Cerebellum

Question 0

Rhombic lip structures

Answer 0

Granule, basket, and stellate neurons

*Also gives rise to pontine nuclei and inferior olive

Question 1

Cerebellar developmental origin

Answer 1

Comes from the two sources of the alar plate:

1. Ventricular zone => cerebellar plate
2. Mantle Layer => deep cerebellar nuclei, Purkinje cells, and Golgi cells

Question 2

Flocculonodular Lobe

Answer 2

Oldest area of cerebellum phylogenetically that receives input from vestibular nuclei and projects to same nuclei

Question 3

Location of basket and stellate interneurons

Answer 3

Molecular layer of Cerebellar cortex

Question 4

Output of Purkinje cells

Answer 4

Inhibitory; fibers run to deep nuclei

*Except for Purkinje cells in the Flocculonodular lobe

Question 5

Location of Golgi and Granule interneurons

Answer 5

Granule Cell Layer; granule cells have axons that branch and form parallel fibers

Question 6

Deep nuclei of Cerebellum

Answer 6

1. Fastigial nucleus (efferents to vestibular/reticular nuclei)
2. Globose nucleus (efferents to red nucleus; VA/VL
3. Emboliform nucleus (efferents to red nucleus; VA/VL)
4. Dentate nucleus (efferents to red nucleus; VA/VL)
   * Can see these dorsally in the caudal pons

Question 7

Interpositus Nuclei

Answer 7

Globose + Emboliform nuclei

Question 8

Restiform Body

Answer 8

Inferior Cerebellar Peduncle

Connects to spinal cord and medulla; contains efferents from flocculonodular lobe

Question 9

Brachium pontis

Answer 9

Contains a connection for pontine nuclei to project their axons to the CONTRALATERAL cerebellar cortex

Question 10

Brachium conjuntivum

Answer 10

Major output peduncle; contains axons from…

• Interpositus nuclei
• Dentate nuclei
• Ventral spinocerebellar axons

Question 11

Spinal cord projections to cerebellum

Answer 11

DRG cells representing C8-L2 synapse in Clarke’s column and ascend ipsilaterally as the dorsal spinocerebellar tract

=>enters Restiform body with proprioceptive info

*Ends up on same side as 1st order neuron

Question 12

Lumbosacral projections to cerebellum

Answer 12

Axons cross from this region and form the ventral spinocerebellar tract

=>Enters the Superior Cerebellar peduncle

*Info ends up on same side as 1st order neurons

Question 13

What’s the only afferent pathway in the Superior Cerebellar Peduncle?

Answer 13

Ventral Spinocerebellar Tract

Question 14

Cuneocerebellar Pathway

Answer 14

Contains proprioceptive input from >C8 and synapses in the accessory cuneate nucleus

=>Axons ipsilaterally project thru Restiform body

Question 15

“Climbing Fibers”

Answer 15

Axons from the inferior olive cells rising to travel in the restiform body

Question 16

Mossy Fibers

Answer 16

All sources of input to the cerebellum excluding the climbing fibers

Question 17

Source of inhibitory input to the cerebellum

Answer 17

Reticular formation nuclei

Question 18

Ventral Zone of Cerebellum

Answer 18

(Medial Zone)

Involved in the coordination of ongoing movement; sends efferents to fastigial nucleus

Question 19

Intermediate Zone of Cerebellum

Answer 19

(Paramedian Zone)

Involved in the coordination of ongoing movement; receives afferents from the spino/cuneocerebellar tracts

*Efferents project to interpositus nuclei

Question 20

Spinocerebellum

Answer 20

Median and paramedian areas of cerebellum; main input is unconscious proprioceptive info

*Head, neck, trunk= median

Extremities= Paramedian

Question 21

Lateral Zone

Answer 21

Involved in the planning and timing of movement; receives afferents via the ventral spinocerebellar tract

*Efferents project to dentate nucleus

Question 22

Midline lesions of cerebellum

Answer 22

Truncal ataxia

Wide-stance

Cerebellar dysarthria

Ocular atxia

Question 23

Hemisphere lesions of cerebellum

Answer 23

Ataxia
*Pt. will fall to side of lesion

Dysmetria
*Test w/ finger-nose test

Dysrhythmia

Tremor

*All signs/symptoms are ipsilateral

Question 24

Medulloblastoma

Answer 24

Produces truncal ataxia and possible hydrocephalus

• Vomiting
• Most common brain tumor in children

Question 25

Most common cancers to metastasize to the brain

Answer 25

1. Breast
2. Lung
3. Skin

Question 26

Friedrich’s Ataxia

Answer 26

AR disorder resulting from mutation of Chromosone 9; GAA repeat

=>degeneration of DRGs, Purkinje cells, peduncles, etc.

Signs:
Ataxia
Areflexia
Impaired fine touch
Progressive paralysis w/ Babinski
*Scoliosis 

*Most pts. typically die @ 25-30yrs

Question 27

Frataxin

Answer 27

Protein encoded for mitochondrial fnxn

-Abnormal in Friedrich’s ataxia

Question 28

Wernicke’s Encephalopathy

Answer 28

Thiamine deficiency resulting in acute symptoms

• Triad:
  1. Cognitive dysfunction
  2. Ataxia
  3. Oculomotor abnormalities
• Pt. will also show confabulation due to degeneration of MDS nuclei and hippocampus
• Treated w/ Thiamine

Question 29

Paraneoplasia

Answer 29

Immune cells recruited to fight cancer turn on normal cells in cerebellum

Question 30

Most common cancers to cause paraneoplasia

Answer 30

1. Lung
2. Breast
3. Ovarian

Question 31

Cerebellar Pathway

Answer 31

Cerebellum compares intended movement (via pontine nuclei) w/ actual movement (via proprioceptive info)

=>projects to VA/VL to modulate further movement

Question 32

For the purposes of this test, if you see a child w/ cerebellar symptoms, what should you consider first?

Answer 32

Medulloblastoma