Clin Neuro Cerebellum done Flashcards
(99 cards)
0
Q
Dysmetria of limbs
A
(inaccuracy of tar-geted movements)
1
Q
Cerebellar ataxia produces a characteris-tic set of signs…
A
1.Gait becomes unsteady with tendency to falls 2.Hand coordination is impaired 3.Dysarthria or Dysphagia 4.Possible ocular symptoms related to ab-normal control of eye movements
2
Q
2.Kinetic tremor of limbs and an uncon-trolled oscillation of limbs during rela-
tively slow but…
A
Targeted movment.
Intentional tremors.
3
Q
3.Early stance and gait problems include
A
3.1.the inability to do a tandem stance orstand with feet together
3.2.stance becomes broad-based and
displays increased sway of the body
4
Q
- Tandem gait becomes impaired and,
later, regular gait can be frankly ataxic
with a broad-based and lurching quality.
5.Eye movements show gaze-evoked or
other types of nystagmus, abnormal pur-suit of visually presented objects (jerky appearance due to intrusion of saccadesinto pursuit)
5.1.and inaccurate saccades when the person is asked to move the eyes quickly towards a target (hypometric or hypermetric saccades) 6.There is also a scanning type of dysar- thria.
A
.
5
Q
Etiology of Cerebellum Damage most coomon
A
TBI
6
Q
Etiology of Cerebellum Damage
Developmental abnormality
A
Arnold ChiariMalformation
7
Q
Etiology of Cerebellum Damage
Demyelinating disease
A
MS
8
Q
Etiology of Cerebellum Damage
Hereditary disease
A
Friedreich’s Ataxia
9
Q
Etiology of Cerebellum Damage
Vascular insufficiency
A
CVA
10
Q
Etiology of Cerebellum Damage
A
Drug and alcohol intoxications
Neoplasms
11
Q
Cerebellum Organization“A structure of “three’s”
A
- 3 zones (Hemisphere’s)
- Vermal (Median) Zone
- Paravermal (Intermediate) Zone• Hemispheric (Lateral) Zone
- 3 lobes
- Anterior lobe
- Posterior lobe
- Flocculonodular lobe
- 3 functional areas
- Spinocerebellum
- Cerebrocerebellum
- Vestibulocerebellum
- 3 deep nuclei
- Fastigial Nucleus
- Interposed Nuclei
- Globose Nucleus
- Emboliform Nucleus
- Dentate Nucleus
- 3 cellular layers
- Molecular Layer
- Purkinje Layer
- Granular Layer
- 3 “highways” (peduncles)
- Superior Cerebellar Peduncle
- Middle Cerebellar Peduncle
- Inferior Cerebellar Peduncle
- 3 major afferents
- Corticopontocerebellar Pathway• Spinocerebellar Pathway
- Cortico-olivocerebellar Pathway• 3 major efferents
- Dentorubrothalamic Pathway
- Medial descending system
- Lateral descending system
12
Q
Vermal!
(Median)!
Vermis!
A
Fastigial Nucleus
The worm is fast!
13
Q
Paravermal%
(Intermediate)!
Medial!Cb!
Hemispheres!
A
Interposed!
Nuclei!(Globose!&!Emboliform)!
The side medial is to have so ething i terposed there.
14
Q
Hemispheric%
(Lateral)!
Lateral!Cb!
Hemispheres!
A
Dentate!Nucleus!
Like Dante’s peak that it spewed all that ash into the atmosphere which sounds like hemisphere.
15
Q
Anatomically divided into 3 lobes
A
- Anterior lobe
- Posterior lobe
- Flocculonodular lobe
• It is connected to the rest of the brain by 3 dense fiberbundles called peduncles
16
Q
Anterior lobe’s name
A
Spinocerebellum,
Because here we see a change from the original idea of the spinal cord. That there it was the anterior that was motor and the dorsal that was sensory, but here the cerebellum is sensory at its anterior, like, no more of this sensory being at the posterior, its time to take a front row seat! V
17
Q
Spinocerebellum
A
Muscle tone posture
stereotyped activities
The anterior is with the vermis, the worm like structure, so this looks like a spine, so we can say that it is to be for posture.
18
Q
Cerebro,
cerebellum
A
Non-stereotyped activities.
This is brainy and so it does not require the usualy way to do things, it can go and do things that are all different.
Ha ha ha
Yes it can!
That worm, vermis, anterior, needs things that are stereotyped
19
Q
Flocculo,nodular((
A
Ves=bulo,
cerebellum
Nodulus(&(Flocculi(
Head,eye(mvt/(coord,(balance(
&((posture(
Foliculous is the eye which needs the head, which when you have the eyes and head you also have the posture
20
Q
Spinocerebellum
A
Controls proprioception related to:
• Muscle tone
• Maintenance of posture, because the spino is about posture
• Controls the execution & coordination of muscle ac-tivity of stereotyped activities, the vermis needs simple stereotyped actions
• Somatotopic Organization of Spinocerebellum
• Vermis – controls axial ms (head/trunk)
• Superior vermis – fine, precise motor coordina-
tion
• Inferior vermis – gross motor coordination
• Paravermis – controls limb ms (hands/feet)
21
Q
Cerebrocerebellum function
A
Associated with planning, coordination, & execution of:• Rapid, Fine, non-stereotyped movements
• (ie. Ice skating, water skiing)
22
Q
Vestibulocerebellum
Function
A
- Vestibular function
- Eye functions
- Coordination of Head and Eye Movements
- Constant maintenance of Balance & Posture
23
Q
3 “highways” (peduncles)
A
- Superior Cerebellar Peduncle
- Middle Cerebellar Peduncle
- Extra large in size
- The structure connecting the cb to pons•
Inferior Cerebellar Peduncle
24
3 major afferents
• Corticopontocerebellar Pathway
Spinocerebellar Pathway
• Cortico-olivocerebellar Pathway
25
Corticopontocerebellar Pathway is the __________ pathway in the cerebelum.
Largest
26
Corticopontocerebellar Pathway enters through...
Enters via the Middle Cerrebellar Peduncle
We did say that the middle was the largest, that it. Connects the poms to the cerebellum.
And such a big name needs such a big channel.
27
Corticopontocerebellar Pathway
• Responsible for transmitting:
• Info about actual movement in progress•
Impending mnovement
Cortico=brains
So it actualy thinks of now and not just what is prearranged to happen.
• Allows for continuous monitoring & adjustment to produce smooth, fluid, coordinated movements.
28
3 major efferents
Dentorubrothalamic Pathway
Medial descending system
Lateral descending system
29
Dentorubrothalamic Pathway
• Output from hemispheric zone --> Dentate
• Principal efferent projection of the cerebellum
• Travels: Cerebellum to the Red Nucleus & Thalamus•
Responsible for:
• Motor planning
• Initiation
• Timing
• Precision of movements
• esp. the reciprocal contraction between agonist
and antagonist muscles of the limbs
30
Medial Descending System
• Output from vermal zone --> fastigial nucleus-->:
• Lateral vestibular nucleus (vestibulospinal tract)
• Reticular formation (reticulospinal tract) ! together this is known as the medial descending system
• Responsible for Maintenance of:
• Posture
• Balance
• Tone of extensor muscles
• Thalamus VL nucleus --> premotor & Primary MotorCortex --> Anterior corticospinal tract
• Controls motor activity of the axial & girdle mus-
cles
31
Lateral Descending System
• Output from the paravermal zone --> Interposed nuclei(Globose & Emboliform) -->:
• Red nucleus --> rubrospinal tracts that facilitates
tone in flexor muscles
• Thalamus --> lateral corticospinal tract
• Controls motor activity of the distal musculature of the limbs (esp. in the hands)
32
Cerebellum acts along with the ________ to regulate normal motorfunction.
Neither the Cerebellum or the ______ can
control muscle function by themselves
Cerebellum is defined as the perfect balance to the ______ and the epcerebellum but neither can do it alone.
Basal
| Ganglia (BG)
33
What is movement (motor output)?
Movement is produced by complex interactions of
three systems:
1. Cerebral Cortex – planning & execution of movement
2. Basal Ganglia – initiation of motor activity & modula-
tion of cortical output
3. Cerebellum – coordination of movement
We already did say cerebellum and the basal ganglia, but we also are to make use of the cerebral cortex.
34
Cerebellum – coordination of movement
Is what particularly.
• Timing
• Speed
• Direction
Precision
You need to move and you need to move properly, ehich is the specific tine for the specific amount for the specific speed and the specific direction.
If you lack direction, then where are you going.
If you cannot choose its time, then when will yupou move.
If you cannot control the speed, then how fast.
And if you cannot aim your actions, then for what will you go and do the job.
So the cerebellum needs to be able to do,
Timing, speed, direction, and precision.
Right?
35
The Cerebellar effects on Motor output
• Sequence the motor activities
• Monitors and makes corrective
adjustments in the body’s motor
activities while they are being executed so that they will conform to the motor
signals directed by the cerebral motor
cortex and other parts of the brain
Consistently is gettig information in and it is
getting information out, and sometimes it is not using the cerebrum, but the basal ganglia must have the cerebrum.
Real time adjustements.
The most important part that will help out with
timing. Like dribbling a basketball.
We did mention the idea of timing, precision, speed , and direction.
But we also have to make it work with the cerebral cortex.
Additionaly, there is the issue of it acting in real tine so that all the aspects, of time, speed, direction, and precision are to actually be worked out properly.
36
Always function in association with other systems of motor control.
• The cerebellum plays major roles in:
• Timing of motor activities, timing
• Rapid, smooth progression from one muscle
movement to the next, precision, speed, and direction, and timing.
• Control the intensity of muscle contraction when themuscle load changes
• Controls the necessary instantaneous interplay
between agonist and antagonist muscle groups
By drippling the fingers, the finger tips, to make
sure that you are feeling the feelings, the
pressures, and all the againists and the
antagonist, to make all the different parts will be
able to work.
At some activities , it can just be the cerebellum
and not the the cerebrum.
Central pattern generators- it can be the
cerebellum, if all is controlled for.
37
The Role of the Cerebellum in Movement
```
Interacts with the other 2 parts of the brain to promote• Synchrony of movement
• Accuracy of movement
• Coordination of But especially:
• Postural responses
• Equilibrium
• Voluntary and reflex muscular actions
• Normal levels of muscle tone
• Motor learning & memory of skilled motor activity
```
Thesea re all sub categories of timing, speed, precision, and direction.
You need all of thise four points for proper fine tuned movements. And one of the most well fine tuned movement is that if balance and posture.
38
• Receives Afferent projections from the:
Regulation of Movement (“Regulator”)
• Cord
• Cortex, since it gets info and sends that info to the cerebellum
• Subcortical brain regions, just like by the cortex, but there are areas below the cortex, like the basal ganglia
• Receives input from:
• Motor & non-motor areas
• Somatosensory, Vestibular, Auditory, & Visual•
Input and out is the point of reference, the cereberum to the
cerebellum is the input to cerebellum and output from the cerebrum.
39
So why is the cerebellum called the regulator?
Because it has to take all that information from the cortex, subcortex, cord, and motor and non-motor area and make use of all of it, but that is the gross job, of just making use of all that information, but the cerebellum also has other jobs which we shall see soon.
40
Comparison (“Comparitor”)
“Compares the actual movements as depicted by the peripheral sensory feedback information with the move-ments intended by the motor system. If the two do not compare favorably, then instantaneous subconscious corrective signals are transmitted back into the motor system to increase or decrease the levels of activation
of specific muscles.”
I say that this is again just another angle, perspective, facet of the original cardinal principles of the job of the cerebellum.
The timing, speed, direction, and precision.
There are focuses on each aspect, but as whole these are used to allow for movement, but a movement that we will be happy to call a functional movement.
Like, ground steak is steak, but which self respecting cowboy will allow that on their fine china?
41
* Compares motor performance occurring peripher-ally with motor signals from the cerebral cortex
* Compensates for errors in movement by compar-ing intention with actual performance
• To do this the Cerebellum receives input from all
levels of the CNS and from the periphery.
So wea re again at the comperator,
That we already have the speed, timing, the precision, and the direction.
That we will planning for all of these points.
So wea re comparing, that which is wanting to happen, cortex, to that which we would prefer, the real functional movements, and then compare back to that which actually did happen, so more sensory information to the body, and then seeing if it is actually that which we prefer to happen, and then we will get to the other jobs that we will present soon.
42
Planning (“The Planner”)
“aids the cerebral cortex in planning the
next sequential movement a fraction of a
second in advance while the current move-ment is still being executed, thus helping
the person to progress smoothly from one
movement to the next”
Not sure what the difference here is.
So it just seems to be that all of these are so similar in that they will make use of the timing, speed, direction, and precision, and how all of them merge and meld with each other.
43
Learning (“The Learner”)
“Learns by its mistakes—that is, if a
movement does not occur exactly as intended, the cerebellar circuit learns to
make a stronger or weaker movement
the next time”
How?
• Changes occur in the excitability of ap-
propriate cerebellar neurons
• Subsequent muscle contractions have
better correspondence with the in-
tended movements
Once you do all that you will be able to actually get to have learned a new activituy.
Thank you cerebellum for allowing me to ride a bike.
44
Adaptive Feed-Forward Control System
Programs or models voluntary movement skills
based on a memory of previous sensory input & mo-tor output
So it not only uses what info it is getting now, but it also compares to what it has seen work and what it has not seen work and uses all of that information to go and be able to program or model movements.
45
Major role in Motor Learning
| • When the Cerebellum is damaged:
* Learned motor programs cannot be used
* Forced to rely on slow sensory feedback loopsthrough the cerebral cortex
There really is 't any movement memory to be had, the cerebral cortex can go and do movement, but can it remeber movements?
Your memory center remembers events, but propioception, fine antagonist and agonist reltionships, speed, timing, direction, and precision, these are all parts that are really not at all concious, like breathing, if the breathing center was destroyed breathing will be active, if you loose focus, you stop breathing, like by keeping your arm raised, if you stop thinking about it, you will drop your arm.
46
3 Functional Centers
The vestibulocerebellum, think vestibule and cerebellum, because we do deal with balance.
The spinocerebellum, think info from the spine to the cerebellum
The cerebrocerebellum, think info between the cerebellum and the cortex.
So infor to and from the spine and cortex, thats thepath, and balance.
And cerebellum is always at the end.
Somspino cerebellum
Cerebro cerebellum
And
Vestibulo cerebellum
47
The vestibulocerebellum does?
Most of the body’s equilibrium movements.
Vestibular, its in the name!
48
The spinocerebellum does?
Coordinating mainly movements of the distalportions of the limbs
Especially the hands and fingers.
Think of the spine going to all the distant body parts
49
The cerebrocerebellum does?
Receives virtually all its input from the cerebral
motor cortex and adjacent premotor and soma-
tosensory cortices of the cerebrum
Functions in a feedback manner with the cere-
bral cortical sensorimotor system
Plans sequential voluntary body and limb move-ments
Planning these as much as tenths of a secondin advance of the actual movements
This is called development of “motor im-
agery” of movements to be performed
50
From the motor cortex to the muscle is one patheay, a direct pathway, this happens, it does.
But while the signal is going from the MC to the muscle it does split and a copy is effernced to the intermediate zone of the cerebellum.
At this IZC the signal goes to the red nucleas, from there it goes tonthe muscles and also splits to the thalamus.
From the thalamus it goes to the MC and then the whole cycle does repeat feom that MC going to the muscles.
.
51
The cerebellar (via the Intermediate zone)receives two types of information when a
movement is performed:
1. Information from the ___________ and __________.
```
1. Information from the cerebral motor
cortex and from the midbrain red nu-
cleus
1. telling the cerebellum the intendedsequential plan of movement for the
next few fractions of a second
```
It needs to know what the cerebral cortex plans to do, but at the very same time that signal is sent to the muscle prior to its modulation, but then the copy that is also modulated is sent to the cortex, eventually, after passing throught the red nucleas and the thalamus, and then that signal, the modulate info is processed and sent to the muscles, but again a copy is sent to the cerebellum, just so that it knows that the modulations that it did, are what shoukd have been done.
Its like an editor, he sees the rough draft, edits it, and then send it back to the print floor, and when it is being printed, again takes a look to see if they understoood the editor properly.
2. Feedback information from the periph-eral parts of the body, especially from
the distal proprioceptors of the limbs
1.Telling the cerebellum what actual
movements result
But then not only does ithe editor need to see that the signal was sent properly, but it also needs to see if the muscles understood the sognal properly, did the readers understand the message correctly, if not, then we will need to go and reasses how we are sending the signal out, because as correct as the message is, if people are making mistakes, then it is not good.
52
Processing of movement has the basal ganglia involved, but in __________ it will be more clear.
Parkinsons
53
There isn't a real loop by the MVPC, muscles, the Cerebellum, the Red nuleas, the BG, the Thalamus, but rather the involvement of the Bg is?
Just adjusting the thalamus, but the signal is not going into it.
54
The basal ganglia is a group of..
Group of neurons.
55
The prefrontal cortex depends alot on...
Dopamine, for executive motor function. At the premotor cortex, the frontal lobe, relies on dopamine.
56
Dopamine is control by the basal ganglia, which affetcts the __________ lobe.
The prefrontal lobe, which also affects the movements and the cognitive tasks.
So these two aspects need dopamine from the bg.
57
Based off the thalamus, the hypothalamus, the amygdala, and anything in the brain affect the amount of __________, that the BG makes.
Neurotransmitters.
58
There are _____ main functional paths.
Vestibulocerebellum
Spinocerebellum
And
Cerebrocerebellum
59
If you take vision out... Then it is putting more stress on...
Somatosensory and vestibular
And you follow this path to know if it is oe or the other
60
How would you know that it is the vision or that the information from the visioon is coming in properly but it is not being used properly, so cerebellar?
CN are the motor for the eyes. Cerebellum affects it. Sacades and nystagmus, if the cerebellum cannot assist the motor eye muscles.
61
Parkisonianism is a problem with...
The basal ganglia.
62
Trochlear does...
.
63
How do we treat a cerebellar issue?
Maybe neuroplasticity could help.
Teach him how to make use cardinal movemnts and not more functional activities.
But for a cerebellar treatment... That is affecting the spinocerebellar and the cerebrocerebellu...
VOR, vestibular occular reflex, and VSR, vestibular spino relfex.
64
You have to look at the higher function and see what he can't do and then see if it is affecting his other functions as well, other activities, other functional tasks.
.
65
When you see the symptoms neurologicaly you need to trace it ____________ and then see how it affects _____________.
To the original damaged area and how it affects the other jobs that that structure is responsible for.
Like if they are with weak muscle, you also check the dermatomes to see if it is atrophy or if it indeed is neuro.
66
A javalon through the skull and seperating the cerbellum will give you the symptoms of...
1. Ataxia
2. Dysmetria
3. Dysdiadochokinesia
4. Tremor
5. Dyssynergia
6. Hypotonia
7. Dysarthria
8. Nystagmus
9. Ocular Dysmetria
10. Asthenia
11. Gait Abnormalities
67
One Function of the Cerebellum to Prevent _________ of Movements and to
___________ Movements.
Overshoot
Dampen
68
Ballistic Movements are?
Very fast movements that the body nas no time to process the information sent back from it.
69
How is the cerebellum involved in ballistic movements?
Because ballistic movements are too quick of a movement to use the cerebral cortex for, then the cerebellum goes and has "combo" moves all preprogrammed into being able to do a specific set of movements.
Lets call it "second nature" or reflexive.
70
Cerebrocerebellum does which aspect of movement?
```
Plan, Sequence, and Time Complex
Movements
Responsible for the indirect aspects of mo-tor control
1. The planning of sequential movement
2. The “timing” of the sequential move-
ments.
```
So we still have vestibulocerebellum and we also have spinocerebellum.
Now the cerbrocerebellum, the thinker, cerbrum, is to plan the timing of the movements, even though this is the cerebellum, but it is the specific cerbrocerebellum of the cerebellum that is involved in the timing of our job.
We also make use of direction, speed, and precision.e
71
Lateral cerebellar zone and the basal ganglia.
The BG is involved with what is going on now, and the LCZ is involved with the movements that will be had soon enough.
72
Extramotor Predictive Functions of theCerebrocerebellum?
Aids in timing of the rates of progression
of both auditory and visual phenomena
Aids in interpreting rapidly changing spatio-temporal relations in sensory information
So we did say that Cerebrocerebellum is about timing.
So the cerebrocerebellum needs to calculate the way that it understands the visual information amd the way that ot understands the auditory information.
73
• Although the initiation of a motor program may begin at the cortical level, the Cerebellum plays a predomi-
nant role in the execution of the task itself, sparing usfrom having the think out every movement
.
74
• Rapid & accurate shifts in attention is impaired incerebellum patients, even in the absence of any
motor demands
We see that there is a major functional component to the cerebellum.
Here, in this point very specific, that if the cerebellum is impaired, then it csnnot do one of its jobs, and one of those jobs being that if things are happening very rapidly areound them or to them, then they falter.
75
• Lesions to the central anterior and posterior lobes of the Cerebellum, including the vermis (spinocerebellum), will result in:
* LE dyscoordination
* Deficits in LE equilibrium responses
The vermis is long wormy, so it is the spinocerebellum, because the spine is long and wormy. But the vermis, the spinocerebellum, would also affect the LE because the Vermis is long and thin and so are the legs long and thin.
76
• Compensatory strategy is employed, when there is cerebellum injury, results in:
• Lower than expected falls, but gait was stiff-legged, they may be over compensating to their risk of falling, so we will not see falls as much as we expected to have seen falls, but they are stifflegged, which could be the compensation.
BOS is widened to lower the COG, to decrease the chance to fall.
* + Tandem walking test, a test for balance, it would show positive for any issues.
* + heel to shin test, this test would also show positive since it is a coordination test.
* Arm swing is generally absent, not sure why, but we can maybe guess that if their coordination is off then they will have less arm swing since that is one sort of coordination.
77
Lesions of the vestibulocerebellum have predominant sx of...
dysequilibrium rather than ataxia
Since maybe this area of the cerebellum is for keeping to a proper movement and not for a lack of movement.
78
Vestibulocerebellum
• Output to the vestibular system:
• VOR (Vestibular Ocular Reflex)•
VSR (Vestibular Spinal Reflex)
There are only two vestibular reflexes that we have to know about and these are those reflexes.
The vestibular section of the cerebellum, not the spinal nor the cerbro, but the vestibular, this is with reflexes.
The VOR and the VSR.
79
• Vestibulocerebellum lesions instability seen primarilyin the head & trunk, resulting in...
deficits in walking, standing & even sitting
• Inability to substitute with visual fixation
So balance is not just for static, but it is related to the issue of functional as well.
80
• Symptoms of the vestibulocerebellum that is not in movement...
Nausea & Vomiting, Nystagmus, Vertigo
Because these are issues that are related to the issue of balance and equilibrium, but not in the area of directly pointed to function.
But these all affect function, but it is not something that is only directed towards function, these symptoms of n&v, verigo, and nystagmus is present even when not moving.
So we have balance this is issue that is at static and so if it turns dynamic it will also be an issue, and these, seem to be constitutional symptoms, that the person gets,n&v, nystagmus, and vertigo.
81
Spinocerebellum recieves info from?
SC, visual system, auditory
system & somatosensory system, giving feedback
about the external environment regarding movements
So what are the areas that someone needs to get info from to be able to have a good mapping of their surroundings to be able to function well?
Sight? Yes
Auditory? Yes, to see if there are object coming your way just from its sound, like when you do not look both way and just rely on the engine roar.
The somatsensory, the propioception? Sure, you must know the feeling of the ground.
82
Spinocerebellum
Takes the information from the sc, the somatosensory, the visual, and the auditory, and does what with all of that?
• Regulates muscle activity to compensate for changesin load during movement via its connections with the
cortex
• Regulates tone also by modulating the appropriate
amount of force to the muscles
It now sees the world from a mapping and from a force perspective, so it will allow for tone modulation and muscle coordination so that you would move properly.
Like the vestibulocerebellum that was interested in balance and equilibrium to help with movement, here the spinocerebellum, a npbig long cord, it has tone, is conected to the muscles, is interested to keep the tone of the muscles properly intune and to also go and coordinate the muscle activities so that one would move efficiently.
83
Ataxia
• A common and classic sign of Cerebellum dysfunction• Defined as incoordination, or “clumsiness of mvt”
• Can occur as a result of incorrect programming of the rate & force of muscle contractions (dysmetria) and/or the inability to regulate posture and balance
(dysequilibrium)
• Characterized by difficulty regulating & maintaining
force accuracy, range, direction, rhythm & synergy or
organization of muscle movements
• Can affect the trunk, extremities, head, mouth, and
tongue (speech)
• Multi-joint movements are more affected than single-
joint movements
84
incorrect programming of therate & force of muscle contractions
(dysmetria)
Like metric, distance, or lets say muscle length,
So force of contraction
85
the inability to regulate posture and balance
(dysequilibrium)
Are you balanced, are you inequilibrium?
86
Ataxic Gait
```
• Uneven step length
• Irregular step width
• Absent rhythm
• Excessively high steps
Lack of armswing
```
87
• Testing for dysmetria
• Finger to Nose
| Heel to Shin
88
Dysdiadochokinesia
• Difficulty with smooth transition from agonist to antago-nist, particularly in acceleration and deceleration
• Tested by asking patient to perform rapid alternating
movements (RAM):
• Forearm Supination/Pronation
• Ankle DF/PF
• Cerebellum patients will have slower mvts that quickly
lose range and rhythm
Dys, malfunctional
Dia, double
Do, not sure
Kinesia, movement
So the dysfunction of double movement, agtagonist to agonist or vice versa
89
Difference between dysdidokinesia and dysmetria is ....
Dysdiadokinesia is sbout tprefersal and dysmetria is about a one directional proper movement.
90
Tremor
• An oscillatory movement about a joint due to alternat-
ing contractions of the agonist & the antagonist
• Intention Tremor: Occurs during movement, absent at
rest; aka a goal-directed tremor
• Oscillations may worsen during targeted mvts
• More marked at the end of movement
• Significant limitations in precision of mvts – ie. drinkingfrom a cup, placing key in door, putting on makeup
91
Dyssynergia
• A lack of coordinated, synergistic movement between
agonist and antagonist
• Results in the movement appearing comprised of multi-ple small segments
They will start the movement properly but it will just keep on getting worse.
Its actually giving you the wrong information.
92
Hypotonia
Defined: ↓ resistance to passive stretch
• The damaged cerebellum does not exert its influence on the stretch reflex, thus DTRs are normal
• Not the same as weakness, although the two can oc-
cur simultaneously
• Ability to achieve maximal force output is unimpaired, but the ability to sustain force is.
• Characteristic “loose-jointed” or “rag-doll appearance”
93
Dysarthria
• Reflects the same type of motor control loss, but seen
in the oral musculature
• Poor coordination of the speech apparatus & breath
support, resulting in scanning speech, explosive
speech, or staccato speech
• Due to dyssynergy of oral musculature as well as hypo-tonicity of larynx
• Spacing of sounds is irregular with pauses in the
wrong places
94
Nystagmus
Seen in lesions involving the flocculonodular lobe
• Nystagmus is usually pure torsional or pure vertical
• Gaze-evoked nystagmus direction-changing
• The flocculonodular lobe projects into other Cerebel-
lum regions, and therefore, nystagmus can be seen
with lesions outside of the vestibulocerebellum as well
95
Ocular Dysmetria
• Inability to move the eyes accurately to a target in theperiphery
• Dysmetria becomes apparent during
• Smooth pursuit
• Normal individuals have ~30 of ocular ROM
before cervical motion kicks in
• Cerebellum pts typically move their heads w/in first 30
• Saccades
• Corrective saccades take place as a result of
overshooting the target
96
Asthenia
• The medical term for generalized muscle weakness
• The Cerebellum does not directly affect muscle
strength
• Weakness is the result of a lack of control & coordina-tion of forces & timing of muscle contraction
• Common c/o: sense of heaviness, excessive effort for simple tasks, early onset fatigue
97
Gait/Balance Abnormalities
• Midline lesions of the cerebellum result in deficits in
maintaining upright stance, the vermis, the spine looking thing, it does the posture.
• Visual input has little influence on cerebellar ataxia
• Cerebellar gait is frequently staggering, similar to that seen in someone who is intoxicated
98
Clinical Presentation
• If the patient has a (L) Cerebellum pathology, evalua-
tion will reveal normal motor and sensory function, ex-cept:
• ↑ base of support during gait
• Possible veering to the left during ambulation
• Difficulty maintaining unilateral (L) stance
• Intention tremor in the (L) UE
• (L) sided dysmetria and dysdiadochokinesia
