cerebellar nuclei (dentate and interposed)

Answer 3

false – there are 3 (dentate, interposed, and festigial)

Question 4

what is the overall function of the cerebellum?

Answer 4

the cerebellum is largely INHIBITORY, meaning it receives sensory feedback from the spinal cord and receives motor commands, then FINE TUNES movements.

1/2 of the dog/cat’s neurons live in the cerebellum, so if there is pathology present, the changes are very noticeable!

Question 5

T/F: the cerebellum is split into 2 lateral hemispheres and 1 vermis

Answer 5

true

Question 6

what are the 3 microscopic layers of the cerebellum?

Answer 6

1. molecular layer (outermost)
2. purkinje cell layer (middle)
3. granular layer (inner)

Question 7

what are the clinical signs associated with cerebrocerebellar disease (the rostral cerebellum)?

Answer 7

intention tremors
hypermetria

Question 8

what are the clinical signs associated with spinocerebellar disease (caudal cerebellum)?

Answer 8

increased muscle tone
titubation

Question 9

what are the clinical signs associated with disease of the flocculonodular lobe of the cerebellum?

Answer 9

vestibular signs
incoordination

Question 10

T/F: patients with decerebellate posture are usually comatose whereas patients with decerebrate posture can be normal-to-obtunded

Answer 10

false – opposite.
Decerebellate posture is characterized by a patient having extensor rigidity of the thoracic limbs, but flexed pelvic limbs. They also have opisthotonus and can have normal-to-obtunded mentation.

Question 11

If a patient with cerebellar disease has FULL body tremors, what does this tell you about the localization?

Answer 11

it is diffuse (the entire cerebellum)

Question 12

What portion of the cerebellum is affected in paradoxical vestibular disease?

Answer 12

flocculonodular lobe

Question 13

what is unique about paradoxical vestibular disease as opposed to peripheral and central vestibular disease?

Answer 13

paradoxical vestibular disease is characterized by a patient having a head tilt on the OPPOSITE side of the lesion.

For example, a patient may have a LEFT head tilt and be drifting to the LEFT, but may have RIGHT-sided hypermetria and proprioceptive deficits.
From this, we know that the lesion is in the RIGHT cerebellum because the lesion is always opposite of the head tilt and the proprioceptive deficits are alwas ipsilateral.
This occurs due to LACK of inhibition from the right cerebellum d/t disease. This lack of inhibition leads to increased tone on the side of the lesion (RIGHT) and increased inhibition on the contralateral side (LEFT) causing the contralateral head tilt.

Question 14

T/F: cerebellar cortical abiotrophy is a non-progressive disease in which the NORMAL neuronal cells degenerate shortly after birth.

Answer 14

false – all is true except that this disease is SLOWLY progressive.
they start having cerebellar signs and they worsen over time until the animal is unable to walk.

Question 15

T/F: there is no treatment for cerebellar cortical abiotrophy

Answer 15

true

Question 16

how do you diagnose cerebellar cortical abiotrophy?

Answer 16

MRI – contrast enhancement around cerebellum where CSF is filling the area
necropsy – decreased size of hemispheres and vermis
histopathology – decreased thickness of the molecular, granular, and purkinje cell layers.

Question 17

T/F: cerebellar cortical abiotrophy is commonly seen in 1-2 year old american staffordshire terriers.

Answer 17

false – it is later onset in this breed. more so 4-6 years old.

Question 18

Chiari-like malformation occurs when there is an abnormal craniocervical junction. What is the ultimate result of this abnormality?

Answer 18

herniation of the cerebellum through the foramen magnum and kinking of the medulla which causes disruption of CSF flow.

d/t disrupted CSF flow, there is possibility of syrinx (syringohydromyelia) formation

Question 19

A dog presents to your clinic because the owners report that it is barely able to walk only because it keeps scratching itself so much. It has random times where it screams out appearing to be in pain, but nothing happened. On presentation, the dog is clearly ataxic and has some weakness. What is your presumptive diagnosis?

Answer 19

chiari-like malformation syndrome (COMS)

Question 20

how do you treat COMS?

Answer 20

gaba for pain
pred to decrease CSF production
foramen magnum decompression sx

Question 21

A kitten presents to your clinic with what appears to be cerebellar ataxia. The owner asks you what caused this, what do you tell them?

Answer 21

perinatal panleukopenia infection
it affects the granular cells, prevents their migration, and leads to degeneration of the granular cell layer.

Question 22

how do you treat cerebellar hypoplasia?

Answer 22

no treatment but these kittens can compensate pretty well so there is no need to euthanize.

Question 23

what is the prognosis of puppies infected with canine herpes virus?

Answer 23

poor – high fatality rate.

Question 24

what is the difference in pathophysiology between dogs infected with canine distemper virus at a young age versus at an old age?

Answer 24

if young, they get polioencephalomyelopathy (gray matter disease) which leads to seizures and death.

if old, they get white matter disease and suffer from continuous myoclonus. this may require eventual limb amputation in order to stop it.

Question 25

what other feline virus causes cerebellar disease but has an effective treatment that we are not allowed to offer in the US?

Answer 25

feline infectious peritonitis (usually dry form)

FIP results in inflammation of the ependyma, choroid plexus, and meninges.

Question 26

how do we diagose FIP affecting the CNS?

Answer 26

high CSF titers
MRI – severe dilation of 4th ventricle and contrast enhancement around ventricles

Question 27

what are the 4 “other” infectious causes of cerebellar disease?
(besides FIP, feline panleukopenia virus, CDV, CHV)

Answer 27

fungal dz: crypto, blasto, coccidioides
rickettsial: RMSF, erhlichiosis
protozoal: toxoplasma, neospora
algal: protheca

Question 28

A white scottish terrier presents to your clinic with acute onset of tremors. You perform an MRI and see contrast enhancement around the cerebellum (resembling meningitis type of inflammation).
How do you treat this dog?

Answer 28

immunosuppressive steroids

the diagnosis is corticosteroid-responsive tremor syndrome (aka white shaker syndrome)

Question 29

A 2 yo yorkie presents to your clinic with multifocal CNS and cerebellar signs. You diagnose this based on EXLCUSION. what is most likely the diagnosis.

Answer 29

granulomatous meningoencephalitis.

Question 30

what is the most common primary brain tumor to cause cerebellar signs?

Answer 30

meningioma (an extraaxial tumor)

Question 31

what is the most common intraaxial tumor to cause cerebellar signs?

Answer 31

glioma

Question 32

T/F: the cerebellum is the most common location for infarction in the dog/cat.

Answer 32

true

Question 33

When you have a case of cerebellar infarction (that you diagnosed based on clearly demarcated hyperintensity on MRI), you are attempting to give the owner a prognosis. What is the most important component of prognosis for these cases?

Answer 33

the underlying cause.
the prognosis can be good.

underlying causes include: hyperadrenocorticism, hypothyroidism, bacterial endocarditis, heartworm disease, hyperlipidemia, hypertension, neoplasia (anything pro-thrombotic)