4. Cerebellum Flashcards

1
Q

Where is the cerebellum found?

A

In the posterior cranial fossa

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2
Q

What are ‘folia’?

A

A folia is the equivalent to a gyrus but is found in the cerebellum

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3
Q

Does the cerebellum cross the midline of the brain?

A

Yes

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4
Q

What is the path of the folia, when looking at the cerebellum from above?

A

The folia run medio-laterally - from inside to the out vice/versa

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5
Q

What is the vermis?

A

This is the midline connection of the two cerebellar hemispheres - where the folia meet centrally
This is a worm-like structure

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6
Q

What are the divisions of the vermis?

A

There is an anterior lobe and a posterior lobe

This division occurs via the primary fissure

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7
Q

What are the different divisions of the cerebellum?

A

The cerebellum is divided into three lobes - the first two are the same as that of the vermis
Anterior
Posterior

The third is the flocculonodular lobes - this is a tiny lobe but is very important

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8
Q

Where are the different lobes of the cerebellum visible?

A

Anterior and posterior lobes are visible from the and anterior and the posterior view of the cerebellum

The flocculonudular lobe is only visible from the anterior view

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9
Q

What is the function of the anterior and posterior cerebellar lobes?

A

These function to coordinate body movements
Medial portions - motor activities of the trunk
Lateral portions - motor activities of limbs and skilled movements

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10
Q

What is the function of the flocculonodular lobe?

A

Receives input from the inner ear for the maintenance of balance and posture

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11
Q

What is the relation of the flocculonodular lobe to the ventricular system?

A

This lobe is present on the ventral surface of the cerebellum
This lobe forms part of the roof of the fourth ventricle

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12
Q

Where are the cerebellar tonsils located?

A

These are just lateral to the vermis, at the inferior surface of the cerebellum

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13
Q

What is the significance of the cerebellar tonsils?

A

No functional significance but have a pathological significance - herniate out and compress blood vessels around spinal cord and the reticulospinal tract in cases of raised ICP
Tonsillar herniation –> damage to spinal cord

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14
Q

What is the blood supply to the cerebellum?

A

Posterior inferior cerebellar artery and the superior cerebellar artery

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15
Q

What infarct location is the most common form of damage to the cerebellum?

A

The hairpin bend in the PICA - very common site for a clinical infarct

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16
Q

Where does information enter and leave the cerebellum from?

A

Via the cerebellar peduncles

17
Q

What are the different cerebellar peduncles and what passes through them?

A
Superior CP - output
Middle CP (largest) - input from contralateral cerebral cortex and cranial nerves via pons
Inferior CP - input from spinal cord via dorsal and ventral spinocerebellar tracts
18
Q

Is the spinocerebellar tract contra or ipsilateral?

A

Dorsal spinocerebellar tract is ipsilateral

Ventral spinocerebellar tract is contralateral

19
Q

What information does the spinocerebellar tract convey?

A

Dorsal - information from proprioceptors

Ventral - information about state of reflexes and interneurones in the spinal cord

20
Q

What is the role of cerebellar nuclei and what are they called?

A

Deep cerebellar nuclei control what is entering and leaving the cerebellum, rather than the cerebellar cortex
Fastigial - controls the anterior lobe and the vermis
Globose - controls the anterior lobe
Emboliform
Dentate - controls the posterior lobe (the cerebral hemispheres)- this is the largest

21
Q

What is the floculonodular lobe controlled by?

A

This is not controlled by one of the deep cerebellar nuclei and instead is controlled by the vestibular nuclei of the pons

22
Q

How does damage to the cerebellum present?

A

Overall clumsiness in the individual
Abnormal fatigue
Instability of movement
Damage to eye movements

23
Q

What is the tract between the cerebral cortex and the cerebellum?

A

The corticocerebellar tract

24
Q

What are the three functional zones of the cerebellum?

A

Vestibulocerebellum - flocculonodular lobe
Spinocerebellum - anterior lobe and the vermis
Cerebrocerebellum - posterior lobe (cerebellar hemispheres)

25
Q

What is the function of the vestibulocerebellum?

A

Coordinates head and eye movements to ensure stability of gaze
Balance of head via medial vestibulospinal tract nad balance of body via lateral

26
Q

What is the function of the spinocerebellum?

A

Controls locomotion and limb coordination

Vestibulospinal and reticulospinal tracts

27
Q

What is the function of the cerebrocerebellum?

A

Coordinates movements initiated by the motor cortex

Speech, voluntary movements of hands and arms, hand-eye coordination

28
Q

How does flocculonodular syndrome present?

What is a common cause?

A

Poor balance, disordered eye movements, ataxic gait, nystagmus

Medulloblastoma in the fourth ventricle

29
Q

How does anterior lobe syndrome present?

What is a common cause?

A
Incoordination of the limbs 
Ataxic gait 
Hypotonia 
Depressed reflexes 
Dysdiadochokinesis

Often seen in alcoholics due to malnutrition and lack of B vitmains

30
Q

How does neocerebellar syndrome present?

What are common causes?

A

Loss of hand-eye coordiantion
Intention tremor
Dysdiadochokinesis
Slurred speech

Stroke, tumour, degenerative diseases, trauma

31
Q

What is a cerebellar stroke?

A

This is when the whole cerebellar cortex on one side lacks perfusion

32
Q

What are the global signs of cerebellar stroke?

A
Headache, vertigo, nausea, vomiting
Eye changes 
Dysarthia and dysphagia
Ataxia
Arm weakness and incoordination
33
Q

What is a common differential diagnosis for cerebellar stroke and why?

A

Alcohol intoxication mimics many features of cerebellar damage

This is because alcohol seems so selectively effect GABA-ergic neurones and these are heavily involved in the cerebellum

34
Q

What is the arbor vitae?

A

(Tree of life)

This is a leaf-like structure - distinctive pattern of white matter in the cerebellum

35
Q

What is the general function of the cerebellum?

A

Modulates and refines motor movements using feedback from proprioceptors and other sensory organs