L45 Movement Disorders Cerebellum

Question 1

what are the functions of the cerebellum?

Answer 1

synergy of movement
posture

fine tunes movement!

Question 2

what is synergy of movement?

Answer 2

many elements of muscular contraction are collectively coordinated to create purposeful movement (walking etc.)

Question 3

what is posture

Answer 3

the body is orientated appropriately relative to the vector of gravity - dictated by muscle tone

Question 4

the cerebellum acts as a ____

Answer 4

comparator

• receives copies of motor instructions that were already sent to LMN
• compares sensory feedback to original motor instructions
• errors are reported back to motor centers

Question 5

the cerebellum regulates ___body

Answer 5

ipsilateral

Question 6

acute cerebellar damage often yields ______

Answer 6

pronounced motor deficits (ipsilaterally)

Question 7

substantial functional recovery may occur in _____

Answer 7

chronic, but non-progressive cerebellar damage

Question 8

what separates the anterior lobe from the posterior lobe?

Answer 8

primary fissure

Question 9

what CN are sort of associated with the flocculo-nodular lobe of the cerebellum

Answer 9

CN 7 and 8

Question 10

more medial structures of the cerebellum regulate ___

Answer 10

trunk

Question 11

more lateral structures of the cerebellum regulate ___

Answer 11

limbs

Question 12

describe the flocculonodular lobe/vestibulo-cerebellum

Answer 12

think equilibrium!
afferents from vestibular apparatus (balance, eye movements)
works with CN 8

Question 13

describe the spino-cerebellum/anterior lobe?

Answer 13

sensory feedback (trunk and limb movement)

Question 14

describe the cerebro-cerebellum/posterior lobe?

Answer 14

integrates motor with sensory feedback (precise movements - location and timing, planning)

receives afferent connections from the deep pontine nuclei

Question 15

superior cerebellar peduncle carries what and where is it

Answer 15

efferents

cerebellum to midbrain and pons

Question 16

middle cerebellar peduncle carries what and where is it

Answer 16

afferent

pons to cerebellum

Question 17

inferior cerebellar peduncle carries what and where is it

Answer 17

afferent ( + many efferents)

spinal cord and medulla to cerebellum

Question 18

what is similar between the cortex and cerebellum

Answer 18

from outside:

gray, white, gray, ventricles

Question 19

how many layers does the cerebellum have? what are their names

Answer 19

3
molecular layer
purkinje layer
granule layer

Question 20

what does the vermis and flocculonodular lobe communicate with

Answer 20

fastigial nuclei –> vestibular system

Question 21

what does the paravermis communicate with?

Answer 21

interposed nuclei –> red nucleus

Question 22

what does the lateral hemispheres communicate with?

Answer 22

dentate nuclei –> thalamus

Question 23

what are sx/sx associated with vestibule-cerebellum/flocculonodular lobe lesions?

Answer 23

affect equilibrium related motor functions

• nystagmus (ocular ataxia)
• tilted head
• titubation (head-nodding)
• truncal ataxia (imbalance) with compensatory wide-based stance – impaired tandem walking

Question 24

what are sx/sx associated with spino-cerebellum/anteiror lobe lesions?

Answer 24

affect posture and movement of limbs

• ataxias of the limbs common (ipsilateral)
• gait ataxia accompanies by lurching to the side of the lesion

Question 25

what are sx/sx associated with cerebro-cerebellum/posterior lobe lesions?

Answer 25

affect accuracy and timing of movement - ataxia - decomp of movement - dysarthia (slurred monotonous speech) - dyssynergia (uncoordinated limbs) - dysdiadokinesia - inability to perform rapidly alternating movenets - dysmetria - past pointing - intention tremor - hypotonia - rebound phenomenon

Question 26

in what population do midline astrocytomas most commonly occur in?

Answer 26

children

Question 27

what are the motor signs of tumors?

Answer 27

- nystagmus - truncal ataxia - broad-based stance with impaired tandem walking - hypotonia

Question 28

what are other manefestations of tumors?

Answer 28

- headache - hydrocephalus - intracranial pressure elevated - papilledema - nausea and vomiting

Question 29

what arterial system is implicated in cerebellar stroke?

Answer 29

vertebral | unilateral occlusive disease is common

Question 30

what are the motor signs of cerebellar stroke

Answer 30

- dysarthia - dyssynergia (ipsilateral) - dysmetria - dysdiadokinesia - intension tremor (ipsilateral) - rebound phenomenon (ipsilateral) - limb ataxia (ipsiateral) - truncal ataxia brainstem signs are not uncommon - cerebellar arteries supply the brainstem en route to the cerebellum!

Question 31

what is vitamin B1 (thiamin) deficiency linked to

Answer 31

degeneration of the rostral vermis and adjacent parts of the remaining anterior cerebellar lobe cortical purkinje cells degenerate motor signs involve leg and trunk some resolution may follow abstinence and diet supplementation alcoholics at higher risk

Question 32

describe louis-bar syndrome

Answer 32

autosomal recessive | widespread degeneration fo cerebellar purkinje cells and compromised immune function (chromosome 11)

Question 33

what are sx/sx of louis-bar syndrome?

Answer 33

delayed development of motor skills accompanies increased vulnerability to infection - most obvious related to walking, talking, facial and ocular movements - long term: heightened sensitivity to ionizing radiation is observed along with increased vulnerability to cancers - skin and eyes tend to express small dilated blood vessels

Question 34

describe cerebellar cognitive affective syndrome (CCAS)

Answer 34

lesions of the posteiror lobe are considered to correlate with dysfunctional cognitive and emotional systems -leads to: emotional blunting and depression disinhibition psychosis executive, visual-spatial and linguistic deterioration condition is conceptualized in relation to "dysmetria of thought"

Question 35

what are the two fiber inputs of the cerebellar cortex?

Answer 35

climbing fibers | mossy fibers

Question 36

what are climbing fibers

Answer 36

input from inferior olivary nucleus

Question 37

what are mossy fibers?

Answer 37

carry all other inputs