L10 motor disorders Flashcards
higher cognitive aspects of motor planning include
sequencing,
planning and timing, imagery (motor neurons), expertise (e.g. musical instrument)
execution
motor cortex
preparation
pre motor cortex (Internal = SMA, external = lateral)
planning
prefrontal cortex
sensory motor links
parietal lobe
hemiplegia
paralysis of one side of the body
hemiparesis
weakness of one side of the body
saccades (speed duration)
1000deg/sec, 20-200ms, perception is suppressed during movement
smooth pursuit (speed and need)
50deg/sec, needs a stimulus to follow
coordination of bimanual tasks
is in the SMA, CEREBELLUM AND PMCs
Learning sequences
–> automatic = inrceased activity in the SMA and decreased in the motor cortex and dorsal prefrontal areas and lateral PMC
TMS sequence learning
SMA effected complex sequences only. Motor cortex effected all.
lateral PMC is associated with
manipulating objects
Medial PMC
SMA gets proprioceptive feedback from limbs
prefrontal areas
not specific to task and select actions and maintain goals
finger moving free will
= more activity in the dorsal prefrontal cortex
prefrontal lesions cause
preservation, utilisation, frontal ataxia and disinhibition
utilisation
impaired selectivity of SAS
Frontal apraxia
unable to make tea
SAS model
schemas for actions are competitive and are selected/deactivated by the prefrontal cortex (contention scheduling). allows for offline control. can be triggered by external cues or internally driven.
disinhibition
anti saccade task
contention scheduling
schemas for actions are competitive and are selected/deactivated by the prefrontal cortex
frontal apraxia
either SAS damage or parietal lobe damage preventing performance of purposeful skillful actions
ideomotor apraxia
idea and execution become dissociated leading to lack of meaningless mimicry and inability to perform components of a sequence, though whole sequence is fine.
cerebellum
dysmetria = over or undershooting of movements, constant tremor
basal ganglia
parkinsons (SNc) - intitation tremor
parkinsons symptoms
-smaller writing -esp. internally genrated but also extern gened are harder -impairement in complex bimanual movements - cognitive effects such as attention