Hirsch - Cerebellum Flashcards
function of cerebellum
compare motor plans with physical execution
make adjustments to keep movements coordinated, fluid, and on target
also involved in motor learning
cerebellar disorder
- ataxia
reeling, wide based gait
cerebellar disorder
- decomposition of movement (general)
inability to correctly sequence fine, coordinated acts
cerebellar disorder 2.1. dysarthria
inability to articulate words correctly with slurring and inappropriate phrasing
cerebellar disorder 2.2. dysdiadochokinesia
inability to perform rapid alternating movements
cerebellar disorder 2.3. dysmetria
inability to control range of movement (hypo or hypermetria)
cerebellar disorder 2.4. hypotonia
decreased muscle tone
cerebellar disorders 2.5. nystagmus
involuntary, rapid oscillation of the eyeballs in a horizontal, vertical or rotary direction with the fast component maximal toward the side of the cerebellar lesion
cerebellar disorders 2.6. tremor
rhythmic, alternating, oscillatory movement of a limb as it approaches a target (intention tremor) or of proximal musculature when fixed posture or weight bearing is attempted (postural tremor)
arbor vitae
whitematter of cerebellum
functional divisions of cerebellar cortex
cerebrocerebellum (neocerebellum)
spinocerebellum (paleocerebellum)
vestibulocerebellum
cerebrocerebellum
lateral
phylogenetically new
receive input from contralateral cerebral cortex
regulate complex sequence of movement including speech
spinocerebellum
paramedian and median (vermis zone)
phylogenetically older than neocerebellum
receive input from spinal cord
somatotopic organization
* paramedian: regulate distal muscles
* median: regulate proximal muscle and some eye movements
vestibulocerebellum
caudal and inferior lobes
phylogenetically ancient
receives input from vestibular nuclei (in brainstem)
regulate posture and balance including eye movements
deep cerebellar nuclei
dentate
interposed
fastigial
dentate nucleus
input from cerebrocerebellar zone
projects to:
- contralateral premotor cortex
- association cortices of frontal lobe involved in planning movement