Cerebellum

Question 1

What separates the anterior and posterior lobes of the cerebellum?

Answer 1

The primary fissure

Question 2

Where are the cerebellar tonsils located?

Answer 2

Lie next to the lower medulla above the foramen magnum

Question 3

Describe the histology of the three layers of the cerebellum

Answer 3

Outer layer: pale with mostly axons and few cells
Middle layer: single row of Purkinge cells
Inner layer: thick granule layer

Question 4

What connections are there from the superior cerebellar peduncle?

Answer 4

Only outputs from the cerebellum to the brain and rest of the body

Question 5

What connections are there from the middle cerebellar peduncle?

Answer 5

Inputs from the contralateral cortex and cranial nerves via the pons

Question 6

What connections are there from the inferior cerebellar peduncle?

Answer 6

Input from the spinal cord via spinocerebellar tracts

Question 7

How do the spinocerebellar tracts enter the cerebellum?

Answer 7

Via the inferior cerebellar peduncle

Question 8

Describe the path of the dorsal (posterior) spinocerebellar tract

Answer 8

Travels from the ipsilateral side up the brainstem and into the inferior cerebellar peduncle on the same side (entirely IPSILATERAL)

Question 9

Describe the path of the ventral (anterior) spinocerebellar tract

Answer 9

Carries information from the contralateral side of the body

Question 10

Describe the path of the anterior/ventral spinothalamic tract

Answer 10

Decussates at the level of spinal cord entry but then recrosses in the brainstem and therefore enters the brainstem ipsilaterally to origin

Question 11

What is the purpose of the dorsal spinocerebellar tract?

Answer 11

Carries information from proprioceptors (joints, muscle spindles etc)

Question 12

What is the purpose of the ventral spinocerebellar tract?

Answer 12

Carries information about the state of reflexes and neurones in the spinal cord

Question 13

What are the names of the deep cerebellar nuclei?

Answer 13

Fastigial nucleus, globose nucleus, emboli form nucleus and dentate nucleus

Question 14

What is the general function of the cerebellum?

Answer 14

Involved in aiding the motor cortex in producing accurate and smooth movement

Question 15

What are the consequences of cerebellar damage?

Answer 15

Clumsiness, abnormal fatigue and instability of movement; extraocular eye muscles are particularly affected.

Question 16

What are the three main functional zones of the cerebellum?

Answer 16

Vestibulocerebellum, spinocerebellum and cerebrocerebellum

Question 17

What makes up the vestibulocerebellum?

Answer 17

The flocculonodular lobe

Question 18

What it is the function of the vestibulocerebellum?

Answer 18

To coordinate head and eye movements and control the balance of the head via the vestibulospinal tracts

Question 19

What makes up the spinocerebellum?

Answer 19

Anterior lobe and the vermis (with fastigial and interposed deep nuclei)

Question 20

What is the function of the spinocerebellum?

Answer 20

Controls locomotion and limb coordination via lateral vertibulospinal and reticulospinal tracts

Question 21

What makes up the cerebrocerebellum?

Answer 21

Posterior lobe of cerebellum and dentate nuclei; input from cerebral cortex via middle cerebral peduncle and output to the central thalamus via the superior cerebral peduncle

Question 22

What is the function of the cerebrocerebellum?

Answer 22

Involved in coordinating movement e.g.speech, voluntary movement of hands and arms and hand-eye coordination

Question 23

What are three three main cerebellar syndromes?

Answer 23

Floculonodular syndrome, anterior lobe syndrome and neocerebellar syndrome

Question 24

What is a common cause of flocculonodular syndrome?

Answer 24

Medulloblastoma - usually originating the floor of the 4th ventricle . Most common in young children

Question 25

Where do medulloblastomas usually originate?

Answer 25

In the floor of the 4th ventricle

Question 26

What are the clinical symptoms of flocculonodular syndrome?

Answer 26

Poor balance and disordered eye movements, ataxic gate

Question 27

What are the clinical symptoms of anterior lobe syndrome?

Answer 27

Incoordination of the limbs (dysdiadochokinesia)

Question 28

What is a common cause of anterior lobe syndrome?

Answer 28

Alcoholism due to malnutrition and lack of B vitamins

Question 29

What are the clinical symptoms of neocerebellar syndrome?

Answer 29

Loss of hand-eye coordination, dysmetria (inaccurate reaching), intention tremor, slurred speech

Question 30

What are the common causes of neocrebellar syndrome

Answer 30

Stroke, tumour and degenerative disease

Question 31

What are the symptoms of cerebellar stroke?

Answer 31

Headache, eye changes (nystagmus, constriction or ptosis), dysarthria (weakened muscles of the mouth –> slurred speech), ataxia and arm weakness and incoordination