Normal cerebellar function
Responsible for muscle synergy (coordination) throughout the body
Coordinates the action od muscles and times their contraction à movement smoothly and accurately
As a monitor of other center of the brain (not the iniator!)
The modulator (regulator) of motor activities; integrated with :
• Vestibular system (maintain muscle tone and equilibrium)
• General proprioceptive and exteroceptive receptors
• Auditory and visual system
Basically a somatic afferent organ !!
• Neocerebellum
– Dysmetria –inability to stop the movement at the desired point (overshoots or stops before it is reached)
– Intention tremor – evident during purposeful movement, but absent/diminished with rest. Titubation : rhytmic tremor iof the head, 3-4x/minute- lesion in the midline of cerebellum
– Postural disturbance
– A/dysdiadochokinesis - inability to stop a movement and follow it immediately by directly opposite action
– Hypotonia – ipsilateral to the lesion site; loss of cerebellar facilitation to the stretch reflex
– Eye disturbance : skew deviation and nystagmus (also occurred in vestibular lesion and its connections)
– Disturbance of articulation and phonation : scanning speech/stacatto
– Gait disturbance : cerebellar ataxia (tend to fall to the lesion site)
• Paleocerebellum
– Symptoms and signs of postural and muscle tone disrturbance
• Archicerebellum
– Truncal ataxia (swaying while sitting)
– Vertigo
• Equilibratory coordination - maintanance of balance and the coordination of the body as a whole; examination of station and gait
– Truncal ataxia, titubation
– Romberg sign, Walk tandem
• Non-equilibratory coordination – ability to carry out discrete, relatively fine, intentional movement with extremities.
– Dysmetria, Dysdiadochokinesia
– Nose-to-finger test, finger-to-finger test, heel-to-knee-to-toe test
– Rebound test, test pointing and past pointing
– Functional test : button-unbuttoning, writing, picking coin at desk
