Transcript Vestibulo-cerebellum

Cerebellum
Cerebellum
• Site: Posterior cranial fossa, behind pons &
medulla oblongata.
• 2 Surfaces: Superior & Inferior.
• 3 Parts:
* Vermis
- Superior: indistinct from sup. surface.
- Inferior: lodged in the vallecula.
Anatomy of the Cerebellum
• 2 symmetrical hemispheres connected
medially by the Vermis
• Folia: Transversely oriented gyri
• Neural arrangement: Gray matter (Cortex),
White matter (Internal),
• Scattered cerebellar nuclei: dentate, globose,
emboliform, fastigial
Cerebellum
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* 3 Lobes:
Anterior
Middle
floccculonodular
3 Fissures:
* Primary
* Horizontal
* Posterolateral
Anterior lobe
Primary fissure
Posterior lobe
Functional Divisions:
* Paleo-cerebellum: spino-cerebellum.
* Neo-cerebellum: cerebro-cerebellum.
*Archi-cerebellum:vestibulo-cerebellum.
• Spinocerebellum : (Vermis + Intermed. Hem)
• Cerebrocerebellum : (Lateral hemisphere)
• Vestibulo-cerebellum : (Floculo-nodular lobe)
Paleocerebellum
Neocerebellum
Archicerebellum
Functions of cerebellum
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 Maintenance of Equilibrium
- balance, posture, eye movement
 Coordination of half-automatic movement of
walking and posture maintenace
- posture, gait
 Adjustment of Muscle Tone
 Motor Leaning – Motor Skills
 Cognitive Function
- (attention and language)
• Ataxia( is a neurological sign consisting of
lack of voluntary coordination of muscle
movements
• .Ataxia is a non-specific clinical
manifestation implying dysfunction of the
parts of the nervous system that coordinate
movement, such as the cerebellum
The damage to cerebellum may lead to may
problems in an individual.
These problems affect the brain as follows:
Asynergia: This is loss of coordination of motor
movement.
Dysmetria: The person finds it difficult to judge distance
and when to stop.
Adiadochokinesia: This is a condition where the person is
unable to perform rapid alternating movements.
Intention tremor: The patient may tremor while carrying
out certain movements.
Ataxic gait: Staggering and swaying while walking.
Hypotonia: A person develops weak muscles.
Ataxic dysarthria: Development of slurred speech.
Nystagmus: Abnormal eye movements.
Cerebellum Function Test
There are certain neurological tests carried out to check the
functions of the cerebellum. The cerebellum function test carried
out generally are as follows:
• Finger-to-nose.
• Alternating hand movements.
• Romberg test
• Gait test
• Vestibular exam
Romberg test
• ask the patient to stand, feet together with
eyes closed and arms at sides
• Romberg-only positive if loss of balance
occurs
• The Romberg test is used to investigate the cause
of loss of motor coordination( ataxia)
• .A positive Romberg test suggests that the ataxia
is sensory in nature, that is, depending on loss of
proprioception. If a patient is ataxic and
Romberg's test is not positive, it suggests that
ataxia is cerebellar in nature, that is, depending
on localized cerebellar dysfunction instead .
FTN test (Finger-to-nose.)
• ask the patient to alternately point from his
or her nose to the examiner’s finger
• the examiner will typically move his or her
finger to different locations
HTS test (heel to shin)
• ask the patient to run the heel of one foot
along the shin of the opposite leg
• the patient then does the same procedure on
the opposite side