Cerebellum

Question 1

Superior cerebellar peduncles

Answer 1

Connects to rostrum pons

Contains mostly efferent fibers

Question 2

Middle cerebellar peduncles

Answer 2

Connects to pons

Contains mostly afferent fibers from cerebral cortex

Question 3

Inferior cerebellar peduncles

Answer 3

Connects to caudal pons/rostrum medulla

Coattails mostly afferent fibers for BS and SC

Contains efferent to vestibular nuclei and RF in brainstem

Question 4

Cerebellum function

Answer 4

Detects movement that deviates from the intended cortical command

Contributes to motor planning

Smoothly coordinates ongoing movements and posture by comparing the intended movement w/ actual movement

Question 5

Cerebellum receives sensor input from

Answer 5

SC cerebellar tracts

• muscle spindles
• GTOs
• joint and cutaneous receptors
• vestibular apparatus

Integrates this sensory info and adjusts movement as necessary

Question 6

Cerebellum - three main functions

Answer 6

Synergy of movement
Maintenance of upright posture
Maintenance of tone (during muscle contraction)

Question 7

Other cerebellum functions

Answer 7

Speech articulation
Respiratory movement
Motor learning
Possibly higher order cognitive processes

Question 8

Lateral cerebellar hemispheres

Answer 8

Motor planning for extreme ties

Lateral corticospinal tract

Question 9

Intermediate cerebellar hemisphere (B/n lat and vermis)

Answer 9

Distal limb coordination

Lateral corticospinal tract, rubrospinal tract

Question 10

Vermis and flocculonodular lobe

Answer 10

Proximal limb and trunk coordination — anterior corticospinal tract, reticulospinal tract, vestibulospinal tract, tectospinal tract

Balance and vestibulo-ocular reflexes — medial longitudinal fascicles

Question 11

Cerebellar lesions result in

Answer 11

Ataxia — uncoordinated movements

Question 12

Input to cerebellar cortex

Answer 12

Mossy fibers (excitatory)
Climbing fibers (excitatory)

Synapse directly or indirectly onto purkinje cells
-input to cerebellar cortex also have collateral fibers that synapse on deep cerebellar nuclie

Question 13

Output from cerebellar cortex

Answer 13

Purkinje fibers (inhibitory)

Project to the deep cerebellar nuclei and/or vestibular nuclei (excitatory)

Question 14

On/off center for cerebellar output

Answer 14

Deep cerebellar nuclei

Question 15

Deep cerebellar nuclei - lateral to medial

Answer 15

Don’t eat greasy foods

Debate
Emboliform
Global economic
Fastigial

Question 16

Denate cerebellar nucleus

Answer 16

Deep

Input from lateral hemisphere

Question 17

Emboliform cerebellar nuclei

Answer 17

Deep

Input from intermediate hemisphere

Question 18

Globase cerebellar nuclei

Answer 18

Deep

Input from intermediate hemisphere

Question 19

Fastigial cerebellar nuclei

Answer 19

Deep

Input from vermis

Question 20

Vestibular nuclei

Answer 20

Function in some ways like deep cerebellar nuclei

Input form inferior vermis and flocculonodular lobe

Question 21

Why do cerebellar lesions cause ipilateral deficits?

Answer 21

Pathways from cerebellum that influence the lateral motor systems and periphery are double crossed

Question 22

Lesions of the vermis don’t cause unilateral deficits because

Answer 22

Medial motor systems influence bilateral proximal trunk musculature

Question 23

Cerebellar input

Answer 23

From virtually all areas of cerebral cortex
Many sensory modalities
BS nuclei
SC

Vestibular nuclie, RF nuclei, inferior Oliver’s nucleus

Question 24

Corticopontine fibers

Answer 24

Fibers traveling from the cerebral cortex to the cerebellum

Synapse in pons, then are called pronto cerebellar fibers

Question 25

Spinocerebellar pathways

Answer 25

Unconscious proprioception of limb movements - dorsal spinocerebellar tract (LE) - cuneocerebllar tract (UE) Unconscious information regarding activity of spinal interneurons as well as spinal reflex circuit - ventral spinocerebellar tract (LE) - rostrum spinocerebellar tract (UE)

Question 26

Each cerebellar hemisphere receives inform from

Answer 26

Ipsilateral limbs Inputs either don’t cross or are double crossed

Question 27

Cerebellar somatotopy

Answer 27

Add picture here later

Question 28

Cerebellar lesions

Answer 28

1. Ataxia 2. Midline lesions 3. Lesion lateral to vermis

Question 29

Cerebellar lesion- ataxia

Answer 29

Ipsilateral to side of lesion Disordered contractions of agonist and antagonist muscles and lack of normal coordination between movements at different joints Movements have irregular, wavering course that consists of continuous overshooting and over correcting

Question 30

Cerebellar lesion- midline lesions

Answer 30

Unsteady gait and eye movement abnormalities

Question 31

Cerebellar lesion- lesions lateral to vermis

Answer 31

Limb ataxia

Question 32

Three classic signs of cerebellar damage

Answer 32

Ataxia Nystagmus (Intention) tremor (with movement)

Question 33

Cerebellar damage also involves

Answer 33

Dysrhythmia (abnormal timing) Dysdiadochokinesia (ab rapid alternating movement) Dysmetria (ab distance trajectory)

Question 34

Other possible S/S of cerebellar damage

Answer 34

``` Vertigo N/V Unsteadiness Slurred speech HA -side of lesion ```

Question 35

Abnormalities in other systems can confound the cerebellar exam

Answer 35

UMN - slow, clumsy movement of extreme tiers LMN- weakness, test requiring little strength can be helpful Basal ganglia - slow clumsy momvements and or gait unsteadiness Sensory ataxia - severe loss of position sense (dorsal column/sensory nerves)- should improve w/ visual feedback

Question 36

Truncal ataxia

Answer 36

Lesion of vermis Wide based, unsteady, drunk like gait Severe cases: may also have problems sitting up w/out support Bilateral disorder affects medial motor systems - fall or sway toward side of lesion

Question 37

Appendicular ataxia

Answer 37

Lesion of intermediate or lateral cerebellum Uncoordinated movement of extreme ties Intention tremor - irregular oscillating movements in multiple planes through trajectory when attempting to move limb toward a target

Question 38

Lesion of vermis and both cerebellar hemisphere

Answer 38

Exhibit truncal and appendicular ataxia

Question 39

Ipsilateral localization of ataxia

Answer 39

Lesion of cerebellar hemispheres cause ipsilateral ataxia of extremeties

Question 40

False localization of ataxia

Answer 40

Can be caused by lesion outside cerebellar cortex that involve cerebellar input or output pathways

Question 41

Testing for appendicular ataxia

Answer 41

Finger- nose- finger test -watch for dysmetria and dysrhythmia Rapid hand movements, foot patting, precision finger tap, rapid alternating movements, overshoot

Question 42

Testing for truncal ataxia

Answer 42

``` Tandem gait (heal-to-toe-gait) -pt will tend to fall/sway to side of lesion if it extends slightly into cerebellar hemisphere ``` Romberg test -note increased sway or fall

Question 43

Vasculature

Answer 43

Add picture here

Question 44

S/s of cerebellar artery infarcts

Answer 44

``` Limb ataxia Unsteady gait Nystagmus Vertigo N/V HA ```

Question 45

SCA and PICA infarct - cerebellum

Answer 45

Most common

Question 46

SCA infarct cerebellum

Answer 46

Ipsilateral ataxia w/ little/no BS signs Mostly involves cerebellum itself and usually spares the lateral BS

Question 47

PICA infarct cerebellum

Answer 47

Ipsilateral ataxia w/ nystagmus, vertigo, N/V Involves inf cerebellar peduncle and vestibular nuclei Also can see signs of lateral medullary (Wallenberg) sysndrome

Question 48

AICA infarct - cerebellum

Answer 48

Supplies internal auditory artery Unilateral hearing loss

Question 49

What can mimic S/S of cerebellar infarcts?

Answer 49

Infarcts to lateral pons or medulla because of cerebellar peduncles and vestibular nuclei involvement

Question 50

What happens if the cerebellum swells?

Answer 50

Can cause hydrocephalus because of compression of the fourth ventricle, as well as compression of vital brainstem structures, and subsequent herniation