Cerebellum

Front 1

What cerebellar peduncle connects to the midbrain?

Back 1

Superior cerebellar peduncle

Front 2

What cerebellar peduncle connects to the pons?

Back 2

Middle cerebellar peduncle

Front 3

What cerebellar peduncle connects to the medulla?

Back 3

Inferior cerebellar peduncle

Front 4

What type of fibers are in the outer molecular layer of the cerebellar cortex?

Back 4

Mainly unmyelinated fibers, with sparse stellate and basket cells

Front 5

What cell bodies are in the middle cell layer of the cerebellar cortex?

Back 5

Purkinje cells

Front 6

What cell godies are in the inner layer of the cerebellar cortex?

Back 6

Granule cells

Front 7

Afferents to the cerebellar cortex mainly end on the dendrites of Purkinje cells as ___ fibers or upon granule cells as ____ fibers?

Back 7

purkinje cells = climbing fibers
Granule cells = mossy fibers

Front 8

Climbing fibers are the endings of _______ fibers

Back 8

olivocerebellar fibers

Front 9

Mossy fibers are the endings of ____, _____, and excite Purkinje cells via the Mossy fibers' parallel fibers

Back 9

Spinocerebellar, pontocerebellar fibers.

Front 10

All cerebellar output originates from ____ or _____.

Back 10

Cerebellar nuclei or Purkinje cells

Front 11

What are the two main types of cerebellar afferent fibers?

Back 11

Mossy fibers and Climbing fibers

Front 12

What is the main purpose of the dorsal spinocerebellar pathway?

Back 12

This pathway provides proprioceptive mechanoreceptor input to help coordinate movement, but is not for conscious perception

Front 13

What is the name of the nucleus in cord segments T1-L2 where dorsal root fibers from the trunk and lower limb reach?

Back 13

Nucleus dorsalis (aka Clarke's nucleus).

Front 14

From the nucleus dorsalis, what tract does mechanoreceptor proprioceptive input follow, where is this tract in the spinal cord, and what cerebellar peduncle does this tract enter to get to the cerebellum?

Back 14

Dorsal spinocerebellar tract
Posterolateral portion of the SC
Ipsilateral inferior cerebellar peduncle

Front 15

What tract provides input from the motor cortex to the cerebellum?

Back 15

corticopontocerebellar pathway

Front 16

Once these two pathways get to the cerebellum, what type of cerebellar fibers do they hook up with?

Back 16

Mossy fibers

Front 17

Describe the tract that provides input to the cerebellum from the motor cortex

Back 17

Motor cortex to ipsilateral pontine nuclei in basilar pons via corticopontine fibers. From pontine nuclei to opposite middle cerebellar peduncle via pontocerebellar (transverse pontine) fibers.

Front 18

Lesions of the middle cerebellar peduncle cause ipsilateral or contralateral signs?

Back 18

ipsilateral

Front 19

Do cerebellar or UMN signs dominate with most lesions of the motor cortex, internal capsule, cerebral peduncle, or basilar pons?

Back 19

UMN signs like
spastic paralysis
Babinski

Front 20

Fibers from what pathway provide afferents to the cerebellum via climbing fibers? What cerebral peduncle does this tract use to get to the cerebellum?

Back 20

The olivocerebellar fibers. They go from the inferior olivary nucleus to the cerebellum via the inferior cerebellar peduncle.

Front 21

What is the name of the division of cerebellar efferents that provides ipsilateral limb coordination?

Back 21

Hemisphere Efferent Division

Front 22

Describe the course of the first neuron of the hemisphere efferent division.

Back 22

1 - Purkinje cells to the dentate, emboliform, and globose nucleus of cerebellar hemisphere

Front 23

Describe the course of the second neuron of the hemisphere efferent division.

Back 23

Cerebellothalamic fibers from nuclei through the SCP, decussates, around contralateral red nucleus to contralateral thalamus

Front 24

Describe the course of the third neuron of the hemisphere efferent division.

Back 24

From the ventral lateral nucleus, posterior part (aka that ventral intermediate nucleus, also the surgical target to relieve severe tremor) to the primary motor and premortor cortex.

Front 25

Describe the course of the fourth neuron of the hemisphere efferent division.

Back 25

From the primary motor and premotor cortex via the corticospinal tract to the opposite side to affect limb coordination ipsilateral to the cerebellar hemisphere.

Front 26

What cerebellar efferent division controls axial muscles and saccades?

Back 26

Vermis Efferent Division

Front 27

Describe the course of the vermis efferent division that controls axial muscles

Back 27

From purkinje cells, through the ICP to the vestibular nuclei and the reticular formation, which give rise to the vestibulospinal and reticulospinal tract, which affect axial muscles

Front 28

What part of the cerebellum calibrates saccades?

Back 28

The vermis

Front 29

What efferent division of the cerebellum controls eye movements?

Back 29

Vestibulocerebellum division

Front 30

Describe the course of the vestibulocerebellum division

Back 30

Purkinje cells project ipsilaterally via the ICP to the vestibular nuclei, through the medial longitudinal fasciculus to the nuclei of CN III, IV, and VI.

Front 31

What particular eye movements are coordinated via the vestibulocerebellum efferent division?

Back 31

Gaze holding, smooth pursuit, and vestibular eye movements

Front 32

Hemisphere disease primarily effects what?

Back 32

ipsilateral limb coordination

Front 33

Define cerebellar ataxia

Back 33

Defective cerebellar coordination of muscular contraction (as opposed to sensory ataxia which is defective proprioception).

Front 34

How do you test cerebellar ataxia?

Back 34

disturbed stance and gait ataxia (pt falls toward affected side if a unilateral hemisphere lesion). Tandem gait would also be difficult.

Front 35

What two abnormalities of the finger to nose test are signs of limb ataxia (cerebellar hemisphere lesion)

Back 35

Decomposition of movement - jerky movement, moving one joint at a time
Dysmetria - Limb falls short of goal (hypometria) or overshoots it (hypermetria).
Dysdiadochokinesia - inability to rapidly pronate-supinate or tap index finger to thumb

Front 36

What are three signs of cerebellar ataxia using some reflexes (not the normal reflexes we've learned about)?

Back 36

Impaired check - pts flexed forearm, upon release, flies back to pts chest
Excessive rebound - tap wrist of pt's extended arm, limb displacement is exaggerated and it oscilates before returning to the origial position.
Pendular reflex - initial leg swing of normal amplitude, followed by more swings.

Front 37

What is an intention tremor?

Back 37

A characteristic cerebellar tremor. The movement of the body part worsens as the target is neared.

Front 38

How is intention tremor tested?

Back 38

Finger to nose test (may produce tremor and decomposition of movement, and dysmetria)
Heel-shin test

Front 39

When does hypotonia occur as a sign of cerebellar disease?

Back 39

Primarily in acute or sub-acute situations. Hypotonia rarely occurs in chronic, degenerative disease.

Front 40

Vermis disease primarily affects what?

Back 40

Axial muscles and saccades

Front 41

What axial muscle signs would you see upon cerebellar vermis disease?

Back 41

Unsteadiness while sitting
Disturbed stance and gait ataxia (also difficulty in tandem gait, due to effect on axial muscles, not limb muscles)
Titubation (rocking of the head as a postural tremor)

Front 42

What saccadic signs would you see upon cerebellar vermis disease?

Back 42

hypometria or hypermetria

Front 43

What are three signs of an efferent cerebellar vestibulocerebellum disorder?

Back 43

1 - Gaze-evoked nystagmus
2 - Impaired smooth pursuit
3 - Downbeat nystagmus

Front 44

Alcoholic cerebellar degeneration is characterized by what region of the cerebellum, as well as what signs?

Back 44

Anterior lobe vermal and paravermal disease.
Disturbed stance and gait ataxia, and lower limb ataxia, with relative sparing of the arms

Front 45

Acute vertigo is common with what two cerebellar lesions?

Back 45

acute infarct (especially due to the PICA) and acute hemorrhage.

Front 46

What 3 features are NOT typical of isolated cerebellar disease?

Back 46

1 - Loss of strength
2 - Loss of sensation
3 - Positive Romberg sign (upon eye closure, body sway increases modestly, not drastically).