Cerebellum - Friedman - Exam 1

Question 1

The cerebellum coordinates _____. It is connected to two major circuits. One is the ___ cortex. When the ___ cortex sends out a command to make a movement, it sends a collateral projection to the cerebullum (to the deep nuclei). So the cerebellum knows what the command is.

The cerebellum has an intimate connection with the motor cortex. It sends a huge projection back through the ___ thalamus right back to the primary motor cortex.

The other circuit that the cerebellum is related to is the brain stem and spinal cord. The cerebellum gets direct input from the spinal cord and brain stem via vermis and paravermis areas (____cerebellum). From the spinal cord it, it gets propriocecption input and sensory input. So all the sensory inputs that go to the ventral horn and come up to consciousness.

The cerebellum knows all about where the body is.

Although the cerebellum plays a major role in coordinating movements, it does not project directly to motor neurons. Instead, it exerts its effects by projections to the cerebral cortex (especially motor cortex), red nucleus, reticular formation and vestibular nuclei (brainstem). It compares the intended movement with the actual movement to make needed adjustments.

In influences the ___ side of the body.

Answer 1

The cerebellum coordinates movement. It is connected to two major circuits. One is the motor cortex. When the motor cortex sends out a command to make a mvmt, it sends a collateral projection to the cerebellum. So, the cerebellum knows what the command it.

The cerebellum has an intimate connection with the motor cortex. It sends out a huge projection back through the thalamus (VL) right back to the primary motor cortex.

The other circuit that the cerebellum is intimately related to is the brain stem and spinal cord. The cerebellum gets direct input from the spinal cord and brain stem via vermic and paravermic areas (spinocerebellum). From the spinal cord it, it gets propriocecption input and sensory input. So all the sensory inputs that go to the ventral horn and come up to consciousness

It influences the ipsilateral side of the body.

Question 2

Classic cerebellar symptoms all come from different parts of the cerebellum. Some of the symptoms include:

1. Delay in the initiation of mvmt –> if you give someone a signal to move, the normal person can move right away. A person with a cerebellar dysfunction can’t move (due to ____ ___ dysfunction), which is responsible for mediating voluntary motor planning of extremities. (ataxia)
2. _____ (spinocerebellum) - this has two components. One is that the mvmt itself is uncoordinated. The second is that, as the movement approaches the target (like if a person is asked to touch their nose), they display an “__ __” (dysmetria). The closer the person gets to their target, the more uncoordinated their mvmt becomes. Eventually you see the mvmt oscilate, and this oscilation gets bigger and bigger as they approach to their target. This is differentin PD because resting tremor goes away as they move.
3. ____ - you cannot pronate or supinate your hand (dysfunction in ____)
4. Loss of muscle tone - loss of tonic excitation of ____ motor neurons.
5. Unsteady gait (from ____)
6. Nausea and Vomiting (from ___)

Answer 2

Classic cerebellar symptoms all come from different parts of the cerebellum. Some of the symptoms include:

1. Delay in the initiation of mvmt –> if you give someone a signal to move, the normal person can move right away. A person with a cerebellar dysfunction can’t move (due to lateral hemispheric dysfunction), which is responsible for mediating voluntary motor planning of extremities. (ataxia)
2. Ataxia (spinocerebellum) - this has two components. One is that the mvmt itself is uncoordinated. The second is that, as the movement approaches the target (like if a person is asked to touch their nose), they display an “intential tremor” (dysmetria). The closer the person gets to their target, the more uncoordinated their mvmt becomes. Eventually you see the mvmt oscillate, and this oscillation gets bigger and bigger as they approach to their target. This is differentin PD because resting tremor goes away as they move.
3. disdiadochokinesis - you cannot pronate or supinate your hand (dysfunction in spinocerebellum)
4. Loss of muscle tone - loss of tonic excitation of gamma motor neurons.
5. Unsteady gait (from spinocerebellum)
6. Nausea and Vomiting (from spinocerebellum)

Question 3

The ___ modulates cognitive, limbic and ANS functions

Answer 3

Cerebellum

Question 4

The cerebellum is connected with:

Answer 4

The cerebellum is connected with the entire cerebral cortex, limbic structures, hypothalamus, brainsteam and autonomic control centers.

Question 5

There are three layers of the cerebellum:

1.

2.

3.

Answer 5

1. Molecular layer - Purkinje cell later dendrites and granule cell axons
2. Purkinje layer - 1 cell thick - output
3. Granule cell later - where all neurons are - input

Question 6

Two types of input fibers:

1. ___ fibers terminates of granule cells. This is the bulk of cerebellar inputs
2. ____ fibers - synapse on Purkinje cells. They arise only in the inf. olive and terminate on a single purkinje cell. They play a major role in motor learning

Answer 6

Two types of input fibers:

1. Mossy fibers terminates of granule cells. This is the bulk of cerebellar inputs

2. Climbing fibers - synapse on Purkinje cells. They arise only in the inf. olive and terminate on a single Purkinje cell. They play a major role in motor learning.

Question 7

Below the cerebellar cortex, there are deep nuclei. These are the output of the cerebellum. All the mossy fibers that come into the cerebellum, drop off a collateral in the __ ___ and excite those neurons. Right away, these deep nuclei are excited and start sending signals. The eventual target of the mossy fibers are the ___ cells. These cells get excited and excite the purkinje cells (inhibitory) and inhibit the deep nucleus and turn off the activity.

Answer 7

Below the cerebellar cortex, there are deep nuclei. These are the output of the cerebellum. All the mossy fibers that come into the cerebellum, drop off a collateral in the deep nucleus and excite those neurons. Right away, these deep nuclei are excited and start sending signals. The eventual target of the mossy fibers are the granule cells. These cells get excited and excite the purkinje cells (inhitory) and inhibit the deep nucleus and turn off the activity.

Question 8

There are two kinds of afferent fibers:

1. __ fibers terminate on granule cells and makes up the bulk of cerebellar inputs.
2. ___ fibers arise only from the inf. olive. They terminate on a single purkinje cell and play a major role in motor learning.

Answer 8

There are two kinds of afferent fibers:

1. Mossy fibers terminate on granule cells and makes up the bulk of cerebellar inputs.
2. Climbing fibers arise only from the inf. olive. They terminate on a single purkinje cell and play a major role in motor learning

Question 9

The cerebellar circuit: the cortex modules the deep nuclei.

1. All mossy fibers, on their way to exciting ___ cells, drop off a collateral and excite the ___ nuclei (these are the outputs of the cerebellum)
2. They then excite ___ cells
3. ___ cells excite purkinje cells (which are inhibitory). Since the Purkinje cells are GABAergic, the output of the cerebellar cortex is wholly inhibitory. However, the deep cerebellar nuclei receive excitatory input from the collaterals of the mossy and climbing fibers.
4. ____ cells inhibit deep nuclei (turn off the activity of the deep nuclei).
5. Deep nuclei normally send excitatory projections to targets. ___ is a common early symptom of cerebellar lesion.

Answer 9

The cerebellar circuit: the cortex modules the deep nuclei.

1. All mossy fibers, on their way to exciting granule cells, drop off a collateral and excite the deep nuclei (these are the outputs of the cerebellum)
2. They then excite granule cells
3. Granule cells excite purkinje cells (which are inhibitory)
4. Purkinje cells inhibit deep nuclei (turn off the activity of the deep nuclei).
5. Deep nuclei normally send excitatory projections to targets. Hypotonia is a common early symptom of cerebellar lesion.

Question 10

There are two kinds of inputs to the cerebellum

1. Most inputs are called mossy fibers. They arise in the brainstem and spinal cord and terminate on ____ cells
2. A select set of inputs are called climbing fibers. They arise only from the inferior olive and terminate on __ cells

Answer 10

There are two kinds of inputs to the cerebellum

1. Most inputs are called mossy fibers. They arise in the brainstem and spinal cord and terminate on granule cells
2. A select set of inputs are called climbing fibers. They arise only from the inferior olive and terminate on Purkinje cells

Question 11

Input information coming from the cerebral cortex to the cerebellum, first synapses on the __ nuclei. It then travels through ___ fibers and then through the ___ cerebellar peduncle, then finally gets the info to the cerebellar cortex.

Input information coming from red nucleus synapse in inferior olive. From their, the info travels on ___ fibers and go through the ___ cerebellar peduncle, then finally reaches the cerebellar corte.

Information coming from the spinal cord (dorsal spinocerebellar and cuneocerebellar tracts) travel on the ___ fibers, then go through the ___ cerebellar peduncles, then finally reach the cerebellar cortex.

Answer 11

Input information coming from the cerebral cortex to the cerebellum, first synapses on the pontine nuclei. It then travels through mossy fibers and then through the middle cerebellar peduncle, then finally gets the info to the cerebellar cortex.

Input information coming from red nucleus synapse in inferior olive. From their, the info travels on climbing fibers and go through the inferior cerebellar peduncle, then finally reaches the cerebellar corte.

Information coming from the spinal cord (dorsal spinocerebellar and cuneocerebellar tracts) travel on the mossy fibers, then go through the inferior cerebellar peduncles, then finally reach the cerebellar cortex.

Question 12

Cerebellar efferents all arise from the ___nuclei.

The cerebro and spinocerebellum give off fibers that travel through the ___ cerebellar peduncle. It then crosses the midline and synpases on the red nucleus as well as the VL nucleus of the thalamus.

The ___and ___ -cerebellum send fibers through the uncinate fasciculus and juxtarestiform body, then finally go to the brainstem (reticular formation, vestibular complex).

Answer 12

Cerebellar efferents all arise from the deep nuclei.

The cerebro and spinocerebellum give off fibers that travel through the superior cerebellar peduncle. It then crosses the midline and synpases on the red nucleus as well as the VL nucleus of the thalamus.

The spino and vestibulo-cerebellum send fibers through the uncinate fasciculus and juxtarestiform body, then finally go to the brainstem (reticular formation, vestibular complex).

Question 13

The flocculonodular lobe of the cerebellum processes what?

Answer 13

It processes vestibular information and modulates balance and eye movement.

Question 14

From a midsaggital section of the cerebellum, the anterior lobe is primarily concerned with ____ coordination. It is functionally like the vermis and paravermis.

The posterior lobe is primarily concerned with motor coordination (medially) and ____ functions (laterally).

The _____ lobe is concerned with balance and eye movements.

The __ __ modulates limbic and autonomic nervous system functions

A useful way to look at the cerebellum is as if it had been unrolled, or flattened, as in the right-hand image. Rostral is to the top and caudal to the bottom. In this view the medial to lateral organization can be visualized, with the vermis being the most medial part of the cerebellum and the hemisphere residing more laterally. The ____ lobe (important for processing vestibular info and modulating balance and eye mvmts) is the most caudal structure, and though it is extended medially to laterally, it can be considered a midline structure, like the vermis.

Answer 14

From a mid sagittal perspective, the anterior lobe is primarily concerned with motor coordination. It is functionally like the vermis and paravermis.

The posterior lobe is primarily concerned with motor coordination (medially) and cognitive functions (laterally).

The flocculonodular lobe is concerned with balance and eye movements.

The caudal vermis modulates limbic and autonomic nervous system functions

A useful way to look at the cerebellum is as if it had been unrolled, or flattened, as in the right-hand image. Rostral is to the top and caudal to the bottom. In this view the medial to lateral organization can be visualized, with the vermis being the most medial part of the cerebellum and the hemisphere residing more laterally. The flocculonodular lobe is the most caudal structure, and though it is extended medially to laterally, it can be considered a midline structure, like the vermis.

Question 15

Control of the trunk and axial muscular is presented in which area of the cerebellum? What would happen if there was damage in this area?

Hands and feet are extended in the ___ area.

Midline lesions of the cerebellum give ___ ataxia, which lateral lesions give dysfunction in the __ and ___.

Neurological deficiency will be on the same/opposite side in the cerebellum.

Answer 15

Control of the trunk and axial muscular is presented in which area of the cerebellum? –> vermal area

What would happen if there was damage in this area? –> neck, shoulder, hip and trunk dysfunction

Hands and feet are extended in the paravermal area.

Midline lesions of the cerebellum give axial ataxia, which lateral lesions give dysfunction in the hands and feet

Neurological deficiency will be on the same side in the cerebellum.

Question 16

There are three longitudinal zones in the cerebellum. All of them have different inputs:

Vermis receieves: ___ and ___ inputs

Paravermis receives: ____ inputs

Lateral hemisphere receives: ___ ___ inputs

Answer 16

There are three longitudinal zones in the cerebellum. All of them have different inputs:

Vermis receieves: vestibular and spinal inputs

Paravermis receives: spinal inputs

Lateral hemisphere receives: cerebral cortical input

Question 17

The cerebellum can be divided into anatomical sections:

Vestibulocerebellum includes the: ___ lobe (connected to the ___ nucleus). This lobe is responsible for balance, posture, and eye movements

The spinocerebellum includes the ___ and ___ (connected to the __ and ___ nuclei ), and is responsible for muscular coordination

The cerebrocerebellum (neocerebellum) includes the ___ ___ (it is connected to the __ nucleus) and is involved with planning and cognitive functions

Answer 17

The cerebellum can be divided into anatomical sections:

Vestibulocerebellum includes the: flocculonodular lobe (connected to the fastigigial nucleus). This lobe is responsible for balance, posture, and eye movements

The spinocerebellum includes the vermis and paravermis, (globus and emboliform) and is responsible for muscular coordination.

The cerebrocerebellum (neocerebellum) includes the lateral hemispheres (it is connected to the dentate nucleus) and is involved with planning and cognitive functions

Question 18

Answer 18

Question 19

The cerebellum is attached to to the brain stem by three peduncles.

The middle peduncle gets input from the ___ pons. The inferior one gets input from the ___ __ and ___ cord. The superior one is mainly output of the ___.

Answer 19

The cerebellum is attached to to the brain stem by three peduncles.

The middle peduncle gets input from the ventral pons. The inferior one gets input from the brain stem and spinal cord. The superior one is mainly output of the cerebellum.

Question 20

Peduncles:

Superior = output from the ___ cortex to the thalamus, ___ nucleus and brainstem motor nuclei

Middle = receives input from ___ ____

Inferior = receives input from spinal cord, brainstem, ___ nuclei (CN VIII) and olives

Answer 20

Peduncles:

Superior = output from the cerebellar cortex to the thalamus, red nucleus and brainstem motor nuclei

Middle = receives input from ventral pons

Inferior = receives input from spinal cord, brainstem, vestibular nuclei (CN VIII), and olives

Question 21

___cerebellum include the anterior lobe, paravermis and vermis. It receives input from the brain stem and spinal cord. The information goes through the ___ peduncles ad synapse on the deep nuclei __ and ___ (globus and emboliform deep nuclei).

It then has outputs that go to the brain stem by existing via the ___ peduncles. It targets the __ nucleus and ___ formation, and aids in ___ coordination.

Answer 21

Spinocerebellum include the anterior lobe, paravermis and vermis. It receives input from the brain stem and spinal cord. The information goes through the inferior peduncles ad synapse on the deep nuclei fastigial and interposed (globus and emboliform deep nuclei).

It then has outputs that go to the brain stem by existing via the superior peduncles. It targets the red nucleus and reticular formation, and aids in muscle coordination.

Question 22

The neocerebellum (lateral) receives inputs from the ___ ___ via the __ pons and ___ peduncles. It synapses on the __ nucleus and goes out the __ peduncle. It targets the __ nucleus, ventral lateral ___ to motor cortex It aids in motor ___.

Answer 22

The neocerebellum (lateral) receives inputs from the cerebral cortex via the pons and middle peduncles. It synapses on the dentate nucleus and goes out the superior peduncle. It targets the red nucleus, ventral lateral thalamus to motor cortex It aids in motor planning

Question 23

The __cerebellum includes the __ vermis and the flocculonodular lobe. It receives inputs from the vestibular nuclei and vestibular ganglia cells via the ___ peduncles. It synapses with the __ and __ deep nuclei. It projects out via the __ and __ peduncles, and targets the __ nuclei, reticulo and vestibulospinal tracts. It aids in posture, vestibulo-ocular reflexes and equilibrium.

Answer 23

The vestibulocerebellum includes the inferior vermis and the flocculonodular lobe. It receives inputs from the vestibular nuclei and vestibular ganglia cells via the inferior peduncles. It synapses with the fastigial and vestibular deep nuclei. It projects out via the inferior and superior peduncles, and targets the vestibular nuclei, reticulo and vestibulospinal tracts. It aids in posture, vestibulo-ocular reflexes and equilibrium.

Question 24

There cerebellum is supplied from three arteries.

The __ ___ artery supplies the rostral half of the cerebellum, including the anterior lobe, rostral vermis and rostral hemisphere

The ____ supplies the ventral surface of the mid-cerebellum, including the peduncles. It also supplies the dorsolateral portion of the dorsolateral rostral medulla

The ___ supplies the caudal half of the cerebellum, including the vermis and hemisphere. It also supplies the caudal dorsolateral medulla

Answer 24

There cerebellum is supplied from three arteries.

The superior cerebellar artery supplies the rostral half of the cerebellum, including the anterior lobe, rostral vermis and rostral hemisphere

The Anterior Inferior Cerebellar Artery (AICA) supplies the ventral surface of the mid-cerebellum, including the peduncles. It also supplies the dorsolateral portion of the dorsolateral rostral medulla

The Posterior Inferior Cerebellar Artery (PICA) supplies the caudal half of the cerebellum, including the vermis and hemisphere. It also supplies the caudal dorsolateral medulla

Question 25

Name the vascular territories:

Answer 25

Question 26

Lesion in the SCA area will cause the patient to have what kind of dysfunction?

Answer 26

Motor dysfunction. Remember, the SCA covers the superior cerebellar surface, so there will be lots of motor issues since the cerebellum sends info out through the S. peduncle to the brainstem (red nucleus, reticular formationm thalamus, motor cortex, etc.)

Question 27

What type of dysfunction is this? Ataxia Abnormalities in rate, range, and force of movement ØDysarthria ØIntention tremor ØNystagmus, ocular dysmetria Disorders of gait and equilibrium Diminished muscle tone (with acute lesions) What is the memonic used to remember the symtpoms of a cerebellar dysfunction?

Answer 27

**This is a cerebellar dysfunction** Ataxia\* Abnormalities in rate, range, and force of movement ØDysarthria ØIntention tremor ØNystagmus, ocular dysmetria Disorders of gait and equilibrium Diminished muscle tone (with acute lesions) Mnemonic: DANISH To remember the clinical features of cerebellar disease the word DANISH may be helpful: dysdiadochokinesis - inability to supinate/pronate arm. ataxia - loss of full control fo mvmts nystagmus - involun. mvmt of eye intention tremor - more tremor as you move to target (finger to nose test) scanning dysarthria - slurred or slowed speech heel-shin test positivity - dysmetria - refers to a lack of coordination of movement typified by the undershoot or overshoot of intended position with the hand, arm, leg, or eye

Question 28

Which side presents a basal ganglia dysfunction? Which side presents a cerebellar dysfunction? With __ dysfunction, you may be able to recover, however with __ dysfunction, it gets worse. With __ dysfunction you get intention tremor, with __ dysfunction you get resting tremors. With __ dysfunctions, you get ipsi/contra loss. With ___ dysfunction, you get ipsi/contra loss. With __ dysfunction, you get hypotonia, but with __ dysfunction, you get rigidity.

Answer 28

Right side - Cerebellar dysfunction Left side - Basal ganglia dysfunction With **cerebellar** dysfunction, you may be able to recover, however with **basal ganglia** dysfunction, it gets worse. With **cerebellar** dysfunction you get intention tremor, with **basal ganglia** dysfunction you get resting tremors. With **cerebellar** dysfunctions, you get **ipsilateral** loss. With **basal ganglia** dysfunction, you get **contralateral** loss. With **cerebellar** dysfunction, you get hypotonia, but with **basal ganglia** dysfunction, you get rigidity.

Question 29

A 27 month old female presents with **unsteady gait, poor balance**, and falling frequently over the past 13 months. Significant truncal **ataxia** present sitting or standing. **Gait was broad based** and **ataxic**. There was no ataxia or tremor of the limbs. Imaging revealed a mass in the **fourth ventricle** arising from the nodulus. The **fourth ventricle was deformed,** the cerebral aqueduct compressed and the 3rd and lateral ventricles enlarged. What does the patient have?

Answer 29

A 27 month old female presents with unsteady gait, poor balance, and falling frequently over the past 13 months. Significant truncal ataxia present sitting or standing. Gait was broad based and ataxic. There was no ataxia or tremor of the limbs. Imaging revealed a mass in the fourth ventricle arising from the nodulus. The fourth ventricle was deformed, the cerebral aqueduct compressed and the 3rd and lateral ventricles enlarged. The patient has a **cerebellar tumor.**

Question 30

Nystagmus is usually seen in ____ dysfunctions, but not in ___ \_\_\_dysfunctions.

Answer 30

Nystagmus is usually seen in **cerebellar** dysfunctions (fastigial nuclei), but not in **basal ganglia** dysfunctions.