<< Chapter < Page Chapter >> Page >

Ataxia

A movement disorder of the cerebellum is referred to as ataxia    . It presents as a loss of coordination in voluntary movements. Ataxia can also refer to sensory deficits that cause balance problems, primarily in proprioception and equilibrium. When the problem is observed in movement, it is ascribed to cerebellar damage. Sensory and vestibular ataxia would likely also present with problems in gait and station.

Ataxia is often the result of exposure to exogenous substances, focal lesions, or a genetic disorder. Focal lesions include strokes affecting the cerebellar arteries, tumors that may impinge on the cerebellum, trauma to the back of the head and neck, or MS. Alcohol intoxication or drugs such as ketamine cause ataxia, but it is often reversible. Mercury in fish can cause ataxia as well. Hereditary conditions can lead to degeneration of the cerebellum or spinal cord, as well as malformation of the brain, or the abnormal accumulation of copper seen in Wilson’s disease.

Watch this short video to see a test for station. Station refers to the position a person adopts when they are standing still. The examiner would look for issues with balance, which coordinates proprioceptive, vestibular, and visual information in the cerebellum. To test the ability of a subject to maintain balance, asking them to stand or hop on one foot can be more demanding. The examiner may also push the subject to see if they can maintain balance. An abnormal finding in the test of station is if the feet are placed far apart. Why would a wide stance suggest problems with cerebellar function?

Everyday connections

The field sobriety test

The neurological exam has been described as a clinical tool throughout this chapter. It is also useful in other ways. A variation of the coordination exam is the Field Sobriety Test (FST) used to assess whether drivers are under the influence of alcohol. The cerebellum is crucial for coordinated movements such as keeping balance while walking, or moving appendicular musculature on the basis of proprioceptive feedback. The cerebellum is also very sensitive to ethanol, the particular type of alcohol found in beer, wine, and liquor.

Walking in a straight line involves comparing the motor command from the primary motor cortex to the proprioceptive and vestibular sensory feedback, as well as following the visual guide of the white line on the side of the road. When the cerebellum is compromised by alcohol, the cerebellum cannot coordinate these movements effectively, and maintaining balance becomes difficult.

Another common aspect of the FST is to have the driver extend their arms out wide and touch their fingertip to their nose, usually with their eyes closed. The point of this is to remove the visual feedback for the movement and force the driver to rely just on proprioceptive information about the movement and position of their fingertip relative to their nose. With eyes open, the corrections to the movement of the arm might be so small as to be hard to see, but proprioceptive feedback is not as immediate and broader movements of the arm will probably be needed, particularly if the cerebellum is affected by alcohol.

Reciting the alphabet backwards is not always a component of the FST, but its relationship to neurological function is interesting. There is a cognitive aspect to remembering how the alphabet goes and how to recite it backwards. That is actually a variation of the mental status subtest of repeating the months backwards. However, the cerebellum is important because speech production is a coordinated activity. The speech rapid alternating movement subtest is specifically using the consonant changes of “lah-kah-pah” to assess coordinated movements of the lips, tongue, pharynx, and palate. But the entire alphabet, especially in the nonrehearsed backwards order, pushes this type of coordinated movement quite far. It is related to the reason that speech becomes slurred when a person is intoxicated.

Chapter review

The cerebellum is an important part of motor function in the nervous system. It apparently plays a role in procedural learning, which would include motor skills such as riding a bike or throwing a football. The basis for these roles is likely to be tied into the role the cerebellum plays as a comparator for voluntary movement.

The motor commands from the cerebral hemispheres travel along the corticospinal pathway, which passes through the pons. Collateral branches of these fibers synapse on neurons in the pons, which then project into the cerebellar cortex through the middle cerebellar peduncles. Ascending sensory feedback, entering through the inferior cerebellar peduncles, provides information about motor performance. The cerebellar cortex compares the command to the actual performance and can adjust the descending input to compensate for any mismatch. The output from deep cerebellar nuclei projects through the superior cerebellar peduncles to initiate descending signals from the red nucleus to the spinal cord.

The primary role of the cerebellum in relation to the spinal cord is through the spinocerebellum; it controls posture and gait with significant input from the vestibular system. Deficits in cerebellar function result in ataxias, or a specific kind of movement disorder. The root cause of the ataxia may be the sensory input—either the proprioceptive input from the spinal cord or the equilibrium input from the vestibular system, or direct damage to the cerebellum by stroke, trauma, hereditary factors, or toxins.

Watch this short video to see a test for station. Station refers to the position a person adopts when they are standing still. The examiner would look for issues with balance, which coordinates proprioceptive, vestibular, and visual information in the cerebellum. To test the ability of a subject to maintain balance, asking them to stand or hop on one foot can be more demanding. The examiner may also push the subject to see if they can maintain balance. An abnormal finding in the test of station is if the feet are placed far apart. Why would a wide stance suggest problems with cerebellar function?

A wide stance would suggest the person needs to maintain balance by broadening their base. Instead of continuous correction to posture, this can keep the body stable when the cerebellum cannot.

Got questions? Get instant answers now!

Questions & Answers

What is the differences between anabolism and catabolism?
Ikenze Reply
what are steroid hormones
Mwesige
it doesn't have nothing to do with are sex hormones
isaiah
it's something with food we eat,the air we breathe into the energy we need to function
isaiah
There are two parts to metabolism: Catabolism and Anabolism. An example of Anabolism is steroids. They build muscle. Where as Catabolism is the dagratative process or the breakdown process.
Eric
Yes, in a way. Insulin is catabolic when it comes to glucose. Where as glucacon is anabolic when it comes to sugar. The two words are like the prepositions up and down. They describe a position. In which can be used to describe anything. However, they are biologic terms to describe metabolism.
Eric
The food analogy has merrit. The conversation if food and oxygen into energy. Is a part of our metabolism called cellular respiration. In which is a METABOLIC PROCESS. Respiration has many steps and products. So, it is both anabolic and catabolic.
Eric
FOR ALL OF MY SCIENTIST, ALWAYS BREAK UP WORDS YOU DO NOT KNOW. BREAK THEM UP INTO THEIR BASE, PREFIX AND SUFIX. LET'S USE HYDROLYSIS. HYDRO MEANS WATER AND LYSIS MEANS TO BREAK DOWN. SO A HYDROLYTIC REACTION IS ONE WHERE WATER IS BROKEN DOWN.
Eric
I hope my explanation helped.
Eric
Yes sr
JERRY
whats the difference between regional anatomy and systematic anatomy?
mitchxidyllic Reply
Regional anatomy is the scientific study of the structure of a particular region of the body, e.g the heart. systematic anatomy is the scientific study of the structure of a particular body system. e.g The reproductive system.
Ikenze
Cells are the building blocks of life. A city is a living organism, hypotheticly. You have Ave, Streets, Blvd, Rd, Pkwy and Interstates. These would be transportation systems. The human body is the same way. You can study the whole body. Or you can study the respiratory system, nervous system, etc.
Eric
Some of these systems overlap, of course. As a doctor, it is important to understand them individually. But it is most important to understand them as a whole.
Eric
how many litres of blood does a human body have
George Reply
hi
Sweetlin
hliii
Mohd
there are around 10.5p.(5literes) adult body
Shubu
what is homeostasis
Antwi Reply
it is self regulating ability of the body to adjust to the surroundings
Angela
it is like maintaining an equilibrium type of environment between the inside and outside of the body, so that our body can adjust to the external environmental changes
Angela
this is the negative feedback loop of the body,.... that naturally helps to keep the body in a stable or constant internal environment.
Matthew
this is the activities in the body that keeps the internal environment of the body in equilibrium or to keep it constant.
Ikenze
You also have negative feed back loops. These are rare in the human body.
Eric
list four long bones
Mary Reply
the four long bones are: tibia, fibula, femur, and humerus.
Isaac
from Zambia
Mary
femur, radius , ulnar, humerus
Om
humerus, femur, tibia and fibula
Sheryl
Humerus,redius,ulnar,in hand. Femur,tibia,fibula in leg. it is long bone.
Sneha
there is contradiction between radius ulna & tibia fibula because of the variation in the upper and lower limb of the according to growth and development of human body so humerus & femur are longer bones ( ex you can see Michael phaleps upper limb is longer than the lower limb)
Prashant
if anyone having dout so he she can please explain it to me
Prashant
which one want explain something
Dr
sir post which I have send look at it & tell is it correct or not
Prashant
about four long bones is the topic
Prashant
femur, humerus, tibia and fibula
Ikenze
Radius and ulnar are in the lower arm. However the phalanges, which are the bones in the fingers, are a part of the hand. The bones in the hand would be refered to as the metacarpels.
Eric
One way to remember the shorter bones of the lower arm is. The radial and ulnar nerves run in the arm. These nerves run adjacent to the bones with the same name.
Eric
how are you doing
Rekah Reply
hi everyone.
AR
Im new here, I came from the philippines. I study nursing. Im a first year student.
AR
really
Isaac
so what help do you want
Isaac
yeah I came from the philippines..and I have struggle about this subject the anatomy and physiology because I dont any books that I barrowed with. I cant afford buy books.
AR
hii
Meher
I'm from India
Jamy
I struggle with this subject
Jamy
can I ask here a question I hope you can help me because I dont have any references/books that I should see or read it.
AR
AR
Meher
you are from india nice to talk to you jamy.
AR
Alright Always drop your concerns here and they will be addressed. Thanks sister.
Isaac
nice meeting with you
Jamy
I am also from India
shiv
thank you Isaac.
AR
yes Meher?
AR
you are all india
AR
By the way I have question
AR
describe a person in anatomical position?
AR
i come from Ghana
Isaac
are you all nursing students?
AR
no I'm pharmacy student
Jamy
oh nice.
AR
yes
shiv
jamy me too
Meher
yes
shiv
yes
shiv
my name is sweety
Jamy
you have any chat group that we can talk there.
AR
Anatomical position is the description of any region or part of the body in a specific stance. In the anatomical position, the body is upright, directly facing the observer, feet flat and directed forward. The upper limbs are at the body's sides with the palms facing forward. The standard anatomic
Isaac
yes
shiv
jamy is my nick name
Jamy
I am a nursing student
Isaac
thank you Isaac
AR
Final year, level 400
Isaac
ohh what year are you now?
AR
Nice
AR
welcome madam
Isaac
do you have any chat group here
AR
describe the six levels of organization of the body and describe the major characteristics of each level?
AR
ahh its okay jammy
AR
jammy i am from kashmir nd u
Meher
It is convenient to consider the structures of the body in terms of fundamental levels of organization that increase in complexity, such as (from smallest to largest): chemicals, cells, tissues, organs, organ systems, and an organism.
Isaac
hi
Yaminah
am from somalia
Yaminah
5th year in medical student nice to meet ya all
Yaminah
thxs yaminah
Meher
y not.. jamy for what purpose...?
Meher
inbox me i will guide u ...?
Meher
i also dont know...?
Meher
open this app - click 'start learning' - click 'preface' - select the chat that you wanna join into I guess that is it !
Angela
Hello am from Sierra Leone
junisa
I am from Kerala
Angela
I am from india
Om
tell the easyst way to learn anatomy
Khaliif Reply
try to draw 👌
Rahil
what
shiv
learn subject with drawing anatomy diagrams some with flow chart i dont say it is easiest way bt yes u can rember for longer period
Shakerah
ooh
shiv
Can u say me parturation
Sweetlin
parturition is one of the 7 stages of human reproduction. parturition is actually that last or the 7th stage, that is giving birth to the baby or the delivery of the baby.
Angela
Mr. khaliff.. never ever use a short cut or easiest way to Acquire knowledge.. the knowledge what we got from an easiest way , cuz it will be become temporary, not permanent.. especially in the anatomy.. cuz it's a complex subject.. you can shortlist as per your syllabus, not yourself..
Sanjith
I think shakeerah's ideology of learning anatomy is one of a best method to easy learning.. and try to share with your friends or here, what you've acknowledged each day.. thankyu
Sanjith
I am agree with that point
shiv
if u get time aftr learning this 2_3 ppl join , make group make questions if urself even if its silly make it as flash card sometimes u fail , its okay. dont be less heart. u vl do it anyway if u concentrate. bt choosing ppl or the selection of ppl during studying it really matters.
Shakerah
if u get time aftr learning this 2_3 ppl join , make group make questions if urself even if its silly make it as flash card sometimes u fail , its okay. u vl do it anyway if u concentrate. bt choosing ppl or the selection of ppl during studying it really matters.
Shakerah
😊
Sanjith
what Tk
shiv
good night all... stay safe.. bye
Sanjith
hello im new here, im a nursing student
SHUGA Reply
ooh
shiv
welcome
shiv
wlcm
Rahil
dub
Ndowmi
maleria
Ndowmi
Anopheles
shiv
welcome shuga
Om
please am new here. Am a nurse awaiting to be posted .
Ntiamoah
hi I'm new here too
faleke
FAKE DrLUPO thank you
faleke
hello guys
Chuks
hello guys 🤗
Sneha
hello
Chuks
whose in Nigeria
Chuks
🙋🙋
faleke
what is inner breeding
Vijay Reply
you don't have any answer
Vijay
please don't waste my time
Vijay
wait
shiv
inbreeding is mating or breeding with organism that are genetically related
shiv
s
Pankaj
who this SRY
Pankaj
inner breeding is breeding among the same species of organisms
Anna
*inbreeding
Anna
yes same speciesor same genetic organism
shiv
description of the menstruation cycle
Namyalo Reply
explain the menstruation cycle
Namyalo
explain the menstrual cycle
Ugo
menstrual cycle is came due to FSH and LH
shiv
fsh
Ndowmi
This is the periodic release of waste(blood) from the reproductive organ of the females (human) for a period of some days, after which or during then, ovulation takes place, which is the release of eggs from the ovaries for fertilization by the spermatozoa.
Ikenze
Description of menestraul cycle
Amos Reply
i want to improve my study i like this app i interest physiology and anatomy
Su Reply
I also like this app am really interested in learning anatomy and physiology.
Johny
I have this book with my anatomy class it's awesome! also if look at crashcourse anatomy on you tube!
AMY
what the name
isaiah
umesh. rede
Rede
what is heart and long type answer
Lalita Reply
its a organ in the body
ay
describe about hear chambers.. valves.. arteries.. veins.. circulation.. inferior/superior venacava, aorta., tricuspid valve, mitral valve. pulmonary artery/vein, how oxigenation occur,systolic presure diastolic pressure.. stroke volume,cardiac output, ets.. heart located in which place, describe it
Sanjith
if you describe what I cited up, thogh you can write a long type answer about heart
Sanjith
hi
Riyaz
autonomic functions took over
Vanarith Reply
What did they take over?
Eric
what is the average volume of blood in men and why does it varrie from women?
Esther Reply
what is the average volume of blood in men
Esther
5to6liter
Sarita
5to6liter dt
Sarita
umesh. rede
Rede
estimated at 5.5litres
Ikenze

Get the best Anatomy & Physiology course in your pocket!





Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Anatomy & Physiology' conversation and receive update notifications?

Ask