NEUROPHYSIOLOGY
CEREBELLUM
Neurophysiology
Ms. Chanda Chisunka
• Located caudally to the cerebral cortex, the
cerebellum contributes about 10% to the brain’s
weight but contains more than half of all the neurons
in the brain.
• It plays a fundamental role in coordinating and finetuning movements initiated in other areas of the
brain.
• It adjusts the outputs of the pyramidal and extrapyramidal
system. Any damage to the cerebellum translates in rougher
movements as if these were improperly calculated
• To achieve the desired coordination, the cerebellum uses
the input information coming from the pyramidal and
extrapyramidal system indicating the intended
movement.
• It also integrates the information gathered from muscle
spindles throughout the body, from the visual system,
from the vestibular system and many other receptors
which indicate what movement is actually taking place.
Functional divisions of the cerebellum
Information from
• Pyramidal
• Extrapyramidal
Compared to
• Information from
• Spindles
• Vision
• Vestibule
• Other receptors
• Corrected output
Functional divisions of the cerebellum
Spinocerebellum
• Coordinates muscle tone and movement
Vestibulocerebellum
• Coordination of balance and eye movements
Cerebrocerebellum
• Coordinates planning movement of extremities
Spinocerebellum
• The spinocerebellum is located in the medial portion of the
cerebellum, it collects information from the muscle and skin carried
by the spinal cord. It also receives inputs from auditory, visual and
vestibular systems.
Spinocerebellum
• The spinocerebellum processes all this information and sends efferent
output through the deep cerebellar nuclei to the pyramidal and
extrapyramidal system. The outputs are corrections or adjustments
between the intended and actual movements. Modifying the
movement itself and the muscle tone achieve these adjustments
Vestibulocerebellum
• The vestibulocerebellum is located in the flocculonodular lobe
(posterior ventral area), it collects inputs from the visual and
vestibular system and sends efferent output to the vestibular nuclei
to regulate balance as well as head and eye movement.
Cerebrocerebellum
• The cerebrocerebellum is located in the lateral hemispheres of the
cerebellum. Input comes from the area of the cerebral cortex
controlling sensory and motor functions.
• The output is directed back to the premotor area of the cerebral
cortex with the information to execute specific movements of the
extremities.
Spinocerebellum
• The spinocerebellum is located in the medial portion of the
cerebellum, it collects information from the muscle and skin carried
by the spinal cord. It also receives inputs from auditory, visual and
vestibular systems.
Spinocerebellum
• The spinocerebellum processes all this information and sends efferent
output through the deep cerebellar nuclei to the pyramidal and
extrapyramidal system. The outputs are corrections or adjustments
between the intended and actual movements. Modifying the
movement itself and the muscle tone achieve these adjustments
Cerebellar deficiencies
• Wide-base gait Compensates imbalance
• Ataxia Uncoordinated
• Dysmetria Overshooting
• Intention tremor Oscillating approach
Cerebellar deficiencies
• Past pointing Exaggerated movement
• Dysdiadochokinesia Sequencing problems
• Dysarthria Vocal sequence problems
• Cerebellar nystagmus Eyeball oscillation
• Hypotonia Lower peripheral muscle tone
• END