Neuro Lab 6 - Cerebellum

Question 1

vermis

Answer 1

truncal coordination

Question 2

intermediate hemisphere

Answer 2

limb coordination

Question 3

lateral hemisphere

Answer 3

higher order

Question 4

dysdiadochokinesia

Answer 4

impaired ability to perform rapid alternating movements

(indicates cerebellar intermediate hemisphere dysfunction.)

Question 5

dysmetria

Answer 5

overshooting or undershooting the intended position
test with finger-to-nose and heel-knee-shin

Question 6

intention tremor

Answer 6

broad, coarse, low frequency (<5 Hz) tremor
amplitude increases as extremity approaches endpoint of a deliberate, visually guided movement
usually perpendicular to direction of movement

Question 7

dysarthria

Answer 7

“slurring” or poor articulation of speech

(can happen w/ cerebellar dysfunction in the coordination of the muscles of articulation)

Question 8

truncal ataxia

Answer 8

In patients with cerebellar vermis dysfunction, coordination of core muscles is impaired leading to unsteadiness in maintaining posture. This can be exaggerated with closing the eyes to remove the added visual input. In this case, the patient sways when sitting on the edge of the bed with eyes closed, indicating “truncal ataxia” or incoordination of trunk muscles

Question 9

gait ataxi

Answer 9

• due to incoordination of the motor and sensory systems
• Patients with cerebellar ataxia tend to have a wide-based stance, with worsening imbalance if feet are placed together. When unilateral, cerebellar vermis dysfunction can lead to “listing” or a tendency to fall or lean toward the ipsilateral side

Question 10

What might we see if there is a problem with the flocculonodular lobe of the cerebellum?

Answer 10

eye movement abnormalities – nystagmus, saccadic intrusions, saccadic overshoot

Question 11

flocculonodular lobe

Answer 11

balance and eye movements

Question 12

cerebellar input

Answer 12

• Spinocerebellarpathways (sensory input via Clark’s nucleus, accessory cuneatenucleus)
• Pontocerebellarfibers (cortical input via pontinenuclei)
• Vestibular system
• Red nucleus via Inferior Olivary Nucleus

Question 13

medial longitudinal fasciculus

Answer 13

• carries information about the direction that the eyes should move
• connects the cranial nerve nuclei III (Oculomotor nerve), IV (Trochlear nerve) and VI (Abducens nerve) together, and integrates movements directed by the gaze centers (frontal eye field) and information about head movement (from cranial nerve VIII, Vestibulocochlear nerve)