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Flashcards in Cerebellum Deck (31):
1

Cerebellum location

posterior cranial fossa
separated from cerebrum by tentorium cerebelli
lies over fourth ventricle
connected to brainstem by 3 cerebellar peduncles

2

Cerebellum surfaces

Superior: touching tentorium
Inferior: touching inferior cranial fossa
Anterior: touching brainstem

3

Vermis

midline structure of cerebellum

4

Folia

extensive folds of cerebellum

5

Anterior lobe of cerebellum

superior surface
separated from posterior lobe by primary fissure

6

Flocculonodular lobe

visible on anterior surface
nodule: the most anterior part of vermis, connected to flocculus
Most medial area of inferior surface of cerebellum - sits just above foramen magnum, the cerebellar tonsils

7

Superior cerebellar peduncle afferents

anterior spinocerebellar tract
acoustic and optic information

8

Superior cerebellar peduncle efferents

detatorubrothalamic tract
dentatothalamic tract

9

Middle cerebellar peduncle afferents

Pontocerebellar tract

10

Inferior cerebellar peduncle afferents

vestibulocerebellar tract
olivocerebellar tract
posterior spinocerebellar tract

11

Inferior cerebellar peduncle efferents

cerebellovestibular tract
cerebelloolivary tract

12

Cerebellum function

receives andi nterprets proprioceptive info
coordinates balance (linked to vestibular nuclei)
coordinates fine movement, eye-hand coordination
predicts sensory consequences of movement
coordinator/predictor of cortical output (movement and cognition)
information sent to cerebellum can be used for skilled manipulation of muscles and mental concepts
Same consistent wiring, with differnet types of cnonections
outflow through segregated fibers

13

Homunculus on cerebellum

Trunk always in midline on vermis
extremities on cerebellar hemispheres
Anterior lobe: extremities
Posterior lobe: mirror image representations of both head and extremities

14

Archicerebellum

vestibulocerebellum
flocculonodular lobe (and vermis)
trunk control

15

Paleocerebellum

spinocerebellum
vermis and anterior lobe
synergistic movement of extremities

16

Neocerebellum

Cerebrocerebellum
posterior lobe
topographical representation of extremities
areas for eye movement
speech coordination of intricate and complex movements

17

Vestibulocerebellar connections

Afferents from vestibular nuclei --> paravermis, flocculonodular lobes
Efferent to fastigial nucleus
Bilateral projections to vestibular nuclei and reticular formation
Information projects through vestibulospinal/reticulospinal tracts to spinal cord motor neurons

18

Vestibulocerebellar fxn

adjust axial stability and balance
provide information of position of head and body in space
help orient eye movements during locomotion (vestibulo-ocular reflex)

19

Spinocerebellar connections

Muscle spindles/Golgi tendon organs (where/how the limbs are positioned)--> dorsal spinocerebellar tract through ICP
Spinal border cells in anterior horn of spinal cord (copy of movement command that went to LMNs) --> ventral spinocerebellar through SCP
Terminate in anterior lobe (limbs) and vermis (trunk)

20

Spinocerebellar fxn

proprioceptive information enters cerebellum
information goes to all players involved in movement
feedback to spinal cord and to cortex
correction and fine-tuning of ongoing movement patterns

21

Cerebrocerebellar connections

Cortex --> pontine nuclei --> cerebellar hemispheres (pontocerebellar tract through MCP), cross over to contralateral side
Additional afferent information from the contralateral olivary nuclear complex
Feedback to red nucleus, thalamus, cortex
Red nucleus: major relay nucleus
Olives: project to all of cerebellum, receive input from all loops, calculate feed forward loops

22

Reciprocal connections in cerebrocerebellar connections

Output from neocerebellar cortex mainly to dentate nucleus --> red nucleus --> VL of thalamus (dentatorubrothalamic tract)
Direct projections from dentate nucleus --> thalamus (dentatothalamic tract)
Thalamus --> projects back to motor/sensory areas of cortex

23

Midline cerebellar disease

gait difficulty
truncal imbalance
wide-based irregular steps
veers to one side
abnormal head postures
head tilt
oculomotor dysfunction
nystagmus

24

Flocculonodular lobe syndrome

most commonly seen in children with a medulloblastoma
Truncal ataxia --> inability to stabilize/balance axial musculature - wide-based stance as well as swaying
Nystagmus - damage to vestibuloocular pathways

25

Lateral cerebellar disease

Hypotonia - decreased resistance to passive movement
Dysarthria
Limb ataxia - dysmetria, decomposition, dysdiadochokinesia
Intention tremor - irregular, rhythmic tremor that increases as patient approaches a target
Impaired check
Oculomotor disorders

26

Posterior lobe syndrome

areas for eye movement and speech --> cerebellar mutism
Coordination of intricate/fine movements
most commonly seen in:
- demyelinating diseases (MS)
- midbrain infarctions affecting dentatorubrothalamic tract (cerebellar efferent)
- infarcts to cerebellar hemispheres

Deficits in hand-eye coordination, dysmetria, dysdiadochokinesia
typical language disorders characterized by linguistic incoordination --> inability to use grammar/syntax

27

Lesions to anterior lobe

spinocerebellar input
gait ataxia

28

Ethanol - cerebellum

toxic to Purkinje cells in cerebellar cortex
anterior lobe most affected
usually reversible
permanent damage possible in chronic alcoholics

leads to gait ataxia

29

Anterior inferior cerebellar artery supply

all cerebellar peduncles
flocculus
all deep cerebellar nuclei

30

Posterior inferior cerebellar artery supply

inferior 2/3 of posterior lobe
tonsils
nodulus

31

superior cerebellar artery supply

anterior lobe
superior 1/3 of posterior lobe
vermis