Week 10 Movement disorders Flashcards
Describe the function of the primary motor cortex (PMC)
Execution of voluntary movement. Different regions of the PMC represent different areas of the body, known as somatotopic organisation. The larger the area in the PMC equate to areas with more sensitivity/refined movements
Describe the function of the Premotor Cortex (PrMC)
Links actions with objects in the environment - critical for movement stimulated by external cues.
Describe the function of the Supplementary motor area (SMA)
Deals with well learned/internally stimulated movements that don’t require constant monitoring of external environment. I.e. playing a well learned tune on an instrument
What region of the brain would be stimulated by simple tasks?
PMC
What regions of the brain would be stimulated by increasingly complex tasks?
PMC and SMA
What regions of the brain would be stimulated by visualtation of tasks?
SMA
What regions of the brain would be stimulated when tasks are guided by external stimuli?
PrMC
What is apraxia?
Difficulty in the performance of voluntary action. It effects use of objects for actions, gestures and pantomimes, and performing meaningful gestures to command
What sort of damage is typical of apraxia?
Typically left hemisphere, parietal common, frontal occasionally.
What are the three types of gestures?
Transitive: movements that involve objects - e.g. brushing teeth,
Intransitive: do not involve objects but involve communication or meaning. E.g. saluting or waving
Intransitive, non-representative gestures. Gestures that do not involve objects or meaning
What are the difficulties in diagnosing apraxia?
Often comorbid with right hemiparesis (problem attributed to working with non-dominant limb
patient often agnostic for own apraxia
caregivers often compensate
Why would corpus collosum damage affect premotor functions on one hand?
action representation needs to reach premotor areas on both side of the brain. While it could reach the premotor areas on one side, it wouldn’t be able to cross over the corpus callosum to reach the opposite sides premotor area
What is ideomotor apraxia (IMA)?
Difficulties in execution of actions, even though knowledge about the actions are preserved.
Typically more impair in executions of actions to command (pantomimes) but also impaired on imitation
Use body parts incorrectly (using finger as key)
Often incorrectly use whole limb movement (use whole arm rather than wrist)
Deficits in all types of gestures
What is ideational apraxia? (IA)
More severe form of IMA.
In IA, the knowledge of the intent of an action is disrupted
Difficulties in performing sequences of movements o complex actions (making coffee)
Have a chat about the amnesia of usage theory of IA
Claims errors are due to loss of semantic knowledge regarding object use.
Errors on MOT support this - stuffing up how to use objects
However, did not test visual recognition ability
Rumiati subjects could name objects, identify them through description, and name the object based on what it does (CHECK)
