Corticomotor function

Question 1

what is the function of the premotor cortex?

Answer 1

visually guided movement (via mirror neurons)

Question 2

what is the function of the supplementary motor area?

Answer 2

1. planning or preparing for sequential motor actions based on memory 2. coordinating movement on both sides of the body

Question 3

what is the function of the frontal eye fields?

Answer 3

1. collaborates with cells in the superior colliculus / vertical gaze centers to control eye movements 2. voluntary and memory guided eye movements

Question 4

what are the general motor deficits associated with a lesion to the internal capsule?

Answer 4

pure motor signs contralateral to lesion

Question 5

what are the functions of the lateral corticospinal tract?

Answer 5

1. sensory - facilitate or suppress transmission of afferent input to sensory relay nuclei 2. motor - fine control of distal extremities and coarse regulation of proximal fibers

Question 6

what are the effects of lesions to the supplementary motor cortex?

Answer 6

1. problems initiating or suppressing movement 2. problems using both hands / limbs

Question 7

what are the inputs to the frontal eye fields?

Answer 7

1. visual association cortex 2. basal ganglia 3. thalamic relays

Question 8

what type of lesion causes inferior alternating hemiplegia? what are the symptoms?

Answer 8

1. medullary lesion affecting corticospinal tract and fibers from hypoglossal nerve 2. ipsilateral flaccid paralysis of tongue and contralateral hemiparesis of extremities

Question 9

what are the effects of lesion to the primary motor cortex?

Answer 9

1. paresis 2. spasticity 3. persistent hypotonia (restricted to primary motor cortex)

Question 10

where are mirror neurons found?

Answer 10

premotor area (and parietal motor area)

Question 11

what are the neuronal pathways associated with lateral gaze?

Answer 11

frontal eye fields - paramedian pontine reticular formation - abucens nucleus - (oculomotor nucleus)

Question 12

what is the effect of a lesion of the frontal eye fields?

Answer 12

1. permanent deficit in the ability to make saccades that are not guided by an external target 2. inability to voluntarily direct eyes away from a stimulus in their visual field

Question 13

reflexive saccades are controlled by what area of the brain?

Answer 13

superior colliculus

Question 14

smooth pursuit involves what brain areas?

Answer 14

vestibulocerebellum, vestibular nuclei, frontal eye fields