4 - Cerebellum Flashcards
What is the vermis?
Runs along the midline of the cerebellum
What divides the anterior and posterior lobes?
primary fissure
3 lobes of cerebellum
Anterior
Posterior
Flocculonodular
Blood supply to the Cerebellum
PICA
Superior cerebellar artery
Branches of basillar
Most common site of infarct
PICA
3 layers of cerebellar cortex
Outer - pale, axons, few cells
Middle - purkinje cells
Inner - granule layer
Superior cerebellar peduncle
output fibers only(Mainly to VL thalamus)
Middle cerebellar peduncle
input fibers from (contralateral) cerebral cortex and cranial nerves via pons
Inferior cerebellar peduncle
input fibers from the spinal cord via dorsal and ventral spinocerebellar tracts
Dorsal spinocerebellar tract
Ipsilateral
carries information from proprioceptors
Ventral spinocerebellar tract
Contralateral
Carries information about state of reflexes
Ventral spinothalamic
Contralateral in SC
Recrosses in BS - same side
Where are the signs with a lesion in the cerebellum?
Same side
Deep cerebellar nuclei
Fastigial n. Globose n. Emboliform n. Dentate
Which nuclei connects to the Cerebellar Hemispheres & lateral part of anterior lobe
dentate nuclei
Which nuclei connect to the vermis and medial parts of hemispheres
Fastigial and interposed nucleu
Which nuclei connect the flocculo-nodular lobe
Lateral vestibular nuclei of pons
Role of cerebellum
Accurate and smooth movements
Cerebellar damage
clumsiness, abnormal fatigue and instability of movement.
Extraocular eye muscles are particularly affected
neuronal plasticity here so can be recovered
Vestibulocerebellum
Flocculonodular lobe
Spinocerebellum
vermis, cortex just lateral to vermis
Cerebrocerebellum
Lateral parts of cerebellar hemispheres (both anterior and posterior lobes
Function of the Vestibulocerebellum
Co-ordinates head and eye movements to ensure the stability of gaze
Difference between function of medial and lateral vestibulospinal tract
It controls balance of the head on the body, via the medial vestibulospinal tract
Helps balance of the body on the ground via the lateral vestibulospinal tract
Function of the spinocerebellum
Controls locomotion and limb coordination
Spinocerebellum inputs
spinocerebellar tracts
Cerebrocerebellum function
Co-ordinates movement initiated by motor cortex (speech, voluntary movements of hands and arms, and hand-eye co-ordination)
Flocculonodular syndrome
Poor balance and disordered eye movements
unable to stand in romberg test
What is titubation
bobbing motion of head or trunk
Common cause of flocculonodular syndrome
Medulloblastoma in 4th ventricle
Spinocerebellar syndrome
Incoordination of the limbs
Ataxia, hypotonia, dysdiadochokinesis
seen in alcoholics
Cerebellar stroke
Global signs headache vomiting nystagmus, ptosis ataxia
Cerebellar damage symptoms
'like being drunk' Ataxia Vertigo Nystagmis Dysdiadochokinesia Hypotonia Intention tremor Dysarthria Dysphagia
