Chapter 14

Question 1

Cerebellum function

Answer 1

Constant monitoring of cortical motor output

Correction of discrepancy movements

Error control device for rapid, alternating, and sequential movements

Compared efferent commands for intended movement, along with sensory info and established programs

Takes into consideration body position, muscle preparedness, and tone, distance duration of movement

Question 2

What is needed to move

Answer 2

Ascending feedback

Modifications necessary for limb preparation

Descending feedback modulated muscle and tone necessary for movement

Cerebellum monitors these and makes adjustments

Question 3

Innervation pattern of cerebellum

Answer 3

Ipsilateral cerebellar sensorimotor organization to input source and output targets

Effect of lesion on body ipsilateral of cerebellar fibers

Question 4

Location of cerebellum

Answer 4

Dorsal to junction of pons and medulla

Occupies most posterior cerebellar fossa under tentorium cerebelli

Question 5

Cerebellar anatomy

Answer 5

Cerebellar cortex

2 hemoispheres

3 loves

Internal white substance

Four deep cerebellar nuclei embedded within white matter

Threw cerebellar peduncles

Surface folded into smaller folds because of its size

Question 6

Three transverse lobes of cerebellum

Answer 6

Anterior (paleocerebellum)

Posterior (neocerebellum)

Floccular-nodular (Archicerebellum)

Question 7

Anterior (paleocerebellum)

Answer 7

Motor tone and walking position

Contains vermis, paravermal zone

Receives impulses from stretch receptors in arms legs trunk face

Tone and walking posture

Projections through reticulospinal, rubrospinal, vestibulospinal

Question 8

Posterior (neocerebellum)

Answer 8

Coordination of cortically directed skilled movements (speaking writing)

Includes lateral regions of cerebellar hemispheres

Receives crossed afferent from contralateral sensorimotor cortex

Afferent fibers make up most of middle cerebral peduncle

Love projectuons to contralateral motor cortex and spinal cord through dentists and red nucleus

Question 9

Floccular (archicerebellum)

Answer 9

Receives vestibular projections

Regulates muscle tone via vestibulospinal tract, equilibrium and eye movements

Question 10

Three longitudinal cerebellar regions

Answer 10

Vermis- maintenance of
Body posture

Paravermal- ipsilateral movements

Lateral hemispheres- skilled extremity movements

Question 11

Deep cerebellar nuclei

Answer 11

Dentate

Emboliform and globose regulation of ipslilateral movements

Fastigial- equilibrium

Question 12

Dentate

Answer 12

Largest most fibers traveling through the superior peduncle state here limb movements

Question 13

Two sensory body representations for tactile stimulation

Answer 13

Ipsilateral in anterior

Bilateral in posterior

Question 14

Cerebellar cortex layers

Answer 14

Molecular

Purkinje

Granular

Question 15

Molecular

Answer 15

Parallel fibers synapsing with purkinje cells

External later

Parallel fibers run in medial lateral directions

Synapse with each successive purkinje

Question 16

Purkinje

Answer 16

Middle

Penetrate into granular later and terminate in the deep cerebellar nuclei

All impulses leaving cerebellar cortex pass through purkinje axon

Question 17

Granular cells

Answer 17

Synapse into mossy fibers

Become the middle cerebral peduncle

Also project to dendritic spine of purkinje cells

Question 18

Cerebellum and motor learning

Answer 18

Plays role during conscious acquisition of a skilled motor movement

Once the skill is acquired monitoring is no longer necessary

Patients with cerebellar injury with revert back to conscious control of motor patterns
Will rely heavily on climbing fibers than would
Be required for unconscious skilled movement

Question 19

Cerebellar plasticity

Answer 19

Smaller unilateral cerebellar lesions- easily compensable by retraining

Massive/bilateral lesions- long term effects, unless occurring in young age

Question 20

Importance of posterior lobe

Answer 20

Precision in sequential movements

Question 21

Romberg test

Answer 21

Standing with extended arms in front, feet together

If eyes are closed and arms drift to downward and/or body tilt to side
Loses of proprioception (vestibular or cerebellar disorder)

If eyes are opened and continues presence of arms drifting or unsteadiness
Suggestive of cerebellar abnormality or cerebellar malfunctioning

Question 22

Tests of cerebellar dysfunction

Answer 22

Tandem gait- toes of back foot touch heel of food front at each step

Finger to nose test

Alternating movements

Limb rebounding

Diadpchokinesia

Question 23

Three signs to watch for

Answer 23

Ipsilateral character to signs

Deficits related to motor function with no sensory loss or paralysis

Gradual natural recover unless a lesion is progressive in nature

Minor lesions are hard to spot

Lesions will be more severe if deep nuclei dentate is involved

Patience cannot control body parts

Will be seen on rapid alternating movements

Question 24

Common cerebellar impairments

Answer 24

Ataxia

Segmented and clumsy movements

Question 25

Ataxia

Answer 25

Lack of order and coordination in muscle activities

Question 26

Bradykinesia

Answer 26

Slow movements

Question 27

Asthenia

Answer 27

Mild muscular weakness

Question 28

Asynergia

Answer 28

Impaired direction and force of movement

Question 29

Dysdiadochokinesia

Answer 29

Failure in sequential progression of motor activities Clumsiness in rapid and alternating movements Test on movements like tapping, articulation of sequences phonemes, or rotating movements

Question 30

Dysarthria

Answer 30

Impaired motor speech processes Impaired ability for modifications and alterations in ongoing oral-facial movements Implication of bilateral cerebellar lesions Slow, slurred, and disjointed speech with each word spoken individually

Question 31

Dysmetria

Answer 31

Error in judgement of movements range or distance to target Undershooting, overshooting Failure to incorporate range and distance o stationary and moving targets

Question 32

Intention (movement) tremor

Answer 32

Impaired ability to damped accessory movements Motion tremor- demand of cerebellum during movement

Question 33

Hypotonia

Answer 33

Decreased muscle tension, muscle becoming floppy Detection during passive manipulation of limbs Ipsilateral to the lesion side

Question 34

Rebounding

Answer 34

Impaired motor tone adjustments with loss of rapid and precise corrective response Loss in ability to predict, stop, or dampen movements

Question 35

Disequilibrium

Answer 35

Impaired integrated vestibular processing affecting the legs Unsteady gait Wavering toward lesion side

Question 36

Cerebellar pathologies

Answer 36

Cerebrovsscular accident Vertebrobasilar artery- vascular supply to all cerebellar arteries

Question 37

Toxicity- chronic alcoholism

Answer 37

Progressive subacute cerebellar degeneration, gross cerebellar atrophy and loss of cellular elements in anterior love. Most crucially the purkinje cel Wavering gait, dysmetria, dyskinesia Speech impairment Monotonous and explosive Disappear with attenuation of blood alcohol lever over Time

Question 38

Progressive cerebellar degeneration

Answer 38

Fridreich ataxia Symptoms- ataxia, dysarthria, tremor, weakness, lower to upper progrsssion, loss of proprioception, nystagmus, dysmetria, and scanning speech No medical treatment

Question 39

Friedreich ataxia

Answer 39

Autosomal recessive genetic degeneration condition